Chore: split component to transport

transport/ssr/protocol/auth_sha1_v4.go

@@ -0,0 +1,182 @@
+package protocol
+
+import (
+	"bytes"
+	"encoding/binary"
+	"hash/adler32"
+	"hash/crc32"
+	"math/rand"
+	"net"
+
+	"github.com/Dreamacro/clash/common/pool"
+	"github.com/Dreamacro/clash/transport/ssr/tools"
+)
+
+func init() {
+	register("auth_sha1_v4", newAuthSHA1V4, 7)
+}
+
+type authSHA1V4 struct {
+	*Base
+	*authData
+	iv            []byte
+	hasSentHeader bool
+	rawTrans      bool
+}
+
+func newAuthSHA1V4(b *Base) Protocol {
+	return &authSHA1V4{Base: b, authData: &authData{}}
+}
+
+func (a *authSHA1V4) StreamConn(c net.Conn, iv []byte) net.Conn {
+	p := &authSHA1V4{Base: a.Base, authData: a.next()}
+	p.iv = iv
+	return &Conn{Conn: c, Protocol: p}
+}
+
+func (a *authSHA1V4) PacketConn(c net.PacketConn) net.PacketConn {
+	return c
+}
+
+func (a *authSHA1V4) Decode(dst, src *bytes.Buffer) error {
+	if a.rawTrans {
+		dst.ReadFrom(src)
+		return nil
+	}
+	for src.Len() > 4 {
+		if uint16(crc32.ChecksumIEEE(src.Bytes()[:2])&0xffff) != binary.LittleEndian.Uint16(src.Bytes()[2:4]) {
+			src.Reset()
+			return errAuthSHA1V4CRC32Error
+		}
+
+		length := int(binary.BigEndian.Uint16(src.Bytes()[:2]))
+		if length >= 8192 || length < 7 {
+			a.rawTrans = true
+			src.Reset()
+			return errAuthSHA1V4LengthError
+		}
+		if length > src.Len() {
+			break
+		}
+
+		if adler32.Checksum(src.Bytes()[:length-4]) != binary.LittleEndian.Uint32(src.Bytes()[length-4:length]) {
+			a.rawTrans = true
+			src.Reset()
+			return errAuthSHA1V4Adler32Error
+		}
+
+		pos := int(src.Bytes()[4])
+		if pos < 255 {
+			pos += 4
+		} else {
+			pos = int(binary.BigEndian.Uint16(src.Bytes()[5:7])) + 4
+		}
+		dst.Write(src.Bytes()[pos : length-4])
+		src.Next(length)
+	}
+	return nil
+}
+
+func (a *authSHA1V4) Encode(buf *bytes.Buffer, b []byte) error {
+	if !a.hasSentHeader {
+		dataLength := getDataLength(b)
+
+		a.packAuthData(buf, b[:dataLength])
+		b = b[dataLength:]
+
+		a.hasSentHeader = true
+	}
+	for len(b) > 8100 {
+		a.packData(buf, b[:8100])
+		b = b[8100:]
+	}
+	if len(b) > 0 {
+		a.packData(buf, b)
+	}
+
+	return nil
+}
+
+func (a *authSHA1V4) DecodePacket(b []byte) ([]byte, error) { return b, nil }
+
+func (a *authSHA1V4) EncodePacket(buf *bytes.Buffer, b []byte) error {
+	buf.Write(b)
+	return nil
+}
+
+func (a *authSHA1V4) packData(poolBuf *bytes.Buffer, data []byte) {
+	dataLength := len(data)
+	randDataLength := a.getRandDataLength(dataLength)
+	/*
+		2:	uint16 BigEndian packedDataLength
+		2:	uint16 LittleEndian crc32Data & 0xffff
+		3:	maxRandDataLengthPrefix (min:1)
+		4:	adler32Data
+	*/
+	packedDataLength := 2 + 2 + 3 + randDataLength + dataLength + 4
+	if randDataLength < 128 {
+		packedDataLength -= 2
+	}
+
+	binary.Write(poolBuf, binary.BigEndian, uint16(packedDataLength))
+	binary.Write(poolBuf, binary.LittleEndian, uint16(crc32.ChecksumIEEE(poolBuf.Bytes()[poolBuf.Len()-2:])&0xffff))
+	a.packRandData(poolBuf, randDataLength)
+	poolBuf.Write(data)
+	binary.Write(poolBuf, binary.LittleEndian, adler32.Checksum(poolBuf.Bytes()[poolBuf.Len()-packedDataLength+4:]))
+}
+
+func (a *authSHA1V4) packAuthData(poolBuf *bytes.Buffer, data []byte) {
+	dataLength := len(data)
+	randDataLength := a.getRandDataLength(12 + dataLength)
+	/*
+		2:	uint16 BigEndian packedAuthDataLength
+		4:	uint32 LittleEndian crc32Data
+		3:	maxRandDataLengthPrefix (min: 1)
+		12:	authDataLength
+		10:	hmacSHA1DataLength
+	*/
+	packedAuthDataLength := 2 + 4 + 3 + randDataLength + 12 + dataLength + 10
+	if randDataLength < 128 {
+		packedAuthDataLength -= 2
+	}
+
+	salt := []byte("auth_sha1_v4")
+	crcData := pool.Get(len(salt) + len(a.Key) + 2)
+	defer pool.Put(crcData)
+	binary.BigEndian.PutUint16(crcData, uint16(packedAuthDataLength))
+	copy(crcData[2:], salt)
+	copy(crcData[2+len(salt):], a.Key)
+
+	key := pool.Get(len(a.iv) + len(a.Key))
+	defer pool.Put(key)
+	copy(key, a.iv)
+	copy(key[len(a.iv):], a.Key)
+
+	poolBuf.Write(crcData[:2])
+	binary.Write(poolBuf, binary.LittleEndian, crc32.ChecksumIEEE(crcData))
+	a.packRandData(poolBuf, randDataLength)
+	a.putAuthData(poolBuf)
+	poolBuf.Write(data)
+	poolBuf.Write(tools.HmacSHA1(key, poolBuf.Bytes()[poolBuf.Len()-packedAuthDataLength+10:])[:10])
+}
+
+func (a *authSHA1V4) packRandData(poolBuf *bytes.Buffer, size int) {
+	if size < 128 {
+		poolBuf.WriteByte(byte(size + 1))
+		tools.AppendRandBytes(poolBuf, size)
+		return
+	}
+	poolBuf.WriteByte(255)
+	binary.Write(poolBuf, binary.BigEndian, uint16(size+3))
+	tools.AppendRandBytes(poolBuf, size)
+}
+
+func (a *authSHA1V4) getRandDataLength(size int) int {
+	if size > 1200 {
+		return 0
+	}
+	if size > 400 {
+		return rand.Intn(256)
+	}
+	return rand.Intn(512)
+}