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chore: decrease memory copy in quic sniffer

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This commit is contained in:
wwqgtxx
2023-10-19 23:51:37 +08:00
parent 8e637a2ec7
commit ea7e15b447
5 changed files with 41 additions and 35 deletions
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64
component/sniffer/quic_sniffer.go
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@ -107,10 +107,7 @@ func (quic QuicSniffer) SniffData(b []byte) (string, error) {
return "", errNotQuic
}
hdrLen := len(b) - int(buffer.Len())
origPNBytes := make([]byte, 4)
copy(origPNBytes, b[hdrLen:hdrLen+4])
hdrLen := len(b) - buffer.Len()
var salt []byte
if versionNumber == version1 {
@ -126,31 +123,40 @@ func (quic QuicSniffer) SniffData(b []byte) (string, error) {
return "", err
}
cache := buf.New()
cache := buf.NewPacket()
defer cache.Release()
mask := cache.Extend(int(block.BlockSize()))
mask := cache.Extend(block.BlockSize())
block.Encrypt(mask, b[hdrLen+4:hdrLen+4+16])
b[0] ^= mask[0] & 0xf
for i := range b[hdrLen : hdrLen+4] {
b[hdrLen+i] ^= mask[i+1]
firstByte := b[0]
// Encrypt/decrypt first byte.
if isLongHeader {
// Long header: 4 bits masked
// High 4 bits are not protected.
firstByte ^= mask[0] & 0x0f
} else {
// Short header: 5 bits masked
// High 3 bits are not protected.
firstByte ^= mask[0] & 0x1f
}
packetNumberLength := b[0]&0x3 + 1
var packetNumber uint32
{
n, err := buffer.ReadByte()
if err != nil {
return "", err
}
packetNumber = uint32(n)
packetNumberLength := int(firstByte&0x3 + 1) // max = 4 (64-bit sequence number)
extHdrLen := hdrLen + packetNumberLength
// copy to avoid modify origin data
extHdr := cache.Extend(extHdrLen)
copy(extHdr, b)
extHdr[0] = firstByte
packetNumber := extHdr[hdrLen:extHdrLen]
// Encrypt/decrypt packet number.
for i := range packetNumber {
packetNumber[i] ^= mask[1+i]
}
if packetNumber != 0 && packetNumber != 1 {
if packetNumber[0] != 0 && packetNumber[0] != 1 {
return "", errNotQuicInitial
}
extHdrLen := hdrLen + int(packetNumberLength)
copy(b[extHdrLen:hdrLen+4], origPNBytes[packetNumberLength:])
data := b[extHdrLen : int(packetLen)+hdrLen]
key := hkdfExpandLabel(crypto.SHA256, secret, []byte{}, "quic key", 16)
@ -163,24 +169,20 @@ func (quic QuicSniffer) SniffData(b []byte) (string, error) {
if err != nil {
return "", err
}
nonce := cache.Extend(8) // 64-bit sequence number
binary.BigEndian.PutUint64(nonce[len(nonce)-8:], uint64(packetNumber))
// copy from crypto/tls.aeadAESGCMTLS13
for i, b := range nonce {
iv[4+i] ^= b
}
decrypted, err := aead.Open(b[extHdrLen:extHdrLen], iv, data, b[:extHdrLen])
// We only decrypt once, so we do not need to XOR it back.
//for i, b := range nonce {
// iv[4+i] ^= b
//}
// https://github.com/quic-go/qtls-go1-20/blob/e132a0e6cb45e20ac0b705454849a11d09ba5a54/cipher_suites.go#L496
for i, b := range packetNumber {
iv[len(iv)-len(packetNumber)+i] ^= b
}
dst := cache.Extend(len(data))
decrypted, err := aead.Open(dst[:0], iv, data, extHdr)
if err != nil {
return "", err
}
buffer = buf.As(decrypted)
cryptoLen := uint(0)
cryptoData := make([]byte, buffer.Len())
cryptoData := cache.Extend(buffer.Len())
for i := 0; !buffer.IsEmpty(); i++ {
frameType := byte(0x0) // Default to PADDING frame
for frameType == 0x0 && !buffer.IsEmpty() {