mirror of
https://github.com/amnezia-vpn/amneziawg-go.git
synced 2026-05-17 00:05:50 +03:00
0361c54dca
- fix the bug that transport packet interprets as init/resp/cookie with the same size - cleanup error responses - reduce buffer allocations
64 lines
1.2 KiB
Go
64 lines
1.2 KiB
Go
package device
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import (
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"crypto/rand"
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"errors"
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"fmt"
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"math/big"
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"strconv"
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"strings"
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)
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type magicHeader struct {
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start uint32
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end uint32
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}
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func newMagicHeader(spec string) (*magicHeader, error) {
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parts := strings.Split(spec, "-")
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if len(parts) < 1 || len(parts) > 2 {
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return nil, errors.New("bad format")
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}
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start, err := strconv.ParseUint(parts[0], 10, 32)
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if err != nil {
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return nil, fmt.Errorf("failed to parse %s: %w", parts[0], err)
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}
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var end uint64
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if len(parts) > 1 {
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end, err = strconv.ParseUint(parts[1], 10, 32)
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if err != nil {
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return nil, fmt.Errorf("failed to parse %s: %w", parts[1], err)
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}
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} else {
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end = start
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}
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if end < start {
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return nil, errors.New("wrong range specified")
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}
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return &magicHeader{
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start: uint32(start),
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end: uint32(end),
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}, nil
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}
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func (h *magicHeader) GenSpec() string {
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if h.start == h.end {
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return fmt.Sprintf("%d", h.start)
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}
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return fmt.Sprintf("%d-%d", h.start, h.end)
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}
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func (h *magicHeader) Validate(val uint32) bool {
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return h.start <= val && val <= h.end
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}
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func (h *magicHeader) Generate() uint32 {
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high := int64(h.end - h.start + 1)
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r, _ := rand.Int(rand.Reader, big.NewInt(high))
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return h.start + uint32(r.Int64())
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}
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