mirror of
https://github.com/XTLS/Xray-core.git
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120 lines
2.7 KiB
Go
120 lines
2.7 KiB
Go
package encoding
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import (
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"crypto/md5"
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"encoding/binary"
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"hash/fnv"
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"github.com/xtls/xray-core/common"
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"golang.org/x/crypto/sha3"
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)
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// Authenticate authenticates a byte array using Fnv hash.
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func Authenticate(b []byte) uint32 {
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fnv1hash := fnv.New32a()
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common.Must2(fnv1hash.Write(b))
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return fnv1hash.Sum32()
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}
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type NoOpAuthenticator struct{}
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func (NoOpAuthenticator) NonceSize() int {
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return 0
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}
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func (NoOpAuthenticator) Overhead() int {
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return 0
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}
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// Seal implements AEAD.Seal().
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func (NoOpAuthenticator) Seal(dst, nonce, plaintext, additionalData []byte) []byte {
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return append(dst[:0], plaintext...)
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}
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// Open implements AEAD.Open().
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func (NoOpAuthenticator) Open(dst, nonce, ciphertext, additionalData []byte) ([]byte, error) {
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return append(dst[:0], ciphertext...), nil
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}
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// FnvAuthenticator is an AEAD based on Fnv hash.
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type FnvAuthenticator struct {
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}
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// NonceSize implements AEAD.NonceSize().
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func (*FnvAuthenticator) NonceSize() int {
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return 0
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}
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// Overhead impelements AEAD.Overhead().
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func (*FnvAuthenticator) Overhead() int {
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return 4
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}
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// Seal implements AEAD.Seal().
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func (*FnvAuthenticator) Seal(dst, nonce, plaintext, additionalData []byte) []byte {
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dst = append(dst, 0, 0, 0, 0)
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binary.BigEndian.PutUint32(dst, Authenticate(plaintext))
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return append(dst, plaintext...)
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}
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// Open implements AEAD.Open().
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func (*FnvAuthenticator) Open(dst, nonce, ciphertext, additionalData []byte) ([]byte, error) {
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if binary.BigEndian.Uint32(ciphertext[:4]) != Authenticate(ciphertext[4:]) {
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return dst, newError("invalid authentication")
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}
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return append(dst, ciphertext[4:]...), nil
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}
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// GenerateChacha20Poly1305Key generates a 32-byte key from a given 16-byte array.
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func GenerateChacha20Poly1305Key(b []byte) []byte {
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key := make([]byte, 32)
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t := md5.Sum(b)
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copy(key, t[:])
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t = md5.Sum(key[:16])
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copy(key[16:], t[:])
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return key
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}
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type ShakeSizeParser struct {
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shake sha3.ShakeHash
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buffer [2]byte
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}
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func NewShakeSizeParser(nonce []byte) *ShakeSizeParser {
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shake := sha3.NewShake128()
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common.Must2(shake.Write(nonce))
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return &ShakeSizeParser{
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shake: shake,
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}
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}
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func (*ShakeSizeParser) SizeBytes() int32 {
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return 2
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}
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func (s *ShakeSizeParser) next() uint16 {
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common.Must2(s.shake.Read(s.buffer[:]))
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return binary.BigEndian.Uint16(s.buffer[:])
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}
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func (s *ShakeSizeParser) Decode(b []byte) (uint16, error) {
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mask := s.next()
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size := binary.BigEndian.Uint16(b)
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return mask ^ size, nil
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}
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func (s *ShakeSizeParser) Encode(size uint16, b []byte) []byte {
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mask := s.next()
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binary.BigEndian.PutUint16(b, mask^size)
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return b[:2]
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}
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func (s *ShakeSizeParser) NextPaddingLen() uint16 {
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return s.next() % 64
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}
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func (s *ShakeSizeParser) MaxPaddingLen() uint16 {
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return 64
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}
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