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Correctly implement quic sniffer's frame parsing

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Vigilans 2023-02-18 05:47:59 +08:00 committed by yuhan6665
parent 242f3b0e0b
commit 039e5f2078
1 changed files with 83 additions and 22 deletions
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105
common/protocol/quic/sniff.go
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@ -10,6 +10,7 @@ import (
"github.com/quic-go/quic-go/quicvarint"
"github.com/xtls/xray-core/common"
"github.com/xtls/xray-core/common/buf"
"github.com/xtls/xray-core/common/bytespool"
"github.com/xtls/xray-core/common/errors"
ptls "github.com/xtls/xray-core/common/protocol/tls"
"golang.org/x/crypto/hkdf"
@ -141,7 +142,7 @@ func SniffQUIC(b []byte) (*SniffHeader, error) {
packetNumber = uint32(n)
}
if packetNumber != 0 {
if packetNumber != 0 && packetNumber != 1 {
return nil, errNotQuicInitial
}
@ -159,32 +160,92 @@ func SniffQUIC(b []byte) (*SniffHeader, error) {
return nil, err
}
buffer = buf.FromBytes(decrypted)
frameType, err := buffer.ReadByte()
if err != nil {
return nil, io.ErrUnexpectedEOF
cryptoLen := uint(0)
cryptoData := bytespool.Alloc(buffer.Len())
defer bytespool.Free(cryptoData)
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 nil, io.ErrUnexpectedEOF
}
if _, err = quicvarint.Read(buffer); err != nil { // Field: ACK Delay
return nil, io.ErrUnexpectedEOF
}
ackRangeCount, err := quicvarint.Read(buffer) // Field: ACK Range Count
if err != nil {
return nil, io.ErrUnexpectedEOF
}
if _, err = quicvarint.Read(buffer); err != nil { // Field: First ACK Range
return nil, io.ErrUnexpectedEOF
}
for i := 0; i < int(ackRangeCount); i++ { // Field: ACK Range
if _, err = quicvarint.Read(buffer); err != nil { // Field: ACK Range -> Gap
return nil, io.ErrUnexpectedEOF
}
if _, err = quicvarint.Read(buffer); err != nil { // Field: ACK Range -> ACK Range Length
return nil, io.ErrUnexpectedEOF
}
}
if frameType == 0x03 {
if _, err = quicvarint.Read(buffer); err != nil { // Field: ECN Counts -> ECT0 Count
return nil, io.ErrUnexpectedEOF
}
if _, err = quicvarint.Read(buffer); err != nil { // Field: ECN Counts -> ECT1 Count
return nil, io.ErrUnexpectedEOF
}
if _, err = quicvarint.Read(buffer); err != nil { //nolint:misspell // Field: ECN Counts -> ECT-CE Count
return nil, io.ErrUnexpectedEOF
}
}
case 0x06: // CRYPTO frame, we will use this frame
offset, err := quicvarint.Read(buffer) // Field: Offset
if err != nil {
return nil, io.ErrUnexpectedEOF
}
length, err := quicvarint.Read(buffer) // Field: Length
if err != nil || length > uint64(buffer.Len()) {
return nil, 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 nil, 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 nil, io.ErrUnexpectedEOF
}
if _, err = quicvarint.Read(buffer); err != nil { // Field: Frame Type
return nil, io.ErrUnexpectedEOF
}
length, err := quicvarint.Read(buffer) // Field: Reason Phrase Length
if err != nil {
return nil, io.ErrUnexpectedEOF
}
if _, err := buffer.ReadBytes(int32(length)); err != nil { // Field: Reason Phrase
return nil, 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 nil, errNotQuicInitial
}
}
if frameType != 0x6 {
// not crypto frame
return &SniffHeader{domain: ""}, nil
}
if common.Error2(quicvarint.Read(buffer)) != nil {
return nil, io.ErrUnexpectedEOF
}
dataLen, err := quicvarint.Read(buffer)
if err != nil {
return nil, io.ErrUnexpectedEOF
}
if dataLen > uint64(buffer.Len()) {
return nil, io.ErrUnexpectedEOF
}
frameData, err := buffer.ReadBytes(int32(dataLen))
common.Must(err)
tlsHdr := &ptls.SniffHeader{}
err = ptls.ReadClientHello(frameData, tlsHdr)
err = ptls.ReadClientHello(cryptoData[:cryptoLen], tlsHdr)
if err != nil {
return nil, err
}
return &SniffHeader{domain: tlsHdr.Domain()}, nil
}