mirror of
https://github.com/v2fly/v2ray-core.git
synced 2024-10-31 00:08:08 -04:00
105 lines
2.6 KiB
Go
105 lines
2.6 KiB
Go
package handshake
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import (
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"crypto/cipher"
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"encoding/binary"
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"v2ray.com/core/external/github.com/lucas-clemente/quic-go/internal/protocol"
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)
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type sealer struct {
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aead cipher.AEAD
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hpEncrypter cipher.Block
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// use a single slice to avoid allocations
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nonceBuf []byte
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hpMask []byte
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// short headers protect 5 bits in the first byte, long headers only 4
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is1RTT bool
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}
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var _ Sealer = &sealer{}
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func newSealer(aead cipher.AEAD, hpEncrypter cipher.Block, is1RTT bool) Sealer {
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return &sealer{
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aead: aead,
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nonceBuf: make([]byte, aead.NonceSize()),
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is1RTT: is1RTT,
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hpEncrypter: hpEncrypter,
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hpMask: make([]byte, hpEncrypter.BlockSize()),
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}
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}
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func (s *sealer) Seal(dst, src []byte, pn protocol.PacketNumber, ad []byte) []byte {
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binary.BigEndian.PutUint64(s.nonceBuf[len(s.nonceBuf)-8:], uint64(pn))
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// The AEAD we're using here will be the qtls.aeadAESGCM13.
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// It uses the nonce provided here and XOR it with the IV.
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return s.aead.Seal(dst, s.nonceBuf, src, ad)
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}
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func (s *sealer) EncryptHeader(sample []byte, firstByte *byte, pnBytes []byte) {
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if len(sample) != s.hpEncrypter.BlockSize() {
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panic("invalid sample size")
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}
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s.hpEncrypter.Encrypt(s.hpMask, sample)
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if s.is1RTT {
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*firstByte ^= s.hpMask[0] & 0x1f
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} else {
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*firstByte ^= s.hpMask[0] & 0xf
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}
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for i := range pnBytes {
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pnBytes[i] ^= s.hpMask[i+1]
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}
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}
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func (s *sealer) Overhead() int {
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return s.aead.Overhead()
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}
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type opener struct {
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aead cipher.AEAD
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pnDecrypter cipher.Block
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// use a single slice to avoid allocations
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nonceBuf []byte
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hpMask []byte
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// short headers protect 5 bits in the first byte, long headers only 4
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is1RTT bool
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}
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var _ Opener = &opener{}
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func newOpener(aead cipher.AEAD, pnDecrypter cipher.Block, is1RTT bool) Opener {
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return &opener{
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aead: aead,
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nonceBuf: make([]byte, aead.NonceSize()),
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is1RTT: is1RTT,
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pnDecrypter: pnDecrypter,
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hpMask: make([]byte, pnDecrypter.BlockSize()),
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}
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}
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func (o *opener) Open(dst, src []byte, pn protocol.PacketNumber, ad []byte) ([]byte, error) {
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binary.BigEndian.PutUint64(o.nonceBuf[len(o.nonceBuf)-8:], uint64(pn))
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// The AEAD we're using here will be the qtls.aeadAESGCM13.
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// It uses the nonce provided here and XOR it with the IV.
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return o.aead.Open(dst, o.nonceBuf, src, ad)
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}
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func (o *opener) DecryptHeader(sample []byte, firstByte *byte, pnBytes []byte) {
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if len(sample) != o.pnDecrypter.BlockSize() {
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panic("invalid sample size")
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}
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o.pnDecrypter.Encrypt(o.hpMask, sample)
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if o.is1RTT {
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*firstByte ^= o.hpMask[0] & 0x1f
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} else {
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*firstByte ^= o.hpMask[0] & 0xf
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}
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for i := range pnBytes {
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pnBytes[i] ^= o.hpMask[i+1]
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}
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}
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