refactor

proxy/balancer.py

@@ -29,7 +29,8 @@ class _Balancer:
 
     def get_domains_for_dc(self, dc_id: int) -> Iterator[str]:
         current_domain = self._dc_to_domain.get(dc_id)
-        yield current_domain
+        if current_domain is not None:
+            yield current_domain
 
         shuffled_domains = self.domains[:]
         random.shuffle(shuffled_domains)

proxy/bridge.py

@@ -127,7 +127,7 @@ class MsgSplitter:
 
 
 async def do_fallback(reader, writer, relay_init, label,
-                       dc, is_media, media_tag,
+                       dc: int, is_media: bool, media_tag: str,
                        ctx: CryptoCtx, splitter=None):
     fallback_dst = DC_DEFAULT_IPS.get(dc)
     use_cf = proxy_config.fallback_cfproxy
@@ -141,9 +141,9 @@ async def do_fallback(reader, writer, relay_init, label,
     for method in methods:
         if method == 'cf':
             ok = await _cfproxy_fallback(
-                reader, writer, relay_init, label,
+                reader, writer, relay_init, label, ctx,
                 dc=dc, is_media=is_media,
-                ctx=ctx, splitter=splitter)
+                splitter=splitter)
             if ok:
                 return True
         elif method == 'tcp' and fallback_dst:
@@ -151,15 +151,16 @@ async def do_fallback(reader, writer, relay_init, label,
                      label, dc, media_tag, fallback_dst)
             ok = await _tcp_fallback(
                 reader, writer, fallback_dst, 443,
-                relay_init, label, dc=dc, is_media=is_media, ctx=ctx)
+                relay_init, label, ctx)
             if ok:
                 return True
     return False
 
 
 async def _cfproxy_fallback(reader, writer, relay_init, label,
-                            dc=None, is_media=False,
-                            ctx: CryptoCtx = None, splitter=None):
+                            ctx: CryptoCtx,
+                            dc: int, is_media: bool,
+                            splitter=None):
     media_tag = ' media' if is_media else ''
     ws = None
     chosen_domain = None
@@ -185,14 +186,13 @@ async def _cfproxy_fallback(reader, writer, relay_init, label,
 
     stats.connections_cfproxy += 1
     await ws.send(relay_init)
-    await bridge_ws_reencrypt(reader, writer, ws, label,
+    await bridge_ws_reencrypt(reader, writer, ws, label, ctx,
                                dc=dc, is_media=is_media,
-                               ctx=ctx, splitter=splitter)
+                               splitter=splitter)
     return True
 
 
-async def _tcp_fallback(reader, writer, dst, port, relay_init, label,
-                        dc=None, is_media=False, ctx: CryptoCtx = None):
+async def _tcp_fallback(reader, writer, dst, port, relay_init, label, ctx: CryptoCtx):
     try:
         rr, rw = await asyncio.wait_for(
             asyncio.open_connection(dst, port), timeout=10)
@@ -204,15 +204,14 @@ async def _tcp_fallback(reader, writer, dst, port, relay_init, label,
     stats.connections_tcp_fallback += 1
     rw.write(relay_init)
     await rw.drain()
-    await _bridge_tcp_reencrypt(reader, writer, rr, rw, label,
-                                dc=dc, is_media=is_media, ctx=ctx)
+    await _bridge_tcp_reencrypt(reader, writer, rr, rw, label, ctx)
     return True
 
 
 async def bridge_ws_reencrypt(reader, writer, ws: RawWebSocket, label,
+                               ctx: CryptoCtx,
                                dc=None, is_media=False,
-                               ctx: CryptoCtx = None,
-                               splitter: MsgSplitter = None):
+                               splitter: Optional[MsgSplitter] = None):
     """
     Bidirectional TCP(client) <-> WS(telegram) with re-encryption.
     client ciphertext → decrypt(clt_key) → encrypt(tg_key) → WS
@@ -309,8 +308,7 @@ async def bridge_ws_reencrypt(reader, writer, ws: RawWebSocket, label,
 
 
 async def _bridge_tcp_reencrypt(reader, writer, remote_reader, remote_writer,
-                                label, dc=None, is_media=False,
-                                ctx: CryptoCtx = None):
+                                label, ctx: CryptoCtx):
     """Bidirectional TCP <-> TCP with re-encryption."""
 
     async def forward(src, dst_w, is_up):

proxy/raw_websocket.py

@@ -25,7 +25,7 @@ _ssl_ctx.verify_mode = ssl.CERT_NONE
 
 class WsHandshakeError(Exception):
     def __init__(self, status_code: int, status_line: str,
-                 headers: dict = None, location: str = None):
+                 headers: Optional[dict] = None, location: Optional[str] = None):
         self.status_code = status_code
         self.status_line = status_line
         self.headers = headers or {}

proxy/tg_ws_proxy.py

@@ -36,7 +36,7 @@ log = logging.getLogger('tg-mtproto-proxy')
 DC_FAIL_COOLDOWN = 30.0
 WS_FAIL_TIMEOUT = 2.0
 ws_blacklist: Set[str] = set()
-dc_fail_until: Dict[Tuple[int, bool], float] = {}
+dc_fail_until: Dict[str, float] = {}
 
 
 def _try_handshake(handshake: bytes, secret: bytes) -> Optional[Tuple[int, bool, bytes, bytes]]:
@@ -191,7 +191,7 @@ class _WsPool:
         except Exception:
             pass
 
-    async def warmup(self, dc_redirects: Dict[int, Optional[str]]):
+    async def warmup(self, dc_redirects: Dict[int, str]):
         for dc, target_ip in dc_redirects.items():
             if target_ip is None:
                 continue
@@ -207,6 +207,146 @@ class _WsPool:
 _ws_pool = _WsPool()
 
 
+async def _read_client_init(reader, writer, secret, label, masking):
+    if proxy_config.proxy_protocol:
+        try:
+            pp_line = await asyncio.wait_for(
+                reader.readline(), timeout=10)
+        except asyncio.IncompleteReadError:
+            log.debug("[%s] disconnected during PROXY header", label)
+            return None
+        pp_text = pp_line.decode('ascii', errors='replace').strip()
+        if pp_text.startswith('PROXY '):
+            parts = pp_text.split()
+            if len(parts) >= 6:
+                label = f"{parts[2]}:{parts[4]}"
+            log.debug("[%s] PROXY protocol: %s", label, pp_text)
+        else:
+            log.debug("[%s] expected PROXY header, got: %r", label,
+                      pp_text[:60])
+
+    try:
+        first_byte = await asyncio.wait_for(
+            reader.readexactly(1), timeout=10)
+    except asyncio.IncompleteReadError:
+        log.debug("[%s] client disconnected before handshake", label)
+        return None
+
+    if first_byte[0] == TLS_RECORD_HANDSHAKE and masking:
+        try:
+            hdr_rest = await asyncio.wait_for(
+                reader.readexactly(4), timeout=10)
+        except asyncio.IncompleteReadError:
+            log.debug("[%s] incomplete TLS record header", label)
+            return None
+
+        tls_header = first_byte + hdr_rest
+        record_len = struct.unpack('>H', tls_header[3:5])[0]
+
+        try:
+            record_body = await asyncio.wait_for(
+                reader.readexactly(record_len), timeout=10)
+        except asyncio.IncompleteReadError:
+            log.debug("[%s] incomplete TLS record body", label)
+            return None
+
+        client_hello = tls_header + record_body
+
+        tls_result = verify_client_hello(client_hello, secret)
+
+        if tls_result is None:
+            log.debug("[%s] Fake TLS verify failed (size=%d rec=%d) "
+                      "-> masking",
+                      label, len(client_hello), record_len)
+            await proxy_to_masking_domain(
+                reader, writer, client_hello, masking, label)
+            return None
+
+        client_random, session_id, ts = tls_result
+        log.debug("[%s] Fake TLS handshake ok (ts=%d)", label, ts)
+
+        server_hello = build_server_hello(secret, client_random, session_id)
+        writer.write(server_hello)
+        await writer.drain()
+
+        tls_stream = FakeTlsStream(reader, writer)
+
+        try:
+            handshake = await asyncio.wait_for(
+                tls_stream.readexactly(HANDSHAKE_LEN), timeout=10)
+        except asyncio.IncompleteReadError:
+            log.debug("[%s] incomplete obfs2 init inside TLS", label)
+            return None
+
+        return handshake, tls_stream, tls_stream, label
+
+    elif masking:
+        log.debug("[%s] non-TLS byte 0x%02X -> HTTP redirect", label,
+                  first_byte[0])
+        redirect = (
+            f"HTTP/1.1 301 Moved Permanently\r\n"
+            f"Location: https://{masking}/\r\n"
+            f"Content-Length: 0\r\n"
+            f"Connection: close\r\n\r\n"
+        ).encode()
+        writer.write(redirect)
+        await writer.drain()
+        return None
+
+    else:
+        try:
+            rest = await asyncio.wait_for(
+                reader.readexactly(HANDSHAKE_LEN - 1), timeout=10)
+        except asyncio.IncompleteReadError:
+            log.debug("[%s] client disconnected before handshake", label)
+            return None
+        return first_byte + rest, reader, writer, label
+
+
+def _build_crypto_ctx(client_dec_prekey_iv, secret, relay_init):
+    # key = SHA256(prekey + secret), iv from handshake
+    # "dec" = decrypt data from client; "enc" = encrypt data to client
+    clt_dec_prekey = client_dec_prekey_iv[:PREKEY_LEN]
+    clt_dec_iv = client_dec_prekey_iv[PREKEY_LEN:]
+    clt_dec_key = hashlib.sha256(clt_dec_prekey + secret).digest()
+
+    clt_enc_prekey_iv = client_dec_prekey_iv[::-1]
+    clt_enc_key = hashlib.sha256(
+        clt_enc_prekey_iv[:PREKEY_LEN] + secret).digest()
+    clt_enc_iv = clt_enc_prekey_iv[PREKEY_LEN:]
+
+    clt_decryptor = Cipher(
+        algorithms.AES(clt_dec_key), modes.CTR(clt_dec_iv)
+    ).encryptor()
+    clt_encryptor = Cipher(
+        algorithms.AES(clt_enc_key), modes.CTR(clt_enc_iv)
+    ).encryptor()
+
+    # fast-forward client decryptor past the 64-byte init
+    clt_decryptor.update(ZERO_64)
+
+    # relay side: standard obfuscation (no secret hash, raw key)
+    relay_enc_key = relay_init[SKIP_LEN:SKIP_LEN + PREKEY_LEN]
+    relay_enc_iv = relay_init[SKIP_LEN + PREKEY_LEN:
+                              SKIP_LEN + PREKEY_LEN + IV_LEN]
+
+    relay_dec_prekey_iv = relay_init[SKIP_LEN:
+                                     SKIP_LEN + PREKEY_LEN + IV_LEN][::-1]
+    relay_dec_key = relay_dec_prekey_iv[:KEY_LEN]
+    relay_dec_iv = relay_dec_prekey_iv[KEY_LEN:]
+
+    tg_encryptor = Cipher(
+        algorithms.AES(relay_enc_key), modes.CTR(relay_enc_iv)
+    ).encryptor()
+    tg_decryptor = Cipher(
+        algorithms.AES(relay_dec_key), modes.CTR(relay_dec_iv)
+    ).encryptor()
+
+    tg_encryptor.update(ZERO_64)
+
+    return CryptoCtx(clt_decryptor, clt_encryptor, tg_encryptor, tg_decryptor)
+
+
 async def _handle_client(reader, writer, secret: bytes):
     stats.connections_total += 1
     stats.connections_active += 1
@@ -215,115 +355,25 @@ async def _handle_client(reader, writer, secret: bytes):
 
     set_sock_opts(writer.transport, proxy_config.buffer_size)
 
-    tls_stream = None
-    masking = proxy_config.fake_tls_domain
-
     try:
-        if proxy_config.proxy_protocol:
-            try:
-                pp_line = await asyncio.wait_for(
-                    reader.readline(), timeout=10)
-            except asyncio.IncompleteReadError:
-                log.debug("[%s] disconnected during PROXY header", label)
-                return
-            pp_text = pp_line.decode('ascii', errors='replace').strip()
-            if pp_text.startswith('PROXY '):
-                parts = pp_text.split()
-                if len(parts) >= 6:
-                    label = f"{parts[2]}:{parts[4]}"
-                log.debug("[%s] PROXY protocol: %s", label, pp_text)
-            else:
-                log.debug("[%s] expected PROXY header, got: %r", label,
-                          pp_text[:60])
-
-        try:
-            first_byte = await asyncio.wait_for(
-                reader.readexactly(1), timeout=10)
-        except asyncio.IncompleteReadError:
-            log.debug("[%s] client disconnected before handshake", label)
+        init = await _read_client_init(
+            reader, writer, secret, label, proxy_config.fake_tls_domain)
+        if init is None:
             return
 
-        if first_byte[0] == TLS_RECORD_HANDSHAKE and masking:
-            try:
-                hdr_rest = await asyncio.wait_for(
-                    reader.readexactly(4), timeout=10)
-            except asyncio.IncompleteReadError:
-                log.debug("[%s] incomplete TLS record header", label)
-                return
-
-            tls_header = first_byte + hdr_rest
-            record_len = struct.unpack('>H', tls_header[3:5])[0]
-
-            try:
-                record_body = await asyncio.wait_for(
-                    reader.readexactly(record_len), timeout=10)
-            except asyncio.IncompleteReadError:
-                log.debug("[%s] incomplete TLS record body", label)
-                return
-
-            client_hello = tls_header + record_body
-
-            tls_result = verify_client_hello(client_hello, secret)
-
-            if tls_result is None:
-                log.debug("[%s] Fake TLS verify failed (size=%d rec=%d) "
-                          "-> masking",
-                          label, len(client_hello), record_len)
-                await proxy_to_masking_domain(
-                    reader, writer, client_hello, masking, label)
-                return
-
-            client_random, session_id, ts = tls_result
-            log.debug("[%s] Fake TLS handshake ok (ts=%d)", label, ts)
-
-            server_hello = build_server_hello(secret, client_random, session_id)
-            writer.write(server_hello)
-            await writer.drain()
-
-            tls_stream = FakeTlsStream(reader, writer)
-
-            try:
-                handshake = await asyncio.wait_for(
-                    tls_stream.readexactly(HANDSHAKE_LEN), timeout=10)
-            except asyncio.IncompleteReadError:
-                log.debug("[%s] incomplete obfs2 init inside TLS", label)
-                return
-        elif masking:
-            log.debug("[%s] non-TLS byte 0x%02X -> HTTP redirect", label,
-                      first_byte[0])
-            redirect = (
-                f"HTTP/1.1 301 Moved Permanently\r\n"
-                f"Location: https://{masking}/\r\n"
-                f"Content-Length: 0\r\n"
-                f"Connection: close\r\n\r\n"
-            ).encode()
-            writer.write(redirect)
-            await writer.drain()
-            return
-        else:
-            try:
-                rest = await asyncio.wait_for(
-                    reader.readexactly(HANDSHAKE_LEN - 1), timeout=10)
-            except asyncio.IncompleteReadError:
-                log.debug("[%s] client disconnected before handshake", label)
-                return
-            handshake = first_byte + rest
+        handshake, clt_reader, clt_writer, label = init
 
         result = _try_handshake(handshake, secret)
         if result is None:
             stats.connections_bad += 1
             log.warning("[%s] bad handshake (wrong secret or proto)", label)
             try:
-                drain_src = tls_stream or reader
-                while await drain_src.read(4096):
+                while await clt_reader.read(4096):
                     pass
             except Exception:
                 pass
             return
 
-        clt_reader = tls_stream or reader
-        clt_writer = tls_stream or writer
-
         dc, is_media, proto_tag, client_dec_prekey_iv = result
 
         if proto_tag == PROTO_TAG_ABRIDGED:
@@ -339,48 +389,7 @@ async def _handle_client(reader, writer, secret: bytes):
                   label, dc, ' media' if is_media else '', proto_int)
 
         relay_init = _generate_relay_init(proto_tag, dc_idx)
-
-        # key = SHA256(prekey + secret), iv from handshake
-        # "dec" = decrypt data from client; "enc" = encrypt data to client
-        clt_dec_prekey = client_dec_prekey_iv[:PREKEY_LEN]
-        clt_dec_iv = client_dec_prekey_iv[PREKEY_LEN:]
-        clt_dec_key = hashlib.sha256(clt_dec_prekey + secret).digest()
-
-        clt_enc_prekey_iv = client_dec_prekey_iv[::-1]
-        clt_enc_key = hashlib.sha256(
-            clt_enc_prekey_iv[:PREKEY_LEN] + secret).digest()
-        clt_enc_iv = clt_enc_prekey_iv[PREKEY_LEN:]
-
-        clt_decryptor = Cipher(
-            algorithms.AES(clt_dec_key), modes.CTR(clt_dec_iv)
-        ).encryptor()
-        clt_encryptor = Cipher(
-            algorithms.AES(clt_enc_key), modes.CTR(clt_enc_iv)
-        ).encryptor()
-
-        # fast-forward client decryptor past the 64-byte init
-        clt_decryptor.update(ZERO_64)
-
-        # relay side: standard obfuscation (no secret hash, raw key)
-        relay_enc_key = relay_init[SKIP_LEN:SKIP_LEN + PREKEY_LEN]
-        relay_enc_iv = relay_init[SKIP_LEN + PREKEY_LEN:
-                                  SKIP_LEN + PREKEY_LEN + IV_LEN]
-
-        relay_dec_prekey_iv = relay_init[SKIP_LEN:
-                                         SKIP_LEN + PREKEY_LEN + IV_LEN][::-1]
-        relay_dec_key = relay_dec_prekey_iv[:KEY_LEN]
-        relay_dec_iv = relay_dec_prekey_iv[KEY_LEN:]
-
-        tg_encryptor = Cipher(
-            algorithms.AES(relay_enc_key), modes.CTR(relay_enc_iv)
-        ).encryptor()
-        tg_decryptor = Cipher(
-            algorithms.AES(relay_dec_key), modes.CTR(relay_dec_iv)
-        ).encryptor()
-        
-        tg_encryptor.update(ZERO_64)
-
-        ctx = CryptoCtx(clt_decryptor, clt_encryptor, tg_encryptor, tg_decryptor)
+        ctx = _build_crypto_ctx(client_dec_prekey_iv, secret, relay_init)
 
         dc_key = f'{dc}{"m" if is_media else ""}'
         media_tag = " media" if is_media else ""
@@ -490,9 +499,9 @@ async def _handle_client(reader, writer, secret: bytes):
 
         await ws.send(relay_init)
 
-        await bridge_ws_reencrypt(clt_reader, clt_writer, ws, label,
+        await bridge_ws_reencrypt(clt_reader, clt_writer, ws, label, ctx,
                                    dc=dc, is_media=is_media,
-                                   ctx=ctx, splitter=splitter)
+                                   splitter=splitter)
 
     except asyncio.TimeoutError:
         log.warning("[%s] timeout during handshake", label)

proxy/utils.py

@@ -31,7 +31,7 @@ def human_bytes(n: int) -> str:
     for unit in ('B', 'KB', 'MB', 'GB'):
         if abs(n) < 1024:
             return f"{n:.1f}{unit}"
-        n /= 1024
+        n /= 1024  # type: ignore
     return f"{n:.1f}TB"