tests: check the resume pass survived, don't assume it

48_local-crange-memresume ran pass 2 and printed "terminated" whatever came
back, so a crashed engine read as a clean run. It fails on Windows with an
empty log and an empty mirror, which is what that blind spot looks like.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Signed-off-by: Xavier Roche <roche@httrack.com>

.gitattributes

@@ -1,3 +1,8 @@
 # Resource scripts are Windows tooling input and must stay CRLF: the engine has no
 # encoding guard, so an autocrlf checkout could otherwise flatten them silently.
 *.rc text eol=crlf
+
+# The test scripts run under Git Bash on the Windows CI; a CRLF checkout makes
+# bash die on $'\r' on every line of them.
+*.test text eol=lf
+*.sh text eol=lf

.github/workflows/ci.yml

@@ -41,7 +41,7 @@ jobs:
           sudo apt-get update
           sudo apt-get install -y --no-install-recommends \
             build-essential clang autoconf automake libtool autoconf-archive \
-            zlib1g-dev libssl-dev
+            zlib1g-dev libssl-dev libbrotli-dev libzstd-dev
 
       - name: Configure
         run: |
@@ -50,6 +50,9 @@ jobs:
           # committed generated files already let a plain checkout build.
           autoreconf -fi
           ./configure
+          # a missing decoder would silently drop the coding from Accept-Encoding
+          grep -q "define HTS_USEBROTLI 1" config.h
+          grep -q "define HTS_USEZSTD 1" config.h
 
       - name: Build
         run: make -j"$(nproc)"
@@ -82,7 +85,7 @@ jobs:
           sudo apt-get update
           sudo apt-get install -y --no-install-recommends \
             build-essential autoconf automake libtool autoconf-archive \
-            zlib1g-dev libssl-dev
+            zlib1g-dev libssl-dev libbrotli-dev libzstd-dev
 
       - name: Configure
         run: |
@@ -123,14 +126,18 @@ jobs:
       - name: Install build dependencies
         run: |
           set -euo pipefail
-          brew install autoconf automake libtool autoconf-archive
+          brew install autoconf automake libtool autoconf-archive brotli zstd
 
       - name: Configure
         run: |
           set -euo pipefail
           ssl="$(brew --prefix openssl@3)"
+          brewp="$(brew --prefix)"
           autoreconf -fi
-          ./configure CPPFLAGS="-I${ssl}/include" LDFLAGS="-L${ssl}/lib"
+          ./configure CPPFLAGS="-I${ssl}/include -I${brewp}/include" \
+            LDFLAGS="-L${ssl}/lib -L${brewp}/lib"
+          grep -q "define HTS_USEBROTLI 1" config.h
+          grep -q "define HTS_USEZSTD 1" config.h
 
       - name: Build
         run: make -j"$(sysctl -n hw.ncpu)"
@@ -166,14 +173,16 @@ jobs:
       - name: Install build dependencies
         run: |
           set -euo pipefail
-          brew install autoconf automake libtool autoconf-archive
+          brew install autoconf automake libtool autoconf-archive brotli zstd
 
       - name: Build and install into a temp prefix
         run: |
           set -euo pipefail
           ssl="$(brew --prefix openssl@3)"
+          brewp="$(brew --prefix)"
           autoreconf -fi
-          ./configure CPPFLAGS="-I${ssl}/include" LDFLAGS="-L${ssl}/lib" \
+          ./configure CPPFLAGS="-I${ssl}/include -I${brewp}/include" \
+            LDFLAGS="-L${ssl}/lib -L${brewp}/lib" \
             --prefix="$RUNNER_TEMP/inst"
           make -j"$(sysctl -n hw.ncpu)"
           make install
@@ -201,7 +210,8 @@ jobs:
           sudo apt-get update
           sudo apt-get install -y --no-install-recommends \
             build-essential gcc-multilib autoconf automake libtool \
-            autoconf-archive zlib1g-dev:i386 libssl-dev:i386
+            autoconf-archive zlib1g-dev:i386 libssl-dev:i386 \
+            libbrotli-dev:i386 libzstd-dev:i386
 
       - name: Configure
         run: |
@@ -242,7 +252,7 @@ jobs:
           sudo apt-get update
           sudo apt-get install -y --no-install-recommends \
             build-essential autoconf automake libtool autoconf-archive \
-            zlib1g-dev libssl-dev
+            zlib1g-dev libssl-dev libbrotli-dev libzstd-dev
 
       - name: Configure (sanitized)
         run: |
@@ -344,7 +354,7 @@ jobs:
           sudo apt-get update
           sudo apt-get install -y --no-install-recommends \
             build-essential clang autoconf automake libtool autoconf-archive \
-            zlib1g-dev libssl-dev
+            zlib1g-dev libssl-dev libbrotli-dev libzstd-dev
 
       - name: Configure (fuzzers, static)
         run: |
@@ -424,7 +434,7 @@ jobs:
           apt-get install -y --no-install-recommends \
             ca-certificates git \
             build-essential autoconf automake libtool autoconf-archive \
-            zlib1g-dev libssl-dev \
+            zlib1g-dev libssl-dev libbrotli-dev libzstd-dev \
             debhelper devscripts lintian fakeroot
 
       - uses: actions/checkout@v6
@@ -468,7 +478,7 @@ jobs:
           sudo apt-get update
           sudo apt-get install -y --no-install-recommends \
             build-essential autoconf automake libtool autoconf-archive \
-            zlib1g-dev libssl-dev
+            zlib1g-dev libssl-dev libbrotli-dev libzstd-dev
 
       - name: distcheck
         run: |

.github/workflows/windows-build.yml

@@ -119,6 +119,77 @@ jobs:
             throw "CRT mismatch across the boundary: libhttrack.dll=$a httrack.exe=$b"
           }
 
+      # The engine ships ~90 tests and none had ever run on Windows: "make check"
+      # is Linux/macOS only. These are the offline ones, driven from Git Bash
+      # against the native httrack.exe. They subsume the self-tests this step
+      # used to run inline (codecs, cache, fsize).
+      # The *_local-* ones crawl the bundled Python server over loopback: the real
+      # TLS handshake, cache and file writer, which nothing else on Windows covers.
+      - name: Run the engine test suite (offline tests)
+        shell: bash
+        working-directory: tests
+        timeout-minutes: 45
+        run: |
+          set -u
+          bin="$(cygpath -u "$GITHUB_WORKSPACE")/src/${{ matrix.platform }}/${{ matrix.configuration }}"
+          export PATH="$bin:$PATH"
+          command -v httrack >/dev/null || { echo "::error::no httrack.exe in $bin"; exit 1; }
+
+          # httrack.exe is native, so MSYS rewrites any argument shaped like a
+          # POSIX path, and a URL path is shaped exactly like one: "/a/b.html"
+          # reached the engine as "C:/Program Files/Git/a/b.html". Switch that
+          # off, and hand the tests a TMPDIR that is already a Windows path.
+          export MSYS_NO_PATHCONV=1
+          export MSYS2_ARG_CONV_EXCL='*'
+          TMPDIR="$(cygpath -m "$RUNNER_TEMP")"
+          export TMPDIR
+
+          # Mirror what configure hands the suite. LC_ALL sets the codeset MSYS maps
+          # a UTF-8 mirror name onto UTF-16 with, which the intl crawls "test -f".
+          export HTTPS_SUPPORT=yes BROTLI_ENABLED=yes ZSTD_ENABLED=yes
+          export LC_ALL=C.UTF-8
+
+          # A wedged crawl must not eat the job's whole timeout budget.
+          watchdog=""
+          command -v timeout >/dev/null && watchdog="timeout 600"
+
+          pass=0 fail=0 skip=0 failed="" skipped=""
+          for t in 00_runnable.test 01_engine-*.test 01_zlib-*.test \
+                   *_local-*.test 13_crawl_proxy_https.test; do
+            rc=0
+            # shellcheck disable=SC2086
+            $watchdog bash "$t" >"$t.log" 2>&1 || rc=$?
+            case "$rc" in
+              0) pass=$((pass + 1)); echo "PASS $t" ;;
+              77) skip=$((skip + 1)) skipped="$skipped $t"; echo "SKIP $t" ;;
+              *)
+                fail=$((fail + 1)) failed="$failed $t"
+                echo "FAIL $t (exit $rc)"
+                # These assert with `test "$(...)" == "..." || exit 1`, which
+                # says nothing at all on failure. Re-run traced.
+                bash -x "$t" >>"$t.log" 2>&1 || true
+                tail -n 25 "$t.log" | sed 's/^/      /'
+                ;;
+            esac
+          done
+          echo "ran=$((pass + fail + skip)) pass=$pass fail=$fail skip=$skip" |
+            tee -a "$GITHUB_STEP_SUMMARY"
+
+          # Every gate here exits 77, so an all-skipped suite would report green having
+          # tested nothing: pin the skips, and floor the passes in case the glob empties.
+          expected_skips=" 19_local-connect-fallback.test"  # pending #579
+          [ "$pass" -ge 90 ] || { echo "::error::only $pass tests passed ($skip skipped)"; exit 1; }
+          [ "$skipped" = "$expected_skips" ] || { echo "::error::unexpected skips:$skipped"; exit 1; }
+          [ "$fail" -eq 0 ] || { echo "::error::failing:$failed"; exit 1; }
+
+      - name: Upload the test logs
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: engine-tests-${{ matrix.platform }}-${{ matrix.configuration }}
+          path: tests/*.log
+          if-no-files-found: warn
+
       - name: Upload MSBuild logs
         if: always()
         uses: actions/upload-artifact@v4

CLAUDE.local.md

@@ -0,0 +1 @@
+/home/roche/git/httrack-works/CLAUDE.httrack.local.md

configure.ac

@@ -173,6 +173,10 @@ AC_CHECK_HEADERS([execinfo.h])
 ### zlib
 CHECK_ZLIB()
 
+### brotli and zstd content codings (optional)
+CHECK_BROTLI()
+CHECK_ZSTD()
+
 ### OpenSSL is explicitly enabled/disabled ?
 AC_MSG_CHECKING(whether to enable https support)
 AC_ARG_ENABLE([https],

debian/control

@@ -2,7 +2,7 @@ Source: httrack
 Section: web
 Maintainer: Xavier Roche <roche@httrack.com>
 Standards-Version: 4.7.4
-Build-Depends: debhelper-compat (= 14), autoconf, autoconf-archive, automake, libtool, zlib1g-dev, libssl-dev
+Build-Depends: debhelper-compat (= 14), autoconf, autoconf-archive, automake, libtool, zlib1g-dev, libssl-dev, libbrotli-dev, libzstd-dev
 Rules-Requires-Root: no
 Homepage: http://www.httrack.com
 Vcs-Git: https://github.com/xroche/httrack.git

m4/check_codecs.m4

@@ -0,0 +1,66 @@
+dnl @synopsis CHECK_BROTLI()
+dnl @synopsis CHECK_ZSTD()
+dnl
+dnl Look for libbrotlidec and libzstd, the decoders for the "br" and "zstd"
+dnl HTTP content codings. Both are optional: a missing library only drops the
+dnl coding from Accept-Encoding. --with-brotli=DIR / --with-zstd=DIR point at a
+dnl prefix; --without-brotli / --without-zstd disable the coding; the default
+dnl is to use the library when it is found.
+dnl
+dnl Define HTS_USEBROTLI / HTS_USEZSTD to 1 or 0, and substitute BROTLI_LIBS /
+dnl ZSTD_LIBS.
+
+dnl CHECK_CODEC(name, NAME, header, library, symbol, companion-libs)
+AC_DEFUN([CHECK_CODEC], [
+AC_ARG_WITH([$1],
+	[AS_HELP_STRING([--with-$1@<:@=DIR@:>@],[Enable the $1 content coding @<:@default=auto@:>@])],
+	[codec_want=$withval], [codec_want=auto])
+$2_LIBS=""
+codec_have=no
+if test "$codec_want" != "no"; then
+	codec_old_cppflags="$CPPFLAGS"
+	codec_old_ldflags="$LDFLAGS"
+	codec_dir=no
+	if test "$codec_want" != "yes" -a "$codec_want" != "auto"; then
+		codec_dir=yes
+		# An explicit prefix is authoritative: if the header is not under
+		# it, error rather than silently pick a system copy.
+		if test ! -f "$codec_want/include/$3"; then
+			AC_MSG_ERROR([$1 requested at $codec_want but $codec_want/include/$3 is missing])
+		fi
+		CPPFLAGS="$CPPFLAGS -I$codec_want/include"
+		LDFLAGS="$LDFLAGS -L$codec_want/lib"
+	fi
+	AC_CHECK_HEADER([$3], [codec_h=yes], [codec_h=no])
+	AC_CHECK_LIB([$4], [$5], [codec_lib=yes], [codec_lib=no], [$6])
+	CPPFLAGS="$codec_old_cppflags"
+	LDFLAGS="$codec_old_ldflags"
+	if test "$codec_h" = "yes" -a "$codec_lib" = "yes"; then
+		codec_have=yes
+		$2_LIBS="-l$4 $6"
+		if test "$codec_dir" = "yes"; then
+			$2_LIBS="-L$codec_want/lib -l$4 $6"
+			# The rest of configure still needs the header path.
+			CPPFLAGS="$CPPFLAGS -I$codec_want/include"
+		fi
+	elif test "$codec_want" != "auto"; then
+		AC_MSG_ERROR([$1 requested but lib$4/$3 not found])
+	fi
+fi
+AC_MSG_CHECKING([whether to enable the $1 content coding])
+AC_MSG_RESULT([$codec_have])
+if test "$codec_have" = "yes"; then
+	AC_DEFINE([HTS_USE$2], [1], [Define to 1 to decode the $1 content coding])
+else
+	AC_DEFINE([HTS_USE$2], [0], [Define to 1 to decode the $1 content coding])
+fi
+AC_SUBST([$2_LIBS])
+AC_SUBST([$2_ENABLED], [$codec_have])
+])
+
+dnl brotlidec needs brotlicommon (the static dictionary) for a fully-static link.
+AC_DEFUN([CHECK_BROTLI],
+	[CHECK_CODEC([brotli], [BROTLI], [brotli/decode.h], [brotlidec], [BrotliDecoderDecompressStream], [-lbrotlicommon])])
+
+AC_DEFUN([CHECK_ZSTD],
+	[CHECK_CODEC([zstd], [ZSTD], [zstd.h], [zstd], [ZSTD_decompressStream], [])])

man/httrack.1

@@ -3,7 +3,7 @@
 .\"
 .\" This file is generated by man/makeman.sh; do not edit by hand.
 .\" SPDX-License-Identifier: GPL-3.0-or-later
-.TH httrack 1 "12 July 2026" "httrack website copier"
+.TH httrack 1 "14 July 2026" "httrack website copier"
 .SH NAME
 httrack \- offline browser : copy websites to a local directory
 .SH SYNOPSIS
@@ -135,7 +135,7 @@ continue an interrupted mirror using the cache (\-\-continue)
 mirror ALL links located in the first level pages (mirror links) (\-\-mirrorlinks)
 .SS Proxy options:
 .IP \-P
-proxy use (\-P proxy:port or \-P user:pass@proxy:port) (\-\-proxy <param>)
+proxy use (\-P [socks5://][user:pass@]proxy:port) (\-\-proxy <param>)
 .IP \-%f
 *use proxy for ftp (f0 don't use) (\-\-httpproxy\-ftp[=N])
 .IP \-%b

src/Makefile.am

@@ -61,7 +61,7 @@ libhttrack_la_SOURCES =  htscore.c htsparse.c htsback.c htscache.c \
 	htshelp.c htslib.c htscoremain.c \
 	htsname.c htsrobots.c htstools.c htswizard.c \
 	htsalias.c htsthread.c htsindex.c htsbauth.c \
-	htsmd5.c htszlib.c htswrap.c htsconcat.c \
+	htsmd5.c htscodec.c htsproxy.c htszlib.c htswrap.c htsconcat.c \
 	htsmodules.c htscharset.c punycode.c htsencoding.c htssniff.c \
 	md5.c \
 	minizip/ioapi.c minizip/mztools.c minizip/unzip.c minizip/zip.c \
@@ -72,13 +72,13 @@ libhttrack_la_SOURCES =  htscore.c htsparse.c htsback.c htscache.c \
 	htshelp.h htsindex.h htslib.h htsmd5.h \
 	htsmodules.h htsname.h htsnet.h htssniff.h \
 	htsopt.h htsrobots.h htsthread.h  \
-	htstools.h htswizard.h htswrap.h htszlib.h  \
+	htstools.h htswizard.h htswrap.h htscodec.h htsproxy.h htszlib.h  \
 	htsstrings.h htsarrays.h httrack-library.h \
 	htscharset.h punycode.h htsencoding.h \
 	htsentities.h htsentities.sh htsbasiccharsets.sh htscodepages.h \
 	md5.h coucal/murmurhash3.h \
 	minizip/crypt.h minizip/ioapi.h minizip/mztools.h minizip/unzip.h minizip/zip.h
-libhttrack_la_LIBADD = $(THREADS_LIBS) $(ZLIB_LIBS) $(OPENSSL_LIBS) $(DL_LIBS) $(SOCKET_LIBS) $(ICONV_LIBS)
+libhttrack_la_LIBADD = $(THREADS_LIBS) $(ZLIB_LIBS) $(BROTLI_LIBS) $(ZSTD_LIBS) $(OPENSSL_LIBS) $(DL_LIBS) $(SOCKET_LIBS) $(ICONV_LIBS)
 libhttrack_la_CFLAGS = $(AM_CFLAGS) -DLIBHTTRACK_EXPORTS -DZLIB_CONST
 libhttrack_la_LDFLAGS = $(AM_LDFLAGS) -version-info $(VERSION_INFO)
 

src/htsback.c

@@ -44,6 +44,8 @@ Please visit our Website: http://www.httrack.com
 #include "htsback.h"
 
 #include "htsftp.h"
+#include "htscodec.h"
+#include "htsproxy.h"
 #if HTS_USEZLIB
 #include "htszlib.h"
 #else
@@ -556,6 +558,14 @@ static int create_back_tmpfile(httrackp *opt, lien_back *const back,
   return 0;
 }
 
+/* Move src onto dst; RENAME does not clobber an existing target on Windows. */
+static hts_boolean replace_file(const char *src, const char *dst) {
+  if (RENAME(src, dst) == 0)
+    return HTS_TRUE;
+  (void) UNLINK(dst);
+  return RENAME(src, dst) == 0 ? HTS_TRUE : HTS_FALSE;
+}
+
 /* Commit or restore a re-fetch backup (#77 follow-up): a re-fetch over an
    existing file moved the good copy to back->tmpfile before truncating url_sav.
    commit keeps the new file and drops the backup; else restore it so an aborted
@@ -571,10 +581,9 @@ static void back_finalize_backup(httrackp *opt, lien_back *const back,
       fclose(back->r.out);
       back->r.out = NULL;
     }
-    (void) UNLINK(back->url_sav); /* drop the failed partial */
-    /* On rename failure keep the backup: it still holds the good copy, so
-       losing it would be worse than an orphaned temp. */
-    if (RENAME(back->tmpfile, back->url_sav) != 0)
+    /* On failure keep the backup: an orphaned temp beats losing the good copy.
+     */
+    if (!replace_file(back->tmpfile, back->url_sav))
       hts_log_print(opt, LOG_WARNING | LOG_ERRNO,
                     "could not restore %s; previous copy kept as %s",
                     back->url_sav, back->tmpfile);
@@ -627,8 +636,7 @@ int back_finalize(httrackp * opt, cache_back * cache, struct_back * sback,
       if (!back[p].testmode) {  // not test mode
         const char *state = "unknown";
 
-        /* décompression */
-#if HTS_USEZLIB
+        /* Undo the content coding */
         if (back[p].r.compressed) {
           if (back[p].r.size > 0) {
             // stats
@@ -674,28 +682,67 @@ int back_finalize(httrackp * opt, cache_back * cache, struct_back * sback,
             // décompression
             if (back[p].tmpfile != NULL) {
               if (back[p].url_sav[0]) {
+                const hts_codec codec =
+                    hts_codec_parse(back[p].r.contentencoding);
+                /* Never decode over url_sav: a failed decode would destroy the
+                   copy an --update re-fetch is supposed to refresh (#557). */
+                char BIGSTK unpacked[HTS_URLMAXSIZE * 2 + 4]; // room for ".u"
                 LLint size;
 
-                file_notify(opt, back[p].url_adr, back[p].url_fil,
-                            back[p].url_sav, 1, 1, back[p].r.notmodified);
-                filecreateempty(&opt->state.strc, back[p].url_sav);     // filenote & co
-                if ((size = hts_zunpack(back[p].tmpfile, back[p].url_sav)) >= 0) {
+                snprintf(unpacked, sizeof(unpacked), "%s.u", back[p].url_sav);
+                if ((size = hts_codec_unpack(codec, back[p].tmpfile,
+                                             unpacked)) >= 0) {
                   back[p].r.size = back[p].r.totalsize = size;
-                  // fichier -> mémoire
                   if (!back[p].r.is_write) {
+                    // fichier -> mémoire ; le fichier est écrit plus tard
                     deleteaddr(&back[p].r);
-                    back[p].r.adr = readfile_utf8(back[p].url_sav);
+                    back[p].r.adr = readfile_utf8(unpacked);
                     if (!back[p].r.adr) {
                       back[p].r.statuscode = STATUSCODE_INVALID;
                       strcpybuff(back[p].r.msg,
                                  "Read error when decompressing");
                     }
-                    UNLINK(back[p].url_sav);
+                    UNLINK(unpacked);
+                  } else if (replace_file(unpacked, back[p].url_sav)) {
+                    /* The temp bypassed filecreate(), which is what chmods. */
+#ifndef _WIN32
+                    chmod(back[p].url_sav, HTS_ACCESS_FILE);
+#endif
+                    file_notify(opt, back[p].url_adr, back[p].url_fil,
+                                back[p].url_sav, 1, 1, back[p].r.notmodified);
+                    filenote(&opt->state.strc, back[p].url_sav, NULL);
+                  } else {
+                    back[p].r.statuscode = STATUSCODE_INVALID;
+                    strcpybuff(back[p].r.msg,
+                               "Write error when decompressing (can not rename "
+                               "the temporary file)");
+                    /* Keep the decoded body: the failed replace may have
+                       removed the previous copy, leaving this as the only one.
+                     */
+                    hts_log_print(
+                        opt, LOG_WARNING | LOG_ERRNO,
+                        "could not replace %s; decoded copy kept as %s",
+                        back[p].url_sav, unpacked);
                   }
                 } else {
                   back[p].r.statuscode = STATUSCODE_INVALID;
-                  strcpybuff(back[p].r.msg, "Error when decompressing");
+                  snprintf(back[p].r.msg, sizeof(back[p].r.msg),
+                           codec == HTS_CODEC_UNSUPPORTED
+                               ? "Unsupported Content-Encoding (%s)"
+                               : "Error when decompressing (%s)",
+                           back[p].r.contentencoding);
+                  /* Drop the undecoded body so the writer can't commit the
+                     coded bytes as the page; url_sav is left untouched. */
+                  if (!back[p].r.is_write)
+                    deleteaddr(&back[p].r);
+                  UNLINK(unpacked);
                 }
+                /* A failed decode keeps the previously-mirrored copy: note it,
+                   or the update purge (in old.lst, absent from new.lst) would
+                   delete what we just took care not to overwrite. */
+                if (back[p].r.statuscode == STATUSCODE_INVALID &&
+                    fexist_utf8(back[p].url_sav))
+                  filenote(&opt->state.strc, back[p].url_sav, NULL);
               }
               /* ensure that no remaining temporary file exists */
               unlink(back[p].tmpfile);
@@ -708,7 +755,6 @@ int back_finalize(httrackp * opt, cache_back * cache, struct_back * sback,
             // unflag
           }
         }
-#endif
         /* Body fully received: keep the freshly written url_sav, drop the
            backup of the previous copy. */
         back_finalize_backup(opt, &back[p], HTS_TRUE);
@@ -730,7 +776,7 @@ int back_finalize(httrackp * opt, cache_back * cache, struct_back * sback,
         if (back[p].r.statuscode == HTTP_OK) {  // OK (ou 304 en backing)
           if (back[p].r.is_write) {     // Written file
             if (may_be_hypertext_mime(opt, back[p].r.contenttype, back[p].url_fil)) {   // to parse!
-              off_t sz;
+              LLint sz;
 
               sz = fsize_utf8(back[p].url_sav);
               if (sz > 0) {     // ok, exists!
@@ -807,7 +853,7 @@ int back_finalize(httrackp * opt, cache_back * cache, struct_back * sback,
           else
             strcatbuff(flags, "-");
           if (back[p].r.compressed)
-            strcatbuff(flags, "Z");     // gzip
+            strcatbuff(flags, "Z"); // content coding
           else
             strcatbuff(flags, "-");
           /* Err I had to split these.. */
@@ -816,9 +862,7 @@ int back_finalize(httrackp * opt, cache_back * cache, struct_back * sback,
           fprintf(cache->txt, LLintP, (LLint) back[p].r.totalsize);
           fprintf(cache->txt, "\t%s\t", flags);
         }
-#if HTS_USEZLIB
         back[p].r.compressed = 0;
-#endif
 
         if (back[p].r.statuscode == HTTP_OK) {
           if (back[p].r.size >= 0) {
@@ -1909,7 +1953,7 @@ int back_add(struct_back * sback, httrackp * opt, cache_back * cache, const char
       /* Not in cache ; maybe in temporary cache ? Warning: non-movable
          "url_sav" */
       else if (back_unserialize_ref(opt, adr, fil, &itemback) == 0) {
-        const off_t file_size = fsize_utf8(itemback->url_sav);
+        const LLint file_size = fsize_utf8(itemback->url_sav);
 
         /* Found file on disk */
         if (file_size > 0) {
@@ -1944,7 +1988,7 @@ int back_add(struct_back * sback, httrackp * opt, cache_back * cache, const char
       }
       /* Not in cache or temporary cache ; found on disk ? (hack) */
       else if (fexist_utf8(save)) {
-        const off_t sz = fsize_utf8(save);
+        const LLint sz = fsize_utf8(save);
 
         // Bon, là il est possible que le fichier ait été partiellement transféré
         // (s'il l'avait été en totalité il aurait été inscrit dans le cache ET existerait sur disque)
@@ -2068,6 +2112,17 @@ int back_add(struct_back * sback, httrackp * opt, cache_back * cache, const char
                         "error: forbidden test with ftp link for back_add");
           return -1;            // erreur pas de test permis
         }
+        // the ftp client dials the origin itself: over socks that would bypass
+        // the proxy, so fail the link rather than leak the connection (#563)
+        if (back[p].r.req.proxy.active &&
+            hts_proxy_is_socks(back[p].r.req.proxy.name)) {
+          back[p].r.statuscode = STATUSCODE_NON_FATAL;
+          strcpybuff(back[p].r.msg,
+                     "ftp:// is not supported over a SOCKS proxy");
+          back[p].status = STATUS_READY;
+          back_set_finished(sback, p);
+          return 0;
+        }
         if (!(back[p].r.req.proxy.active && opt->ftp_proxy)) {  // connexion directe, gérée en thread
           FTPDownloadStruct *str =
             (FTPDownloadStruct *) malloc(sizeof(FTPDownloadStruct));
@@ -2670,13 +2725,40 @@ void back_wait(struct_back * sback, httrackp * opt, cache_back * cache,
           }
           busy_state = 1;
 
+          // socks5: tunnel to the origin before anything is written, for http
+          // as well as https. Skip on a reused keep-alive socket (already
+          // tunneled) and on the post-TLS re-entry (ssl_con set) (#563).
+          if (back[i].r.req.proxy.active &&
+              hts_proxy_is_socks(back[i].r.req.proxy.name) &&
+              !back[i].r.keep_alive
+#if HTS_USEOPENSSL
+              && back[i].r.ssl_con == NULL
+#endif
+          ) {
+            const int timeout = back[i].timeout > 0 ? back[i].timeout : 30;
+
+            if (!socks5_handshake(opt, &back[i].r, back[i].url_adr, timeout)) {
+              if (!strnotempty(back[i].r.msg))
+                strcpybuff(back[i].r.msg, "SOCKS5 handshake failed");
+              deletehttp(&back[i].r);
+              back[i].r.soc = INVALID_SOCKET;
+              back[i].r.statuscode = STATUSCODE_NON_FATAL;
+              back[i].status = STATUS_READY;
+              back_set_finished(sback, i);
+              continue;
+            }
+          }
+
 #if HTS_USEOPENSSL
           /* SSL mode */
           if (back[i].r.ssl) {
             int tunnel_ok = 1;
 
-            // https via proxy: CONNECT-tunnel before TLS (#85)
-            if (back[i].r.req.proxy.active && back[i].r.ssl_con == NULL) {
+            // https via an http proxy: CONNECT-tunnel before TLS (#85); socks
+            // already carries the origin connection
+            if (back[i].r.req.proxy.active &&
+                !hts_proxy_is_socks(back[i].r.req.proxy.name) &&
+                back[i].r.ssl_con == NULL) {
               const int timeout = back[i].timeout > 0 ? back[i].timeout : 30;
 
               tunnel_ok =
@@ -2941,11 +3023,13 @@ void back_wait(struct_back * sback, httrackp * opt, cache_back * cache,
                             int last_errno = 0;
 
                             back[i].r.is_write = 1;     // écrire
+                            /* a .gz/.br/.zst saved under its own coding stays
+                               packed on disk */
                             if (back[i].r.compressed &&
-                                /* .gz are *NOT* depacked!! */
-                                strfield(get_ext(catbuff, sizeof(catbuff), back[i].url_sav), "gz") == 0
-                                && strfield(get_ext(catbuff, sizeof(catbuff), back[i].url_sav), "tgz") == 0
-                              ) {
+                                !hts_codec_is_archive_ext(
+                                    hts_codec_parse(back[i].r.contentencoding),
+                                    get_ext(catbuff, sizeof(catbuff),
+                                            back[i].url_sav))) {
                               if (create_back_tmpfile(opt, &back[i], "z") ==
                                   0) {
                                 assertf(back[i].tmpfile != NULL);
@@ -3611,7 +3695,7 @@ void back_wait(struct_back * sback, httrackp * opt, cache_back * cache,
                       if (back[i].r.statuscode == HTTP_OK && !back[i].testmode) {       // 'OK'
                         if (!is_hypertext_mime(opt, back[i].r.contenttype, back[i].url_fil)) {  // not HTML
                           if (strnotempty(back[i].url_sav)) {   // target found
-                            off_t size = fsize_utf8(back[i].url_sav);
+                            LLint size = fsize_utf8(back[i].url_sav);
 
                             if (size >= 0) {
                               if (back[i].r.totalsize == size) {        // same size!
@@ -3830,7 +3914,7 @@ void back_wait(struct_back * sback, httrackp * opt, cache_back * cache,
                     // traiter 206 (partial content)
                     // xxc SI CHUNK VERIFIER QUE CA MARCHE??
                     if (back[i].r.statuscode == 206) {  // on nous envoie un morceau (la fin) coz une partie sur disque!
-                      off_t sz = fsize_utf8(back[i].url_sav);
+                      LLint sz = fsize_utf8(back[i].url_sav);
                       /* RFC 7233: resume at the server's Content-Range start,
                          not the offset we requested; a server may resume
                          earlier and appending the overlap duplicates bytes

src/htscache.c

@@ -356,7 +356,7 @@ void cache_add(httrackp * opt, cache_back * cache, const htsblk * r,
       FILE *fp;
 
       // On recopie le fichier->.
-      off_t file_size = fsize_utf8(fconv(catbuff, sizeof(catbuff), url_save));
+      LLint file_size = fsize_utf8(fconv(catbuff, sizeof(catbuff), url_save));
 
       if (file_size >= 0) {
         fp = FOPEN(fconv(catbuff, sizeof(catbuff), url_save), "rb");
@@ -1241,23 +1241,27 @@ char *readfile(const char *fil) {
 char *readfile2(const char *fil, LLint * size) {
   char *adr = NULL;
   char catbuff[CATBUFF_SIZE];
-  INTsys len = 0;
+  const LLint len = fsize(fil);
 
-  len = fsize(fil);
-  if (len >= 0) {               // exists
+  /* a size too large for size_t (32-bit Windows/i386) must fail closed: it
+     would wrap malloct() short while fread() still read the untruncated len */
+  const size_t buflen = len >= 0 ? llint_to_size_t(len) : (size_t) -1;
+
+  if (buflen != (size_t) -1) { // exists, and is addressable
     FILE *fp;
 
     fp = fopen(fconv(catbuff, sizeof(catbuff), fil), "rb");
     if (fp != NULL) {           // n'existe pas (!)
-      adr = (char *) malloct(len + 1);
+      adr = (char *) malloct(buflen + 1);
       if (size != NULL)
         *size = len;
       if (adr != NULL) {
-        if (len > 0 && fread(adr, 1, len, fp) != len) { // fichier endommagé ?
+        if (buflen > 0 &&
+            fread(adr, 1, buflen, fp) != buflen) { // fichier endommagé ?
           freet(adr);
           adr = NULL;
         } else
-          *(adr + len) = '\0';
+          *(adr + buflen) = '\0';
       }
       fclose(fp);
     }
@@ -1269,19 +1273,21 @@ char *readfile2(const char *fil, LLint * size) {
 char *readfile_utf8(const char *fil) {
   char *adr = NULL;
   char catbuff[CATBUFF_SIZE];
-  const off_t len = fsize_utf8(fil);
+  const LLint len = fsize_utf8(fil);
+  const size_t buflen = len >= 0 ? llint_to_size_t(len) : (size_t) -1;
 
-  if (len >= 0) {               // exists
+  if (buflen != (size_t) -1) { // exists, and is addressable (see readfile2)
     FILE *const fp = FOPEN(fconv(catbuff, sizeof(catbuff), fil), "rb");
 
     if (fp != NULL) {           // n'existe pas (!)
-      adr = (char *) malloct(len + 1);
+      adr = (char *) malloct(buflen + 1);
       if (adr != NULL) {
-        if (len > 0 && fread(adr, 1, len, fp) != len) { // fichier endommagé ?
+        if (buflen > 0 &&
+            fread(adr, 1, buflen, fp) != buflen) { // fichier endommagé ?
           freet(adr);
           adr = NULL;
         } else {
-          adr[len] = '\0';
+          adr[buflen] = '\0';
         }
       }
       fclose(fp);

src/htscache_selftest.c

@@ -232,11 +232,10 @@ static int disk_fallback_selftest(httrackp *opt) {
   static const char body[] = "BINARY-on-disk-body-0123456789-no-trailing-nul";
   const size_t body_len = sizeof(body) - 1;
 
-  /* X-Save must start with path_html_utf8 so the reader resolves it verbatim
-     (otherwise it re-roots it as a pre-3.40 relative path); then the body we
-     create at fconv(save) is exactly where cache_readex looks for it. */
-  fconcat(save, sizeof(save), StringBuff(opt->path_html_utf8),
-          "example.com/blob.bin");
+  /* a DOS-ified X-Save loses the path_html_utf8 prefix the reader matches on,
+     and gets re-rooted as a pre-3.40 relative path; fconv() only on access */
+  concat(save, sizeof(save), StringBuff(opt->path_html_utf8),
+         "example.com/blob.bin");
 
   /* write only the header (X-In-Cache: 0); the body stays on disk */
   selftest_open_for_write(&cache, opt);
@@ -939,9 +938,9 @@ static void reconcile_put(httrackp *opt, const char *name, size_t size) {
 }
 
 /* Expect `name` to weigh `size` bytes, or be absent when size == -1. */
-static int reconcile_expect(httrackp *opt, const char *name, off_t size,
+static int reconcile_expect(httrackp *opt, const char *name, LLint size,
                             const char *what) {
-  const off_t got = fsize(reconcile_st_path(opt, name));
+  const LLint got = fsize(reconcile_st_path(opt, name));
 
   if (got != size) {
     fprintf(stderr, "cache-reconcile: %s: %s is %d bytes, expected %d\n", what,
@@ -955,7 +954,7 @@ int cache_reconcile_selftest(httrackp *opt, const char *dir) {
   int failures = 0;
 
   /* around the interrupted-run thresholds (new < 32768, old > 65536) */
-  static const off_t TINY = 1024, MID = 40000, SOLID = 131072;
+  static const LLint TINY = 1024, MID = 40000, SOLID = 131072;
 
   golden_setup(opt, dir);
 #ifdef _WIN32
@@ -1253,8 +1252,9 @@ static void corrupt_build_disk(httrackp *opt) {
   memset(corrupt_body_a, 'a', sizeof(corrupt_body_a) - 1);
   remove(reconcile_st_path(opt, "hts-cache/new.zip"));
   remove(reconcile_st_path(opt, "hts-cache/old.zip"));
-  fconcat(save, sizeof(save), StringBuff(opt->path_html_utf8),
-          CORRUPT_ADR "/victim.bin");
+  /* X-Save stored verbatim: see disk_fallback_selftest */
+  concat(save, sizeof(save), StringBuff(opt->path_html_utf8),
+         CORRUPT_ADR "/victim.bin");
   selftest_open_for_write(&cache, opt);
   store_entry(opt, &cache, CORRUPT_ADR, "/canary.html", "canary.html", 200,
               "OK", "text/html", "utf-8", "", "", "", "", corrupt_body_a,

src/htscharset.c

@@ -31,6 +31,9 @@ Please visit our Website: http://www.httrack.com
 /* ------------------------------------------------------------ */
 
 #include "htscharset.h"
+#ifdef _WIN32
+#include <shellapi.h>
+#endif
 #include "htsbase.h"
 #include "punycode.h"
 #include "htssafe.h"
@@ -386,6 +389,40 @@ char *hts_convertStringSystemToUTF8(const char *s, size_t size) {
   return hts_convertStringCPToUTF8(s, size, GetACP());
 }
 
+HTSEXT_API void hts_argv_utf8(int *pargc, char ***pargv) {
+  int wargc = 0;
+  LPWSTR *const wargv = CommandLineToArgvW(GetCommandLineW(), &wargc);
+  char **argv;
+  int i;
+
+  // On any failure keep the CRT's ANSI argv: lossy, but never half-converted.
+  if (wargv == NULL)
+    return;
+  if (wargc <= 0 ||
+      (argv = calloct((size_t) wargc + 1, sizeof(char *))) == NULL) {
+    LocalFree(wargv);
+    return;
+  }
+  for (i = 0; i < wargc; i++) {
+    const int wsize = (int) wcslen(wargv[i]);
+
+    // hts_convertUCS2StringToUTF8() returns NULL on an empty string
+    argv[i] =
+        wsize != 0 ? hts_convertUCS2StringToUTF8(wargv[i], wsize) : strdupt("");
+    if (argv[i] == NULL) {
+      while (i-- != 0)
+        freet(argv[i]);
+      freet(argv);
+      LocalFree(wargv);
+      return;
+    }
+  }
+  argv[wargc] = NULL; // callers may rely on argv[argc] == NULL
+  LocalFree(wargv);
+  *pargc = wargc;
+  *pargv = argv; // never freed: argv lives for the process
+}
+
 #else
 
 #include <errno.h>

src/htscharset.h

@@ -34,6 +34,7 @@ Please visit our Website: http://www.httrack.com
 #define HTS_CHARSET_DEFH
 
 /** Standard includes. **/
+#include "htsglobal.h"
 #include <stdlib.h>
 #include <string.h>
 #ifdef _WIN32
@@ -175,6 +176,15 @@ extern char *hts_convertUCS2StringToUTF8(LPWSTR woutput, int wsize);
  * This function is WIN32 specific.
  **/
 extern char *hts_convertStringSystemToUTF8(const char *s, size_t size);
+
+/**
+ * Replace the CRT's ANSI argv by a UTF-8 one decoded from the real UTF-16
+ * command line: every char* is UTF-8 on Windows (FOPEN, STAT, ... convert at
+ * the syscall boundary). Keeps the CRT's argv on failure; the new array is
+ * writable, NULL-terminated, and lives for the process.
+ * This function is WIN32 specific.
+ **/
+HTSEXT_API void hts_argv_utf8(int *pargc, char ***pargv);
 #endif
 
 #endif

src/htscodec.c

@@ -0,0 +1,366 @@
+/* ------------------------------------------------------------ */
+/*
+HTTrack Website Copier, Offline Browser for Windows and Unix
+Copyright (C) 2026 Xavier Roche and other contributors
+
+SPDX-License-Identifier: GPL-3.0-or-later
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+Ethical use: we kindly ask that you NOT use this software to harvest email
+addresses or to collect any other private information about people. Doing so
+would dishonor our work and waste the many hours we have spent on it.
+
+Please visit our Website: http://www.httrack.com
+*/
+
+/* ------------------------------------------------------------ */
+/* File: HTTP content codings (gzip/deflate, brotli, zstd)      */
+/* Author: Xavier Roche                                         */
+/* ------------------------------------------------------------ */
+
+/* Internal engine bytecode */
+#define HTS_INTERNAL_BYTECODE
+
+#include "htsbase.h"
+#include "htscore.h"
+#include "htscodec.h"
+#include "htszlib.h"
+
+#if HTS_USEBROTLI
+#include <brotli/decode.h>
+#endif
+
+#if HTS_USEZSTD
+#include <zstd.h>
+/* 8 MB, the window an HTTP zstd decoder must honor (RFC 9659); libzstd
+   defaults to 128 MB. */
+#define HTS_ZSTD_WINDOWLOG_MAX 23
+#endif
+
+/* Decoded-size budget, bounding a bomb: brotli and zstd reach a million to one.
+   Deflate cannot pass 1032x, so it only meets this at the 2 GiB ceiling. */
+#define HTS_CODEC_MAX_RATIO 4096
+#define HTS_CODEC_MIN_MAXOUT (1024 * 1024)
+
+LLint hts_codec_maxout(LLint in_size) {
+  LLint maxout;
+
+  if (in_size <= 0 || in_size > INT_MAX / HTS_CODEC_MAX_RATIO)
+    maxout = INT_MAX;
+  else
+    maxout = in_size * HTS_CODEC_MAX_RATIO;
+  if (maxout < HTS_CODEC_MIN_MAXOUT)
+    maxout = HTS_CODEC_MIN_MAXOUT;
+  return maxout;
+}
+
+hts_codec hts_codec_parse(const char *encoding) {
+  if (encoding == NULL || encoding[0] == '\0' ||
+      strfield2(encoding, "identity"))
+    return HTS_CODEC_IDENTITY;
+  if (strfield2(encoding, "gzip") || strfield2(encoding, "x-gzip") ||
+      strfield2(encoding, "deflate") || strfield2(encoding, "x-deflate"))
+    return HTS_USEZLIB ? HTS_CODEC_DEFLATE : HTS_CODEC_UNSUPPORTED;
+  if (strfield2(encoding, "br"))
+    return HTS_USEBROTLI ? HTS_CODEC_BROTLI : HTS_CODEC_UNSUPPORTED;
+  if (strfield2(encoding, "zstd"))
+    return HTS_USEZSTD ? HTS_CODEC_ZSTD : HTS_CODEC_UNSUPPORTED;
+  if (strfield2(encoding, "compress") || strfield2(encoding, "x-compress"))
+    return HTS_CODEC_UNSUPPORTED; /* LZW: never advertised, no decoder here */
+  /* Not a coding at all: broken servers put charsets and the like here, and
+     the plain body they sent must survive it. */
+  return HTS_CODEC_IDENTITY;
+}
+
+#if HTS_USEBROTLI
+#define HTS_AE_BROTLI ", br"
+#else
+#define HTS_AE_BROTLI ""
+#endif
+#if HTS_USEZSTD
+#define HTS_AE_ZSTD ", zstd"
+#else
+#define HTS_AE_ZSTD ""
+#endif
+
+const char *hts_acceptencoding(hts_boolean compressible, hts_boolean secure) {
+  if (!compressible)
+    return "identity";
+#if HTS_USEZLIB
+  /* br and zstd over TLS only, as browsers do: a cleartext intermediary that
+     rewrites a coding it can not read would corrupt the mirror. */
+  if (secure)
+    return "gzip, deflate" HTS_AE_BROTLI HTS_AE_ZSTD ", identity;q=0.9";
+  return "gzip, deflate, identity;q=0.9";
+#else
+  (void) secure;
+  return "identity";
+#endif
+}
+
+hts_boolean hts_codec_is_archive_ext(hts_codec codec, const char *ext) {
+  if (ext == NULL || ext[0] == '\0')
+    return HTS_FALSE;
+  switch (codec) {
+  case HTS_CODEC_DEFLATE:
+    return strfield2(ext, "gz") || strfield2(ext, "tgz") ? HTS_TRUE : HTS_FALSE;
+  case HTS_CODEC_BROTLI:
+    return strfield2(ext, "br") ? HTS_TRUE : HTS_FALSE;
+  case HTS_CODEC_ZSTD:
+    return strfield2(ext, "zst") || strfield2(ext, "tzst") ? HTS_TRUE
+                                                           : HTS_FALSE;
+  default:
+    return HTS_FALSE;
+  }
+}
+
+#if HTS_USEBROTLI || HTS_USEZSTD
+/* Append produced bytes to out under the decoded-size budget, advancing *total.
+   HTS_FALSE on a short write or once the budget is exceeded (a bomb); the
+   over-budget bytes are never written. */
+static hts_boolean codec_sink(FILE *out, const void *buf, size_t produced,
+                              LLint *total, LLint maxout) {
+  if (produced == 0)
+    return HTS_TRUE;
+  *total += (LLint) produced;
+  if (*total > maxout)
+    return HTS_FALSE;
+  return fwrite(buf, 1, produced, out) == produced ? HTS_TRUE : HTS_FALSE;
+}
+#endif
+
+#if HTS_USEBROTLI
+static int codec_unpack_brotli(FILE *in, FILE *out, LLint maxout) {
+  BrotliDecoderState *const state =
+      BrotliDecoderCreateInstance(NULL, NULL, NULL);
+  hts_boolean ok = HTS_TRUE, done = HTS_FALSE;
+  LLint total = 0;
+
+  if (state == NULL)
+    return -1;
+  while (ok && !done) {
+    unsigned char BIGSTK inbuf[8192];
+    size_t avail_in = fread(inbuf, 1, sizeof(inbuf), in);
+    const uint8_t *next_in = inbuf;
+
+    if (avail_in == 0)
+      break; /* EOF; a stream still hungry for input is truncated */
+    for (;;) {
+      unsigned char BIGSTK outbuf[8192];
+      uint8_t *next_out = outbuf;
+      size_t avail_out = sizeof(outbuf);
+      size_t produced;
+      BrotliDecoderResult res;
+
+      res = BrotliDecoderDecompressStream(state, &avail_in, &next_in,
+                                          &avail_out, &next_out, NULL);
+      produced = sizeof(outbuf) - avail_out;
+      if (!codec_sink(out, outbuf, produced, &total, maxout)) {
+        ok = HTS_FALSE;
+        break;
+      }
+      if (res == BROTLI_DECODER_RESULT_ERROR) {
+        ok = HTS_FALSE;
+        break;
+      }
+      if (res == BROTLI_DECODER_RESULT_SUCCESS) {
+        done = HTS_TRUE;
+        break;
+      }
+      if (res == BROTLI_DECODER_RESULT_NEEDS_MORE_INPUT)
+        break;
+    }
+    if (ferror(in))
+      ok = HTS_FALSE;
+  }
+  BrotliDecoderDestroyInstance(state);
+  return (ok && done && !ferror(in)) ? (int) total : -1;
+}
+
+static size_t codec_head_brotli(const void *in, size_t in_len, void *out,
+                                size_t out_len) {
+  BrotliDecoderState *const state =
+      BrotliDecoderCreateInstance(NULL, NULL, NULL);
+  const uint8_t *next_in = (const uint8_t *) in;
+  uint8_t *next_out = (uint8_t *) out;
+  size_t avail_in = in_len, avail_out = out_len;
+  BrotliDecoderResult res;
+
+  if (state == NULL)
+    return 0;
+  res = BrotliDecoderDecompressStream(state, &avail_in, &next_in, &avail_out,
+                                      &next_out, NULL);
+  BrotliDecoderDestroyInstance(state);
+  return (res != BROTLI_DECODER_RESULT_ERROR) ? out_len - avail_out : 0;
+}
+#endif
+
+#if HTS_USEZSTD
+static int codec_unpack_zstd(FILE *in, FILE *out, LLint maxout) {
+  ZSTD_DStream *const zds = ZSTD_createDStream();
+  hts_boolean ok = HTS_TRUE, eof = HTS_FALSE;
+  size_t zret = 1; /* 0 once a frame is fully flushed */
+  LLint total = 0;
+
+  if (zds == NULL)
+    return -1;
+  if (ZSTD_isError(ZSTD_DCtx_setParameter(zds, ZSTD_d_windowLogMax,
+                                          HTS_ZSTD_WINDOWLOG_MAX))) {
+    ZSTD_freeDStream(zds);
+    return -1;
+  }
+  while (ok && !eof) {
+    unsigned char BIGSTK inbuf[8192];
+    ZSTD_inBuffer input;
+
+    input.src = inbuf;
+    input.size = fread(inbuf, 1, sizeof(inbuf), in);
+    input.pos = 0;
+    if (input.size == 0) {
+      eof = HTS_TRUE;
+      break;
+    }
+    while (input.pos < input.size) {
+      unsigned char BIGSTK outbuf[8192];
+      ZSTD_outBuffer output;
+
+      output.dst = outbuf;
+      output.size = sizeof(outbuf);
+      output.pos = 0;
+      zret = ZSTD_decompressStream(zds, &output, &input);
+      if (ZSTD_isError(zret)) {
+        ok = HTS_FALSE;
+        break;
+      }
+      if (!codec_sink(out, outbuf, output.pos, &total, maxout)) {
+        ok = HTS_FALSE;
+        break;
+      }
+    }
+    if (ferror(in))
+      ok = HTS_FALSE;
+  }
+  ZSTD_freeDStream(zds);
+  /* zret != 0 at EOF: the last frame never completed */
+  return (ok && zret == 0 && !ferror(in)) ? (int) total : -1;
+}
+
+static size_t codec_head_zstd(const void *in, size_t in_len, void *out,
+                              size_t out_len) {
+  ZSTD_DStream *const zds = ZSTD_createDStream();
+  ZSTD_inBuffer input;
+  ZSTD_outBuffer output;
+  size_t zret;
+
+  if (zds == NULL)
+    return 0;
+  if (ZSTD_isError(ZSTD_DCtx_setParameter(zds, ZSTD_d_windowLogMax,
+                                          HTS_ZSTD_WINDOWLOG_MAX))) {
+    ZSTD_freeDStream(zds);
+    return 0;
+  }
+  input.src = in;
+  input.size = in_len;
+  input.pos = 0;
+  output.dst = out;
+  output.size = out_len;
+  output.pos = 0;
+  zret = ZSTD_decompressStream(zds, &output, &input);
+  ZSTD_freeDStream(zds);
+  return ZSTD_isError(zret) ? 0 : output.pos;
+}
+#endif
+
+LLint hts_codec_coded_size(FILE *in) {
+  long size;
+
+  if (fseek(in, 0, SEEK_END) != 0)
+    return -1;
+  size = ftell(in);
+  if (size < 0 || fseek(in, 0, SEEK_SET) != 0)
+    return -1;
+  return (LLint) size;
+}
+
+int hts_codec_unpack(hts_codec codec, const char *filename,
+                     const char *newfile) {
+  if (filename == NULL || newfile == NULL || !filename[0] || !newfile[0])
+    return -1;
+  switch (codec) {
+  case HTS_CODEC_DEFLATE:
+#if HTS_USEZLIB
+    return hts_zunpack(filename, newfile);
+#else
+    return -1;
+#endif
+  case HTS_CODEC_BROTLI:
+  case HTS_CODEC_ZSTD:
+    break;
+  default: /* IDENTITY never reaches the unpacker; UNSUPPORTED must fail */
+    return -1;
+  }
+#if HTS_USEBROTLI || HTS_USEZSTD
+  {
+    char catbuff[CATBUFF_SIZE];
+    FILE *out, *in = FOPEN(fconv(catbuff, sizeof(catbuff), filename), "rb");
+    LLint maxout;
+    int ret = -1;
+
+    if (in == NULL)
+      return -1;
+    maxout = hts_codec_maxout(hts_codec_coded_size(in));
+    out = FOPEN(fconv(catbuff, sizeof(catbuff), newfile), "wb");
+    if (out == NULL) {
+      fclose(in);
+      return -1;
+    }
+#if HTS_USEBROTLI
+    if (codec == HTS_CODEC_BROTLI)
+      ret = codec_unpack_brotli(in, out, maxout);
+#endif
+#if HTS_USEZSTD
+    if (codec == HTS_CODEC_ZSTD)
+      ret = codec_unpack_zstd(in, out, maxout);
+#endif
+    fclose(out);
+    fclose(in);
+    return ret;
+  }
+#else
+  return -1;
+#endif
+}
+
+size_t hts_codec_head(hts_codec codec, const void *in, size_t in_len, void *out,
+                      size_t out_len) {
+  if (in == NULL || in_len == 0 || out == NULL || out_len == 0)
+    return 0;
+  switch (codec) {
+#if HTS_USEZLIB
+  case HTS_CODEC_DEFLATE:
+    return hts_zhead(in, in_len, out, out_len);
+#endif
+#if HTS_USEBROTLI
+  case HTS_CODEC_BROTLI:
+    return codec_head_brotli(in, in_len, out, out_len);
+#endif
+#if HTS_USEZSTD
+  case HTS_CODEC_ZSTD:
+    return codec_head_zstd(in, in_len, out, out_len);
+#endif
+  default:
+    return 0;
+  }
+}

src/htscodec.h

@@ -0,0 +1,79 @@
+/* ------------------------------------------------------------ */
+/*
+HTTrack Website Copier, Offline Browser for Windows and Unix
+Copyright (C) 2026 Xavier Roche and other contributors
+
+SPDX-License-Identifier: GPL-3.0-or-later
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+Ethical use: we kindly ask that you NOT use this software to harvest email
+addresses or to collect any other private information about people. Doing so
+would dishonor our work and waste the many hours we have spent on it.
+
+Please visit our Website: http://www.httrack.com
+*/
+
+/* ------------------------------------------------------------ */
+/* File: HTTP content codings (gzip/deflate, brotli, zstd)      */
+/* Author: Xavier Roche                                         */
+/* ------------------------------------------------------------ */
+
+#ifndef HTS_DEFCODEC
+#define HTS_DEFCODEC
+
+#include "htsglobal.h"
+
+/* Content codings we may meet in a Content-Encoding header. */
+typedef enum {
+  HTS_CODEC_IDENTITY = 0, /**< no coding, or a token we treat as none */
+  HTS_CODEC_DEFLATE,      /**< gzip, x-gzip, deflate, x-deflate */
+  HTS_CODEC_BROTLI,       /**< br */
+  HTS_CODEC_ZSTD,         /**< zstd */
+  HTS_CODEC_UNSUPPORTED   /**< a real coding we can not decode */
+} hts_codec;
+
+#ifdef HTS_INTERNAL_BYTECODE
+
+/* Codec for a Content-Encoding token. A known coding we can not decode is
+   UNSUPPORTED; an unrecognized token is IDENTITY (servers do emit junk). */
+extern hts_codec hts_codec_parse(const char *encoding);
+
+/* Accept-Encoding value to advertise; secure (TLS) also offers br and zstd. */
+extern const char *hts_acceptencoding(hts_boolean compressible,
+                                      hts_boolean secure);
+
+/* HTS_TRUE if ext is the codec's own archive extension: a foo.gz served as
+   Content-Encoding: gzip stays packed on disk. */
+extern hts_boolean hts_codec_is_archive_ext(hts_codec codec, const char *ext);
+
+/* Decode filename into newfile. Returns the decoded size, or -1 on a truncated
+   or corrupt stream, an unsupported coding, a bomb over the budget, or I/O. */
+extern int hts_codec_unpack(hts_codec codec, const char *filename,
+                            const char *newfile);
+
+/* Decode up to out_len leading bytes of a coded body for the MIME sniffer;
+   0 when nothing could be decoded. */
+extern size_t hts_codec_head(hts_codec codec, const void *in, size_t in_len,
+                             void *out, size_t out_len);
+
+/* Ceiling on the decoded size of a body of in_size coded bytes. */
+extern LLint hts_codec_maxout(LLint in_size);
+
+/* Coded size of an open stream, left rewound; -1 if unknown. */
+extern LLint hts_codec_coded_size(FILE *in);
+
+#endif
+
+#endif

src/htscore.c

@@ -855,7 +855,7 @@ int httpmirror(char *url1, httrackp * opt) {
       char *filelist_buff = NULL;
       size_t filelist_sz = 0;
       const char *filelist_err = NULL; /* failure reason, NULL on success */
-      const off_t fs = fsize(StringBuff(opt->filelist));
+      const LLint fs = fsize(StringBuff(opt->filelist));
 
       if (fs < 0) {
         /* fsize() hides the cause; redo stat() for a precise errno (#49) */
@@ -863,7 +863,7 @@ int httpmirror(char *url1, httrackp * opt) {
         filelist_err = stat(StringBuff(opt->filelist), &st) != 0
                            ? strerror(errno)
                            : "not a regular file";
-      } else if ((filelist_sz = off_t_to_size_t(fs)) == (size_t) -1) {
+      } else if ((filelist_sz = llint_to_size_t(fs)) == (size_t) -1) {
         filelist_err = "file too large";
         filelist_sz = 0;
       } else {
@@ -2089,10 +2089,9 @@ int httpmirror(char *url1, httrackp * opt) {
               (OPT_GET_BUFF(opt), OPT_GET_BUFF_SIZE(opt), StringBuff(opt->path_log),
                "hts-cache/old.lst"), "rb");
       if (old_lst) {
-        const size_t sz =
-          off_t_to_size_t(fsize(fconcat
-                (OPT_GET_BUFF(opt), OPT_GET_BUFF_SIZE(opt), StringBuff(opt->path_log),
-                 "hts-cache/new.lst")));
+        const size_t sz = llint_to_size_t(
+            fsize(fconcat(OPT_GET_BUFF(opt), OPT_GET_BUFF_SIZE(opt),
+                          StringBuff(opt->path_log), "hts-cache/new.lst")));
         new_lst =
           fopen(fconcat
                 (OPT_GET_BUFF(opt), OPT_GET_BUFF_SIZE(opt), StringBuff(opt->path_log),

src/htscoremain.c

@@ -1509,7 +1509,7 @@ static int hts_main_internal(int argc, char **argv, httrackp * opt) {
                   htsmain_free();
                   return -1;
                 } else {
-                  off_t fz;
+                  LLint fz;
 
                   na++;
                   fz = fsize(argv[na]);
@@ -2253,21 +2253,12 @@ static int hts_main_internal(int argc, char **argv, httrackp * opt) {
               htsmain_free();
               return -1;
             } else {
-              char *a;
+              char BIGSTK pname[HTS_URLMAXSIZE * 2];
 
               na++;
               opt->proxy.active = 1;
-              // Rechercher MAIS en partant de la fin à cause de user:pass@proxy:port
-              a = argv[na] + strlen(argv[na]) - 1;
-              while((a > argv[na]) && (*a != ':') && (*a != '@'))
-                a--;
-              if (*a == ':') {  // un port est présent, <proxy>:port
-                sscanf(a + 1, "%d", &opt->proxy.port);
-                StringCopyN(opt->proxy.name, argv[na], (int) (a - argv[na]));
-              } else {          // <proxy>
-                opt->proxy.port = 8080;
-                StringCopy(opt->proxy.name, argv[na]);
-              }
+              hts_parse_proxy(argv[na], pname, sizeof(pname), &opt->proxy.port);
+              StringCopy(opt->proxy.name, pname);
             }
             break;
           case 'F':            // user-agent field
@@ -2593,21 +2584,11 @@ static int hts_main_internal(int argc, char **argv, httrackp * opt) {
                 hts_get_version_info(opt), t, url);
         fprintf(opt->log, "(");
         for(i = 0; i < argc; i++) {
-#ifdef _WIN32
-          char *carg =
-            hts_convertStringSystemToUTF8(argv[i], (int) strlen(argv[i]));
-          char *arg = carg != NULL ? carg : argv[i];
-#else
-          const char *arg = argv[i];
-#endif
+          const char *arg = argv[i]; // already UTF-8 on every platform
           if (strchr(arg, ' ') == NULL || strchr(arg, '\"') != NULL)
             fprintf(opt->log, "%s ", arg);
           else                  // entre "" (si espace(s) et pas déja de ")
             fprintf(opt->log, "\"%s\" ", arg);
-#ifdef _WIN32
-          if (carg != NULL)
-            free(carg);
-#endif
         }
         fprintf(opt->log, ")" LF);
         fprintf(opt->log, LF);

src/htsfilters.c

@@ -122,8 +122,11 @@ int fa_strjoker_dual(int type, char **filters, int nfil, const char *nom1,
 }
 
 /* Real filters/URLs fit HTS_URLMAXSIZE*2; past it a hostile pattern recurses
-   O(len) deep or runs O(n^2*stars). Cap length (depth) and steps (work). */
+   O(len) deep or runs O(n^2*stars). Cap length, recursion depth and steps
+   (work): the length cap alone still allows ~2000 frames, ~900KB of stack,
+   which overflows the 1MB a Windows thread gets (#574). */
 #define STRJOKER_MAXLEN (HTS_URLMAXSIZE * 2)
+#define STRJOKER_MAXDEPTH 256u
 #define STRJOKER_MAXSTEPS 2000000u
 
 /* Failure memo for the recursive matcher: one bit per (chaine, joker) offset
@@ -133,20 +136,28 @@ typedef struct strjoker_memo {
   size_t stride;                /* strlen(joker0) + 1 */
   unsigned char *failed;        /* failed-pair bitmap; NULL: no memo */
   size_t *nsteps; /* shared work counter; NULL: unbounded (oracle) */
+  size_t maxdepth; /* deepest recursion reached */
+  hts_boolean cut; /* a branch hit the depth cap: its failures are not final */
 } strjoker_memo;
 
-static const char *strjoker_impl(const strjoker_memo *memo, const char *chaine,
-                                 const char *joker, LLint *size,
-                                 int *size_flag);
+static const char *strjoker_impl(strjoker_memo *memo, const char *chaine,
+                                 const char *joker, LLint *size, int *size_flag,
+                                 size_t depth);
 
 /* A pair that failed once fails forever (*size is only written on the success
    path), so record NULL results and cut the re-exploration. */
-static const char *strjoker_rec(const strjoker_memo *memo, const char *chaine,
-                                const char *joker, LLint *size,
-                                int *size_flag) {
+static const char *strjoker_rec(strjoker_memo *memo, const char *chaine,
+                                const char *joker, LLint *size, int *size_flag,
+                                size_t depth) {
   size_t bit = 0;
   const char *adr;
 
+  if (depth > memo->maxdepth)
+    memo->maxdepth = depth;
+  if (depth >= STRJOKER_MAXDEPTH) {
+    memo->cut = HTS_TRUE;
+    return NULL; /* nesting beyond any real filter: fail the branch safely */
+  }
   if (memo->nsteps != NULL && ++*memo->nsteps > STRJOKER_MAXSTEPS)
     return NULL; /* work budget spent: fail the match safely */
   if (memo->failed) {
@@ -155,8 +166,9 @@ static const char *strjoker_rec(const strjoker_memo *memo, const char *chaine,
     if (memo->failed[bit >> 3] & (unsigned char) (1u << (bit & 7)))
       return NULL;
   }
-  adr = strjoker_impl(memo, chaine, joker, size, size_flag);
-  if (adr == NULL && memo->failed)
+  adr = strjoker_impl(memo, chaine, joker, size, size_flag, depth + 1);
+  /* a cut branch may fail here yet match when reached at a shallower depth */
+  if (adr == NULL && memo->failed && !memo->cut)
     memo->failed[bit >> 3] |= (unsigned char) (1u << (bit & 7));
   return adr;
 }
@@ -164,13 +176,15 @@ static const char *strjoker_rec(const strjoker_memo *memo, const char *chaine,
 /* Match chaine against joker with a shared work budget *nsteps (a strjokerfind
    sweep passes one counter, bounding the whole scan). */
 static const char *strjoker_bounded(const char *chaine, const char *joker,
-                                    LLint *size, int *size_flag,
-                                    size_t *nsteps) {
-  strjoker_memo memo = {chaine, joker, 0, NULL, nsteps};
+                                    LLint *size, int *size_flag, size_t *nsteps,
+                                    size_t *maxdepth) {
+  strjoker_memo memo = {chaine, joker, 0, NULL, nsteps, 0, HTS_FALSE};
   unsigned char stackbits[2048];
   hts_boolean onheap = HTS_FALSE;
   const char *adr;
 
+  if (maxdepth != NULL)
+    *maxdepth = 0;
   if (chaine != NULL && joker != NULL) {
     const size_t l1 = strlen(chaine), l2 = strlen(joker);
 
@@ -189,9 +203,11 @@ static const char *strjoker_bounded(const char *chaine, const char *joker,
       }
     }
   }
-  adr = strjoker_rec(&memo, chaine, joker, size, size_flag);
+  adr = strjoker_rec(&memo, chaine, joker, size, size_flag, 0);
   if (onheap)
     freet(memo.failed);
+  if (maxdepth != NULL)
+    *maxdepth = memo.maxdepth;
   return adr;
 }
 
@@ -202,34 +218,39 @@ HTS_INLINE const char *strjoker(const char *chaine, const char *joker,
                                 LLint *size, int *size_flag) {
   size_t nsteps = 0;
 
-  return strjoker_bounded(chaine, joker, size, size_flag, &nsteps);
+  return strjoker_bounded(chaine, joker, size, size_flag, &nsteps, NULL);
 }
 
 /* Test-only oracle: the same matcher without the failure memo. */
 const char *strjoker_nomemo(const char *chaine, const char *joker, LLint *size,
                             int *size_flag) {
-  const strjoker_memo memo = {chaine, joker, 0, NULL};
+  strjoker_memo memo = {chaine, joker, 0, NULL, NULL, 0, HTS_FALSE};
 
-  return strjoker_rec(&memo, chaine, joker, size, size_flag);
+  return strjoker_rec(&memo, chaine, joker, size, size_flag, 0);
 }
 
-/* Test-only: strjoker() reporting the work-budget steps spent and the cap, so a
-   self-test can prove the budget bounds a hostile pattern's work. */
-const char *strjoker_steps(const char *chaine, const char *joker,
-                           size_t *nsteps_out, size_t *maxsteps_out) {
-  size_t nsteps = 0;
-  const char *r = strjoker_bounded(chaine, joker, NULL, NULL, &nsteps);
+/* Test-only: strjoker() reporting the work and depth spent and their caps, so a
+   self-test can prove both bound a hostile pattern. */
+const char *strjoker_bounds(const char *chaine, const char *joker,
+                            size_t *nsteps_out, size_t *maxsteps_out,
+                            size_t *depth_out, size_t *maxdepth_out) {
+  size_t nsteps = 0, depth = 0;
+  const char *r = strjoker_bounded(chaine, joker, NULL, NULL, &nsteps, &depth);
 
   if (nsteps_out != NULL)
     *nsteps_out = nsteps;
   if (maxsteps_out != NULL)
     *maxsteps_out = STRJOKER_MAXSTEPS;
+  if (depth_out != NULL)
+    *depth_out = depth;
+  if (maxdepth_out != NULL)
+    *maxdepth_out = STRJOKER_MAXDEPTH;
   return r;
 }
 
-static const char *strjoker_impl(const strjoker_memo *memo, const char *chaine,
-                                 const char *joker, LLint *size,
-                                 int *size_flag) {
+static const char *strjoker_impl(strjoker_memo *memo, const char *chaine,
+                                 const char *joker, LLint *size, int *size_flag,
+                                 size_t depth) {
   if (strnotempty(joker) == 0) {        // fin de chaine joker
     if (strnotempty(chaine) == 0)       // fin aussi pour la chaine: ok
       return chaine;
@@ -403,7 +424,8 @@ static const char *strjoker_impl(const strjoker_memo *memo, const char *chaine,
 
       // tester sans le joker (pas ()+ mais ()*)
       if (!unique) {
-        if ((adr = strjoker_rec(memo, chaine, joker + jmp, size, size_flag))) {
+        if ((adr = strjoker_rec(memo, chaine, joker + jmp, size, size_flag,
+                                depth))) {
           return adr;
         }
       }
@@ -416,7 +438,7 @@ static const char *strjoker_impl(const strjoker_memo *memo, const char *chaine,
       while(i < (int) max) {
         if (pass[(int) (unsigned char) chaine[i]]) {    // caractère autorisé
           if ((adr = strjoker_rec(memo, chaine + i + 1, joker + jmp, size,
-                                  size_flag))) {
+                                  size_flag, depth))) {
             return adr;
           }
           i++;
@@ -427,7 +449,7 @@ static const char *strjoker_impl(const strjoker_memo *memo, const char *chaine,
       // tester chaîne vide
       if (i != max + 2)         // avant c'est ok
         if ((adr = strjoker_rec(memo, chaine + max, joker + jmp, size,
-                                size_flag)))
+                                size_flag, depth)))
           return adr;
 
       return NULL;              // perdu
@@ -449,7 +471,8 @@ static const char *strjoker_impl(const strjoker_memo *memo, const char *chaine,
       // comparaison ok?
       if (ok) {
         // continuer la comparaison.
-        if (strjoker_rec(memo, chaine + jmp, joker + jmp, size, size_flag))
+        if (strjoker_rec(memo, chaine + jmp, joker + jmp, size, size_flag,
+                         depth))
           return chaine;        // retourner 1e lettre
       }
 
@@ -471,8 +494,8 @@ const char *strjokerfind(const char *chaine, const char *joker) {
   if (chaine != NULL && strlen(chaine) > STRJOKER_MAXLEN)
     return NULL;
   while(*chaine) {
-    if ((adr = strjoker_bounded(chaine, joker, NULL, NULL,
-                                &nsteps))) { // ok trouvé
+    if ((adr = strjoker_bounded(chaine, joker, NULL, NULL, &nsteps,
+                                NULL))) { // ok trouvé
       return adr;
     }
     if (nsteps > STRJOKER_MAXSTEPS) // scan budget spent: no match

src/htsfilters.h

@@ -52,10 +52,12 @@ HTS_INLINE const char *strjoker(const char *chaine, const char *joker, LLint * s
    oracle for the memoized matcher. */
 const char *strjoker_nomemo(const char *chaine, const char *joker, LLint *size,
                             int *size_flag);
-/* strjoker() reporting the work-budget steps it spent and the cap; test-only,
-   lets a self-test assert the budget bounds a hostile pattern's work. */
-const char *strjoker_steps(const char *chaine, const char *joker,
-                           size_t *nsteps_out, size_t *maxsteps_out);
+/* strjoker() reporting the work-budget steps and the recursion depth it spent,
+   with their caps; test-only, lets a self-test assert both bound a hostile
+   pattern (depth bounds the stack: an uncapped one overflows Windows' 1MB). */
+const char *strjoker_bounds(const char *chaine, const char *joker,
+                            size_t *nsteps_out, size_t *maxsteps_out,
+                            size_t *depth_out, size_t *maxdepth_out);
 const char *strjokerfind(const char *chaine, const char *joker);
 #endif
 

src/htsglobal.h

@@ -140,6 +140,15 @@ Please visit our Website: http://www.httrack.com
 #define HTS_USEZLIB 1
 #endif
 
+// brotli and zstd content codings; off unless the build opted in (configure,
+// or the Visual Studio projects, which link the vcpkg libraries)
+#ifndef HTS_USEBROTLI
+#define HTS_USEBROTLI 0
+#endif
+#ifndef HTS_USEZSTD
+#define HTS_USEZSTD 0
+#endif
+
 #ifndef HTS_INET6
 #define HTS_INET6 0
 #endif
@@ -313,16 +322,15 @@ typedef int64_t TStamp;
 /* Full printf conversion, '%' included (PRId64 has none): "X: " LLintP. */
 #define LLintP "%" PRId64
 
-/* Integer type for file offsets/sizes passed to the C library. Widens to
-   LLint (with HTS_FSEEKO for fseeko/ftello) under large-file support, plain
-   int otherwise; INTsysP is its printf conversion. */
-#ifdef LFS_FLAG
+/* Integer type for file offsets/sizes passed to the C library; INTsysP is its
+   printf conversion. FIXME: LFS_FLAG is a configure make variable, never a C
+   macro, so this test is dead and INTsys stays int on POSIX despite large-file
+   support (the real macro is HTS_LFS). Widening it there is an installed-header
+   type change, so it is left alone here. */
+#if defined(LFS_FLAG) || defined(_MSC_VER)
 typedef LLint INTsys;
 
 #define INTsysP LLintP
-#ifdef __linux
-#define HTS_FSEEKO
-#endif
 #else
 typedef int INTsys;
 

src/htshelp.c

@@ -477,7 +477,7 @@ void help(const char *app, int more) {
     ("  Y   mirror ALL links located in the first level pages (mirror links)");
   infomsg("");
   infomsg("Proxy options:");
-  infomsg("  P  proxy use (-P proxy:port or -P user:pass@proxy:port)");
+  infomsg("  P  proxy use (-P [socks5://][user:pass@]proxy:port)");
   infomsg(" %f *use proxy for ftp (f0 don't use)");
   infomsg(" %b  use this local hostname to make/send requests (-%b hostname)");
   infomsg("");

src/htsindex.c

@@ -318,7 +318,7 @@ void index_finish(const char *indexpath, int mode) {
   char catbuff[CATBUFF_SIZE];
   char **tab;
   char *blk;
-  off_t size = fpsize(fp_tmpproject);
+  LLint size = fpsize(fp_tmpproject);
 
   if (size > 0) {
     if (fp_tmpproject) {

src/htslib.c

@@ -48,6 +48,7 @@ Please visit our Website: http://www.httrack.com
 #include "htsmodules.h"
 #include "htscharset.h"
 #include "htsencoding.h"
+#include "htscodec.h"
 
 #ifdef _WIN32
 #include <direct.h>
@@ -648,165 +649,6 @@ T_SOC http_fopen(httrackp * opt, const char *adr, const char *fil, htsblk * reto
   return http_xfopen(opt, 0, 1, 1, NULL, adr, fil, retour);
 }
 
-// Read a CRLF line from a non-blocking socket (waits up to timeout per recv).
-// Returns the line length (0 = empty), or -1 on timeout/EOF/error.
-static int proxy_getline(T_SOC soc, char *s, int max, int timeout) {
-  int j = 0;
-
-  for (;;) {
-    unsigned char ch;
-    int n;
-
-    if (!check_readinput_t(soc, timeout))
-      return -1; // timed out waiting for data
-    n = (int) recv(soc, &ch, 1, 0);
-    if (n == 1) {
-      if (ch == 13) // CR
-        continue;
-      if (ch == 10) // LF: end of line
-        break;
-      if (j >= max - 1)
-        return -1; // line too long: bound the read against a hostile proxy
-      s[j++] = (char) ch;
-    } else if (n == 0) {
-      return -1; // connection closed
-    } else {
-#ifdef _WIN32
-      if (WSAGetLastError() == WSAEWOULDBLOCK)
-        continue;
-#else
-      if (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK)
-        continue;
-#endif
-      return -1;
-    }
-  }
-  s[j] = '\0';
-  return j;
-}
-
-int http_proxy_tunnel(httrackp *opt, htsblk *retour, const char *adr,
-                      int timeout) {
-  const T_SOC soc = retour->soc;
-  const char *const host = jump_identification_const(adr); // host[:port]
-  const char *const portsep = jump_toport_const(adr);      // ":port" or NULL
-  char BIGSTK authority[HTS_URLMAXSIZE * 2];
-  char BIGSTK req[HTS_URLMAXSIZE * 4 + 1100];
-  char line[1024];
-  int code;
-
-  if (soc == INVALID_SOCKET)
-    return 0;
-
-  // CONNECT needs an explicit host:port; default the https port
-  authority[0] = '\0';
-  if (portsep != NULL)
-    strlcatbuff(authority, host, sizeof(authority)); // already host:port
-  else
-    snprintf(authority, sizeof(authority), "%s:%d", host, 443);
-
-  // backstop: never let a stray CR/LF in the host smuggle a second line into
-  // the CONNECT request (the host is already sanitized upstream)
-  {
-    const char *c;
-
-    for (c = authority; *c != '\0'; c++) {
-      if ((unsigned char) *c < ' ') {
-        strcpybuff(retour->msg, "proxy CONNECT: invalid host");
-        return 0;
-      }
-    }
-  }
-
-  snprintf(req, sizeof(req), "CONNECT %s HTTP/1.0" H_CRLF "Host: %s" H_CRLF,
-           authority, authority);
-
-  // creds go on the CONNECT, not the tunneled origin request
-  if (link_has_authorization(retour->req.proxy.name)) {
-    const char *a = jump_identification_const(retour->req.proxy.name);
-    const char *astart = jump_protocol_const(retour->req.proxy.name);
-    char autorisation[1100];
-    char user_pass[256];
-
-    autorisation[0] = user_pass[0] = '\0';
-    strncatbuff(user_pass, astart, (int) (a - astart) - 1);
-    strcpybuff(user_pass, unescape_http(OPT_GET_BUFF(opt),
-                                        OPT_GET_BUFF_SIZE(opt), user_pass));
-    code64((unsigned char *) user_pass, (int) strlen(user_pass),
-           (unsigned char *) autorisation, 0);
-    strlcatbuff(req, "Proxy-Authorization: Basic ", sizeof(req));
-    strlcatbuff(req, autorisation, sizeof(req));
-    strlcatbuff(req, H_CRLF, sizeof(req));
-  }
-  strlcatbuff(req, H_CRLF, sizeof(req)); // end of request headers
-
-  // raw send: ssl is set, so sendc() would route to TLS
-  {
-    const char *p = req;
-    size_t remain = strlen(req);
-    int stalls = 0;
-
-    while (remain > 0) {
-      const int n = (int) send(soc, p, (int) remain, 0);
-
-      if (n > 0) {
-        p += n;
-        remain -= (size_t) n;
-        stalls = 0;
-      } else {
-#ifdef _WIN32
-        const int wouldblock = (WSAGetLastError() == WSAEWOULDBLOCK);
-#else
-        const int wouldblock =
-            (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR);
-#endif
-        // don't spin forever on a fatal error or an unwritable socket
-        if (!wouldblock || !check_writeinput_t(soc, timeout) ||
-            ++stalls > 100) {
-          strcpybuff(retour->msg, "proxy CONNECT: write error");
-          return 0;
-        }
-      }
-    }
-  }
-
-  // proxy status line: "HTTP/1.x <code> ..."
-  if (proxy_getline(soc, line, sizeof(line), timeout) < 0) {
-    strcpybuff(retour->msg, "proxy CONNECT: no response");
-    return 0;
-  }
-  if (sscanf(line, "HTTP/%*d.%*d %d", &code) < 1)
-    code = 0;
-  if (code < 200 || code >= 300) {
-    snprintf(retour->msg, sizeof(retour->msg), "proxy CONNECT refused: %s",
-             strnotempty(line) ? line : "(no status)");
-    return 0;
-  }
-
-  // drain headers to the blank line; cap the count so a flooding proxy can't
-  // stall the crawl
-  {
-    int headers = 0;
-
-    for (;;) {
-      const int n = proxy_getline(soc, line, sizeof(line), timeout);
-
-      if (n < 0) {
-        strcpybuff(retour->msg, "proxy CONNECT: truncated response");
-        return 0;
-      }
-      if (n == 0)
-        break; // blank line: tunnel ready
-      if (++headers > 64) {
-        strcpybuff(retour->msg, "proxy CONNECT: too many response headers");
-        return 0;
-      }
-    }
-  }
-
-  return 1;
-}
-
 // ouverture d'une liaison http, envoi d'une requète
 // mode: 0 GET  1 HEAD  [2 POST]
 // treat: traiter header?
@@ -1105,8 +947,9 @@ int http_sendhead(httrackp * opt, t_cookie * cookie, int mode,
           /* widths bound method[256], url[HTS_URLMAXSIZE*2], protocol[256] */
           if (sscanf(line, "%255s %2047s %255s", method, url, protocol) == 3) {
             size_t ret;
-            // selon que l'on a ou pas un proxy
-            if (retour->req.proxy.active) {
+            // absolute-URI for an http proxy; a socks tunnel takes origin-form
+            if (retour->req.proxy.active &&
+                !hts_proxy_is_socks(retour->req.proxy.name)) {
               print_buffer(&bstr,
                       "%s http://%s%s %s\r\n", method, adr, url,
                       protocol);
@@ -1142,8 +985,10 @@ int http_sendhead(httrackp * opt, t_cookie * cookie, int mode,
         print_buffer(&bstr, "HEAD ");
     }
 
-    // si on gère un proxy, il faut une Absolute URI: on ajoute avant http://www.adr.dom
-    if (retour->req.proxy.active && (strncmp(adr, "https://", 8) != 0)) {
+    // an http proxy needs an absolute URI; a socks tunnel does not
+    if (retour->req.proxy.active &&
+        !hts_proxy_is_socks(retour->req.proxy.name) &&
+        (strncmp(adr, "https://", 8) != 0)) {
       if (!link_has_authority(adr)) {   // default http
 #if HDEBUG
         printf("Proxy Use: for %s%s proxy %d port %d\n", adr, fil,
@@ -1187,8 +1032,11 @@ int http_sendhead(httrackp * opt, t_cookie * cookie, int mode,
     if (xsend)
       print_buffer(&bstr, "%s", xsend);  // éventuelles autres lignes
 
-    // for https, auth rides the CONNECT (the tunneled GET would leak it)
-    if (retour->req.proxy.active && strncmp(adr, "https://", 8) != 0) {
+    // for https, auth rides the CONNECT (the tunneled GET would leak it); for
+    // socks, the handshake
+    if (retour->req.proxy.active &&
+        !hts_proxy_is_socks(retour->req.proxy.name) &&
+        strncmp(adr, "https://", 8) != 0) {
       if (link_has_authorization(retour->req.proxy.name)) {     // et hop, authentification proxy!
         const char *a = jump_identification_const(retour->req.proxy.name);
         const char *astart = jump_protocol_const(retour->req.proxy.name);
@@ -1279,11 +1127,16 @@ int http_sendhead(httrackp * opt, t_cookie * cookie, int mode,
       // Compression accepted ?
       if (retour->req.http11) {
         hts_boolean compressible = HTS_FALSE;
+        hts_boolean secure = HTS_FALSE;
+
 #if HTS_USEZLIB
         compressible = (!retour->req.range_used && !retour->req.nocompression);
+#endif
+#if HTS_USEOPENSSL
+        secure = retour->ssl ? HTS_TRUE : HTS_FALSE;
 #endif
         print_buffer(&bstr, "Accept-Encoding: %s" H_CRLF,
-                     hts_acceptencoding(compressible));
+                     hts_acceptencoding(compressible, secure));
       }
 
       /* Authentification */
@@ -1668,22 +1521,10 @@ void treathead(t_cookie * cookie, const char *adr, const char *fil, htsblk * ret
         strcpybuff(retour->contentencoding, tempo);
       else
         retour->contentencoding[0] = '\0';
-#if HTS_USEZLIB
-      /* Check known encodings */
-      if (retour->contentencoding[0]) {
-        if ((strfield2(retour->contentencoding, "gzip"))
-            || (strfield2(retour->contentencoding, "x-gzip"))
-            /*
-               || (strfield2(retour->contentencoding, "compress"))
-               || (strfield2(retour->contentencoding, "x-compress"))
-             */
-            || (strfield2(retour->contentencoding, "deflate"))
-            || (strfield2(retour->contentencoding, "x-deflate"))
-          ) {
-          retour->compressed = 1;
-        }
-      }
-#endif
+      /* A coding to undo (or one we can not undo, which must fail the fetch
+         rather than save the coded bytes as the page) */
+      if (hts_codec_parse(retour->contentencoding) != HTS_CODEC_IDENTITY)
+        retour->compressed = 1;
     }
   } else if ((p = strfield(rcvd, "Location:")) != 0) {
     if (retour) {
@@ -3872,6 +3713,10 @@ const char *jump_protocol_const(const char *source) {
     source += p;
   else if ((p = strfield(source, "file:")))
     source += p;
+  else if ((p = strfield(source, "socks5h:")))
+    source += p;
+  else if ((p = strfield(source, "socks5:")))
+    source += p;
   // net_path
   if (strncmp(source, "//", 2) == 0)
     source += 2;
@@ -3880,6 +3725,48 @@ const char *jump_protocol_const(const char *source) {
 
 DECLARE_NON_CONST_VERSION(jump_protocol)
 
+hts_boolean hts_proxy_is_socks(const char *name) {
+  if (name == NULL)
+    return HTS_FALSE;
+  return (strfield(name, "socks5h:") || strfield(name, "socks5:")) ? HTS_TRUE
+                                                                   : HTS_FALSE;
+}
+
+// default proxy port for a -P argument, keyed on the scheme
+static int proxy_default_port(const char *arg) {
+  return hts_proxy_is_socks(arg) ? 1080 : 8080;
+}
+
+void hts_parse_proxy(const char *arg, char *name, size_t name_size, int *port) {
+  const char *authority = strstr(arg, "://");
+  const char *a;
+  size_t namelen;
+
+  if (name_size == 0)
+    return;
+  // scan back to the port ':' (or userinfo '@'), but never past the authority,
+  // so a scheme's own colon is not read as a port separator; inspect a[-1] from
+  // one-past-end so no pointer below the string is ever formed
+  authority = (authority != NULL) ? authority + 3 : arg;
+  a = arg + strlen(arg);
+  while (a > authority && a[-1] != ':' && a[-1] != '@')
+    a--;
+  if (a > authority && a[-1] == ':') {
+    int p = -1;
+
+    sscanf(a, "%d", &p);
+    *port = (p > 0) ? p : proxy_default_port(arg);
+    namelen = (size_t) (a - 1 - arg);
+  } else {
+    *port = proxy_default_port(arg);
+    namelen = strlen(arg);
+  }
+  if (namelen >= name_size) // arg is user-controlled: truncate, don't overflow
+    namelen = name_size - 1;
+  memcpy(name, arg, namelen);
+  name[namelen] = '\0';
+}
+
 // codage base 64 a vers b
 void code64(unsigned char *a, int size_a, unsigned char *b, int crlf) {
   int i1 = 0, i2 = 0, i3 = 0, i4 = 0;
@@ -4365,11 +4252,6 @@ HTSEXT_API void get_httptype(httrackp *opt, char *s, const char *fil,
   (void) get_httptype_sized(opt, s, HTS_MIMETYPE_SIZE, fil, flag);
 }
 
-/* Advertised Accept-Encoding; gzip and deflate both decode via hts_zunpack */
-const char *hts_acceptencoding(hts_boolean compressible) {
-  return compressible ? "gzip, deflate, identity;q=0.9" : "identity";
-}
-
 // get type of fil (php)
 // s: buffer (text/html) or NULL
 // return: 1 if known by user
@@ -4709,26 +4591,31 @@ int fexist_utf8(const char *s) {
   return 0;
 }
 
-/* Taille d'un fichier, -1 si n'existe pas */
+/* File size, -1 if absent */
 /* Note: NOT utf-8 */
-off_t fsize(const char *s) {
-  struct stat st;
+LLint fsize(const char *s) {
+  STRUCT_STAT st;
 
-  if (!strnotempty(s))          // nom vide: erreur
+  if (!strnotempty(s)) // empty name: error
     return -1;
+  /* _stat64, not stat(): the latter is 32-bit on MSVC */
+#ifdef _WIN32
+  if (_stat64(s, &st) == 0 && S_ISREG(st.st_mode)) {
+#else
   if (stat(s, &st) == 0 && S_ISREG(st.st_mode)) {
+#endif
     return st.st_size;
   } else {
     return -1;
   }
 }
 
-/* Taille d'un fichier, -1 si n'existe pas */
+/* File size, -1 if absent */
 /* Note: utf-8 */
-off_t fsize_utf8(const char *s) {
+LLint fsize_utf8(const char *s) {
   STRUCT_STAT st;
 
-  if (!strnotempty(s))          // nom vide: erreur
+  if (!strnotempty(s)) // empty name: error
     return -1;
   if (STAT(s, &st) == 0 && S_ISREG(st.st_mode)) {
     return st.st_size;
@@ -4737,24 +4624,17 @@ off_t fsize_utf8(const char *s) {
   }
 }
 
-off_t fpsize(FILE * fp) {
-  off_t oldpos, size;
+/* fseeko/ftello, never fseek/ftell: ftell returns long, which cannot carry an
+   offset past 2GB on a 32-bit platform and fails with EOVERFLOW there. */
+LLint fpsize(FILE *fp) {
+  LLint oldpos, size;
 
   if (!fp)
     return -1;
-#ifdef HTS_FSEEKO
   oldpos = ftello(fp);
-#else
-  oldpos = ftell(fp);
-#endif
-  fseek(fp, 0, SEEK_END);
-#ifdef HTS_FSEEKO
+  fseeko(fp, 0, SEEK_END);
   size = ftello(fp);
   fseeko(fp, oldpos, SEEK_SET);
-#else
-  size = ftell(fp);
-  fseek(fp, oldpos, SEEK_SET);
-#endif
   return size;
 }
 
@@ -6518,13 +6398,13 @@ int hts_stat_utf8(const char *path, STRUCT_STAT * buf) {
   LPWSTR wpath = hts_convertUTF8StringToUCS2(path, (int) strlen(path), NULL);
 
   if (wpath != NULL) {
-    const int result = _wstat(wpath, buf);
+    const int result = _wstat64(wpath, buf);
 
     free(wpath);
     return result;
   } else {
     // Fallback on conversion error.
-    return _stat(path, buf);
+    return _stat64(path, buf);
   }
 }
 

src/htslib.h

@@ -207,15 +207,9 @@ int check_readinput(htsblk * r);
 int check_readinput_t(T_SOC soc, int timeout);
 int check_writeinput_t(T_SOC soc, int timeout);
 
-/* Open an HTTP CONNECT tunnel through the active proxy for an https request:
-   `retour->soc` must already be TCP-connected to the proxy, and `adr` is the
-   origin authority (url_adr, e.g. "https://host:port"). Sends the CONNECT
-   request (with Proxy-Authorization when the proxy carries credentials) and
-   reads the proxy's status line, so the caller's TLS handshake then runs
-   end-to-end with the origin. Blocks up to `timeout` seconds. Returns 1 on a
-   2xx tunnel, 0 on failure (retour->msg/statuscode set). */
-int http_proxy_tunnel(httrackp *opt, htsblk *retour, const char *adr,
-                      int timeout);
+/* TRUE if this -P proxy name (which keeps its scheme) is a SOCKS5 proxy. */
+hts_boolean hts_proxy_is_socks(const char *name);
+
 void treathead(t_cookie * cookie, const char *adr, const char *fil, htsblk * retour,
                char *rcvd);
 void treatfirstline(htsblk * retour, const char *rcvd);
@@ -283,15 +277,18 @@ int ishttperror(int err);
 int get_userhttptype(httrackp * opt, char *s, const char *fil);
 int give_mimext(char *s, size_t ssize, const char *st);
 
-/* Advertised Accept-Encoding value (no header name/CRLF); see htslib.c. */
-const char *hts_acceptencoding(hts_boolean compressible);
-
 int may_bogus_multiple(httrackp * opt, const char *mime, const char *filename);
 int may_unknown2(httrackp * opt, const char *mime, const char *filename);
 
 const char *strrchr_limit(const char *s, char c, const char *limit);
 char *jump_protocol(char *source);
 const char *jump_protocol_const(const char *source);
+
+/* Split a -P proxy argument "[scheme://][user:pass@]host[:port]" into the proxy
+   host string (scheme and any user:pass kept, for later stripping and auth),
+   written NUL-terminated into name[name_size] (truncated to fit), and the port
+   in *port. The port defaults by scheme: 1080 for socks5/socks5h, else 8080. */
+void hts_parse_proxy(const char *arg, char *name, size_t name_size, int *port);
 void code64(unsigned char *a, int size_a, unsigned char *b, int crlf);
 
 #define copychar(catbuff,a) concat(catbuff,(a),NULL)
@@ -313,10 +310,11 @@ void cut_path(char *fullpath, char *path, size_t path_size, char *pname,
 int fexist(const char *s);
 int fexist_utf8(const char *s);
 
-/*LLint fsize(const char* s);    */
-off_t fpsize(FILE * fp);
-off_t fsize(const char *s);
-off_t fsize_utf8(const char *s);
+/* File size in bytes, -1 if absent or not a regular file. LLint, not off_t:
+   the latter is a 32-bit long on MSVC, truncating any file of 2GB or more. */
+LLint fpsize(FILE *fp);
+LLint fsize(const char *s);
+LLint fsize_utf8(const char *s);
 
 // Threads
 typedef void *(*beginthread_type) (void *);
@@ -396,7 +394,8 @@ void *hts_get_callback(t_hts_htmlcheck_callbacks * callbacks,
      HTSEXT_API FILE *hts_fopen_utf8(const char *path, const char *mode);
 
 #define STAT hts_stat_utf8
-     typedef struct _stat STRUCT_STAT;
+     /* _stat64: _stat's st_size is a 32-bit long, even in x64 builds */
+     typedef struct _stat64 STRUCT_STAT;
      HTSEXT_API int hts_stat_utf8(const char *path, STRUCT_STAT * buf);
 
 #define UNLINK hts_unlink_utf8
@@ -594,9 +593,9 @@ HTS_STATIC int compare_mime(httrackp * opt, const char *mime, const char *file,
 #endif
 
 // returns (size_t) -1 upon error
-static HTS_UNUSED size_t off_t_to_size_t(off_t o) {
+static HTS_UNUSED size_t llint_to_size_t(LLint o) {
   const size_t so = (size_t) o;
-  if ((off_t) so == o) {
+  if ((LLint) so == o) {
     return so;
   } else {
     return (size_t) -1;

src/htsname.c

@@ -42,6 +42,7 @@ Please visit our Website: http://www.httrack.com
 #include "htscharset.h"
 #include "htsencoding.h"
 #include "htssniff.h"
+#include "htscodec.h"
 #if HTS_USEZLIB
 #include "htszlib.h"
 #endif
@@ -151,29 +152,6 @@ typedef struct sniff_src {
   const char *prev_save; /* previous run's save name (cache X-Save) */
 } sniff_src;
 
-#if HTS_USEZLIB
-/* Inflate the head of a gzip/zlib stream; 0 when undecodable. */
-static size_t sniff_inflate_head(const void *in, size_t in_len, void *out,
-                                 size_t out_len) {
-  z_stream zs;
-  size_t n = 0;
-  int err;
-
-  memset(&zs, 0, sizeof(zs));
-  if (inflateInit2(&zs, 47) != Z_OK) /* 47: gzip or zlib, autodetected */
-    return 0;
-  zs.next_in = (const Bytef *) in;
-  zs.avail_in = (uInt) in_len;
-  zs.next_out = (Bytef *) out;
-  zs.avail_out = (uInt) out_len;
-  err = inflate(&zs, Z_SYNC_FLUSH);
-  if (err == Z_OK || err == Z_STREAM_END || err == Z_BUF_ERROR)
-    n = out_len - zs.avail_out;
-  inflateEnd(&zs);
-  return n;
-}
-#endif
-
 static size_t sniff_read_head(const char *path, void *buf, size_t len) {
   char catbuff[CATBUFF_SIZE];
   FILE *const fp = FOPEN(fconv(catbuff, sizeof(catbuff), path), "rb");
@@ -205,16 +183,12 @@ static size_t sniff_slot_head(const lien_back *slot, void *buf, size_t len) {
       n = sniff_read_head(slot->tmpfile, buf, len);
   }
   if (n > 0 && r->compressed) {
-#if HTS_USEZLIB
     unsigned char raw[HTS_SNIFF_LEN];
 
     if (n > sizeof(raw))
       n = sizeof(raw);
     memcpy(raw, buf, n);
-    n = sniff_inflate_head(raw, n, buf, len);
-#else
-    n = 0;
-#endif
+    n = hts_codec_head(hts_codec_parse(r->contentencoding), raw, n, buf, len);
   }
   return n;
 }

src/htsopt.h

@@ -328,8 +328,8 @@ typedef enum hts_wizard {
 
 typedef enum hts_robots {
   HTS_ROBOTS_NEVER = 0,        /**< ignore robots rules */
-  HTS_ROBOTS_SOMETIMES = 1,    /**< partial obedience (default) */
-  HTS_ROBOTS_ALWAYS = 2,       /**< obey robots rules */
+  HTS_ROBOTS_SOMETIMES = 1,    /**< partial obedience, set by -s */
+  HTS_ROBOTS_ALWAYS = 2,       /**< obey robots rules (default) */
   HTS_ROBOTS_ALWAYS_STRICT = 3 /**< obey even strict rules */
 } hts_robots;
 #endif

src/htsproxy.c

@@ -0,0 +1,539 @@
+/* ------------------------------------------------------------ */
+/*
+HTTrack Website Copier, Offline Browser for Windows and Unix
+Copyright (C) 2026 Xavier Roche and other contributors
+
+SPDX-License-Identifier: GPL-3.0-or-later
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+Ethical use: we kindly ask that you NOT use this software to harvest email
+addresses or to collect any other private information about people. Doing so
+would dishonor our work and waste the many hours we have spent on it.
+
+Please visit our Website: http://www.httrack.com
+*/
+
+/* ------------------------------------------------------------ */
+/* File: Proxy tunneling (HTTP CONNECT, SOCKS5)                 */
+/* Author: Xavier Roche                                         */
+/* ------------------------------------------------------------ */
+
+/* Internal engine bytecode */
+#define HTS_INTERNAL_BYTECODE
+
+#include "htscore.h"
+
+#include "htslib.h"
+#include "htsproxy.h"
+
+#include <string.h>
+
+// Read a CRLF line from a non-blocking socket (waits up to timeout per recv).
+// Returns the line length (0 = empty), or -1 on timeout/EOF/error.
+static int proxy_getline(T_SOC soc, char *s, int max, int timeout) {
+  int j = 0;
+
+  for (;;) {
+    unsigned char ch;
+    int n;
+
+    if (!check_readinput_t(soc, timeout))
+      return -1; // timed out waiting for data
+    n = (int) recv(soc, &ch, 1, 0);
+    if (n == 1) {
+      if (ch == 13) // CR
+        continue;
+      if (ch == 10) // LF: end of line
+        break;
+      if (j >= max - 1)
+        return -1; // line too long: bound the read against a hostile proxy
+      s[j++] = (char) ch;
+    } else if (n == 0) {
+      return -1; // connection closed
+    } else {
+#ifdef _WIN32
+      if (WSAGetLastError() == WSAEWOULDBLOCK)
+        continue;
+#else
+      if (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK)
+        continue;
+#endif
+      return -1;
+    }
+  }
+  s[j] = '\0';
+  return j;
+}
+
+int http_proxy_tunnel(httrackp *opt, htsblk *retour, const char *adr,
+                      int timeout) {
+  const T_SOC soc = retour->soc;
+  const char *const host = jump_identification_const(adr); // host[:port]
+  const char *const portsep = jump_toport_const(adr);      // ":port" or NULL
+  char BIGSTK authority[HTS_URLMAXSIZE * 2];
+  char BIGSTK req[HTS_URLMAXSIZE * 4 + 1100];
+  char line[1024];
+  int code;
+
+  if (soc == INVALID_SOCKET)
+    return 0;
+
+  // CONNECT needs an explicit host:port; default the https port
+  authority[0] = '\0';
+  if (portsep != NULL)
+    strlcatbuff(authority, host, sizeof(authority)); // already host:port
+  else
+    snprintf(authority, sizeof(authority), "%s:%d", host, 443);
+
+  // backstop: never let a stray CR/LF in the host smuggle a second line into
+  // the CONNECT request (the host is already sanitized upstream)
+  {
+    const char *c;
+
+    for (c = authority; *c != '\0'; c++) {
+      if ((unsigned char) *c < ' ') {
+        strcpybuff(retour->msg, "proxy CONNECT: invalid host");
+        return 0;
+      }
+    }
+  }
+
+  snprintf(req, sizeof(req), "CONNECT %s HTTP/1.0" H_CRLF "Host: %s" H_CRLF,
+           authority, authority);
+
+  // creds go on the CONNECT, not the tunneled origin request
+  if (link_has_authorization(retour->req.proxy.name)) {
+    const char *a = jump_identification_const(retour->req.proxy.name);
+    const char *astart = jump_protocol_const(retour->req.proxy.name);
+    char autorisation[1100];
+    char user_pass[256];
+
+    autorisation[0] = user_pass[0] = '\0';
+    strncatbuff(user_pass, astart, (int) (a - astart) - 1);
+    strcpybuff(user_pass, unescape_http(OPT_GET_BUFF(opt),
+                                        OPT_GET_BUFF_SIZE(opt), user_pass));
+    code64((unsigned char *) user_pass, (int) strlen(user_pass),
+           (unsigned char *) autorisation, 0);
+    strlcatbuff(req, "Proxy-Authorization: Basic ", sizeof(req));
+    strlcatbuff(req, autorisation, sizeof(req));
+    strlcatbuff(req, H_CRLF, sizeof(req));
+  }
+  strlcatbuff(req, H_CRLF, sizeof(req)); // end of request headers
+
+  // raw send: ssl is set, so sendc() would route to TLS
+  {
+    const char *p = req;
+    size_t remain = strlen(req);
+    int stalls = 0;
+
+    while (remain > 0) {
+      const int n = (int) send(soc, p, (int) remain, 0);
+
+      if (n > 0) {
+        p += n;
+        remain -= (size_t) n;
+        stalls = 0;
+      } else {
+#ifdef _WIN32
+        const int wouldblock = (WSAGetLastError() == WSAEWOULDBLOCK);
+#else
+        const int wouldblock =
+            (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR);
+#endif
+        // don't spin forever on a fatal error or an unwritable socket
+        if (!wouldblock || !check_writeinput_t(soc, timeout) ||
+            ++stalls > 100) {
+          strcpybuff(retour->msg, "proxy CONNECT: write error");
+          return 0;
+        }
+      }
+    }
+  }
+
+  // proxy status line: "HTTP/1.x <code> ..."
+  if (proxy_getline(soc, line, sizeof(line), timeout) < 0) {
+    strcpybuff(retour->msg, "proxy CONNECT: no response");
+    return 0;
+  }
+  if (sscanf(line, "HTTP/%*d.%*d %d", &code) < 1)
+    code = 0;
+  if (code < 200 || code >= 300) {
+    snprintf(retour->msg, sizeof(retour->msg), "proxy CONNECT refused: %s",
+             strnotempty(line) ? line : "(no status)");
+    return 0;
+  }
+
+  // drain headers to the blank line; cap the count so a flooding proxy can't
+  // stall the crawl
+  {
+    int headers = 0;
+
+    for (;;) {
+      const int n = proxy_getline(soc, line, sizeof(line), timeout);
+
+      if (n < 0) {
+        strcpybuff(retour->msg, "proxy CONNECT: truncated response");
+        return 0;
+      }
+      if (n == 0)
+        break; // blank line: tunnel ready
+      if (++headers > 64) {
+        strcpybuff(retour->msg, "proxy CONNECT: too many response headers");
+        return 0;
+      }
+    }
+  }
+
+  return 1;
+}
+
+/* SOCKS5 client (RFC 1928, RFC 1929 auth), hostname mode only: the proxy
+   resolves the origin name (remote DNS, curl's socks5h). The stream is the
+   proxy socket, or a scripted buffer under -#test=socks5. */
+
+#define SOCKS5_VERSION 0x05
+#define SOCKS5_AUTH_VERSION 0x01
+#define SOCKS5_METHOD_NONE 0x00
+#define SOCKS5_METHOD_USERPASS 0x02
+#define SOCKS5_METHOD_NOACCEPTABLE 0xFF
+#define SOCKS5_CMD_CONNECT 0x01
+#define SOCKS5_ATYP_IPV4 0x01
+#define SOCKS5_ATYP_DOMAIN 0x03
+#define SOCKS5_ATYP_IPV6 0x04
+#define SOCKS5_MAXFIELD 255 /* one length byte: host, user and password */
+
+typedef struct socks5_stream {
+  T_SOC soc; /* INVALID_SOCKET when scripted (self-test) */
+  int timeout;
+  socks5_test_io *io;
+} socks5_stream;
+
+static int socks5_fail(char *msg, size_t msgsize, const char *text) {
+  if (msgsize != 0)
+    strlcpybuff(msg, text, msgsize);
+  return 0;
+}
+
+/* Read exactly n bytes, or fail: SOCKS frames are not self-delimiting, so a
+   short read would desync the stream shared with the origin traffic. */
+static int socks5_read_n(socks5_stream *st, unsigned char *buf, size_t n) {
+  size_t got = 0;
+  int stalls = 0;
+
+  if (st->soc == INVALID_SOCKET) { /* scripted */
+    socks5_test_io *const io = st->io;
+
+    if (n > io->reply_len - io->consumed)
+      return 0;
+    memcpy(buf, io->reply + io->consumed, n);
+    io->consumed += n;
+    return 1;
+  }
+  while (got < n) {
+    const int r = (int) recv(st->soc, (char *) buf + got, (int) (n - got), 0);
+
+    if (r > 0) {
+      got += (size_t) r;
+      stalls = 0;
+    } else if (r == 0) {
+      return 0; // proxy closed mid-frame
+    } else {
+#ifdef _WIN32
+      const int wouldblock = (WSAGetLastError() == WSAEWOULDBLOCK);
+#else
+      const int wouldblock =
+          (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR);
+#endif
+      if (!wouldblock || !check_readinput_t(st->soc, st->timeout) ||
+          ++stalls > 100)
+        return 0;
+    }
+  }
+  return 1;
+}
+
+static int socks5_write_all(socks5_stream *st, const unsigned char *buf,
+                            size_t len) {
+  size_t remain = len;
+  int stalls = 0;
+
+  if (st->soc == INVALID_SOCKET) { /* scripted */
+    socks5_test_io *const io = st->io;
+
+    if (len > sizeof(io->sent) - io->sent_len)
+      return 0;
+    memcpy(io->sent + io->sent_len, buf, len);
+    io->sent_len += len;
+    return 1;
+  }
+  while (remain > 0) {
+    // raw send: the socket is still plain here, sendc() would route to TLS
+    const int n = (int) send(st->soc, (const char *) buf, (int) remain, 0);
+
+    if (n > 0) {
+      buf += n;
+      remain -= (size_t) n;
+      stalls = 0;
+    } else {
+#ifdef _WIN32
+      const int wouldblock = (WSAGetLastError() == WSAEWOULDBLOCK);
+#else
+      const int wouldblock =
+          (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR);
+#endif
+      if (!wouldblock || !check_writeinput_t(st->soc, st->timeout) ||
+          ++stalls > 100)
+        return 0;
+    }
+  }
+  return 1;
+}
+
+static const char *socks5_rep_message(unsigned char rep) {
+  switch (rep) {
+  case 0x01:
+    return "general failure";
+  case 0x02:
+    return "connection not allowed by ruleset";
+  case 0x03:
+    return "network unreachable";
+  case 0x04:
+    return "host unreachable";
+  case 0x05:
+    return "connection refused";
+  case 0x06:
+    return "TTL expired";
+  case 0x07:
+    return "command not supported";
+  case 0x08:
+    return "address type not supported";
+  default:
+    return "unknown error";
+  }
+}
+
+/* The reply's BND.ADDR is variable-length: consume exactly what ATYP says, or
+   the leftover bytes prepend to the first origin (or TLS) read. */
+static int socks5_read_reply(socks5_stream *st, char *msg, size_t msgsize) {
+  unsigned char head[4];
+  unsigned char addr[SOCKS5_MAXFIELD + 2];
+  size_t addrlen;
+
+  if (!socks5_read_n(st, head, sizeof(head)))
+    return socks5_fail(msg, msgsize, "SOCKS5: no reply from proxy");
+  if (head[0] != SOCKS5_VERSION)
+    return socks5_fail(msg, msgsize, "SOCKS5: bad version in reply");
+  if (head[1] != 0x00) {
+    snprintf(msg, msgsize, "SOCKS5 connect failed: %s",
+             socks5_rep_message(head[1]));
+    return 0;
+  }
+  switch (head[3]) {
+  case SOCKS5_ATYP_IPV4:
+    addrlen = 4;
+    break;
+  case SOCKS5_ATYP_IPV6:
+    addrlen = 16;
+    break;
+  case SOCKS5_ATYP_DOMAIN: {
+    unsigned char len;
+
+    if (!socks5_read_n(st, &len, 1))
+      return socks5_fail(msg, msgsize, "SOCKS5: truncated reply");
+    addrlen = len; // <= 255, always fits addr[]
+    break;
+  }
+  default: // unknown length: the stream cannot be resynchronized
+    return socks5_fail(msg, msgsize, "SOCKS5: unknown address type in reply");
+  }
+  if (addrlen != 0 && !socks5_read_n(st, addr, addrlen))
+    return socks5_fail(msg, msgsize, "SOCKS5: truncated reply address");
+  if (!socks5_read_n(st, addr, 2)) // BND.PORT, unused
+    return socks5_fail(msg, msgsize, "SOCKS5: truncated reply port");
+  return 1;
+}
+
+static int socks5_negotiate(socks5_stream *st, const char *host, size_t hostlen,
+                            int port, const char *user, size_t userlen,
+                            const char *pass, size_t passlen, int want_auth,
+                            char *msg, size_t msgsize) {
+  unsigned char frame[3 + SOCKS5_MAXFIELD + SOCKS5_MAXFIELD];
+  unsigned char rep[2];
+
+  /* greeting */
+  frame[0] = SOCKS5_VERSION;
+  frame[1] = (unsigned char) (want_auth ? 2 : 1);
+  frame[2] = SOCKS5_METHOD_NONE;
+  frame[3] = SOCKS5_METHOD_USERPASS;
+  if (!socks5_write_all(st, frame, (size_t) 2 + frame[1]))
+    return socks5_fail(msg, msgsize, "SOCKS5: write error");
+  if (!socks5_read_n(st, rep, sizeof(rep)))
+    return socks5_fail(msg, msgsize, "SOCKS5: no method reply from proxy");
+  if (rep[0] != SOCKS5_VERSION)
+    return socks5_fail(msg, msgsize, "SOCKS5: bad version in method reply");
+  switch (rep[1]) {
+  case SOCKS5_METHOD_NONE:
+    break;
+  case SOCKS5_METHOD_USERPASS:
+    if (!want_auth)
+      return socks5_fail(msg, msgsize,
+                         "SOCKS5: proxy requires authentication, none given");
+    /* RFC 1929 sub-negotiation; its version byte is 0x01, not 0x05 */
+    frame[0] = SOCKS5_AUTH_VERSION;
+    frame[1] = (unsigned char) userlen;
+    memcpy(frame + 2, user, userlen);
+    frame[2 + userlen] = (unsigned char) passlen;
+    memcpy(frame + 3 + userlen, pass, passlen);
+    if (!socks5_write_all(st, frame, 3 + userlen + passlen))
+      return socks5_fail(msg, msgsize, "SOCKS5: write error");
+    if (!socks5_read_n(st, rep, sizeof(rep)))
+      return socks5_fail(msg, msgsize, "SOCKS5: no authentication reply");
+    if (rep[1] != 0x00)
+      return socks5_fail(msg, msgsize, "SOCKS5: authentication failed");
+    break;
+  case SOCKS5_METHOD_NOACCEPTABLE:
+    return socks5_fail(
+        msg, msgsize,
+        "SOCKS5: proxy accepts no authentication method we offer");
+  default:
+    return socks5_fail(msg, msgsize,
+                       "SOCKS5: proxy selected an unknown method");
+  }
+
+  /* CONNECT to the origin, by name */
+  frame[0] = SOCKS5_VERSION;
+  frame[1] = SOCKS5_CMD_CONNECT;
+  frame[2] = 0x00; // RSV
+  frame[3] = SOCKS5_ATYP_DOMAIN;
+  frame[4] = (unsigned char) hostlen;
+  memcpy(frame + 5, host, hostlen);
+  frame[5 + hostlen] = (unsigned char) (port >> 8);
+  frame[6 + hostlen] = (unsigned char) (port & 0xFF);
+  if (!socks5_write_all(st, frame, 7 + hostlen))
+    return socks5_fail(msg, msgsize, "SOCKS5: write error");
+
+  return socks5_read_reply(st, msg, msgsize);
+}
+
+/* Decode the proxy userinfo into the two RFC 1929 fields. Split on the first
+   colon of the still-escaped string, so a %3A stays inside the username. */
+static int socks5_credentials(httrackp *opt, const char *proxy_name, char *user,
+                              size_t user_size, size_t *userlen, char *pass,
+                              size_t pass_size, size_t *passlen, char *msg,
+                              size_t msgsize) {
+  const char *const a = jump_identification_const(proxy_name); // past the '@'
+  const char *const astart = jump_protocol_const(proxy_name);
+  char userinfo[1024];
+  char *colon;
+
+  if (a <= astart || (size_t) (a - astart) - 1 >= sizeof(userinfo))
+    return socks5_fail(msg, msgsize, "SOCKS5: credentials too long");
+  userinfo[0] = '\0';
+  strncatbuff(userinfo, astart, (int) (a - astart) - 1);
+  colon = strchr(userinfo, ':');
+  if (colon != NULL)
+    *colon++ = '\0';
+  strlcpybuff(
+      user, unescape_http(OPT_GET_BUFF(opt), OPT_GET_BUFF_SIZE(opt), userinfo),
+      user_size);
+  strlcpybuff(pass,
+              colon != NULL ? unescape_http(OPT_GET_BUFF(opt),
+                                            OPT_GET_BUFF_SIZE(opt), colon)
+                            : "",
+              pass_size);
+  *userlen = strlen(user);
+  *passlen = strlen(pass);
+  // reject, never truncate: a clipped secret would authenticate as another one
+  if (*userlen > SOCKS5_MAXFIELD || *passlen > SOCKS5_MAXFIELD)
+    return socks5_fail(msg, msgsize, "SOCKS5: credentials too long");
+  if (*userlen == 0)
+    return socks5_fail(msg, msgsize, "SOCKS5: empty proxy username");
+  return 1;
+}
+
+static int socks5_handshake_stream(httrackp *opt, socks5_stream *st,
+                                   const char *adr, const char *proxy_name,
+                                   int ssl, char *msg, size_t msgsize) {
+  const char *const host = jump_identification_const(adr);
+  const char *const portsep = jump_toport_const(adr);
+  const size_t hostlen =
+      portsep != NULL ? (size_t) (portsep - host) : strlen(host);
+  // sized for the whole userinfo: decoding shrinks, so an over-long credential
+  // lands intact and is rejected below rather than silently clipped
+  char user[1024];
+  char pass[1024];
+  size_t userlen = 0, passlen = 0;
+  int want_auth = 0;
+  int port = ssl ? 443 : 80;
+  size_t i;
+
+  if (hostlen == 0 || hostlen > SOCKS5_MAXFIELD)
+    return socks5_fail(msg, msgsize, "SOCKS5: invalid origin host");
+  if (host[0] == '[') // ATYP=domain cannot carry an IPv6 literal
+    return socks5_fail(msg, msgsize,
+                       "SOCKS5: IPv6 literal origin is not supported");
+  for (i = 0; i < hostlen; i++) {
+    if ((unsigned char) host[i] < ' ')
+      return socks5_fail(msg, msgsize, "SOCKS5: invalid origin host");
+  }
+  if (portsep != NULL) {
+    int p = -1;
+
+    sscanf(portsep + 1, "%d", &p);
+    if (p <= 0 || p > 65535)
+      return socks5_fail(msg, msgsize, "SOCKS5: invalid origin port");
+    port = p;
+  }
+  if (link_has_authorization(proxy_name)) {
+    if (!socks5_credentials(opt, proxy_name, user, sizeof(user), &userlen, pass,
+                            sizeof(pass), &passlen, msg, msgsize))
+      return 0;
+    want_auth = 1;
+  }
+  return socks5_negotiate(st, host, hostlen, port, user, userlen, pass, passlen,
+                          want_auth, msg, msgsize);
+}
+
+int socks5_handshake(httrackp *opt, htsblk *retour, const char *adr,
+                     int timeout) {
+  socks5_stream st;
+#if HTS_USEOPENSSL
+  const int ssl = retour->ssl;
+#else
+  const int ssl = 0;
+#endif
+
+  if (retour->soc == INVALID_SOCKET)
+    return 0;
+  st.soc = retour->soc;
+  st.timeout = timeout;
+  st.io = NULL;
+  return socks5_handshake_stream(opt, &st, adr, retour->req.proxy.name, ssl,
+                                 retour->msg, sizeof(retour->msg));
+}
+
+int socks5_handshake_scripted(httrackp *opt, const char *adr,
+                              const char *proxy_name, socks5_test_io *io) {
+  socks5_stream st;
+
+  st.soc = INVALID_SOCKET;
+  st.timeout = 0;
+  st.io = io;
+  io->consumed = 0;
+  io->sent_len = 0;
+  io->msg[0] = '\0';
+  return socks5_handshake_stream(opt, &st, adr, proxy_name, 0, io->msg,
+                                 sizeof(io->msg));
+}

src/htsproxy.h

@@ -0,0 +1,82 @@
+/* ------------------------------------------------------------ */
+/*
+HTTrack Website Copier, Offline Browser for Windows and Unix
+Copyright (C) 2026 Xavier Roche and other contributors
+
+SPDX-License-Identifier: GPL-3.0-or-later
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+Ethical use: we kindly ask that you NOT use this software to harvest email
+addresses or to collect any other private information about people. Doing so
+would dishonor our work and waste the many hours we have spent on it.
+
+Please visit our Website: http://www.httrack.com
+*/
+
+/* ------------------------------------------------------------ */
+/* File: Proxy tunneling (HTTP CONNECT, SOCKS5) .h              */
+/* Author: Xavier Roche                                         */
+/* ------------------------------------------------------------ */
+
+#ifndef HTS_DEFPROXY
+#define HTS_DEFPROXY
+
+#include "htsglobal.h"
+
+/* Forward definitions */
+#ifndef HTS_DEF_FWSTRUCT_httrackp
+#define HTS_DEF_FWSTRUCT_httrackp
+typedef struct httrackp httrackp;
+#endif
+#ifndef HTS_DEF_FWSTRUCT_htsblk
+#define HTS_DEF_FWSTRUCT_htsblk
+typedef struct htsblk htsblk;
+#endif
+
+/* Open an HTTP CONNECT tunnel through the active proxy for an https request:
+   `retour->soc` must already be TCP-connected to the proxy, and `adr` is the
+   origin authority (url_adr, e.g. "https://host:port"). Sends the CONNECT
+   request (with Proxy-Authorization when the proxy carries credentials) and
+   reads the proxy's status line, so the caller's TLS handshake then runs
+   end-to-end with the origin. Blocks up to `timeout` seconds. Returns 1 on a
+   2xx tunnel, 0 on failure (retour->msg/statuscode set). */
+int http_proxy_tunnel(httrackp *opt, htsblk *retour, const char *adr,
+                      int timeout);
+
+/* SOCKS5 (RFC 1928, RFC 1929 auth) handshake on the raw proxy socket, before
+   any TLS: `retour->soc` must be TCP-connected to the proxy and `adr` is the
+   origin (url_adr). The origin name is sent verbatim (ATYP=domain), so the
+   proxy resolves it; a bracketed IPv6 literal origin is rejected. Blocks up to
+   `timeout` seconds. Returns 1 with the stream positioned on the first origin
+   byte, 0 on failure (retour->msg set). */
+int socks5_handshake(httrackp *opt, htsblk *retour, const char *adr,
+                     int timeout);
+
+/* Self-test hook (-#test=socks5): run the handshake against `reply`, a scripted
+   server byte stream, instead of a socket. `sent` captures the client frames,
+   `consumed` the reply bytes eaten (the frame-desync guard). */
+typedef struct socks5_test_io {
+  const unsigned char *reply;
+  size_t reply_len;
+  size_t consumed;
+  unsigned char sent[1024];
+  size_t sent_len;
+  char msg[256];
+} socks5_test_io;
+
+int socks5_handshake_scripted(httrackp *opt, const char *adr,
+                              const char *proxy_name, socks5_test_io *io);
+
+#endif

src/htsselftest.c

@@ -54,12 +54,18 @@ Please visit our Website: http://www.httrack.com
 #include "htsftp.h"
 #include "htsmd5.h"
 #include "htssniff.h"
+#include "htscodec.h"
+#include "htsproxy.h"
 #if HTS_USEZLIB
 #include "htszlib.h"
 #endif
+#if HTS_USEZSTD
+#include <zstd.h>
+#endif
 #include "coucal/coucal.h"
 
 #include <ctype.h>
+#include <errno.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -67,6 +73,9 @@ Please visit our Website: http://www.httrack.com
 #ifndef _WIN32
 #include <sys/socket.h>
 #include <unistd.h>
+#else
+#include <io.h>       /* _get_osfhandle, for the sparse-file hint */
+#include <winioctl.h> /* FSCTL_SET_SPARSE */
 #endif
 
 /* very minimalistic internal tests */
@@ -748,7 +757,7 @@ static int st_filterbounds(httrackp *opt, int argc, char **argv) {
   const size_t subjlen = 2048;
   char *subj = malloct(big + 1);
   char *pat = malloct(2 * stars + 2);
-  size_t steps = 0, maxsteps = 0, i;
+  size_t steps = 0, maxsteps = 0, depth = 0, maxdepth = 0, i;
 
   (void) opt;
   (void) argc;
@@ -769,9 +778,22 @@ static int st_filterbounds(httrackp *opt, int argc, char **argv) {
   subj[subjlen] = '\0';
   /* Budget must fire and hold: steps > cap (deleting the budget zeroes the
      counter that is the enforcement), steps < 10*cap (unbudgeted ~1.26e9). */
-  assertf(strjoker_steps(subj, pat, &steps, &maxsteps) == NULL);
+  assertf(strjoker_bounds(subj, pat, &steps, &maxsteps, &depth, &maxdepth) ==
+          NULL);
   assertf(steps > maxsteps && steps < 10 * maxsteps);
+  /* Depth caps the stack: uncapped this recurses 2046 frames, ~900KB (#574). */
+  assertf(depth == maxdepth);
   assertf(strjokerfind(subj, pat) == NULL);
+  /* Pin the cap from below: 32 segments must still match, so a cap set so low
+     it would break real multi-segment filters (which use far fewer) fails. */
+  for (i = 0; i < 32; i++) {
+    pat[2 * i] = '*';
+    pat[2 * i + 1] = 'a';
+  }
+  pat[64] = '\0';
+  memset(subj, 'a', 32);
+  subj[32] = '\0';
+  assertf(strjoker(subj, pat, NULL, NULL) != NULL);
   freet(pat);
   freet(subj);
   printf("filterbounds: OK\n");
@@ -808,7 +830,11 @@ static int st_mime(httrackp *opt, int argc, char **argv) {
   return 0;
 }
 
+static size_t st_decode_body(const char *arg, char *buf, size_t size);
+
 static int st_charset(httrackp *opt, int argc, char **argv) {
+  char buf[512];
+  size_t len;
   char *s;
 
   (void) opt;
@@ -816,7 +842,8 @@ static int st_charset(httrackp *opt, int argc, char **argv) {
     fprintf(stderr, "charset: needs a charset and a string\n");
     return 1;
   }
-  s = hts_convertStringToUTF8(argv[1], strlen(argv[1]), argv[0]);
+  len = st_decode_body(argv[1], buf, sizeof(buf));
+  s = hts_convertStringToUTF8(buf, len, argv[0]);
   if (s != NULL) {
     printf("%s\n", s);
     freet(s);
@@ -841,16 +868,22 @@ static int st_metacharset(httrackp *opt, int argc, char **argv) {
 }
 
 static int st_isutf8(httrackp *opt, int argc, char **argv) {
+  char buf[512];
+  size_t len;
+
   (void) opt;
   if (argc < 1) {
     fprintf(stderr, "isutf8: needs a string\n");
     return 1;
   }
-  printf("%d\n", hts_isStringUTF8(argv[0], strlen(argv[0])) ? 1 : 0);
+  len = st_decode_body(argv[0], buf, sizeof(buf));
+  printf("%d\n", hts_isStringUTF8(buf, len) ? 1 : 0);
   return 0;
 }
 
 static int st_idna_encode(httrackp *opt, int argc, char **argv) {
+  char buf[512];
+  size_t len;
   char *s;
 
   (void) opt;
@@ -858,7 +891,8 @@ static int st_idna_encode(httrackp *opt, int argc, char **argv) {
     fprintf(stderr, "idna-encode: needs a hostname\n");
     return 1;
   }
-  s = hts_convertStringUTF8ToIDNA(argv[0], strlen(argv[0]));
+  len = st_decode_body(argv[0], buf, sizeof(buf));
+  s = hts_convertStringUTF8ToIDNA(buf, len);
   if (s != NULL) {
     printf("%s\n", s);
     freet(s);
@@ -1020,7 +1054,7 @@ static int st_hashtable(httrackp *opt, int argc, char **argv) {
 
   /* produce random patterns, or read from a file */
   if (sscanf(snum, "%lu", &count) != 1) {
-    const off_t size = fsize(snum);
+    const LLint size = fsize(snum);
     FILE *fp = fopen(snum, "rb");
     if (fp != NULL) {
       buff = malloct(size);
@@ -1120,7 +1154,10 @@ static int st_strsafe(httrackp *opt, int argc, char **argv) {
        comes from argv so its length is opaque to the compiler (no static
        -Wstringop-overflow, genuine runtime check). "overflow-buff" exercises
        htsbuff. */
-    char small[4];
+    /* Not sizeof(char*): on ILP32 a char[4] equals the pointer size, and the
+       MSVC array-vs-pointer heuristic (sizeof(A) != sizeof(char*)) then reads
+       it as a pointer and silently skips the bound. */
+    char small[6];
     const char *const src = (argc >= 2) ? argv[1] : "overflowing";
 
     if (strcmp(argv[0], "overflow-buff") == 0) {
@@ -1304,6 +1341,162 @@ static int st_identurl(httrackp *opt, int argc, char **argv) {
   return 0;
 }
 
+static int st_proxyurl(httrackp *opt, int argc, char **argv) {
+  char BIGSTK name[HTS_URLMAXSIZE * 2];
+  int port = -1;
+
+  (void) opt;
+  if (argc < 1) {
+    fprintf(stderr, "proxyurl: needs a proxy argument\n");
+    return 1;
+  }
+  hts_parse_proxy(argv[0], name, sizeof(name), &port);
+  // host= is what the connect actually resolves (scheme + user:pass stripped)
+  printf("name=%s port=%d host=%s\n", name, port,
+         jump_identification_const(name));
+  return 0;
+}
+
+/* Scripted SOCKS5 server: no-auth method reply, then a success CONNECT reply
+   carrying the given ATYP address, then a sentinel origin byte the handshake
+   must leave unread (an off-by-one in the reply framing eats it). */
+static size_t socks5_reply(unsigned char *buf, unsigned char atyp,
+                           const unsigned char *addr, size_t addrlen) {
+  size_t n = 0;
+
+  buf[n++] = 0x05;
+  buf[n++] = 0x00; /* method: no authentication */
+  buf[n++] = 0x05;
+  buf[n++] = 0x00; /* REP: succeeded */
+  buf[n++] = 0x00;
+  buf[n++] = atyp;
+  memcpy(buf + n, addr, addrlen);
+  n += addrlen;
+  buf[n++] = 0x1f;
+  buf[n++] = 0x90; /* BND.PORT */
+  buf[n++] = 0xAA; /* sentinel */
+  return n;
+}
+
+#define SOCKS5_SENTINEL_LEFT(io, len) ((io).consumed == (len) - 1)
+
+static int st_socks5(httrackp *opt, int argc, char **argv) {
+  static const unsigned char v4[4] = {127, 0, 0, 1};
+  static const unsigned char v6[16] = {0};
+  static const unsigned char domain[6] = {5, 'p', 'r', 'o', 'x', 'y'};
+  const char *const proxy = "socks5://127.0.0.1";
+  unsigned char script[64];
+  socks5_test_io io;
+  size_t len;
+
+  (void) argc;
+  (void) argv;
+
+  /* each reply address type is drained exactly, sentinel untouched */
+  len = socks5_reply(script, 0x01, v4, sizeof(v4));
+  io.reply = script;
+  io.reply_len = len;
+  assertf(socks5_handshake_scripted(opt, "origin.test", proxy, &io) == 1);
+  assertf(SOCKS5_SENTINEL_LEFT(io, len));
+  /* the greeting offers no-auth only, and the origin goes out by name, port 80
+   */
+  assertf(io.sent_len == 3 + 7 + 11);
+  assertf(memcmp(io.sent, "\x05\x01\x00", 3) == 0);
+  assertf(memcmp(io.sent + 3, "\x05\x01\x00\x03\x0borigin.test\x00\x50", 18) ==
+          0);
+
+  len = socks5_reply(script, 0x04, v6, sizeof(v6));
+  io.reply = script;
+  io.reply_len = len;
+  assertf(socks5_handshake_scripted(opt, "origin.test", proxy, &io) == 1);
+  assertf(SOCKS5_SENTINEL_LEFT(io, len));
+
+  len = socks5_reply(script, 0x03, domain, sizeof(domain));
+  io.reply = script;
+  io.reply_len = len;
+  assertf(socks5_handshake_scripted(opt, "origin.test", proxy, &io) == 1);
+  assertf(SOCKS5_SENTINEL_LEFT(io, len));
+
+  /* an unknown address type has no known length: fail, never guess */
+  len = socks5_reply(script, 0x02, v4, sizeof(v4));
+  io.reply = script;
+  io.reply_len = len;
+  assertf(socks5_handshake_scripted(opt, "origin.test", proxy, &io) == 0);
+
+  /* truncated frames (here: no BND.PORT) fail instead of over-reading */
+  len = socks5_reply(script, 0x01, v4, sizeof(v4)) - 3;
+  io.reply = script;
+  io.reply_len = len;
+  assertf(socks5_handshake_scripted(opt, "origin.test", proxy, &io) == 0);
+
+  /* explicit origin port is encoded big-endian (8443 = 0x20fb) */
+  len = socks5_reply(script, 0x01, v4, sizeof(v4));
+  io.reply = script;
+  io.reply_len = len;
+  assertf(socks5_handshake_scripted(opt, "origin.test:8443", proxy, &io) == 1);
+  assertf(memcmp(io.sent + io.sent_len - 2, "\x20\xfb", 2) == 0);
+
+  /* credentials: split on the first colon of the escaped userinfo, so %3a stays
+     inside the username and a colon in the password is not a delimiter */
+  {
+    static const unsigned char auth_script[] = {
+        0x05, 0x02,             /* method: user/pass */
+        0x01, 0x00,             /* auth: success */
+        0x05, 0x00, 0x00, 0x01, /* REP: succeeded, ATYP ipv4 */
+        127,  0,    0,    1,    0x1f, 0x90, 0xAA};
+
+    io.reply = auth_script;
+    io.reply_len = sizeof(auth_script);
+    assertf(socks5_handshake_scripted(opt, "origin.test",
+                                      "socks5://us%3aer:p:ass@127.0.0.1",
+                                      &io) == 1);
+    assertf(SOCKS5_SENTINEL_LEFT(io, sizeof(auth_script)));
+    assertf(memcmp(io.sent, "\x05\x02\x00\x02", 4) == 0);
+    assertf(memcmp(io.sent + 4, "\x01\x05us:er\x05p:ass", 13) == 0);
+  }
+
+  /* a proxy demanding auth we cannot provide, and one refusing every method */
+  io.reply = (const unsigned char *) "\x05\x02";
+  io.reply_len = 2;
+  assertf(socks5_handshake_scripted(opt, "origin.test", proxy, &io) == 0);
+  io.reply = (const unsigned char *) "\x05\xff";
+  io.reply_len = 2;
+  assertf(socks5_handshake_scripted(opt, "origin.test", proxy, &io) == 0);
+
+  /* a refused CONNECT is an error, not a tunnel */
+  io.reply = (const unsigned char
+                  *) "\x05\x00\x05\x05\x00\x01\x7f\x00\x00\x01\x1f\x90";
+  io.reply_len = 12;
+  assertf(socks5_handshake_scripted(opt, "origin.test", proxy, &io) == 0);
+
+  /* over-long host or credentials are rejected before anything is sent */
+  {
+    char host[512];
+    char name[1024];
+    size_t i;
+
+    host[0] = '\0';
+    for (i = 0; i < 256; i++)
+      strcatbuff(host, "a");
+    io.reply = script;
+    io.reply_len = len;
+    assertf(socks5_handshake_scripted(opt, host, proxy, &io) == 0);
+    assertf(io.sent_len == 0);
+
+    strcpybuff(name, "socks5://user:");
+    for (i = 0; i < 256; i++)
+      strcatbuff(name, "p");
+    strcatbuff(name, "@127.0.0.1");
+    io.reply = script;
+    io.reply_len = len;
+    assertf(socks5_handshake_scripted(opt, "origin.test", name, &io) == 0);
+    assertf(io.sent_len == 0);
+  }
+
+  printf("socks5 self-test OK\n");
+  return 0;
+}
+
 /* Regression for the one-byte fil[] overflow: a 2047-byte hostless "?"-URL used
    to abort in strncat_safe_ when the missing leading '/' pushed fil to 2048. */
 static int st_identabs(httrackp *opt, int argc, char **argv) {
@@ -1448,7 +1641,8 @@ static int st_crange(httrackp *opt, int argc, char **argv) {
   return 0;
 }
 
-/* Decode a body argument ("hex:FFD8.." or literal text) into buf. */
+/* Decode an argument ("hex:FFD8.." or literal text) into buf. Raw non-UTF-8
+   bytes cannot survive a Windows command line, so hostile inputs go as hex. */
 static size_t st_decode_body(const char *arg, char *buf, size_t size) {
   size_t n = 0;
 
@@ -1488,6 +1682,94 @@ static int st_sniff(httrackp *opt, int argc, char **argv) {
   return 0;
 }
 
+/* fsize()/fsize_utf8()/fpsize() must report a size past 4GB: 32-bit wraps both
+   ways there (MSVC's off_t and struct _stat st_size are long, 32-bit even on
+   x64), and a size under 4GB would survive an *unsigned* 32-bit truncation. */
+static int st_fsize(httrackp *opt, int argc, char **argv) {
+  const LLint expected = 5 * 1024 * 1024 * 1024LL;
+  char BIGSTK path[HTS_URLMAXSIZE * 2];
+  char BIGSTK absent[HTS_URLMAXSIZE * 2];
+  /* both variants: only fsize() feeds the >2GB readers (file://, --list) */
+  const int width = (int) sizeof(fsize(""));
+  const int width_utf8 = (int) sizeof(fsize_utf8(""));
+  FILE *fp;
+  LLint got, got_utf8, gotp, gone;
+  int rc = 0;
+
+  (void) opt;
+  if (argc < 1) {
+    fprintf(stderr, "fsize: needs a directory\n");
+    return 1;
+  }
+  concat(path, sizeof(path), argv[0], "/sparse-5g.bin");
+  concat(absent, sizeof(absent), argv[0], "/no-such-file.bin");
+
+  /* sparse: seek past 4GB and write the last byte */
+  fp = FOPEN(path, "wb");
+  if (fp == NULL) {
+    fprintf(stderr, "fsize: cannot create '%s': %s\n", path, strerror(errno));
+    return 1;
+  }
+#ifdef _WIN32
+  {
+    /* NTFS allocates the hole unless asked not to; POSIX gives it for free.
+       Best-effort: a non-sparse file still measures the same, just costs 5GB.
+     */
+    HANDLE h = (HANDLE) _get_osfhandle(_fileno(fp));
+    DWORD ret;
+
+    if (h != INVALID_HANDLE_VALUE)
+      (void) DeviceIoControl(h, FSCTL_SET_SPARSE, NULL, 0, NULL, 0, &ret, NULL);
+  }
+#endif
+  if (fseeko(fp, expected - 1, SEEK_SET) != 0 || fputc(0, fp) == EOF ||
+      fclose(fp) != 0) {
+    fprintf(stderr, "fsize: cannot extend '%s' to " LLintP ": %s\n", path,
+            expected, strerror(errno));
+    UNLINK(path);
+    return 1;
+  }
+
+  got = fsize(path);
+  got_utf8 = fsize_utf8(path);
+  fp = FOPEN(path, "rb");
+  if (fp == NULL) {
+    fprintf(stderr, "fsize: cannot reopen '%s': %s\n", path, strerror(errno));
+    gotp = -1;
+  } else {
+    gotp = fpsize(fp);
+    fclose(fp);
+  }
+  UNLINK(path);
+  gone = fsize(absent); /* contract: -1, not 0, when absent */
+
+  printf("fsize: width=%d,%d size=" LLintP "," LLintP " psize=" LLintP
+         " absent=" LLintP "\n",
+         width, width_utf8, got, got_utf8, gotp, gone);
+  if (width != 8 || width_utf8 != 8) {
+    fprintf(stderr, "fsize: return types are %d/%d bytes, expected 8\n", width,
+            width_utf8);
+    rc = 1;
+  }
+  if (got != expected || got_utf8 != expected) {
+    fprintf(stderr,
+            "fsize: fsize/fsize_utf8 are " LLintP "/" LLintP
+            ", expected " LLintP "\n",
+            got, got_utf8, expected);
+    rc = 1;
+  }
+  if (gotp != expected) {
+    fprintf(stderr, "fsize: fpsize is " LLintP ", expected " LLintP "\n", gotp,
+            expected);
+    rc = 1;
+  }
+  if (gone != -1) {
+    fprintf(stderr, "fsize: absent file is " LLintP ", expected -1\n", gone);
+    rc = 1;
+  }
+  return rc;
+}
+
 static int st_savename(httrackp *opt, int argc, char **argv) {
   lien_adrfilsave afs;
   cache_back cache;
@@ -2305,6 +2587,7 @@ static int ae_write_collision(const char *path, const unsigned char *src,
   freet(buf);
   return ok ? 0 : 1;
 }
+#endif
 
 /* Write src[0..len) to path as-is; 0 on success. */
 static int ae_write_raw(const char *path, const unsigned char *src,
@@ -2338,17 +2621,22 @@ static int ae_check_decoded(const char *path, const unsigned char *expect,
   fclose(f);
   return (off == len) ? 0 : 1;
 }
-#endif
 
 /* Accept-Encoding (#450): advertise gzip+deflate; both decode (hts_zunpack) */
 static int st_acceptencoding(httrackp *opt, int argc, char **argv) {
-  const char *off = hts_acceptencoding(HTS_FALSE);
-  const char *on = hts_acceptencoding(HTS_TRUE);
+  const char *off = hts_acceptencoding(HTS_FALSE, HTS_TRUE);
+  const char *on = hts_acceptencoding(HTS_TRUE, HTS_FALSE);
+  const char *tls = hts_acceptencoding(HTS_TRUE, HTS_TRUE);
 
   (void) opt;
   assertf(strcmp(off, "identity") == 0);
   assertf(strstr(on, "gzip") != NULL);
   assertf(strstr(on, "deflate") != NULL); /* fails on the old gzip-only list */
+  /* br and zstd ride on TLS only, so a cleartext proxy can not be handed a
+     coding it may try to rewrite */
+  assertf(strstr(on, "br") == NULL && strstr(on, "zstd") == NULL);
+  assertf((strstr(tls, ", br") != NULL) == (HTS_USEBROTLI != 0));
+  assertf((strstr(tls, "zstd") != NULL) == (HTS_USEZSTD != 0));
 #if HTS_USEZLIB
   if (argc >= 1) {
     static const int windowBits[] = {16 + MAX_WBITS, MAX_WBITS, -MAX_WBITS};
@@ -2436,6 +2724,115 @@ static int st_acceptencoding(httrackp *opt, int argc, char **argv) {
   return 0;
 }
 
+#if HTS_USEBROTLI
+/* No brotli encoder is linked, so the coded bytes are canned: brotli quality 9
+   over cc_text, and over 4 MiB of 'A' (14 bytes, ~300000x). */
+static const unsigned char cc_br_text[] = {
+    0x1b, 0x43, 0x00, 0x00, 0x44, 0xdd, 0x96, 0xea, 0xe8, 0x22, 0xdd, 0x90,
+    0xa4, 0x1b, 0x8a, 0xf7, 0x47, 0x0e, 0xc2, 0xc5, 0x3d, 0x09, 0x1b, 0x70,
+    0xe0, 0x1e, 0x60, 0xa0, 0x8b, 0xcc, 0xbe, 0xcb, 0xb0, 0x31, 0x76, 0x9e,
+    0xcf, 0x6e, 0x41, 0xb5, 0xe8, 0x2e, 0x56, 0x78, 0x08, 0x1b, 0xfa, 0x08,
+    0x8a, 0x50, 0x83, 0x4e, 0x62, 0x7f, 0xbf, 0x05, 0xf2, 0x22, 0x8f, 0xdf,
+    0x28, 0xdc, 0x9f, 0xa9, 0x90, 0x50, 0x37, 0x62, 0x56, 0x4f, 0xa8};
+static const unsigned char cc_br_bomb[] = {0x9b, 0xff, 0xff, 0x3f, 0x00,
+                                           0x24, 0x82, 0xe2, 0xb1, 0x40,
+                                           0x72, 0xef, 0x7f, 0x00};
+#endif
+
+static const unsigned char cc_text[] =
+    "content codings: HTTrack decodes gzip, brotli and zstd bodies alike.";
+
+/* Content codings: br and zstd decode, junk tokens stay identity, a coding we
+   can not undo fails the fetch, and a bomb never lands on disk. */
+static int st_contentcodings(httrackp *opt, int argc, char **argv) {
+  const size_t tlen = sizeof(cc_text) - 1;
+  char inpath[HTS_URLMAXSIZE], outpath[HTS_URLMAXSIZE];
+
+  (void) opt;
+  assertf(hts_codec_parse("gzip") == HTS_CODEC_DEFLATE);
+  assertf(hts_codec_parse("x-deflate") == HTS_CODEC_DEFLATE);
+  assertf(hts_codec_parse("") == HTS_CODEC_IDENTITY);
+  assertf(hts_codec_parse("identity") == HTS_CODEC_IDENTITY);
+  /* servers do label plain bodies with junk; the page must survive that */
+  assertf(hts_codec_parse("utf-8") == HTS_CODEC_IDENTITY);
+  /* a real coding with no decoder here: fail, never save the coded bytes */
+  assertf(hts_codec_parse("compress") == HTS_CODEC_UNSUPPORTED);
+  assertf(hts_codec_parse("br") ==
+          (HTS_USEBROTLI ? HTS_CODEC_BROTLI : HTS_CODEC_UNSUPPORTED));
+  assertf(hts_codec_parse("zstd") ==
+          (HTS_USEZSTD ? HTS_CODEC_ZSTD : HTS_CODEC_UNSUPPORTED));
+  assertf(hts_codec_is_archive_ext(HTS_CODEC_DEFLATE, "tgz"));
+  assertf(!hts_codec_is_archive_ext(HTS_CODEC_DEFLATE, "html"));
+  assertf(hts_codec_is_archive_ext(HTS_CODEC_BROTLI, "br"));
+  assertf(hts_codec_is_archive_ext(HTS_CODEC_ZSTD, "zst"));
+  /* decoded-size budget: 4096x, floor 1 MiB, ceiling INT_MAX */
+  assertf(hts_codec_maxout(1) == 1024 * 1024);
+  assertf(hts_codec_maxout(1024) == 4096 * 1024);
+  assertf(hts_codec_maxout(1024 * 1024) == INT_MAX);
+
+  if (argc >= 1) {
+    snprintf(inpath, sizeof(inpath), "%s/cc-in", argv[0]);
+    snprintf(outpath, sizeof(outpath), "%s/cc-out", argv[0]);
+#if HTS_USEBROTLI
+    {
+      unsigned char head[16];
+
+      assertf(ae_write_raw(inpath, cc_br_text, sizeof(cc_br_text)) == 0);
+      assertf(hts_codec_unpack(HTS_CODEC_BROTLI, inpath, outpath) ==
+              (int) tlen);
+      assertf(ae_check_decoded(outpath, cc_text, tlen) == 0);
+      assertf(hts_codec_head(HTS_CODEC_BROTLI, cc_br_text, sizeof(cc_br_text),
+                             head, sizeof(head)) == sizeof(head));
+      assertf(memcmp(head, cc_text, sizeof(head)) == 0);
+      /* truncated: must fail, not fall back to a verbatim copy */
+      assertf(ae_write_raw(inpath, cc_br_text, sizeof(cc_br_text) - 4) == 0);
+      assertf(hts_codec_unpack(HTS_CODEC_BROTLI, inpath, outpath) < 0);
+      /* cc_br_bomb is a valid stream that expands to 4 MiB; the budget, not a
+         corrupt frame, is what must reject it. */
+      assertf((LLint) (4 * 1024 * 1024) >
+              hts_codec_maxout((LLint) sizeof(cc_br_bomb)));
+      assertf(ae_write_raw(inpath, cc_br_bomb, sizeof(cc_br_bomb)) == 0);
+      assertf(hts_codec_unpack(HTS_CODEC_BROTLI, inpath, outpath) < 0);
+    }
+#endif
+#if HTS_USEZSTD
+    {
+      const size_t bomblen = 4 * 1024 * 1024;
+      const size_t bound = ZSTD_compressBound(bomblen);
+      unsigned char *bomb = malloct(bomblen);
+      unsigned char *zbuf = malloct(bound);
+      unsigned char head[16];
+      size_t zlen;
+
+      assertf(bomb != NULL && zbuf != NULL);
+      zlen = ZSTD_compress(zbuf, bound, cc_text, tlen, 6);
+      assertf(!ZSTD_isError(zlen));
+      assertf(ae_write_raw(inpath, zbuf, zlen) == 0);
+      assertf(hts_codec_unpack(HTS_CODEC_ZSTD, inpath, outpath) == (int) tlen);
+      assertf(ae_check_decoded(outpath, cc_text, tlen) == 0);
+      assertf(hts_codec_head(HTS_CODEC_ZSTD, zbuf, zlen, head, sizeof(head)) ==
+              sizeof(head));
+      assertf(memcmp(head, cc_text, sizeof(head)) == 0);
+      assertf(ae_write_raw(inpath, zbuf, zlen - 4) == 0);
+      assertf(hts_codec_unpack(HTS_CODEC_ZSTD, inpath, outpath) < 0);
+      memset(bomb, 'A', bomblen);
+      zlen = ZSTD_compress(zbuf, bound, bomb, bomblen, 6);
+      assertf(!ZSTD_isError(zlen));
+      /* the fixture must really be past the budget, whatever the ratio is */
+      assertf((LLint) bomblen > hts_codec_maxout((LLint) zlen));
+      assertf(ae_write_raw(inpath, zbuf, zlen) == 0);
+      assertf(hts_codec_unpack(HTS_CODEC_ZSTD, inpath, outpath) < 0);
+      freet(bomb);
+      freet(zbuf);
+    }
+#endif
+    /* a coding we can not undo yields no file at all */
+    assertf(hts_codec_unpack(HTS_CODEC_UNSUPPORTED, inpath, outpath) < 0);
+  }
+  printf("contentcodings self-test OK\n");
+  return 0;
+}
+
 /* Each call parses `txt` under a fresh host, then checkrobots() for `path`. */
 static int rb_decide(robots_wizard *r, const char *txt, const char *path) {
   static int n = 0;
@@ -2519,11 +2916,43 @@ static int st_robots(httrackp *opt, int argc, char **argv) {
   return 0;
 }
 
+/* Connected stream pair over loopback; Windows has no socketpair(). */
+static int st_socketpair(T_SOC sv[2]) {
+  struct sockaddr_in sa;
+  socklen_t len = sizeof(sa);
+  T_SOC srv, cli, acc;
+
+  memset(&sa, 0, sizeof(sa));
+  sa.sin_family = AF_INET;
+  sa.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+  if ((srv = (T_SOC) socket(AF_INET, SOCK_STREAM, 0)) == INVALID_SOCKET)
+    return -1;
+  if (bind(srv, (struct sockaddr *) &sa, sizeof(sa)) != 0 ||
+      listen(srv, 1) != 0 ||
+      getsockname(srv, (struct sockaddr *) &sa, &len) != 0) {
+    deletesoc(srv);
+    return -1;
+  }
+  if ((cli = (T_SOC) socket(AF_INET, SOCK_STREAM, 0)) == INVALID_SOCKET) {
+    deletesoc(srv);
+    return -1;
+  }
+  if (connect(cli, (struct sockaddr *) &sa, sizeof(sa)) != 0 ||
+      (acc = (T_SOC) accept(srv, NULL, NULL)) == INVALID_SOCKET) {
+    deletesoc(cli);
+    deletesoc(srv);
+    return -1;
+  }
+  deletesoc(srv);
+  sv[0] = acc;
+  sv[1] = cli;
+  return 0;
+}
+
 /* get_ftp_line must bound a hostile, CRLF-less reply into its internal
    1024-byte buffer; ASan turns the pre-fix overflow into an abort here. */
-#ifndef _WIN32
 static int st_ftpline(httrackp *opt, int argc, char **argv) {
-  int sv[2];
+  T_SOC sv[2];
   char line[2048];
   char flood[4096];
 
@@ -2531,19 +2960,19 @@ static int st_ftpline(httrackp *opt, int argc, char **argv) {
   (void) argc;
   (void) argv;
   memset(flood, 'x', sizeof(flood));
-  assertf(socketpair(AF_UNIX, SOCK_STREAM, 0, sv) == 0);
-  assertf(write(sv[1], "220 ", 4) == 4); // valid 3-digit code
-  assertf(write(sv[1], flood, sizeof(flood)) == (ssize_t) sizeof(flood));
-  assertf(write(sv[1], "\r\n", 2) == 2); // end the line so we return
-  close(sv[1]);
+  assertf(st_socketpair(sv) == 0);
+  // the 4102-byte reply fits the loopback send buffer, so no reader is needed
+  assertf(send(sv[1], "220 ", 4, 0) == 4); // valid 3-digit code
+  assertf(send(sv[1], flood, (int) sizeof(flood), 0) == (int) sizeof(flood));
+  assertf(send(sv[1], "\r\n", 2, 0) == 2); // end the line so we return
+  deletesoc(sv[1]);
   line[0] = '\0';
   get_ftp_line(sv[0], line, sizeof(line), 5);
-  close(sv[0]);
+  deletesoc(sv[0]);
   printf("ftp-line self-test OK (bounded %d-byte reply)\n",
          (int) sizeof(flood));
   return 0;
 }
-#endif
 
 /* ftp_split_userpass: well-formed split, plus a hostile over-long userinfo
    that pre-fix overran user[256]/pass[256]. */
@@ -2615,11 +3044,11 @@ static const struct selftest_entry {
     {"redirect-samefile", "", "same-file redirect detection self-test (#159)",
      st_redirect_samefile},
     {"mime", "<filename>", "MIME type for a filename", st_mime},
-    {"charset", "<charset> <string>",
+    {"charset", "<charset> <hex:..|string>",
      "convert a string to UTF-8 from a charset", st_charset},
     {"metacharset", "<html>", "extract the <meta> charset from an HTML page",
      st_metacharset},
-    {"isutf8", "<string>", "is the string valid UTF-8 (1/0)", st_isutf8},
+    {"isutf8", "<hex:..|string>", "is the string valid UTF-8 (1/0)", st_isutf8},
     {"idna-encode", "<host>", "encode a hostname to IDNA/punycode",
      st_idna_encode},
     {"idna-decode", "<host>", "decode an IDNA/punycode hostname",
@@ -2637,6 +3066,10 @@ static const struct selftest_entry {
     {"resolve", "<link> <adr> <fil>", "resolve a link against an origin",
      st_resolve},
     {"identurl", "<url>", "split an absolute URL into (adr, fil)", st_identurl},
+    {"proxyurl", "<proxy-arg>", "parse a -P proxy URL into host/port",
+     st_proxyurl},
+    {"socks5", "", "SOCKS5 handshake framing and credential self-test",
+     st_socks5},
     {"identabs", "", "ident_url_absolute one-byte fil[] overflow self-test",
      st_identabs},
     {"header", "<raw-header-line> ...", "response header-line parsing",
@@ -2652,6 +3085,7 @@ static const struct selftest_entry {
      "local save-name for a URL", st_savename},
     {"sniff", "<content-type> <hex:..|text>", "MIME magic consistency",
      st_sniff},
+    {"fsize", "<dir>", "file size past the 2GB signed-32-bit wrap", st_fsize},
     {"cache", "<dir>", "cache read/write round-trip self-test", st_cache},
     {"cacheindex", "", "cache-index (.ndx) parse must stay in bounds",
      st_cacheindex},
@@ -2677,12 +3111,13 @@ static const struct selftest_entry {
     {"status", "", "HTTP status code -> reason phrase self-test", st_status},
     {"acceptencoding", "[dir]",
      "Accept-Encoding advertises gzip+deflate, both decode", st_acceptencoding},
+    {"contentcodings", "[dir]",
+     "brotli and zstd bodies decode; bombs and unknown codings are refused",
+     st_contentcodings},
     {"robots", "", "robots.txt RFC 9309 Allow/Disallow precedence self-test",
      st_robots},
-#ifndef _WIN32
     {"ftp-line", "", "get_ftp_line bounds a hostile FTP reply line",
      st_ftpline},
-#endif
     {"ftp-userpass", "", "ftp_split_userpass bounds URL userinfo", st_ftpuser},
 };
 

src/htszlib.c

@@ -37,6 +37,7 @@ Please visit our Website: http://www.httrack.com
 /* specific definitions */
 #include "htsbase.h"
 #include "htscore.h"
+#include "htscodec.h"
 #include "htszlib.h"
 
 #if HTS_USEZLIB
@@ -46,13 +47,8 @@ Please visit our Website: http://www.httrack.com
 #include "htszlib.h"
 */
 
-/*
-  Unpack file into a new file (gzip, zlib RFC1950 or raw deflate RFC1951).
-  A body provably in no deflate framing is copied verbatim (identity).
-  Return value: size of the new file, or -1 if an error occurred
-*/
 /* Note: utf-8 */
-int hts_zunpack(char *filename, char *newfile) {
+int hts_zunpack(const char *filename, const char *newfile) {
   int ret = -1;
 
   if (filename != NULL && newfile != NULL && filename[0] && newfile[0]) {
@@ -61,6 +57,7 @@ int hts_zunpack(char *filename, char *newfile) {
 
     if (in != NULL) {
       unsigned char BIGSTK inbuf[8192];
+      const LLint maxout = hts_codec_maxout(hts_codec_coded_size(in));
       size_t navail = fread(inbuf, 1, sizeof(inbuf), in);
       /* gzip/zlib headers -> +32 windowBits; else raw deflate (RFC1951) */
       const hts_boolean wrapped =
@@ -73,9 +70,10 @@ int hts_zunpack(char *filename, char *newfile) {
          deflate framing at all. env_error: local I/O or memory failure. */
       hts_boolean not_deflate = HTS_FALSE;
       hts_boolean env_error = HTS_FALSE;
+      hts_boolean bomb = HTS_FALSE;
 
       /* deflate is ambiguous; on failure retry with the other windowBits */
-      for (attempt = 0; attempt < 2 && ret < 0; attempt++) {
+      for (attempt = 0; attempt < 2 && ret < 0 && !bomb; attempt++) {
         const int windowBits =
             (attempt == 0 ? wrapped : !wrapped) ? (32 + MAX_WBITS) : -MAX_WBITS;
         FILE *fpout;
@@ -102,7 +100,7 @@ int hts_zunpack(char *filename, char *newfile) {
         }
         {
           hts_boolean ok = HTS_TRUE;
-          int size = 0;
+          LLint size = 0;
           int zerr = Z_OK;
 
           /* chunked inflate; first chunk in inbuf, single member */
@@ -126,27 +124,33 @@ int hts_zunpack(char *filename, char *newfile) {
                 break;
               }
               produced = sizeof(outbuf) - strm.avail_out;
+              size += (LLint) produced;
+              if (size > maxout) { /* decompression bomb: no retry, no copy */
+                bomb = HTS_TRUE;
+                ok = HTS_FALSE;
+                break;
+              }
               if (produced > 0 &&
                   fwrite(outbuf, 1, produced, fpout) != produced) {
                 env_error = HTS_TRUE;
                 ok = HTS_FALSE;
                 break;
               }
-              size += (int) produced;
             } while (strm.avail_out == 0);
             if (!ok || zerr == Z_STREAM_END)
               break;
             navail = fread(inbuf, 1, sizeof(inbuf), in);
           } while (navail > 0);
           if (ok && zerr == Z_STREAM_END)
-            ret = size;
+            ret = (int) size;
         }
         inflateEnd(&strm);
         fclose(fpout);
       }
       /* keep a mislabeled identity body verbatim only when provably not
          deflate; truncation or a local failure must keep failing (#47) */
-      if (ret < 0 && !wrapped && not_deflate && !env_error && !ferror(in)) {
+      if (ret < 0 && !bomb && !wrapped && not_deflate && !env_error &&
+          !ferror(in)) {
         FILE *const fpout =
             FOPEN(fconv(catbuff, sizeof(catbuff), newfile), "wb");
 
@@ -172,6 +176,25 @@ int hts_zunpack(char *filename, char *newfile) {
   return ret;
 }
 
+size_t hts_zhead(const void *in, size_t in_len, void *out, size_t out_len) {
+  z_stream zs;
+  size_t n = 0;
+  int err;
+
+  memset(&zs, 0, sizeof(zs));
+  if (inflateInit2(&zs, 47) != Z_OK) /* 47: gzip or zlib, autodetected */
+    return 0;
+  zs.next_in = (const Bytef *) in;
+  zs.avail_in = (uInt) in_len;
+  zs.next_out = (Bytef *) out;
+  zs.avail_out = (uInt) out_len;
+  err = inflate(&zs, Z_SYNC_FLUSH);
+  if (err == Z_OK || err == Z_STREAM_END || err == Z_BUF_ERROR)
+    n = out_len - zs.avail_out;
+  inflateEnd(&zs);
+  return n;
+}
+
 int hts_extract_meta(const char *path) {
   char catbuff[CATBUFF_SIZE];
   unzFile zFile = unzOpen(fconcat(catbuff, sizeof(catbuff), path, "hts-cache/new.zip"));

src/htszlib.h

@@ -44,7 +44,13 @@ Please visit our Website: http://www.httrack.com
 
 /* Library internal definictions */
 #ifdef HTS_INTERNAL_BYTECODE
-extern int hts_zunpack(char *filename, char *newfile);
+/* Inflate filename into newfile (gzip, zlib or raw deflate); decoded size, or
+   -1 on a corrupt/truncated stream, an over-budget body, or an I/O failure. A
+   body provably in no deflate framing is copied verbatim. */
+extern int hts_zunpack(const char *filename, const char *newfile);
+/* Inflate the head of a gzip/zlib stream, out_len max; 0 if undecodable */
+extern size_t hts_zhead(const void *in, size_t in_len, void *out,
+                        size_t out_len);
 extern int hts_extract_meta(const char *path);
 extern const char *hts_get_zerror(int err);
 #endif

src/httrack-library.h

@@ -743,7 +743,8 @@ HTSEXT_API hts_boolean hts_findissystem(find_handle find);
 HTSEXT_API FILE *hts_fopen_utf8(const char *path, const char *mode);
 
 #define STAT hts_stat_utf8
-typedef struct _stat STRUCT_STAT;
+/* _stat64: _stat's st_size is a 32-bit long, even in x64 builds */
+typedef struct _stat64 STRUCT_STAT;
 
 HTSEXT_API int hts_stat_utf8(const char *path, STRUCT_STAT *buf);
 

src/httrack.c

@@ -45,6 +45,7 @@ Please visit our Website: http://www.httrack.com
 #include "htsdefines.h"
 #include "httrack.h"
 #include "htslib.h"
+#include "htscharset.h" // after htslib.h: winsock2.h must precede windows.h
 
 /* Static definitions */
 static int fexist(const char *s);
@@ -206,6 +207,7 @@ int main(int argc, char **argv) {
   httrackp *opt;
 
 #ifdef _WIN32
+  hts_argv_utf8(&argc, &argv);
   {
     WORD wVersionRequested;     // requested version WinSock API
     WSADATA wsadata;            // Windows Sockets API data

src/httrack.rc

@@ -1,5 +1,5 @@
-// Version resource for httrack.exe, the command line program. See version.rc.
-#define VER_FILE_DESCRIPTION "HTTrack Website Copier (command line)"
-#define VER_ORIGINAL_FILENAME "httrack.exe"
-#define VER_FILETYPE VFT_APP
-#include "version.rc"
+// Version resource for httrack.exe, the command line program. See version.rc.
+#define VER_FILE_DESCRIPTION "HTTrack Website Copier (command line)"
+#define VER_ORIGINAL_FILENAME "httrack.exe"
+#define VER_FILETYPE VFT_APP
+#include "version.rc"

src/libhttrack.rc

@@ -1,5 +1,5 @@
-// Version resource for libhttrack.dll. See version.rc.
-#define VER_FILE_DESCRIPTION "HTTrack Website Copier engine"
-#define VER_ORIGINAL_FILENAME "libhttrack.dll"
-#define VER_FILETYPE VFT_DLL
-#include "version.rc"
+// Version resource for libhttrack.dll. See version.rc.
+#define VER_FILE_DESCRIPTION "HTTrack Website Copier engine"
+#define VER_ORIGINAL_FILENAME "libhttrack.dll"
+#define VER_FILETYPE VFT_DLL
+#include "version.rc"

src/libhttrack.vcxproj

@@ -59,16 +59,18 @@
   <ItemDefinitionGroup>
     <ClCompile>
       <!-- LIBHTTRACK_EXPORTS turns HTSEXT_API into __declspec(dllexport); ZLIB_DLL
-           imports zlib from its DLL. Windows 7 floor, matching WinHTTrack. -->
-      <PreprocessorDefinitions>WIN32;_WINDOWS;_MBCS;_USRDLL;LIBHTTRACK_EXPORTS;ZLIB_DLL;WINVER=0x0601;_WIN32_WINNT=0x0601;_CRT_SECURE_NO_WARNINGS;_CRT_NONSTDC_NO_DEPRECATE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+           imports zlib from its DLL. HTS_USEBROTLI/HTS_USEZSTD enable the br and
+           zstd content codings. Windows 7 floor, matching WinHTTrack. -->
+      <PreprocessorDefinitions>WIN32;_WINDOWS;_MBCS;_USRDLL;LIBHTTRACK_EXPORTS;ZLIB_DLL;HTS_USEBROTLI=1;HTS_USEZSTD=1;WINVER=0x0601;_WIN32_WINNT=0x0601;_CRT_SECURE_NO_WARNINGS;_CRT_NONSTDC_NO_DEPRECATE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <AdditionalIncludeDirectories>$(MSBuildThisFileDirectory);$(MSBuildThisFileDirectory)coucal;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <WarningLevel>Level3</WarningLevel>
       <MultiProcessorCompilation>true</MultiProcessorCompilation>
       <CompileAs>CompileAsC</CompileAs>
     </ClCompile>
     <Link>
-      <!-- vcpkg auto-links libssl/libcrypto/zlib; only the OS import lib is explicit. -->
-      <AdditionalDependencies>Ws2_32.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <!-- vcpkg auto-links libssl/libcrypto/zlib/brotli/zstd; only the OS import
+           lib is explicit. -->
+      <AdditionalDependencies>Ws2_32.lib;Shell32.lib;%(AdditionalDependencies)</AdditionalDependencies>
       <GenerateDebugInformation>true</GenerateDebugInformation>
     </Link>
   </ItemDefinitionGroup>
@@ -107,6 +109,7 @@
     <ClCompile Include="htscache_selftest.c" />
     <ClCompile Include="htscatchurl.c" />
     <ClCompile Include="htscharset.c" />
+    <ClCompile Include="htscodec.c" />
     <ClCompile Include="htsconcat.c" />
     <ClCompile Include="htscore.c" />
     <ClCompile Include="htscoremain.c" />
@@ -122,6 +125,7 @@
     <ClCompile Include="htsmodules.c" />
     <ClCompile Include="htsname.c" />
     <ClCompile Include="htsparse.c" />
+    <ClCompile Include="htsproxy.c" />
     <ClCompile Include="htsrobots.c" />
     <ClCompile Include="htsselftest.c" />
     <ClCompile Include="htssniff.c" />

src/proxy/store.c

@@ -577,9 +577,11 @@ PT_Index PT_LoadCache(const char *filename) {
           chain = coucal_enum_next(&en);
         }
         if (chain != NULL) {
-          if (!link_has_authority(chain->name))
-            strcat(index->slots.common.startUrl, "http://");
-          strcat(index->slots.common.startUrl, chain->name);
+          const char *scheme = link_has_authority(chain->name) ? "" : "http://";
+
+          snprintf(index->slots.common.startUrl,
+                   sizeof(index->slots.common.startUrl), "%s%s", scheme,
+                   (const char *) chain->name);
         }
       }
     }
@@ -632,7 +634,7 @@ int PT_EnumCache(PT_Indexes indexes,
       const long int index_id = (long int) chain->value.intg;
       const char *const url = chain->name;
 
-      if (index_id >= 0 && index_id <= indexes->index_size) {
+      if (index_id >= 0 && index_id < indexes->index_size) {
         PT_Element item =
           PT_ReadCache(indexes->index[index_id], url,
                        FETCH_HEADERS | FETCH_BODY);
@@ -757,7 +759,7 @@ PT_Element PT_ReadIndex(PT_Indexes indexes, const char *url, int flags) {
     if (strncmp(url, "http://", 7) == 0)
       url += 7;
     if (coucal_read(indexes->cil, url, &index_id)) {
-      if (index_id >= 0 && index_id <= indexes->index_size) {
+      if (index_id >= 0 && index_id < indexes->index_size) {
         PT_Element item = PT_ReadCache(indexes->index[index_id], url, flags);
 
         if (item != NULL) {
@@ -780,7 +782,7 @@ int PT_LookupIndex(PT_Indexes indexes, const char *url) {
     if (strncmp(url, "http://", 7) == 0)
       url += 7;
     if (coucal_read(indexes->cil, url, &index_id)) {
-      if (index_id >= 0 && index_id <= indexes->index_size) {
+      if (index_id >= 0 && index_id < indexes->index_size) {
         return 1;
       } else {
         proxytrack_print_log(CRITICAL,
@@ -967,10 +969,12 @@ int PT_LoadCache__New(PT_Index index_, const char *filename) {
                 /* First link as starting URL */
                 if (!firstSeen) {
                   if (strstr(filenameIndex, "/robots.txt") == NULL) {
+                    const char *scheme =
+                        link_has_authority(filenameIndex) ? "" : "http://";
+
                     firstSeen = 1;
-                    if (!link_has_authority(filenameIndex))
-                      strcat(index->startUrl, "http://");
-                    strcat(index->startUrl, filenameIndex);
+                    snprintf(index->startUrl, sizeof(index->startUrl), "%s%s",
+                             scheme, filenameIndex);
                   }
                 }
               } else {
@@ -1102,7 +1106,8 @@ static PT_Element PT_ReadCache__New_u(PT_Index index_, const char *url,
                                           && (!isalpha(previous_save_[0]) || previous_save_[1] != ':')) // c:/home/foo/bar.gif
               ) {
               index->safeCache = 1;
-              sprintf(previous_save, "%s%s", index->path, previous_save_);
+              snprintf(previous_save, sizeof(previous_save), "%s%s",
+                       index->path, previous_save_);
             }
             // bogus format (includes buggy absolute path)
             else {
@@ -1127,15 +1132,16 @@ static PT_Element PT_ReadCache__New_u(PT_Index index_, const char *url,
                 int saveLen = (int) strlen(previous_save_);
 
                 if (index->fixedPath < saveLen) {
-                  sprintf(previous_save, "%s%s", index->path,
-                          previous_save_ + index->fixedPath);
+                  snprintf(previous_save, sizeof(previous_save), "%s%s",
+                           index->path, previous_save_ + index->fixedPath);
                 } else {
                   snprintf(r->msg, sizeof(r->msg), "Bogus fixePath prefix for %s (prefixLen=%d)",
                           previous_save_, (int) index->fixedPath);
                   r->statuscode = STATUSCODE_INVALID;
                 }
               } else {
-                sprintf(previous_save, "%s%s", index->path, previous_save_);
+                snprintf(previous_save, sizeof(previous_save), "%s%s",
+                         index->path, previous_save_);
               }
             }
           }
@@ -1348,45 +1354,71 @@ static int PT_SaveCache__New(PT_Indexes indexes, const char *filename) {
 /* Old HTTrack cache (dat/ndx) format                           */
 /* ------------------------------------------------------------ */
 
-static int cache_brstr(char *adr, char *s) {
+static int cache_brstr(char *adr, char *s, size_t s_size) {
   int i;
   int off;
-  char buff[256 + 1];
+  char buff[256 + 4];
 
   off = binput(adr, buff, 256);
-  adr += off;
-  sscanf(buff, "%d", &i);
-  if (i > 0)
-    strncpy(s, adr, i);
-  *(s + i) = '\0';
-  off += i;
+  /* binput stops at adr's terminating NUL; a value only follows a real line
+     terminator, so never step past end-of-buffer. */
+  if (adr[off - 1] == '\0') {
+    s[0] = '\0';
+    return off - 1;
+  }
+  /* an empty/non-numeric field leaves i unset: treat as length 0 */
+  if (sscanf(buff, "%d", &i) != 1 || i < 0 || i > 32768)
+    i = 0;
+  if (i > 0) {
+    /* a corrupt cache may declare a length past the buffer end; bound the copy
+       and the advance to the bytes actually present */
+    const size_t avail = strnlen(adr + off, (size_t) i);
+    const size_t store = avail < s_size ? avail : s_size - 1;
+
+    memcpy(s, adr + off, store);
+    s[store] = '\0';
+    off += (int) avail;
+  } else {
+    s[0] = '\0';
+  }
   return off;
 }
 
-static void cache_rstr(FILE * fp, char *s) {
-  INTsys i;
+static void cache_rstr(FILE *fp, char *s, size_t s_size) {
+  INTsys i = 0;
   char buff[256 + 4];
 
   linput(fp, buff, 256);
-  sscanf(buff, INTsysP, &i);
-  if (i < 0 || i > 32768)       /* error, something nasty happened */
+  /* an unmatched sscanf leaves i untouched: length 0, not a stack value */
+  if (sscanf(buff, INTsysP, &i) != 1 || i < 0 || i > 32768)
     i = 0;
   if (i > 0) {
-    if ((int) fread(s, 1, i, fp) != i) {
+    /* store at most s_size-1 bytes, but consume all i bytes so the next field
+       stays aligned when a tampered cache declares more than the destination
+       holds */
+    const size_t want = (size_t) i;
+    const size_t store = want < s_size ? want : s_size - 1;
+
+    if (fread(s, 1, store, fp) != store) {
       assertf(! "fread_cache_failed");
     }
+    if (want > store && fseek(fp, (long) (want - store), SEEK_CUR) != 0) {
+      assertf(!"fseek_cache_failed");
+    }
+    s[store] = '\0';
+  } else {
+    s[0] = '\0';
   }
-  *(s + i) = '\0';
 }
 
 static char *cache_rstr_addr(FILE * fp) {
-  INTsys i;
+  INTsys i = 0;
   char *addr = NULL;
   char buff[256 + 4];
 
   linput(fp, buff, 256);
-  sscanf(buff, "%d", &i);
-  if (i < 0 || i > 32768)       /* error, something nasty happened */
+  /* an unmatched sscanf leaves i untouched: length 0, not a stack value */
+  if (sscanf(buff, INTsysP, &i) != 1 || i < 0 || i > 32768)
     i = 0;
   if (i > 0) {
     addr = malloc(i + 1);
@@ -1400,19 +1432,31 @@ static char *cache_rstr_addr(FILE * fp) {
   return addr;
 }
 
+/* Allocate n+1 bytes for an n-byte cache body, rejecting a hostile/corrupt
+   length that would demand an absurd allocation or wrap n+1. NULL on refuse. */
+static char *cache_alloc_body(size_t n) {
+  if (n >= (size_t) INT32_MAX)
+    return NULL;
+  return (char *) malloc(n + 1);
+}
+
 static void cache_rint(FILE * fp, int *i) {
   char s[256];
 
-  cache_rstr(fp, s);
-  sscanf(s, "%d", i);
+  cache_rstr(fp, s, sizeof(s));
+  if (sscanf(s, "%d", i) != 1)
+    *i = 0;
 }
 
 static void cache_rLLint(FILE * fp, unsigned long *i) {
   int l;
   char s[256];
 
-  cache_rstr(fp, s);
-  sscanf(s, "%d", &l);
+  cache_rstr(fp, s, sizeof(s));
+  /* reject a non-numeric or negative field: a negative length cast to unsigned
+     would wrap a later malloc(size+1) to a tiny buffer */
+  if (sscanf(s, "%d", &l) != 1 || l < 0)
+    l = 0;
   *i = (unsigned long) l;
 }
 
@@ -1472,12 +1516,12 @@ static int PT_LoadCache__Old(PT_Index index_, const char *filename) {
         char *a = use;
 
         use[ndxSize] = '\0';
-        a += cache_brstr(a, firstline);
+        a += cache_brstr(a, firstline, sizeof(firstline));
         if (strncmp(firstline, "CACHE-", 6) == 0) {     // Nouvelle version du cache
           if (strncmp(firstline, "CACHE-1.", 8) == 0) { // Version 1.1x
             cache->version = (int) (firstline[8] - '0');        // cache 1.x
             if (cache->version <= 5) {
-              a += cache_brstr(a, firstline);
+              a += cache_brstr(a, firstline, sizeof(firstline));
               strcpy(cache->lastmodified, firstline);
             } else {
               fclose(cache->dat);
@@ -1523,11 +1567,12 @@ static int PT_LoadCache__Old(PT_Index index_, const char *filename) {
               if (!firstSeen) {
                 if (strstr(line, "/robots.txt") == NULL) {
                   PT_Index__Old index = cache;
+                  const char *scheme =
+                      link_has_authority(line) ? "" : "http://";
 
                   firstSeen = 1;
-                  if (!link_has_authority(line))
-                    strcat(index->startUrl, "http://");
-                  strcat(index->startUrl, line);
+                  snprintf(index->startUrl, sizeof(index->startUrl), "%s%s",
+                           scheme, line);
                 }
               }
 
@@ -1623,9 +1668,13 @@ static PT_Element PT_ReadCache__Old_u(PT_Index index_, const char *url,
           String urlDecoded;
 
           r->statuscode = old_r.statuscode;
-          r->size = old_r.size; // taille fichier
-          strcpy(r->msg, old_r.msg);
-          strcpy(r->contenttype, old_r.contenttype);
+          r->size = old_r.size > 0 ? (size_t) old_r.size : 0; // taille fichier
+          /* these fixed fields come straight from fread and carry no guaranteed
+             NUL; terminate them before the bounded copy */
+          old_r.msg[sizeof(old_r.msg) - 1] = '\0';
+          old_r.contenttype[sizeof(old_r.contenttype) - 1] = '\0';
+          strcpybuff(r->msg, old_r.msg);
+          strcpybuff(r->contenttype, old_r.contenttype);
 
           /* Guess the destination filename.. this sucks, because this method is not reliable.
              Yes, the old 1.0 cache format was *that* bogus. /rx */
@@ -1666,26 +1715,27 @@ static PT_Element PT_ReadCache__Old_u(PT_Index index_, const char *url,
         cache_rint(cache->dat, &r->statuscode);
         cache_rLLint(cache->dat, &size_);
         r->size = (size_t) size_;
-        cache_rstr(cache->dat, r->msg);
-        cache_rstr(cache->dat, r->contenttype);
+        cache_rstr(cache->dat, r->msg, sizeof(r->msg));
+        cache_rstr(cache->dat, r->contenttype, sizeof(r->contenttype));
         if (cache->version >= 3)
-          cache_rstr(cache->dat, r->charset);
-        cache_rstr(cache->dat, r->lastmodified);
-        cache_rstr(cache->dat, r->etag);
-        cache_rstr(cache->dat, r->location);
+          cache_rstr(cache->dat, r->charset, sizeof(r->charset));
+        cache_rstr(cache->dat, r->lastmodified, sizeof(r->lastmodified));
+        cache_rstr(cache->dat, r->etag, sizeof(r->etag));
+        cache_rstr(cache->dat, r->location, sizeof(location_default));
         if (cache->version >= 2)
-          cache_rstr(cache->dat, r->cdispo);
+          cache_rstr(cache->dat, r->cdispo, sizeof(r->cdispo));
         if (cache->version >= 4) {
-          cache_rstr(cache->dat, previous_save_);       // adr
-          cache_rstr(cache->dat, previous_save_);       // fil
+          cache_rstr(cache->dat, previous_save_, sizeof(previous_save_)); // adr
+          cache_rstr(cache->dat, previous_save_, sizeof(previous_save_)); // fil
           previous_save[0] = '\0';
-          cache_rstr(cache->dat, previous_save_);       // save
+          cache_rstr(cache->dat, previous_save_,
+                     sizeof(previous_save_)); // save
         }
         if (cache->version >= 5) {
           r->headers = cache_rstr_addr(cache->dat);
         }
         //
-        cache_rstr(cache->dat, check);
+        cache_rstr(cache->dat, check, sizeof(check));
         if (strcmp(check, "HTS") == 0) {        /* intégrité OK */
           ok = 1;
         }
@@ -1714,7 +1764,8 @@ static PT_Element PT_ReadCache__Old_u(PT_Index index_, const char *url,
                                         && (!isalpha(previous_save_[0]) || previous_save_[1] != ':'))   // c:/home/foo/bar.gif
             ) {
             index->safeCache = 1;
-            sprintf(previous_save, "%s%s", index->path, previous_save_);
+            snprintf(previous_save, sizeof(previous_save), "%s%s", index->path,
+                     previous_save_);
           }
           // bogus format (includes buggy absolute path)
           else {
@@ -1739,15 +1790,16 @@ static PT_Element PT_ReadCache__Old_u(PT_Index index_, const char *url,
               int saveLen = (int) strlen(previous_save_);
 
               if (index->fixedPath < saveLen) {
-                sprintf(previous_save, "%s%s", index->path,
-                        previous_save_ + index->fixedPath);
+                snprintf(previous_save, sizeof(previous_save), "%s%s",
+                         index->path, previous_save_ + index->fixedPath);
               } else {
                 snprintf(r->msg, sizeof(r->msg), "Bogus fixePath prefix for %s (prefixLen=%d)",
                         previous_save_, (int) index->fixedPath);
                 r->statuscode = STATUSCODE_INVALID;
               }
             } else {
-              sprintf(previous_save, "%s%s", index->path, previous_save_);
+              snprintf(previous_save, sizeof(previous_save), "%s%s",
+                       index->path, previous_save_);
             }
           }
         }
@@ -1764,7 +1816,7 @@ static PT_Element PT_ReadCache__Old_u(PT_Index index_, const char *url,
               FILE *fp = fopen(previous_save, "rb");
 
               if (fp != NULL) {
-                r->adr = (char *) malloc(r->size + 1);
+                r->adr = cache_alloc_body(r->size);
                 if (r->adr != NULL) {
                   if (r->size > 0 && fread(r->adr, 1, r->size, fp) != r->size) {
                     r->statuscode = STATUSCODE_INVALID;
@@ -1784,7 +1836,7 @@ static PT_Element PT_ReadCache__Old_u(PT_Index index_, const char *url,
           } else {
             // lire fichier (d'un coup)
             if (flags & FETCH_BODY) {
-              r->adr = (char *) malloc(r->size + 1);
+              r->adr = cache_alloc_body(r->size);
               if (r->adr != NULL) {
                 if (fread(r->adr, 1, r->size, cache->dat) != r->size) { // erreur
                   free(r->adr);

src/vcpkg.json

@@ -1,9 +1,12 @@
 {
-  "$schema": "https://raw.githubusercontent.com/microsoft/vcpkg-tool/main/docs/vcpkg.schema.json",
+  "$schema":
+      "https://raw.githubusercontent.com/microsoft/vcpkg-tool/main/docs/vcpkg.schema.json",
   "name": "libhttrack",
   "version-string": "3.49",
   "dependencies": [
+    "brotli",
     "openssl",
-    "zlib"
+    "zlib",
+    "zstd"
   ]
 }

tests/01_engine-charset.test

@@ -23,7 +23,7 @@ conv 'iso-8859-1' 'café' 'café'
 
 # windows-1252 is NOT latin-1: 0x80 is the euro sign, not U+0080. This is the
 # case that actually exercises the cp1252 table (the 0x80-0x9F range).
-conv 'windows-1252' $'\x80' '€'
+conv 'windows-1252' 'hex:80' '€'
 
 # pure ASCII is charset-invariant
 conv 'us-ascii' 'hello' 'hello'
@@ -34,8 +34,8 @@ conv 'no-such-charset-xyz' 'abc' 'abc'
 test "$(httrack -O /dev/null -#test=charset 'no-such-charset-xyz' 'café' 2>/dev/null)" == "" || exit 1
 
 # malformed UTF-8 (lone continuation byte, truncated lead byte) must not crash
-runs 'utf-8' $'\x80'
-runs 'utf-8' $'\xc3'
+runs 'utf-8' 'hex:80'
+runs 'utf-8' 'hex:c3'
 
 # hts_getCharsetFromMeta: <meta> charset extraction, HTML5 and legacy forms.
 # -#test=metacharset <html> prints the charset, or "(none)".
@@ -89,11 +89,11 @@ utf8() {
 utf8 'plain' '1'
 utf8 'café' '1'
 utf8 '统计' '1'
-utf8 "$(printf 'caf\xe9')" '0'              # latin-1 accent
-utf8 "$(printf '\xc3')" '0'                 # truncated lead byte
-utf8 "$(printf '\xa9')" '0'                 # lone continuation byte
-utf8 "$(printf '\xf0\x9f\x98\x80')" '1'     # 4-byte emoji
-utf8 "$(printf '\xc0\xaf')" '0'             # overlong (latin-1 "À¯" must stay convertible)
-utf8 "$(printf '\xed\xa0\x80')" '0'         # UTF-16 surrogate
-utf8 "$(printf '\xf4\x90\x80\x80')" '0'     # above U+10FFFF
-utf8 "$(printf '\xf8\x88\x80\x80\x80')" '0' # legacy 5-byte form
+utf8 'hex:636166e9' '0'   # latin-1 accent
+utf8 'hex:c3' '0'         # truncated lead byte
+utf8 'hex:a9' '0'         # lone continuation byte
+utf8 'hex:f09f9880' '1'   # 4-byte emoji
+utf8 'hex:c0af' '0'       # overlong (latin-1 "À¯" must stay convertible)
+utf8 'hex:eda080' '0'     # UTF-16 surrogate
+utf8 'hex:f4908080' '0'   # above U+10FFFF
+utf8 'hex:f888808080' '0' # legacy 5-byte form

tests/01_engine-filelist.test

@@ -52,14 +52,15 @@ run "$tmp/dir" "$tmp/adir"
 loghas 'Could not include URL list "[^"]+": not a regular file'
 
 # unreadable regular file: the fopen() errno arm fires, distinct from the
-# directory branch. Root bypasses mode 000, so skip it there.
-if test "$(id -u)" -ne 0; then
-    : >"$tmp/noperm.txt"
-    chmod 000 "$tmp/noperm.txt"
+# directory branch. Needs an OS that enforces mode 000: root bypasses it, and
+# Windows ignores chmod entirely, so probe rather than assume.
+: >"$tmp/noperm.txt"
+chmod 000 "$tmp/noperm.txt"
+if ! cat "$tmp/noperm.txt" >/dev/null 2>&1; then
     run "$tmp/perm" "$tmp/noperm.txt"
-    chmod 644 "$tmp/noperm.txt"
     loghas 'Could not include URL list "[^"]+": .+'
     lognot 'not a regular file'
 fi
+chmod 644 "$tmp/noperm.txt"
 
 exit 0

tests/01_engine-filter.test

@@ -193,5 +193,13 @@ test "$(with_timeout httrack -O /dev/null -#test=filter "$pat" "$subj")" == "$su
 match '*[aX]X*[a]Y' 'aXaXaY'
 nomatch '*[aX]X*[a]Y' 'aXbXaY'
 
-# hostile patterns must not stack-overflow or hang: length + work caps
+# hostile patterns must not stack-overflow or hang: length + depth + work caps
 test "$(with_timeout httrack -O /dev/null -#test=filterbounds)" == "filterbounds: OK" || exit 1
+
+# and the depth cap must hold on the 1MB stack a Windows thread gets (#574):
+# uncapped, the same pattern recursed ~900KB deep. Skipped where 512K is too
+# small to even start the binary.
+if (ulimit -s 512 && httrack --version >/dev/null 2>&1); then
+    out=$(ulimit -s 512 && with_timeout httrack -O /dev/null -#test=filterbounds)
+    test "$out" == "filterbounds: OK" || exit 1
+fi

tests/01_engine-fsize.test

@@ -0,0 +1,18 @@
+#!/bin/bash
+#
+# File sizes past the 32-bit wrap ('httrack -#test=fsize <dir>'). 5GB, so a
+# signed *and* an unsigned truncation both show up; sparse, so it costs no disk.
+
+set -euo pipefail
+
+dir=$(mktemp -d)
+trap 'rm -rf "$dir"' EXIT
+
+out=$(httrack -#test=fsize "$dir")
+echo "$out"
+
+want="fsize: width=8,8 size=5368709120,5368709120 psize=5368709120 absent=-1"
+test "$out" == "$want" || {
+    echo "FAIL: unexpected size report (want '$want')"
+    exit 1
+}

tests/01_engine-idna.test

@@ -38,4 +38,7 @@ dec 'xn--!!!' '㚯'
 dec 'xn--already-encoded.com' 'ǮalǭǮreaǭǫdy.com'
 
 # second label has a truncated UTF-8 sequence: used to leak the segment buffer.
-enc_bad "$(printf 'b\xc3\xbcchev.\xe4\xbe\x8b\xe5\xad\x62\xc3\xbccheple')"
+# Fed as hex: the raw bytes must reach the encoder intact, but invalid UTF-8
+# cannot survive a Windows command line (it round-trips through UTF-16 to valid
+# U+FFFD, which then encodes fine instead of being rejected).
+enc_bad 'hex:62c3bc636865762ee4be8be5ad62c3bc636865706c65'

tests/01_engine-proxyurl.test

@@ -0,0 +1,44 @@
+#!/bin/bash
+#
+
+set -euo pipefail
+
+# hts_parse_proxy splits a -P argument "[scheme://][user:pass@]host[:port]" into
+# the proxy host string and port. -#test=proxyurl <arg> prints
+# "name=.. port=.. host=..", where host= is what the connect resolves.
+
+p() {
+    test "$(httrack -O /dev/null -#test=proxyurl "$1")" == "$2" || exit 1
+}
+
+# bare host, with and without an explicit port
+p 'proxy.example.com:8080' 'name=proxy.example.com port=8080 host=proxy.example.com'
+p 'proxy.example.com' 'name=proxy.example.com port=8080 host=proxy.example.com'
+
+# user:pass@ is kept in name (for proxy auth) and stripped from host
+p 'user:pass@proxy:3128' 'name=user:pass@proxy port=3128 host=proxy'
+p 'user:pass@proxy' 'name=user:pass@proxy port=8080 host=proxy'
+
+# a scheme colon must not be read as a port: http://host with no port used to
+# parse to name=http with a garbage port
+p 'http://proxy:8080' 'name=http://proxy port=8080 host=proxy'
+p 'http://proxy' 'name=http://proxy port=8080 host=proxy'
+
+# socks5/socks5h default to 1080 and resolve to the bare host
+p 'socks5://host:1080' 'name=socks5://host port=1080 host=host'
+p 'socks5://host' 'name=socks5://host port=1080 host=host'
+p 'socks5h://host' 'name=socks5h://host port=1080 host=host'
+# explicit port wins over the 1080 default, with and without userinfo
+p 'socks5://host:9050' 'name=socks5://host port=9050 host=host'
+p 'socks5://user:pass@host:9050' 'name=socks5://user:pass@host port=9050 host=host'
+
+# the split is byte-transparent: percent-escapes stay encoded (decoded later at
+# auth time), only structural ASCII ':'/'@' delimit, and the last '@' ends the
+# userinfo. So %40/%3A and UTF-8 bytes never mis-split host or port.
+p 'socks5://user:p%40ss@host:1080' 'name=socks5://user:p%40ss@host port=1080 host=host'
+p 'socks5://us%3Aer:pass@host:1080' 'name=socks5://us%3Aer:pass@host port=1080 host=host'
+p 'socks5://a@b:c@host:1080' 'name=socks5://a@b:c@host port=1080 host=host'
+p 'socks5://naïve:pass@héllo:1080' 'name=socks5://naïve:pass@héllo port=1080 host=héllo'
+
+# a lone ':' must not underflow the backward scan
+p ':' 'name= port=8080 host='

tests/01_engine-rcfile.test

@@ -32,6 +32,13 @@ esac
 tmp=$(mktemp -d "${TMPDIR:-/tmp}/httrack_rcfile.XXXXXX") || exit 1
 trap 'rm -rf "$tmp"' EXIT HUP INT QUIT PIPE TERM
 
+# HTS_HTTRACKRC is ".httrackrc" on POSIX but "httrackrc" on Windows: write both,
+# each platform reads the one it knows.
+write_rc() {
+    cat >"$1/.httrackrc"
+    cp "$1/.httrackrc" "$1/httrackrc"
+}
+
 # --- 1. alias token survives the bound intact -------------------------------
 d1="$tmp/intact"
 mkdir -p "$d1"
@@ -40,7 +47,7 @@ echo '<html><body>hello</body></html>' >"$d1/index.html"
 # optinclude_file() lowercases each config line, so the marker is lowercase to
 # survive the comparison verbatim.
 marker='zzz_rcfile_marker_0123456789_abcdefghijklmnopqrstuvwxyz_intact'
-printf 'user-agent=%s\n' "$marker" >"$d1/.httrackrc"
+printf 'user-agent=%s\n' "$marker" | write_rc "$d1"
 
 # Run with no -O so the working-directory .httrackrc is loaded (an -O path makes
 # the engine skip the rc files). Output lands in the temp dir. Guard the run so a
@@ -73,7 +80,7 @@ echo '<html><body>hi</body></html>' >"$d2/index.html"
 val=$(printf 'a%.0s' $(seq 1 200))
 for _ in $(seq 1 400); do
     printf 'user-agent=%s\n' "$val"
-done >"$d2/.httrackrc"
+done | write_rc "$d2"
 
 # The process aborts (httrack turns the fatal signal into exit 134 either way),
 # so the exit code does not distinguish the bounded abort from a heap overflow;

tests/01_engine-sniff.test

@@ -35,7 +35,8 @@ chk image/avif hex:0000001C6674797061766966 "$yes"
 chk image/avif hex:0000001C6674797068656963 "$no" # heic brand is not avif
 chk image/heic hex:0000001C6674797068656963 "$yes"
 chk image/svg+xml '<svg xmlns="x">' "$yes"
-chk image/svg+xml $'\xef\xbb\xbf  <?xml version="1.0"?>' "$yes" # BOM+ws skip
+# BOM+ws skip; hex, as Windows argv cannot carry the raw BOM through the ANSI codepage
+chk image/svg+xml hex:EFBBBF20203C3F786D6C2076657273696F6E3D22312E30223F3E "$yes"
 
 # audio / video
 chk audio/mpeg 'ID3xxx' "$yes"

tests/01_engine-socks5.test

@@ -0,0 +1,9 @@
+#!/bin/bash
+#
+
+set -euo pipefail
+
+# The SOCKS5 handshake framing and credential split, driven against scripted
+# server replies (frame draining, oversize rejects, RFC 1929 fields).
+
+httrack -O /dev/null '-#test=socks5' | grep -q "socks5 self-test OK"

tests/01_engine-strsafe.test

@@ -32,10 +32,10 @@ case "$err" in
 esac
 
 # Same guarantee for the htsbuff builder. The source is exactly the buffer
-# capacity (4 bytes into a 4-byte buffer), so this also pins the boundary: a
+# capacity (6 bytes into a 6-byte buffer), so this also pins the boundary: a
 # '<=' off-by-one in the capacity check would let it through (and print "NOT
 # aborted"). Match the specific htsbuff abort message, not just any assert.
-err=$(httrack -#test=strsafe overflow-buff "abcd" 2>&1) || true
+err=$(httrack -#test=strsafe overflow-buff "abcdef" 2>&1) || true
 case "$err" in
 *"strsafe: NOT aborted"*)
     echo "htsbuff over-capacity write was NOT caught" >&2

tests/01_zlib-contentcodings.test

@@ -0,0 +1,11 @@
+#!/bin/bash
+#
+
+set -euo pipefail
+
+# brotli/zstd decode, unknown codings, and the decoded-size budget.
+dir=$(mktemp -d)
+trap 'rm -rf "$dir"' EXIT
+
+httrack -O /dev/null -#test=contentcodings "$dir" run |
+    grep -q "contentcodings self-test OK"

tests/13_crawl_proxy_https.test

@@ -8,22 +8,26 @@ set -euo pipefail
 
 : "${top_srcdir:=..}"
 
+# shellcheck source=tests/testlib.sh
+. "$top_srcdir/tests/testlib.sh"
+
 if test "${HTTPS_SUPPORT:-}" == "no"; then
     echo "no https support compiled, skipping"
     exit 77
 fi
-if ! command -v python3 >/dev/null 2>&1 || ! command -v openssl >/dev/null 2>&1; then
+python=$(find_python) || python=
+if test -z "$python" || ! command -v openssl >/dev/null 2>&1; then
     echo "python3/openssl missing, skipping"
     exit 77
 fi
 
-server="$top_srcdir/tests/proxy-https-server.py"
+server=$(nativepath "$top_srcdir/tests/proxy-https-server.py")
 tmpdir=$(mktemp -d)
 pids=
 
 cleanup() {
     for pid in $pids; do
-        kill "$pid" 2>/dev/null || true
+        stop_server "$pid"
     done
     rm -rf "$tmpdir"
 }
@@ -38,10 +42,13 @@ cat "$tmpdir/key.pem" "$tmpdir/cert.pem" >"$tmpdir/both.pem"
 # start_server <logdir> <mode>: launches a proxy+origin pair, sets $origin_port
 # and $proxy_port from its announced ephemeral ports.
 start_server() {
-    local dir="$1" mode="$2" ports
+    local dir="$1" mode="$2" ports pem
     mkdir -p "$dir"
     ports="$dir/ports.txt"
-    python3 "$server" "$tmpdir/both.pem" "$dir" "$mode" \
+    pem=$(nativepath "$tmpdir/both.pem")
+    dir_native=$(nativepath "$dir")
+    : >"$ports"
+    "$python" "$server" "$pem" "$dir_native" "$mode" \
         >"$ports" 2>"$dir/server.err" &
     pids="$pids $!"
     for _ in $(seq 1 100); do

tests/19_local-connect-fallback.test

@@ -12,14 +12,17 @@ set -euo pipefail
 
 : "${top_srcdir:=..}"
 
+# shellcheck source=tests/testlib.sh
+. "$top_srcdir/tests/testlib.sh"
+
 if test "${V6_SUPPORT:-}" == "no"; then
     echo "no IPv6 support (resolver list/override is IPv6-only), skipping"
     exit 77
 fi
-if ! command -v python3 >/dev/null 2>&1; then
+python=$(find_python) || {
     echo "python3 missing, skipping"
     exit 77
-fi
+}
 # The fixture needs a second loopback IP (dead 127.0.0.2 + live 127.0.0.1) for
 # the fallback to have a target; GNU/Hurd has only 127.0.0.1, so skip there.
 case "$(uname -s)" in
@@ -28,24 +31,26 @@ GNU | GNU/*)
     exit 77
     ;;
 esac
+# TODO: drop once https://github.com/xroche/httrack/issues/579 is fixed.
+if is_windows; then
+    echo "Windows: the connect fallback never runs (#579), skipping"
+    exit 77
+fi
 
-server="$top_srcdir/tests/local-server.py"
-root="$top_srcdir/tests/server-root"
+server=$(nativepath "$top_srcdir/tests/local-server.py")
+root=$(nativepath "$top_srcdir/tests/server-root")
 tmpdir=$(mktemp -d)
 serverpid=
 
 cleanup() {
-    if test -n "$serverpid"; then
-        kill "$serverpid" 2>/dev/null || true
-        wait "$serverpid" 2>/dev/null || true
-    fi
+    stop_server "$serverpid"
     rm -rf "$tmpdir"
     return 0
 }
 trap cleanup EXIT
 
 # bind the live server to 127.0.0.1 only, so 127.0.0.2 refuses the connect
-python3 "$server" --root "$root" --bind 127.0.0.1 >"$tmpdir/srv.out" 2>"$tmpdir/srv.err" &
+"$python" "$server" --root "$root" --bind 127.0.0.1 >"$tmpdir/srv.out" 2>"$tmpdir/srv.err" &
 serverpid=$!
 port=
 for _ in $(seq 1 50); do

tests/20_local-resume-loop.test

@@ -5,19 +5,19 @@ set -u
 
 : "${top_srcdir:=..}"
 testdir=$(cd "$(dirname "$0")" && pwd)
-server="${testdir}/local-server.py"
+# shellcheck source=tests/testlib.sh
+. "${testdir}/testlib.sh"
+server=$(nativepath "${testdir}/local-server.py")
+root=$(nativepath "${testdir}/server-root")
 
-command -v python3 >/dev/null || ! echo "python3 not found; skipping" || exit 77
+python=$(find_python) || ! echo "python3 not found; skipping" >&2 || exit 77
 
 tmpdir=$(mktemp -d "${TMPDIR:-/tmp}/httrack_206.XXXXXX") || exit 1
 serverpid=
 crawlpid=
 cleanup() {
     test -n "$crawlpid" && kill -9 "$crawlpid" 2>/dev/null
-    if test -n "$serverpid"; then
-        kill "$serverpid" 2>/dev/null
-        wait "$serverpid" 2>/dev/null
-    fi
+    stop_server "$serverpid"
     rm -rf "$tmpdir"
 }
 trap cleanup EXIT HUP INT QUIT PIPE TERM
@@ -25,8 +25,9 @@ trap cleanup EXIT HUP INT QUIT PIPE TERM
 # --- start the server, discover its ephemeral port --------------------------
 # RESUME_COUNTER gets a byte per /resume/blob.txt request (pass-2 delta bounds re-gets).
 serverlog="${tmpdir}/server.log"
+: >"$serverlog"
 counter="${tmpdir}/blobcount"
-RESUME_COUNTER="$counter" python3 "$server" --root "${testdir}/server-root" >"$serverlog" 2>&1 &
+RESUME_COUNTER="$counter" "$python" "$server" --root "$root" >"$serverlog" 2>&1 &
 serverpid=$!
 port=
 for _ in $(seq 1 50); do

tests/24_local-resume-overlap.test

@@ -9,29 +9,30 @@ set -eu
 
 : "${top_srcdir:=..}"
 testdir=$(cd "$(dirname "$0")" && pwd)
-server="${testdir}/local-server.py"
+# shellcheck source=tests/testlib.sh
+. "${testdir}/testlib.sh"
+server=$(nativepath "${testdir}/local-server.py")
+root=$(nativepath "${testdir}/server-root")
 
-command -v python3 >/dev/null || ! echo "python3 not found; skipping" || exit 77
+python=$(find_python) || ! echo "python3 not found; skipping" >&2 || exit 77
 
 tmpdir=$(mktemp -d "${TMPDIR:-/tmp}/httrack_198.XXXXXX") || exit 1
 serverpid=
 crawlpid=
 cleanup() {
     if test -n "$crawlpid"; then kill -9 "$crawlpid" 2>/dev/null || true; fi
-    if test -n "$serverpid"; then
-        kill "$serverpid" 2>/dev/null || true
-        wait "$serverpid" 2>/dev/null || true
-    fi
+    stop_server "$serverpid"
     rm -rf "$tmpdir"
 }
 trap cleanup EXIT HUP INT QUIT PIPE TERM
 
 # OVERLAP_COUNTER gets a byte per flaky.bin request so pass 1 knows when to interrupt.
 serverlog="${tmpdir}/server.log"
+: >"$serverlog"
 counter="${tmpdir}/hits"
 resumed="${tmpdir}/resumed" # gets a byte when the server serves a resume 206
 OVERLAP_COUNTER="$counter" OVERLAP_RESUMED="$resumed" \
-    python3 "$server" --root "${testdir}/server-root" \
+    "$python" "$server" --root "$root" \
     >"$serverlog" 2>&1 &
 serverpid=$!
 port=

tests/28_local-pause.test

@@ -9,9 +9,12 @@ set -e
 
 : "${top_srcdir:=..}"
 
+# shellcheck source=tests/testlib.sh
+. "$top_srcdir/tests/testlib.sh"
+
 # python3 runs the local server (mirror local-crawl.sh); skip when absent, else
 # run() swallows its exit-77 and the serverless 0s/0s crawl looks like a fail.
-command -v python3 >/dev/null || {
+find_python >/dev/null || {
     echo "python3 not found; skipping local crawl tests"
     exit 77
 }

tests/46_local-update-304-resume.test

@@ -7,27 +7,28 @@ set -u
 
 : "${top_srcdir:=..}"
 testdir=$(cd "$(dirname "$0")" && pwd)
-server="${testdir}/local-server.py"
+# shellcheck source=tests/testlib.sh
+. "${testdir}/testlib.sh"
+server=$(nativepath "${testdir}/local-server.py")
+root=$(nativepath "${testdir}/server-root")
 
-command -v python3 >/dev/null || ! echo "python3 not found; skipping" || exit 77
+python=$(find_python) || ! echo "python3 not found; skipping" >&2 || exit 77
 
 tmpdir=$(mktemp -d "${TMPDIR:-/tmp}/httrack_c7.XXXXXX") || exit 1
 serverpid=
 crawlpid=
 cleanup() {
     test -n "$crawlpid" && kill -9 "$crawlpid" 2>/dev/null
-    if test -n "$serverpid"; then
-        kill "$serverpid" 2>/dev/null
-        wait "$serverpid" 2>/dev/null
-    fi
+    stop_server "$serverpid"
     rm -rf "$tmpdir"
 }
 trap cleanup EXIT HUP INT QUIT PIPE TERM
 
 serverlog="${tmpdir}/server.log"
+: >"$serverlog"
 counter="${tmpdir}/reqcount"
 mark="${tmpdir}/got304"
-RESUME304_COUNTER="$counter" RESUME304_MARK="$mark" python3 "$server" --root "${testdir}/server-root" >"$serverlog" 2>&1 &
+RESUME304_COUNTER="$counter" RESUME304_MARK="$mark" "$python" "$server" --root "$root" >"$serverlog" 2>&1 &
 serverpid=$!
 port=
 for _ in $(seq 1 50); do

tests/47_local-crange-overflow.test

@@ -8,25 +8,26 @@ set -u
 
 : "${top_srcdir:=..}"
 testdir=$(cd "$(dirname "$0")" && pwd)
-server="${testdir}/local-server.py"
+# shellcheck source=tests/testlib.sh
+. "${testdir}/testlib.sh"
+server=$(nativepath "${testdir}/local-server.py")
+root=$(nativepath "${testdir}/server-root")
 
-command -v python3 >/dev/null || ! echo "python3 not found; skipping" || exit 77
+python=$(find_python) || ! echo "python3 not found; skipping" >&2 || exit 77
 
 tmpdir=$(mktemp -d "${TMPDIR:-/tmp}/httrack_crange.XXXXXX") || exit 1
 serverpid=
 crawlpid=
 cleanup() {
     test -n "$crawlpid" && kill -9 "$crawlpid" 2>/dev/null
-    if test -n "$serverpid"; then
-        kill "$serverpid" 2>/dev/null
-        wait "$serverpid" 2>/dev/null
-    fi
+    stop_server "$serverpid"
     rm -rf "$tmpdir"
 }
 trap cleanup EXIT HUP INT QUIT PIPE TERM
 
 serverlog="${tmpdir}/server.log"
-python3 "$server" --root "${testdir}/server-root" >"$serverlog" 2>&1 &
+: >"$serverlog"
+"$python" "$server" --root "$root" >"$serverlog" 2>&1 &
 serverpid=$!
 port=
 for _ in $(seq 1 50); do

tests/48_local-crange-memresume.test

@@ -8,25 +8,26 @@ set -u
 
 : "${top_srcdir:=..}"
 testdir=$(cd "$(dirname "$0")" && pwd)
-server="${testdir}/local-server.py"
+# shellcheck source=tests/testlib.sh
+. "${testdir}/testlib.sh"
+server=$(nativepath "${testdir}/local-server.py")
+root=$(nativepath "${testdir}/server-root")
 
-command -v python3 >/dev/null || ! echo "python3 not found; skipping" || exit 77
+python=$(find_python) || ! echo "python3 not found; skipping" >&2 || exit 77
 
 tmpdir=$(mktemp -d "${TMPDIR:-/tmp}/httrack_crangemem.XXXXXX") || exit 1
 serverpid=
 crawlpid=
 cleanup() {
     test -n "$crawlpid" && kill -9 "$crawlpid" 2>/dev/null
-    if test -n "$serverpid"; then
-        kill "$serverpid" 2>/dev/null
-        wait "$serverpid" 2>/dev/null
-    fi
+    stop_server "$serverpid"
     rm -rf "$tmpdir"
 }
 trap cleanup EXIT HUP INT QUIT PIPE TERM
 
 serverlog="${tmpdir}/server.log"
-python3 "$server" --root "${testdir}/server-root" >"$serverlog" 2>&1 &
+: >"$serverlog"
+"$python" "$server" --root "$root" >"$serverlog" 2>&1 &
 serverpid=$!
 port=
 for _ in $(seq 1 50); do
@@ -77,7 +78,14 @@ echo "OK (temp-ref present)"
 
 # --- pass 2: --continue -> resume -> hostile INT64_MAX Content-Range ----------
 printf '[pass 2: hostile 206, no overflow, refetch] ..\t'
-httrack "${common[@]}" --continue "${base}/crange206mem/index.html" >"${tmpdir}/log2" 2>&1
+rc=0
+httrack "${common[@]}" --continue "${base}/crange206mem/index.html" >"${tmpdir}/log2" 2>&1 || rc=$?
+# a crash here would otherwise read as a clean "terminated"
+test "$rc" -eq 0 || {
+    echo "FAIL: httrack exited $rc"
+    cat "${tmpdir}/log2" >&2
+    exit 1
+}
 echo "OK (terminated)"
 
 blob=$(find "$out" -name blob.bin 2>/dev/null | head -1)
@@ -86,6 +94,9 @@ full=6008 # len(CRANGE206_BODY) = len("CR206DAT") + 6000
 printf '[file recovered whole] ..\t'
 test -s "$blob" || {
     echo "FAIL: blob.bin missing after the hostile 206"
+    tail -40 "${out}/hts-log.txt" >&2
+    cat "${tmpdir}/log2" >&2
+    find "$out" -type f >&2
     exit 1
 }
 got=$(wc -c <"$blob")

tests/50_local-contentcodings.test

@@ -0,0 +1,38 @@
+#!/bin/bash
+#
+# br and zstd on the wire: both decode, a junk coding leaves the body alone, an
+# undecodable one fails the fetch, and br/zstd are advertised over TLS only.
+
+set -euo pipefail
+
+: "${top_srcdir:=..}"
+
+# Both decoders are needed for the wire fixtures; the codec-off matrix is
+# covered by the fenced 01_zlib-contentcodings self-test.
+if test "${BROTLI_ENABLED:-yes}" != "yes" || test "${ZSTD_ENABLED:-yes}" != "yes"; then
+    echo "brotli/zstd not both compiled, skipping"
+    exit 77
+fi
+
+# bad.html (in memory) and bin.dat (direct-to-disk) both carry an undecodable
+# coding: the fetch fails and neither leaves coded bytes on disk.
+bash "$top_srcdir/tests/local-crawl.sh" --errors 2 --files 5 \
+    --file-matches 'codec/br.html' 'coded body' \
+    --file-matches 'codec/zstd.html' 'coded body' \
+    --file-matches 'codec/junk.html' 'junk coding' \
+    --file-matches 'codec/ae.html' 'AE=gzip, deflate,' \
+    --file-not-matches 'codec/ae.html' ' br' \
+    --file-not-matches 'codec/ae.html' 'zstd' \
+    --not-found 'codec/bad.html' \
+    --not-found 'codec/bin.dat' \
+    --log-found 'Unsupported Content-Encoding' \
+    httrack 'BASEURL/codec/index.html'
+
+if test "${HTTPS_SUPPORT:-}" == "no"; then
+    echo "no https support compiled, skipping the TLS leg"
+    exit 0
+fi
+
+bash "$top_srcdir/tests/local-crawl.sh" --tls --errors 2 --files 5 \
+    --file-matches 'codec/ae.html' 'AE=gzip, deflate, br, zstd,' \
+    httrack 'BASEURL/codec/index.html'

tests/51_local-update-codec.test

@@ -0,0 +1,38 @@
+#!/bin/bash
+#
+# A coded re-fetch that fails to decode must not destroy the mirrored file (#557).
+# Pass 1 mirrors from valid gzip; pass 2 (--update) serves an undecodable body for
+# mem.html (in-memory), disk.bin (direct-to-disk) and unsup.html (a coding we have
+# no decoder for). All three must keep their pass-1 content. fresh.html and
+# freshdisk.bin decode on both passes: they are the controls that a good update
+# still lands, in memory and direct-to-disk (the latter renaming the decoded temp
+# over an existing file). Unfixed, the decode target is the mirror itself, so the
+# first three are lost.
+
+set -euo pipefail
+
+: "${top_srcdir:=..}"
+
+# A restrictive umask makes the decoded direct-to-disk file's mode observable:
+# it is committed by renaming a temp, so it needs the chmod filecreate() does.
+umask 077
+
+bash "$top_srcdir/tests/local-crawl.sh" \
+    --rerun-args '--update' \
+    --errors 3 \
+    --log-found 'decompressing.*upcodec/mem\.html' \
+    --log-found 'decompressing.*upcodec/disk\.bin' \
+    --log-found 'Unsupported Content-Encoding.*upcodec/unsup\.html' \
+    --file-matches 'upcodec/mem.html' 'MIRRORED-MEM-V1' \
+    --file-matches 'upcodec/disk.bin' 'MIRRORED-DISK-V1' \
+    --file-min-bytes 'upcodec/disk.bin' 32768 \
+    --file-mode 'upcodec/disk.bin' 644 \
+    --file-matches 'upcodec/unsup.html' 'MIRRORED-UNSUP-V1' \
+    --file-matches 'upcodec/fresh.html' 'FRESH-V2' \
+    --file-not-matches 'upcodec/fresh.html' 'FRESH-V1' \
+    --file-mode 'upcodec/fresh.html' 644 \
+    --file-matches 'upcodec/freshdisk.bin' 'FRESHDISK-V2' \
+    --file-not-matches 'upcodec/freshdisk.bin' 'FRESHDISK-V1' \
+    --file-min-bytes 'upcodec/freshdisk.bin' 32768 \
+    --file-mode 'upcodec/freshdisk.bin' 644 \
+    httrack 'BASEURL/upcodec/index.html'

tests/52_local-socks5.test

@@ -0,0 +1,218 @@
+#!/bin/bash
+#
+# Issue #563: a SOCKS5 proxy must carry both http and https, resolve the origin
+# name REMOTELY (ATYP=domain, never a local lookup), and authenticate per RFC
+# 1929 without leaking the credentials to the origin.
+
+set -euo pipefail
+
+: "${top_srcdir:=..}"
+
+# shellcheck source=tests/testlib.sh
+. "$top_srcdir/tests/testlib.sh"
+
+if test "${HTTPS_SUPPORT:-}" == "no"; then
+    echo "no https support compiled, skipping"
+    exit 77
+fi
+python=$(find_python) || python=
+if test -z "$python" || ! command -v openssl >/dev/null 2>&1; then
+    echo "python3/openssl missing, skipping"
+    exit 77
+fi
+
+# a .invalid name never resolves (RFC 6761): reaching the page at all proves the
+# proxy did the DNS
+host="socks-origin.invalid"
+server=$(nativepath "$top_srcdir/tests/socks5-server.py")
+tmpdir=$(mktemp -d)
+pids=
+
+cleanup() {
+    for pid in $pids; do
+        stop_server "$pid"
+    done
+    rm -rf "$tmpdir"
+}
+trap cleanup EXIT
+
+openssl req -x509 -newkey rsa:2048 -keyout "$tmpdir/key.pem" \
+    -out "$tmpdir/cert.pem" -days 2 -nodes -subj "/CN=127.0.0.1" \
+    >/dev/null 2>&1
+cat "$tmpdir/key.pem" "$tmpdir/cert.pem" >"$tmpdir/both.pem"
+
+# start_server <logdir> <mode>: sets $tls_port/$http_port/$socks_port
+start_server() {
+    local dir="$1" mode="$2" ports pem
+    mkdir -p "$dir"
+    ports="$dir/ports.txt"
+    pem=$(nativepath "$tmpdir/both.pem")
+    dir_native=$(nativepath "$dir")
+    : >"$ports"
+    "$python" "$server" "$pem" "$dir_native" "$mode" \
+        >"$ports" 2>"$dir/server.err" &
+    pids="$pids $!"
+    for _ in $(seq 1 100); do
+        grep -q "^ready" "$ports" 2>/dev/null && break
+        sleep 0.1
+    done
+    grep -q "^ready" "$ports" 2>/dev/null || {
+        echo "server ($mode) did not start" >&2
+        cat "$dir/server.err" >&2
+        exit 1
+    }
+    tls_port=$(awk '/^TLS/{print $2}' "$ports")
+    http_port=$(awk '/^HTTP/{print $2}' "$ports")
+    socks_port=$(awk '/^SOCKS/{print $2}' "$ports")
+}
+
+# kill a hung httrack so a missing read bound surfaces as $HANG_RC instead of
+# stalling the job (macOS has no `timeout`)
+HANG_RC=137 # 128 + SIGKILL
+run_crawl() {
+    local out="$1" url="$2" proxy="$3"
+    shift 3
+    local extra="$*"
+    test -n "$extra" || extra="-r1 -s0"
+    rm -rf "$out"
+    # shellcheck disable=SC2086
+    httrack "$url" --proxy "$proxy" \
+        -O "$out" $extra --timeout=10 >"$out.log" 2>&1 &
+    local pid=$!
+    (sleep 60 && kill -9 "$pid" 2>/dev/null) &
+    local guard=$!
+    local rc=0
+    wait "$pid" 2>/dev/null || rc=$?
+    kill "$guard" 2>/dev/null || true
+    wait "$guard" 2>/dev/null || true
+    return "$rc"
+}
+
+# --- https over socks, remote DNS -------------------------------------------
+ok="$tmpdir/ok"
+start_server "$ok" ok
+
+run_crawl "$ok/out" "https://${host}:${tls_port}/" "socks5://127.0.0.1:${socks_port}"
+grep -rq "ORIGIN-PAGE-563" "$ok/out" || {
+    echo "FAIL: origin page not downloaded through the socks proxy" >&2
+    cat "$ok/out.log" "$ok/server.err" >&2
+    exit 1
+}
+grep -q "^ATYP domain ${host}\$" "$ok/socks.log" || {
+    echo "FAIL: proxy did not receive ATYP=domain ${host} (no remote DNS)" >&2
+    cat "$ok/socks.log" >&2
+    exit 1
+}
+# a client that resolved locally would have sent an address, not a name
+grep -q "^ATYP ipv4" "$ok/socks.log" && {
+    echo "FAIL: httrack resolved locally and sent an IPv4 to the proxy" >&2
+    cat "$ok/socks.log" >&2
+    exit 1
+}
+echo "OK: https tunneled through socks5 with remote DNS"
+
+# --- plain http over socks --------------------------------------------------
+: >"$ok/origin-headers.log" # the https crawl above also logged a request line
+run_crawl "$ok/outh" "http://${host}:${http_port}/" "socks5://127.0.0.1:${socks_port}"
+grep -rq "ORIGIN-PAGE-563" "$ok/outh" || {
+    echo "FAIL: plain http not tunneled through the socks proxy" >&2
+    cat "$ok/outh.log" "$ok/socks.log" >&2
+    exit 1
+}
+# the tunneled request is origin-form, as on a direct connection: the http-proxy
+# absolute URI would reach the origin as "GET http://host/"
+grep -q "^REQUEST GET / " "$ok/origin-headers.log" || {
+    echo "FAIL: tunneled request is not origin-form" >&2
+    cat "$ok/origin-headers.log" >&2
+    exit 1
+}
+grep -q "^REQUEST GET http" "$ok/origin-headers.log" && {
+    echo "FAIL: absolute-URI request sent through the socks tunnel" >&2
+    cat "$ok/origin-headers.log" >&2
+    exit 1
+}
+echo "OK: plain http tunneled through socks5"
+
+# --- keep-alive socket reuse must NOT re-run the handshake ------------------
+# A reused keep-alive socket is already tunneled; re-injecting the SOCKS
+# greeting corrupts the origin stream. -c1 + the origin's max>1 advert makes
+# httrack serve the whole plain-http crawl over one tunnel: exactly one
+# handshake, every subpage intact.
+ka="$tmpdir/ka"
+start_server "$ka" ok
+run_crawl "$ka/out" "http://${host}:${http_port}/" "socks5://127.0.0.1:${socks_port}" -r3 -c1
+missing=0
+for i in 1 2 3 4 5; do
+    grep -rq "SUBPAGE-563 /p${i}.html" "$ka/out" || missing=1
+done
+test "$missing" -eq 0 || {
+    echo "FAIL: a keep-alive subpage was lost (re-handshake corrupted the reused socket)" >&2
+    cat "$ka/out.log" "$ka/socks.log" >&2
+    exit 1
+}
+handshakes=$(grep -c "^CMD " "$ka/socks.log" || true)
+test "$handshakes" -eq 1 || {
+    echo "FAIL: expected 1 SOCKS handshake for the reused socket, got $handshakes" >&2
+    cat "$ka/socks.log" >&2
+    exit 1
+}
+echo "OK: keep-alive socket reused over one socks tunnel, no re-handshake"
+
+# --- authenticated socks (RFC 1929) -----------------------------------------
+# over plain http: that is the request an http proxy would decorate with
+# Proxy-Authorization, so the no-leak check below has teeth
+auth="$tmpdir/auth"
+start_server "$auth" ok
+run_crawl "$auth/out" "http://${host}:${http_port}/" \
+    "socks5://user:secret@127.0.0.1:${socks_port}"
+grep -rq "ORIGIN-PAGE-563" "$auth/out" || {
+    echo "FAIL: origin not downloaded through the authenticated socks proxy" >&2
+    cat "$auth/out.log" "$auth/socks.log" >&2
+    exit 1
+}
+grep -q "^METHOD userpass\$" "$auth/socks.log" || {
+    echo "FAIL: user/pass method not negotiated (auth ignored)" >&2
+    cat "$auth/socks.log" >&2
+    exit 1
+}
+grep -q "^AUTH user secret\$" "$auth/socks.log" || {
+    echo "FAIL: wrong socks credentials sent" >&2
+    cat "$auth/socks.log" >&2
+    exit 1
+}
+grep -qi "secret\|proxy-authorization" "$auth/origin-headers.log" && {
+    echo "FAIL: socks credentials leaked into the origin request" >&2
+    cat "$auth/origin-headers.log" >&2
+    exit 1
+}
+echo "OK: socks5 user/pass negotiated, creds not leaked to origin"
+
+# --- hostile: refusing proxy ------------------------------------------------
+ref="$tmpdir/refuse"
+start_server "$ref" refuse
+rc=0
+run_crawl "$ref/out" "https://${host}:${tls_port}/" "socks5://127.0.0.1:${socks_port}" || rc=$?
+test "$rc" -ne "$HANG_RC" || {
+    echo "FAIL: crawl hung on a refusing socks proxy" >&2
+    exit 1
+}
+grep -rq "ORIGIN-PAGE-563" "$ref/out" 2>/dev/null && {
+    echo "FAIL: refusing proxy unexpectedly served the page" >&2
+    exit 1
+}
+echo "OK: refusing socks proxy fails cleanly, no hang"
+
+# --- hostile: truncated handshake reply -------------------------------------
+trunc="$tmpdir/trunc"
+start_server "$trunc" truncate
+rc=0
+run_crawl "$trunc/out" "https://${host}:${tls_port}/" "socks5://127.0.0.1:${socks_port}" || rc=$?
+test "$rc" -ne "$HANG_RC" || {
+    echo "FAIL: crawl hung on a truncated socks reply (bounded read missing)" >&2
+    exit 1
+}
+grep -rq "ORIGIN-PAGE-563" "$trunc/out" 2>/dev/null && {
+    echo "FAIL: truncated-reply proxy unexpectedly served the page" >&2
+    exit 1
+}
+echo "OK: bounded socks handshake, no hang on a truncated reply"

tests/53_local-proxytrack-cache-corrupt.test

@@ -0,0 +1,21 @@
+#!/bin/bash
+# A corrupt proxytrack .ndx must not overflow the fixed cache-read buffers. The
+# sanitizer CI build turns any regression here into a hard stack/heap overflow.
+
+set -euo pipefail
+
+dir=$(mktemp -d)
+trap 'rm -rf "$dir"' EXIT
+
+# The first length-prefixed field declares far more than firstline[256] holds;
+# cache_brstr must clamp the copy to the destination, not the declared length.
+{
+    printf '4000\n'
+    head -c 4000 /dev/zero | tr '\0' 'A'
+} >"$dir/foo.ndx"
+: >"$dir/foo.dat" # cache_brstr runs only when the sibling .dat opens
+
+proxytrack --convert "$dir/out.arc" "$dir/foo.ndx" >/dev/null 2>&1 || {
+    echo "FAIL: proxytrack crashed/errored on a corrupt cache index"
+    exit 1
+}

tests/Makefile.am

@@ -2,8 +2,8 @@
 # explicitly: automake does not expand wildcards in EXTRA_DIST, so a glob would
 # silently drop it from the dist tarball and break "make distcheck".
 EXTRA_DIST = $(TESTS) crawl-test.sh run-all-tests.sh check-network.sh \
-	proxy-https-server.py \
-	local-crawl.sh local-server.py server.crt server.key \
+	proxy-https-server.py socks5-server.py \
+	local-crawl.sh local-server.py testlib.sh server.crt server.key \
 	server-root/simple/basic.html server-root/simple/link.html \
 	server-root/stripquery/index.html server-root/stripquery/a.html \
 	server-root/fraglink/index.html server-root/fraglink/target.html \
@@ -15,6 +15,8 @@ TESTS_ENVIRONMENT += PATH=$(top_builddir)/src$(PATH_SEPARATOR)$$PATH
 ### TESTS_ENVIRONMENT += $(SHLIBPATH_VAR)="$(top_builddir)/src/$(LT_CV_OBJDIR)$${$(SHLIBPATH_VAR):+$(PATH_SEPARATOR)}$$$(SHLIBPATH_VAR)"
 TESTS_ENVIRONMENT += ONLINE_UNIT_TESTS=$(ONLINE_UNIT_TESTS)
 TESTS_ENVIRONMENT += HTTPS_SUPPORT=$(HTTPS_SUPPORT)
+TESTS_ENVIRONMENT += BROTLI_ENABLED=$(BROTLI_ENABLED)
+TESTS_ENVIRONMENT += ZSTD_ENABLED=$(ZSTD_ENABLED)
 TESTS_ENVIRONMENT += V6_SUPPORT=$(V6_SUPPORT)
 TESTS_ENVIRONMENT += top_srcdir=$(top_srcdir)
 
@@ -44,6 +46,8 @@ TESTS = \
 	01_engine-header.test \
 	01_engine-idna.test \
 	01_engine-identurl.test \
+	01_engine-proxyurl.test \
+	01_engine-socks5.test \
 	01_engine-identabs.test \
 	01_engine-escape-room.test \
 	01_engine-inplace-escape.test \
@@ -53,6 +57,7 @@ TESTS = \
 	01_engine-pause.test \
 	01_engine-rcfile.test \
 	01_engine-reconcile.test \
+	01_engine-fsize.test \
 	01_engine-redirect.test \
 	01_engine-relative.test \
 	01_engine-robots.test \
@@ -69,6 +74,7 @@ TESTS = \
 	01_engine-version-macros.test \
 	01_engine-xfread.test \
 	01_zlib-acceptencoding.test \
+	01_zlib-contentcodings.test \
 	01_zlib-cache.test \
 	01_zlib-cache-corrupt.test \
 	01_zlib-cache-legacy.test \
@@ -120,6 +126,10 @@ TESTS = \
 	46_local-update-304-resume.test \
 	47_local-crange-overflow.test \
 	48_local-crange-memresume.test \
-	49_local-cookiewall.test
+	49_local-cookiewall.test \
+	50_local-contentcodings.test \
+	51_local-update-codec.test \
+	52_local-socks5.test \
+	53_local-proxytrack-cache-corrupt.test
 
 CLEANFILES = check-network_sh.cache

tests/local-crawl.sh

@@ -17,7 +17,7 @@
 #       --errors N --errors-content N --files N --found PATH ... --directory PATH ... \
 #       --log-found REGEX ... --log-not-found REGEX ... \
 #       --file-matches PATH REGEX ... --file-not-matches PATH REGEX ... \
-#       --file-min-bytes PATH N --max-mirror-bytes N \
+#       --file-min-bytes PATH N --file-mode PATH OCTAL --max-mirror-bytes N \
 #       httrack BASEURL/some/path [httrack-args...]
 # --errors counts every "Error:" log line; --errors-content drops transient
 # network failures (codes -2..-6) that flake on busy loopback under -c8.
@@ -26,6 +26,7 @@
 # --file-matches/--file-not-matches grep (ERE) a mirrored file (PATH under the
 # host root), to assert rewritten link/content survived the crawl.
 # --file-min-bytes asserts a mirrored file (PATH) is at least N bytes.
+# --file-mode asserts its octal permissions (e.g. 644); POSIX hosts only.
 # --rerun-args runs a second pass (same server and mirror dir) with the given
 # extra httrack args appended, e.g. an --update run under a cap.
 # --cookie writes a Netscape cookies.txt (scoped to the discovered host:port,
@@ -37,6 +38,8 @@
 set -u
 
 testdir=$(cd "$(dirname "$0")" && pwd)
+# shellcheck source=tests/testlib.sh
+. "${testdir}/testlib.sh"
 server="${testdir}/local-server.py"
 root="${LOCAL_SERVER_ROOT:-${testdir}/server-root}"
 cert="${testdir}/server.crt"
@@ -71,12 +74,8 @@ function cleanup {
         kill -9 "$crawlpid" 2>/dev/null
         crawlpid=
     fi
-    if test -n "$serverpid"; then
-        kill "$serverpid" 2>/dev/null
-        # Reap it so the port is released before we rm the tmpdir/log.
-        wait "$serverpid" 2>/dev/null
-        serverpid=
-    fi
+    stop_server "$serverpid"
+    serverpid=
     if test -n "$tmpdir" && test -d "$tmpdir"; then
         test -n "$nopurge" || rm -rf "$tmpdir"
     fi
@@ -95,7 +94,7 @@ nopurge=
 trap cleanup EXIT HUP INT QUIT PIPE TERM
 
 # python3 is required; mirror check-network.sh's skip-with-77 convention.
-command -v python3 >/dev/null || ! echo "python3 not found; skipping local crawl tests" || exit 77
+python=$(find_python) || ! echo "python3 not found; skipping local crawl tests" >&2 || exit 77
 
 tmptopdir=${TMPDIR:-/tmp}
 test -d "$tmptopdir" || mkdir -p "$tmptopdir" || die "no temporary directory; set TMPDIR"
@@ -141,7 +140,7 @@ while test "$pos" -lt "$nargs"; do
         audit+=("${args[$pos]}" "${args[$((pos + 1))]}")
         pos=$((pos + 1))
         ;;
-    --file-matches | --file-not-matches | --file-min-bytes)
+    --file-matches | --file-not-matches | --file-min-bytes | --file-mode)
         audit+=("${args[$pos]}" "${args[$((pos + 1))]}" "${args[$((pos + 2))]}")
         pos=$((pos + 2))
         ;;
@@ -157,12 +156,12 @@ done
 # --- start the server --------------------------------------------------------
 test -r "$server" || die "cannot read $server"
 serverlog="${tmpdir}/server.log"
-serverargs=(--root "$root")
+serverargs=(--root "$(nativepath "$root")")
 if test -n "$tls"; then
-    serverargs+=(--tls --cert "$cert" --key "$key")
+    serverargs+=(--tls --cert "$(nativepath "$cert")" --key "$(nativepath "$key")")
 fi
-debug "starting python3 $server ${serverargs[*]}"
-python3 "$server" "${serverargs[@]}" >"$serverlog" 2>&1 &
+debug "starting $python $server ${serverargs[*]}"
+"$python" "$(nativepath "$server")" "${serverargs[@]}" >"$serverlog" 2>&1 &
 serverpid=$!
 
 # Wait for the "PORT <n>" line (server prints it once bound).
@@ -202,7 +201,7 @@ if test "${#cookies[@]}" -gt 0; then
 fi
 
 # --- run httrack -------------------------------------------------------------
-which httrack >/dev/null || die "could not find httrack"
+command -v httrack >/dev/null || die "could not find httrack"
 ver=$(httrack -O /dev/null --version | sed -e 's/HTTrack version //')
 test -n "$ver" || die "could not run httrack"
 
@@ -277,8 +276,7 @@ if test -n "$rerun_dead"; then
     test -s "$zip" || die "no cache was written by the first pass"
     cp "$zip" "${tmpdir}/cache-before.zip"
     cp "${out}/hts-log.txt" "${tmpdir}/log-before.txt"
-    kill "$serverpid" 2>/dev/null
-    wait "$serverpid" 2>/dev/null
+    stop_server "$serverpid"
     serverpid=
     info "re-running httrack against the stopped server"
     httrack -O "$out" --user-agent="httrack $ver local ($(uname -mrs))" \
@@ -319,9 +317,10 @@ done
 test -n "$hostroot" || die "could not find host root under $out"
 debug "host root: $hostroot"
 
-# No crawl, even a cancelled one, may leave .delayed temporaries (#107, #483).
-info "checking for leftover .delayed files"
-leftovers=$(find "$out" -name '*.delayed' 2>/dev/null | head -5)
+# No crawl, even a cancelled one, may leave engine temporaries: .delayed (#107,
+# #483), or the .z/.u content-coding temps (#557).
+info "checking for leftover engine temporaries"
+leftovers=$(find "$out" \( -name '*.delayed' -o -name '*.z' -o -name '*.u' \) 2>/dev/null | head -5)
 if test -z "$leftovers"; then result "OK"; else
     result "leftover: $leftovers"
     exit 1
@@ -436,6 +435,23 @@ while test "$i" -lt "${#audit[@]}"; do
             exit 1
         fi
         ;;
+    --file-mode)
+        path="${audit[$((i + 1))]}"
+        i=$((i + 2))
+        if is_windows; then
+            # No POSIX modes, and the engine only chmods #ifndef _WIN32.
+            info "checking ${path} mode"
+            result "SKIP (no POSIX modes)"
+        else
+            mode=$(stat -c '%a' "${hostroot}/${path}" 2>/dev/null ||
+                stat -f '%Lp' "${hostroot}/${path}" 2>/dev/null)
+            info "checking ${path} mode ${mode:-none} is ${audit[$i]}"
+            if test "$mode" = "${audit[$i]}"; then result "OK"; else
+                result "wrong mode"
+                exit 1
+            fi
+        fi
+        ;;
     esac
     i=$((i + 1))
 done

tests/local-server.py

@@ -14,9 +14,11 @@ stdlib only (http.server + ssl) -- no new build or runtime dependency.
 """
 
 import argparse
+import base64
 import gzip
 import hashlib
 import os
+import sys
 import time
 from http.server import SimpleHTTPRequestHandler, ThreadingHTTPServer
 from urllib.parse import quote, unquote, urlsplit
@@ -633,6 +635,149 @@ class Handler(SimpleHTTPRequestHandler):
             extra_headers=[("Content-Encoding", "gzip")],
         )
 
+    # --- content codings ---------------------------------------------------
+    # Canned br/zstd bodies (no brotli/zstd module in the stdlib): both decode
+    # to CODEC_BODY. Regenerate with the brotli/zstd CLIs over that string.
+    CODEC_BODY = (
+        b"<html><head><title>codec</title></head>"
+        b"<body><p>coded body</p></body></html>"
+    )
+    CODEC_BR = base64.b64decode(
+        "G0sAAAQccqSBBfJlUvOccsDeitqC9CbHwENWiptQj5aExP0mBjjVgy2DF17olLzLo2T2Eg=="
+    )
+    CODEC_ZSTD = base64.b64decode(
+        "KLUv/SBMFQIAFAM8aHRtbD48aGVhZD48dGl0bGU+Y29kZWM8LzwvYm9keT48"
+        "cGQgPC9wPjwvL2h0bWw+BQA7p8QMDNQ1PgcWhjkG"
+    )
+
+    def route_codec_index(self):
+        self.send_html(
+            '\t<a href="br.html">br</a>\n'
+            '\t<a href="zstd.html">zstd</a>\n'
+            '\t<a href="junk.html">junk</a>\n'
+            '\t<a href="bad.html">bad</a>\n'
+            '\t<a href="bin.dat">bin</a>\n'
+            '\t<a href="ae.html">ae</a>\n'
+        )
+
+    def route_codec_br(self):
+        self.send_raw(
+            self.CODEC_BR, "text/html", extra_headers=[("Content-Encoding", "br")]
+        )
+
+    def route_codec_zstd(self):
+        self.send_raw(
+            self.CODEC_ZSTD, "text/html", extra_headers=[("Content-Encoding", "zstd")]
+        )
+
+    # Junk token on a plain body: the page must survive (broken servers do this)
+    def route_codec_junk(self):
+        self.send_raw(
+            b"<html><body><p>junk coding</p></body></html>",
+            "text/html",
+            extra_headers=[("Content-Encoding", "utf-8")],
+        )
+
+    # A real coding we have no decoder for: the fetch must fail rather than
+    # save the coded bytes as the page.
+    def route_codec_bad(self):
+        self.send_raw(
+            b"<html><body><p>never decoded</p></body></html>",
+            "text/html",
+            extra_headers=[("Content-Encoding", "compress")],
+        )
+
+    # Same, on a non-HTML body: this takes the direct-to-disk (is_write) branch,
+    # a different discard path than the in-memory bad.html above.
+    def route_codec_bin(self):
+        self.send_raw(
+            b"\x00\x01\x02 CODED-BINARY-MUST-NOT-LAND \xff\xfe" * 8,
+            "application/octet-stream",
+            extra_headers=[("Content-Encoding", "compress")],
+        )
+
+    # --- coded re-fetch that fails to decode (#557) -------------------------
+    # Pass 1 mirrors each file from a valid gzip body; pass 2 (--update) serves
+    # a body that cannot be decoded. The previously-mirrored copy must survive.
+    # fresh.html is the control: its pass-2 body decodes, so it must be updated.
+    UPCODEC_SEEN = {}
+
+    def upcodec_pass(self):
+        """1 on the first body fetch of this path, 2 on the next ones. HEADs
+        don't count, so a stray one can't shift which pass gets the bad body."""
+        if self.command == "HEAD":
+            return 1
+        seen = Handler.UPCODEC_SEEN.get(self.path, 0) + 1
+        Handler.UPCODEC_SEEN[self.path] = seen
+        return seen
+
+    @staticmethod
+    def gzipped(body):
+        return gzip.compress(body)
+
+    @staticmethod
+    def bad_gzip(body):
+        """A gzip stream whose deflate payload is mangled: inflate fails partway
+        through, after some plausible output has already been produced."""
+        raw = bytearray(gzip.compress(body))
+        raw[20:40] = b"\xff" * 20
+        return bytes(raw[:-4])
+
+    def send_coded(self, body, content_type, coding="gzip"):
+        self.send_raw(body, content_type, extra_headers=[("Content-Encoding", coding)])
+
+    def route_upcodec_index(self):
+        self.send_html(
+            '\t<a href="mem.html">mem</a>\n'
+            '\t<a href="disk.bin">disk</a>\n'
+            '\t<a href="unsup.html">unsup</a>\n'
+            '\t<a href="fresh.html">fresh</a>\n'
+            '\t<a href="freshdisk.bin">freshdisk</a>\n'
+        )
+
+    MEM_V1 = b"<html><body><p>MIRRORED-MEM-V1</p></body></html>"
+    DISK_V1 = b"MIRRORED-DISK-V1\n" + b"\x00\x01\x02\xff" * 8192
+    UNSUP_V1 = b"<html><body><p>MIRRORED-UNSUP-V1</p></body></html>"
+
+    def route_upcodec_mem(self):
+        if self.upcodec_pass() == 1:
+            self.send_coded(self.gzipped(self.MEM_V1), "text/html")
+        else:
+            self.send_coded(self.bad_gzip(self.MEM_V1), "text/html")
+
+    def route_upcodec_disk(self):
+        if self.upcodec_pass() == 1:
+            self.send_coded(self.gzipped(self.DISK_V1), "application/octet-stream")
+        else:
+            self.send_coded(self.bad_gzip(self.DISK_V1), "application/octet-stream")
+
+    # Pass 2 switches to a coding we have no decoder for.
+    def route_upcodec_unsup(self):
+        if self.upcodec_pass() == 1:
+            self.send_coded(self.gzipped(self.UNSUP_V1), "text/html")
+        else:
+            self.send_coded(self.UNSUP_V1, "text/html", coding="compress")
+
+    def route_upcodec_fresh(self):
+        pass1 = self.upcodec_pass() == 1
+        body = b"<html><body><p>FRESH-V%d</p></body></html>" % (1 if pass1 else 2)
+        self.send_coded(self.gzipped(body), "text/html")
+
+    # Same, direct-to-disk: the update pass decodes, so the temp is renamed over
+    # an existing mirror file.
+    def route_upcodec_freshdisk(self):
+        pass1 = self.upcodec_pass() == 1
+        body = b"FRESHDISK-V%d\n" % (1 if pass1 else 2) + b"\x03\x02\x01\xfe" * 8192
+        self.send_coded(self.gzipped(body), "application/octet-stream")
+
+    # Echo what httrack advertised, so a crawl can assert the header.
+    def route_codec_ae(self):
+        self.send_raw(
+            b"<html><body><p>AE=%s</p></body></html>"
+            % self.headers.get("Accept-Encoding", "").encode(),
+            "text/html",
+        )
+
     # --- MIME-type exclusion abort (issue #58) -----------------------------
     # A -mime:application/pdf filter must abort the transfer once the header
     # arrives, not download the whole body and discard it.
@@ -1315,6 +1460,19 @@ class Handler(SimpleHTTPRequestHandler):
         "/gated/index.php": route_gated_index,
         "/gated/secret.php": route_gated_secret,
         "/robots.txt": route_robots,
+        "/codec/index.html": route_codec_index,
+        "/codec/br.html": route_codec_br,
+        "/codec/zstd.html": route_codec_zstd,
+        "/codec/junk.html": route_codec_junk,
+        "/codec/bad.html": route_codec_bad,
+        "/codec/bin.dat": route_codec_bin,
+        "/codec/ae.html": route_codec_ae,
+        "/upcodec/index.html": route_upcodec_index,
+        "/upcodec/mem.html": route_upcodec_mem,
+        "/upcodec/disk.bin": route_upcodec_disk,
+        "/upcodec/unsup.html": route_upcodec_unsup,
+        "/upcodec/fresh.html": route_upcodec_fresh,
+        "/upcodec/freshdisk.bin": route_upcodec_freshdisk,
         "/types/index.html": route_types_index,
         "/types/control.php": route_types,
         "/types/photo.png": route_types,
@@ -1660,7 +1818,8 @@ def main():
         httpd.socket = ctx.wrap_socket(httpd.socket, server_side=True)
 
     port = httpd.socket.getsockname()[1]
-    # The launcher reads this line to discover the ephemeral port.
+    # Keep the port line the launcher parses LF: Windows would emit \r\n.
+    sys.stdout.reconfigure(newline="\n")
     print(f"PORT {port}", flush=True)
 
     try:

tests/proxy-https-server.py

@@ -141,6 +141,8 @@ def main():
         open(os.path.join(logdir, name), "w").close()
     origin_port = start_origin(certfile, logdir)
     proxy_port = start_proxy(logdir, mode)
+    # Keep the port lines the caller parses LF: Windows would emit \r\n.
+    sys.stdout.reconfigure(newline="\n")
     print("ORIGIN %d" % origin_port, flush=True)
     print("PROXY %d" % proxy_port, flush=True)
     print("ready", flush=True)

tests/socks5-server.py

@@ -0,0 +1,230 @@
+#!/usr/bin/env python3
+"""Local SOCKS5 proxy (RFC 1928/1929) + TLS and plain HTTP origins for #563.
+
+Logs the auth method, any user/pass, and the CONNECT ATYP + literal domain, so
+the test proves httrack sent a hostname (remote DNS) and negotiated auth.
+Modes (argv[3]): ok | refuse (REP=5) | truncate (partial reply, must not hang).
+Usage: socks5-server.py <cert.pem> <logdir> [mode]
+Prints "TLS <port>", "HTTP <port>", "SOCKS <port>", "ready" on stdout.
+"""
+import http.server
+import os
+import socket
+import socketserver
+import ssl
+import struct
+import sys
+import threading
+
+# The one name the proxy answers for; a .invalid TLD never resolves (RFC 6761),
+# so a locally-resolving client could not reach us -- success proves remote DNS.
+REMOTE_HOST = b"socks-origin.invalid"
+# index links the subpages so an -r3 crawl reuses one keep-alive socket
+LINKS = "".join('<a href="/p%d.html">%d</a>' % (i, i) for i in range(1, 6))
+ORIGIN_BODY = ("<html><body>ORIGIN-PAGE-563 " + LINKS + "</body></html>").encode()
+SOCKS_LOG = "socks.log"
+ORIGIN_LOG = "origin-headers.log"
+
+
+def make_origin(logdir):
+    class Origin(http.server.BaseHTTPRequestHandler):
+        # HTTP/1.1 + a max>1 advertisement lets httrack keep the socket alive
+        protocol_version = "HTTP/1.1"
+
+        def do_GET(self):
+            with open(os.path.join(logdir, ORIGIN_LOG), "a") as handle:
+                handle.write(
+                    "REQUEST %s %s %s\n"
+                    % (self.command, self.path, self.request_version)
+                )
+                for key in self.headers.keys():
+                    handle.write(key + ": " + self.headers[key] + "\n")
+            if "p" in self.path and ".html" in self.path:
+                body = (
+                    b"<html><body>SUBPAGE-563 " + self.path.encode() + b"</body></html>"
+                )
+            else:
+                body = ORIGIN_BODY
+            self.send_response(200)
+            self.send_header("Content-Type", "text/html")
+            self.send_header("Content-Length", str(len(body)))
+            self.send_header("Keep-Alive", "timeout=15, max=100")
+            self.send_header("Connection", "keep-alive")
+            self.end_headers()
+            self.wfile.write(body)
+
+        def log_message(self, *args):
+            pass
+
+    return Origin
+
+
+class ThreadingTCPServer(socketserver.ThreadingTCPServer):
+    allow_reuse_address = True
+    daemon_threads = True
+
+
+def start_origin(logdir, certfile=None):
+    httpd = ThreadingTCPServer(("127.0.0.1", 0), make_origin(logdir))
+    if certfile is not None:
+        ctx = ssl.SSLContext(ssl.PROTOCOL_TLS_SERVER)
+        ctx.load_cert_chain(certfile)
+        httpd.socket = ctx.wrap_socket(httpd.socket, server_side=True)
+    port = httpd.socket.getsockname()[1]
+    threading.Thread(target=httpd.serve_forever, daemon=True).start()
+    return port
+
+
+def recvn(conn, n):
+    buf = b""
+    while len(buf) < n:
+        chunk = conn.recv(n - len(buf))
+        if not chunk:
+            raise OSError("short read")
+        buf += chunk
+    return buf
+
+
+def pipe(src, dst):
+    try:
+        while True:
+            data = src.recv(65536)
+            if not data:
+                break
+            dst.sendall(data)
+    except OSError:
+        pass
+    finally:
+        for sock in (src, dst):
+            try:
+                sock.shutdown(socket.SHUT_RDWR)
+            except OSError:
+                pass
+
+
+def log(logdir, line):
+    with open(os.path.join(logdir, SOCKS_LOG), "a") as handle:
+        handle.write(line + "\n")
+
+
+def negotiate_auth(conn, logdir):
+    """RFC 1928 greeting + RFC 1929 sub-negotiation. Returns True to proceed."""
+    ver, nmethods = recvn(conn, 2)
+    if ver != 0x05:
+        return False
+    methods = recvn(conn, nmethods)
+    if 0x02 in methods:  # prefer user/pass so the auth test exercises RFC 1929
+        conn.sendall(b"\x05\x02")
+        (subver,) = recvn(conn, 1)
+        (ulen,) = recvn(conn, 1)
+        uname = recvn(conn, ulen)
+        (plen,) = recvn(conn, 1)
+        passwd = recvn(conn, plen)
+        log(logdir, "METHOD userpass")
+        log(logdir, "AUTH %s %s" % (uname.decode(), passwd.decode()))
+        conn.sendall(b"\x01\x00")  # RFC 1929 success
+    elif 0x00 in methods:
+        conn.sendall(b"\x05\x00")
+        log(logdir, "METHOD noauth")
+    else:
+        conn.sendall(b"\x05\xff")  # no acceptable method
+        return False
+    return True
+
+
+def read_request(conn, logdir):
+    """RFC 1928 CONNECT. Logs CMD, ATYP, domain/addr, port. Returns dest port."""
+    ver, cmd, _rsv, atyp = recvn(conn, 4)
+    log(logdir, "CMD %d" % cmd)
+    if atyp == 0x01:
+        addr = socket.inet_ntoa(recvn(conn, 4))
+        log(logdir, "ATYP ipv4 %s" % addr)
+    elif atyp == 0x03:
+        (dlen,) = recvn(conn, 1)
+        domain = recvn(conn, dlen)
+        log(logdir, "ATYP domain %s" % domain.decode())
+    elif atyp == 0x04:
+        recvn(conn, 16)
+        log(logdir, "ATYP ipv6")
+        domain = b""
+    else:
+        return None, None
+    (port,) = struct.unpack(">H", recvn(conn, 2))
+    log(logdir, "PORT %d" % port)
+    name = domain if atyp == 0x03 else b""
+    return name, port
+
+
+def reply(conn, rep):
+    conn.sendall(bytes([0x05, rep, 0x00, 0x01]) + b"\x00\x00\x00\x00" + b"\x00\x00")
+
+
+def handle_socks(conn, logdir, mode):
+    try:
+        if not negotiate_auth(conn, logdir):
+            conn.close()
+            return
+        if mode == "truncate":
+            # one byte of the 10-byte reply, then hold the socket: the client
+            # must bound this handshake read and give up, not hang.
+            conn.sendall(b"\x05")
+            threading.Event().wait()
+            return
+        name, port = read_request(conn, logdir)
+        if mode == "refuse" or name != REMOTE_HOST or port is None:
+            reply(conn, 0x05)  # connection refused
+            conn.close()
+            return
+        try:
+            upstream = socket.create_connection(("127.0.0.1", port))
+        except OSError:
+            reply(conn, 0x05)
+            conn.close()
+            return
+        reply(conn, 0x00)  # succeeded
+        threading.Thread(target=pipe, args=(conn, upstream), daemon=True).start()
+        pipe(upstream, conn)
+    except OSError:
+        try:
+            conn.close()
+        except OSError:
+            pass
+
+
+def start_socks(logdir, mode):
+    srv = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    srv.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+    srv.bind(("127.0.0.1", 0))
+    srv.listen(16)
+    port = srv.getsockname()[1]
+
+    def serve():
+        while True:
+            conn, _ = srv.accept()
+            threading.Thread(
+                target=handle_socks, args=(conn, logdir, mode), daemon=True
+            ).start()
+
+    threading.Thread(target=serve, daemon=True).start()
+    return port
+
+
+def main():
+    certfile, logdir = sys.argv[1], sys.argv[2]
+    mode = sys.argv[3] if len(sys.argv) > 3 else "ok"
+    for name in (SOCKS_LOG, ORIGIN_LOG):
+        open(os.path.join(logdir, name), "w").close()
+    tls_port = start_origin(logdir, certfile)
+    http_port = start_origin(logdir, None)
+    socks_port = start_socks(logdir, mode)
+    # Keep the port lines the caller parses LF: Windows would emit \r\n.
+    sys.stdout.reconfigure(newline="\n")
+    print("TLS %d" % tls_port, flush=True)
+    print("HTTP %d" % http_port, flush=True)
+    print("SOCKS %d" % socks_port, flush=True)
+    print("ready", flush=True)
+    threading.Event().wait()
+
+
+if __name__ == "__main__":
+    main()

tests/testlib.sh

@@ -0,0 +1,45 @@
+#!/bin/bash
+#
+# Helpers shared by the crawl tests. Sourced, not run.
+
+# Python 3 interpreter, or empty: Windows only installs python.exe, and a bare
+# "python" may be 2.x or the Store stub.
+find_python() {
+    local py
+    for py in "${PYTHON:-}" python3 python; do
+        test -n "$py" || continue
+        "$py" -c 'import sys; sys.exit(sys.version_info[0] != 3)' 2>/dev/null || continue
+        printf '%s\n' "$py"
+        return 0
+    done
+    return 1
+}
+
+# Native form of a path: a non-MSYS binary cannot resolve Git Bash's /d/a/... ones.
+nativepath() {
+    if is_windows && command -v cygpath >/dev/null 2>&1; then
+        cygpath -m "$1"
+    else
+        printf '%s\n' "$1"
+    fi
+}
+
+is_windows() {
+    case "$(uname -s)" in
+    MINGW* | MSYS* | CYGWIN*) return 0 ;;
+    *) return 1 ;;
+    esac
+}
+
+# Stop a backgrounded server and reap it; MSYS cannot signal a native python.exe,
+# so only -9 lands. Every step is "|| true": callers run under set -e, and reaping
+# a server we just signalled makes wait return 143.
+stop_server() {
+    test -n "${1:-}" || return 0
+    kill "$1" 2>/dev/null || true
+    if is_windows; then
+        kill -9 "$1" 2>/dev/null || true
+    fi
+    wait "$1" 2>/dev/null || true
+    return 0
+}