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Merge pull request #810 from 5aaee9/Alpha
feat: add quic sniffer
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Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -1,3 +1,290 @@ | ||
package sniffer | ||
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//TODO | ||
import ( | ||
"crypto" | ||
"crypto/aes" | ||
"crypto/cipher" | ||
"crypto/tls" | ||
_ "crypto/tls" | ||
"encoding/binary" | ||
"errors" | ||
"github.com/Dreamacro/clash/common/buf" | ||
"github.com/Dreamacro/clash/common/utils" | ||
C "github.com/Dreamacro/clash/constant" | ||
"github.com/metacubex/quic-go/quicvarint" | ||
"golang.org/x/crypto/hkdf" | ||
"io" | ||
_ "unsafe" | ||
) | ||
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// Modified from https://github.com/v2fly/v2ray-core/blob/master/common/protocol/quic/sniff.go | ||
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const ( | ||
versionDraft29 uint32 = 0xff00001d | ||
version1 uint32 = 0x1 | ||
) | ||
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type cipherSuiteTLS13 struct { | ||
ID uint16 | ||
KeyLen int | ||
AEAD func(key, fixedNonce []byte) cipher.AEAD | ||
Hash crypto.Hash | ||
} | ||
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// github.com/quic-go/quic-go/internal/handshake/cipher_suite.go describes these cipher suite implementations are copied from the standard library crypto/tls package. | ||
// So we can user go:linkname to implement the same feature. | ||
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//go:linkname aeadAESGCMTLS13 crypto/tls.aeadAESGCMTLS13 | ||
func aeadAESGCMTLS13(key, nonceMask []byte) cipher.AEAD | ||
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var ( | ||
quicSaltOld = []byte{0xaf, 0xbf, 0xec, 0x28, 0x99, 0x93, 0xd2, 0x4c, 0x9e, 0x97, 0x86, 0xf1, 0x9c, 0x61, 0x11, 0xe0, 0x43, 0x90, 0xa8, 0x99} | ||
quicSalt = []byte{0x38, 0x76, 0x2c, 0xf7, 0xf5, 0x59, 0x34, 0xb3, 0x4d, 0x17, 0x9a, 0xe6, 0xa4, 0xc8, 0x0c, 0xad, 0xcc, 0xbb, 0x7f, 0x0a} | ||
initialSuite = &cipherSuiteTLS13{ | ||
ID: tls.TLS_AES_128_GCM_SHA256, | ||
KeyLen: 16, | ||
AEAD: aeadAESGCMTLS13, | ||
Hash: crypto.SHA256, | ||
} | ||
errNotQuic = errors.New("not QUIC") | ||
errNotQuicInitial = errors.New("not QUIC initial packet") | ||
) | ||
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type QuicSniffer struct { | ||
*BaseSniffer | ||
} | ||
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func NewQuicSniffer(snifferConfig SnifferConfig) (*QuicSniffer, error) { | ||
ports := snifferConfig.Ports | ||
if len(ports) == 0 { | ||
ports = utils.IntRanges[uint16]{utils.NewRange[uint16](443, 443)} | ||
} | ||
return &QuicSniffer{ | ||
BaseSniffer: NewBaseSniffer(ports, C.UDP), | ||
}, nil | ||
} | ||
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func (quic QuicSniffer) Protocol() string { | ||
return "quic" | ||
} | ||
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func (quic QuicSniffer) SupportNetwork() C.NetWork { | ||
return C.UDP | ||
} | ||
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func (quic QuicSniffer) SniffData(b []byte) (string, error) { | ||
buffer := buf.As(b) | ||
typeByte, err := buffer.ReadByte() | ||
if err != nil { | ||
return "", errNotQuic | ||
} | ||
isLongHeader := typeByte&0x80 > 0 | ||
if !isLongHeader || typeByte&0x40 == 0 { | ||
return "", errNotQuicInitial | ||
} | ||
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vb, err := buffer.ReadBytes(4) | ||
if err != nil { | ||
return "", errNotQuic | ||
} | ||
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versionNumber := binary.BigEndian.Uint32(vb) | ||
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if versionNumber != 0 && typeByte&0x40 == 0 { | ||
return "", errNotQuic | ||
} else if versionNumber != versionDraft29 && versionNumber != version1 { | ||
return "", errNotQuic | ||
} | ||
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if (typeByte&0x30)>>4 != 0x0 { | ||
return "", errNotQuicInitial | ||
} | ||
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var destConnID []byte | ||
if l, err := buffer.ReadByte(); err != nil { | ||
return "", errNotQuic | ||
} else if destConnID, err = buffer.ReadBytes(int(l)); err != nil { | ||
return "", errNotQuic | ||
} | ||
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if l, err := buffer.ReadByte(); err != nil { | ||
return "", errNotQuic | ||
} else if _, err := buffer.ReadBytes(int(l)); err != nil { | ||
return "", errNotQuic | ||
} | ||
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tokenLen, err := quicvarint.Read(buffer) | ||
if err != nil || tokenLen > uint64(len(b)) { | ||
return "", errNotQuic | ||
} | ||
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if _, err = buffer.ReadBytes(int(tokenLen)); err != nil { | ||
return "", errNotQuic | ||
} | ||
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packetLen, err := quicvarint.Read(buffer) | ||
if err != nil { | ||
return "", errNotQuic | ||
} | ||
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hdrLen := len(b) - int(buffer.Len()) | ||
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origPNBytes := make([]byte, 4) | ||
copy(origPNBytes, b[hdrLen:hdrLen+4]) | ||
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var salt []byte | ||
if versionNumber == version1 { | ||
salt = quicSalt | ||
} else { | ||
salt = quicSaltOld | ||
} | ||
initialSecret := hkdf.Extract(crypto.SHA256.New, destConnID, salt) | ||
secret := hkdfExpandLabel(crypto.SHA256, initialSecret, []byte{}, "client in", crypto.SHA256.Size()) | ||
hpKey := hkdfExpandLabel(initialSuite.Hash, secret, []byte{}, "quic hp", initialSuite.KeyLen) | ||
block, err := aes.NewCipher(hpKey) | ||
if err != nil { | ||
return "", err | ||
} | ||
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cache := buf.New() | ||
defer cache.Release() | ||
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mask := cache.Extend(int(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] | ||
} | ||
packetNumberLength := b[0]&0x3 + 1 | ||
var packetNumber uint32 | ||
{ | ||
n, err := buffer.ReadByte() | ||
if err != nil { | ||
return "", err | ||
} | ||
packetNumber = uint32(n) | ||
} | ||
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if packetNumber != 0 && packetNumber != 1 { | ||
return "", errNotQuicInitial | ||
} | ||
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extHdrLen := hdrLen + int(packetNumberLength) | ||
copy(b[extHdrLen:hdrLen+4], origPNBytes[packetNumberLength:]) | ||
data := b[extHdrLen : int(packetLen)+hdrLen] | ||
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key := hkdfExpandLabel(crypto.SHA256, secret, []byte{}, "quic key", 16) | ||
iv := hkdfExpandLabel(crypto.SHA256, secret, []byte{}, "quic iv", 12) | ||
c := aeadAESGCMTLS13(key, iv) | ||
nonce := cache.Extend(int(c.NonceSize())) | ||
binary.BigEndian.PutUint64(nonce[len(nonce)-8:], uint64(packetNumber)) | ||
decrypted, err := c.Open(b[extHdrLen:extHdrLen], nonce, data, b[:extHdrLen]) | ||
if err != nil { | ||
return "", err | ||
} | ||
buffer = buf.As(decrypted) | ||
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cryptoLen := uint(0) | ||
cryptoData := make([]byte, buffer.Len()) | ||
for i := 0; !buffer.IsEmpty(); i++ { | ||
frameType := byte(0x0) // Default to PADDING frame | ||
for frameType == 0x0 && !buffer.IsEmpty() { | ||
frameType, _ = buffer.ReadByte() | ||
} | ||
switch frameType { | ||
case 0x00: // PADDING frame | ||
case 0x01: // PING frame | ||
case 0x02, 0x03: // ACK frame | ||
if _, err = quicvarint.Read(buffer); err != nil { // Field: Largest Acknowledged | ||
return "", io.ErrUnexpectedEOF | ||
} | ||
if _, err = quicvarint.Read(buffer); err != nil { // Field: ACK Delay | ||
return "", io.ErrUnexpectedEOF | ||
} | ||
ackRangeCount, err := quicvarint.Read(buffer) // Field: ACK Range Count | ||
if err != nil { | ||
return "", io.ErrUnexpectedEOF | ||
} | ||
if _, err = quicvarint.Read(buffer); err != nil { // Field: First ACK Range | ||
return "", io.ErrUnexpectedEOF | ||
} | ||
for i := 0; i < int(ackRangeCount); i++ { // Field: ACK Range | ||
if _, err = quicvarint.Read(buffer); err != nil { // Field: ACK Range -> Gap | ||
return "", io.ErrUnexpectedEOF | ||
} | ||
if _, err = quicvarint.Read(buffer); err != nil { // Field: ACK Range -> ACK Range Length | ||
return "", io.ErrUnexpectedEOF | ||
} | ||
} | ||
if frameType == 0x03 { | ||
if _, err = quicvarint.Read(buffer); err != nil { // Field: ECN Counts -> ECT0 Count | ||
return "", io.ErrUnexpectedEOF | ||
} | ||
if _, err = quicvarint.Read(buffer); err != nil { // Field: ECN Counts -> ECT1 Count | ||
return "", io.ErrUnexpectedEOF | ||
} | ||
if _, err = quicvarint.Read(buffer); err != nil { //nolint:misspell // Field: ECN Counts -> ECT-CE Count | ||
return "", io.ErrUnexpectedEOF | ||
} | ||
} | ||
case 0x06: // CRYPTO frame, we will use this frame | ||
offset, err := quicvarint.Read(buffer) // Field: Offset | ||
if err != nil { | ||
return "", io.ErrUnexpectedEOF | ||
} | ||
length, err := quicvarint.Read(buffer) // Field: Length | ||
if err != nil || length > uint64(buffer.Len()) { | ||
return "", io.ErrUnexpectedEOF | ||
} | ||
if cryptoLen < uint(offset+length) { | ||
cryptoLen = uint(offset + length) | ||
} | ||
if _, err := buffer.Read(cryptoData[offset : offset+length]); err != nil { // Field: Crypto Data | ||
return "", io.ErrUnexpectedEOF | ||
} | ||
case 0x1c: // CONNECTION_CLOSE frame, only 0x1c is permitted in initial packet | ||
if _, err = quicvarint.Read(buffer); err != nil { // Field: Error Code | ||
return "", io.ErrUnexpectedEOF | ||
} | ||
if _, err = quicvarint.Read(buffer); err != nil { // Field: Frame Type | ||
return "", io.ErrUnexpectedEOF | ||
} | ||
length, err := quicvarint.Read(buffer) // Field: Reason Phrase Length | ||
if err != nil { | ||
return "", io.ErrUnexpectedEOF | ||
} | ||
if _, err := buffer.ReadBytes(int(length)); err != nil { // Field: Reason Phrase | ||
return "", io.ErrUnexpectedEOF | ||
} | ||
default: | ||
// Only above frame types are permitted in initial packet. | ||
// See https://www.rfc-editor.org/rfc/rfc9000.html#section-17.2.2-8 | ||
return "", errNotQuicInitial | ||
} | ||
} | ||
|
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domain, err := ReadClientHello(cryptoData[:cryptoLen]) | ||
if err != nil { | ||
return "", err | ||
} | ||
|
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return *domain, nil | ||
} | ||
|
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func hkdfExpandLabel(hash crypto.Hash, secret, context []byte, label string, length int) []byte { | ||
b := make([]byte, 3, 3+6+len(label)+1+len(context)) | ||
binary.BigEndian.PutUint16(b, uint16(length)) | ||
b[2] = uint8(6 + len(label)) | ||
b = append(b, []byte("tls13 ")...) | ||
b = append(b, []byte(label)...) | ||
b = b[:3+6+len(label)+1] | ||
b[3+6+len(label)] = uint8(len(context)) | ||
b = append(b, context...) | ||
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out := make([]byte, length) | ||
n, err := hkdf.Expand(hash.New, secret, b).Read(out) | ||
if err != nil || n != length { | ||
panic("quic: HKDF-Expand-Label invocation failed unexpectedly") | ||
} | ||
return out | ||
} |
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