func ReadVMessUDP(buffer []byte, userset user.UserSet) (*VMessUDP, error) {
userHash := buffer[:user.IDBytesLen]
userId, timeSec, valid := userset.GetUser(userHash)
if !valid {
return nil, errors.NewAuthenticationError(userHash)
}
buffer = buffer[user.IDBytesLen:]
aesCipher, err := aes.NewCipher(userId.CmdKey())
if err != nil {
return nil, err
}
aesStream := cipher.NewCFBDecrypter(aesCipher, user.Int64Hash(timeSec))
aesStream.XORKeyStream(buffer, buffer)
fnvHash := binary.BigEndian.Uint32(buffer[:4])
fnv1a := fnv.New32a()
fnv1a.Write(buffer[4:])
fnvHashActual := fnv1a.Sum32()
if fnvHash != fnvHashActual {
log.Warning("Unexpected fhv hash %d, should be %d", fnvHashActual, fnvHash)
return nil, errors.NewCorruptedPacketError()
}
buffer = buffer[4:]
vmess := &VMessUDP{
user: *userId,
version: buffer[0],
token: binary.BigEndian.Uint16(buffer[1:3]),
}
// buffer[3] is reserved
port := binary.BigEndian.Uint16(buffer[4:6])
addrType := buffer[6]
var address v2net.Address
switch addrType {
case addrTypeIPv4:
address = v2net.IPAddress(buffer[7:11], port)
buffer = buffer[11:]
case addrTypeIPv6:
address = v2net.IPAddress(buffer[7:23], port)
buffer = buffer[23:]
case addrTypeDomain:
domainLength := buffer[7]
domain := string(buffer[8 : 8+domainLength])
address = v2net.DomainAddress(domain, port)
buffer = buffer[8+domainLength:]
default:
log.Warning("Unexpected address type %d", addrType)
return nil, errors.NewCorruptedPacketError()
}
vmess.address = address
vmess.data = buffer
return vmess, nil
}
func (request *VMessRequest) ToBytes(idHash user.CounterHash, randomRangeInt64 user.RandomInt64InRange) ([]byte, error) {
buffer := make([]byte, 0, 300)
counter := randomRangeInt64(time.Now().UTC().Unix(), 30)
hash := idHash.Hash(request.UserId.Bytes, counter)
log.Debug("Writing userhash: %v", hash)
buffer = append(buffer, hash...)
encryptionBegin := len(buffer)
randomLength := mrand.Intn(32) + 1
randomContent := make([]byte, randomLength)
_, err := rand.Read(randomContent)
if err != nil {
return nil, err
}
buffer = append(buffer, byte(randomLength))
buffer = append(buffer, randomContent...)
buffer = append(buffer, request.Version)
buffer = append(buffer, request.RequestIV[:]...)
buffer = append(buffer, request.RequestKey[:]...)
buffer = append(buffer, request.ResponseHeader[:]...)
buffer = append(buffer, request.Command)
buffer = append(buffer, request.Address.PortBytes()...)
switch {
case request.Address.IsIPv4():
buffer = append(buffer, addrTypeIPv4)
buffer = append(buffer, request.Address.IP()...)
case request.Address.IsIPv6():
buffer = append(buffer, addrTypeIPv6)
buffer = append(buffer, request.Address.IP()...)
case request.Address.IsDomain():
buffer = append(buffer, addrTypeDomain)
buffer = append(buffer, byte(len(request.Address.Domain())))
buffer = append(buffer, []byte(request.Address.Domain())...)
}
paddingLength := mrand.Intn(32) + 1
paddingBuffer := make([]byte, paddingLength)
_, err = rand.Read(paddingBuffer)
if err != nil {
return nil, err
}
buffer = append(buffer, byte(paddingLength))
buffer = append(buffer, paddingBuffer...)
encryptionEnd := len(buffer)
aesCipher, err := aes.NewCipher(request.UserId.CmdKey())
if err != nil {
return nil, err
}
aesStream := cipher.NewCFBEncrypter(aesCipher, user.Int64Hash(counter))
aesStream.XORKeyStream(buffer[encryptionBegin:encryptionEnd], buffer[encryptionBegin:encryptionEnd])
return buffer, nil
}
func (vmess *VMessUDP) ToBytes(idHash user.CounterHash, randomRangeInt64 user.RandomInt64InRange, buffer []byte) []byte {
if buffer == nil {
buffer = make([]byte, 0, 2*1024)
}
counter := randomRangeInt64(time.Now().UTC().Unix(), 30)
hash := idHash.Hash(vmess.user.Bytes[:], counter)
buffer = append(buffer, hash...)
encryptBegin := 16
// Placeholder for fnv1a hash
buffer = append(buffer, byte(0), byte(0), byte(0), byte(0))
fnvHash := 16
fnvHashBegin := 20
buffer = append(buffer, vmess.version)
buffer = append(buffer, byte(vmess.token>>8), byte(vmess.token))
buffer = append(buffer, byte(0x00))
buffer = append(buffer, vmess.address.PortBytes()...)
switch {
case vmess.address.IsIPv4():
buffer = append(buffer, addrTypeIPv4)
buffer = append(buffer, vmess.address.IP()...)
case vmess.address.IsIPv6():
buffer = append(buffer, addrTypeIPv6)
buffer = append(buffer, vmess.address.IP()...)
case vmess.address.IsDomain():
buffer = append(buffer, addrTypeDomain)
buffer = append(buffer, byte(len(vmess.address.Domain())))
buffer = append(buffer, []byte(vmess.address.Domain())...)
}
buffer = append(buffer, vmess.data...)
fnv1a := fnv.New32a()
fnv1a.Write(buffer[fnvHashBegin:])
fnvHashValue := fnv1a.Sum32()
buffer[fnvHash] = byte(fnvHashValue >> 24)
buffer[fnvHash+1] = byte(fnvHashValue >> 16)
buffer[fnvHash+2] = byte(fnvHashValue >> 8)
buffer[fnvHash+3] = byte(fnvHashValue)
aesCipher, err := aes.NewCipher(vmess.user.CmdKey())
if err != nil {
log.Error("VMess failed to create AES cipher: %v", err)
return nil
}
aesStream := cipher.NewCFBEncrypter(aesCipher, user.Int64Hash(counter))
aesStream.XORKeyStream(buffer[encryptBegin:], buffer[encryptBegin:])
return buffer
}
// ToBytes returns a VMessRequest in the form of byte array.
func (request *VMessRequest) ToBytes(idHash user.CounterHash, randomRangeInt64 user.RandomInt64InRange, buffer []byte) ([]byte, error) {
if buffer == nil {
buffer = make([]byte, 0, 300)
}
counter := randomRangeInt64(time.Now().UTC().Unix(), 30)
hash := idHash.Hash(request.UserId.Bytes[:], counter)
log.Debug("Writing userhash: %v", hash)
buffer = append(buffer, hash...)
encryptionBegin := len(buffer)
buffer = append(buffer, request.Version)
buffer = append(buffer, request.RequestIV[:]...)
buffer = append(buffer, request.RequestKey[:]...)
buffer = append(buffer, request.ResponseHeader[:]...)
buffer = append(buffer, request.Command)
buffer = append(buffer, request.Address.PortBytes()...)
switch {
case request.Address.IsIPv4():
buffer = append(buffer, addrTypeIPv4)
buffer = append(buffer, request.Address.IP()...)
case request.Address.IsIPv6():
buffer = append(buffer, addrTypeIPv6)
buffer = append(buffer, request.Address.IP()...)
case request.Address.IsDomain():
buffer = append(buffer, addrTypeDomain)
buffer = append(buffer, byte(len(request.Address.Domain())))
buffer = append(buffer, []byte(request.Address.Domain())...)
}
encryptionEnd := len(buffer)
fnv1a := fnv.New32a()
fnv1a.Write(buffer[encryptionBegin:encryptionEnd])
fnvHash := fnv1a.Sum32()
buffer = append(buffer, byte(fnvHash>>24))
buffer = append(buffer, byte(fnvHash>>16))
buffer = append(buffer, byte(fnvHash>>8))
buffer = append(buffer, byte(fnvHash))
encryptionEnd += 4
aesCipher, err := aes.NewCipher(request.UserId.CmdKey())
if err != nil {
return nil, err
}
aesStream := cipher.NewCFBEncrypter(aesCipher, user.Int64Hash(counter))
aesStream.XORKeyStream(buffer[encryptionBegin:encryptionEnd], buffer[encryptionBegin:encryptionEnd])
return buffer, nil
}
// ToBytes returns a VMessRequest in the form of byte array.
func (request *VMessRequest) ToBytes(idHash user.CounterHash, randomRangeInt64 user.RandomInt64InRange, buffer *alloc.Buffer) (*alloc.Buffer, error) {
if buffer == nil {
buffer = alloc.NewSmallBuffer().Clear()
}
counter := randomRangeInt64(time.Now().UTC().Unix(), 30)
hash := idHash.Hash(request.UserId.Bytes[:], counter)
buffer.Append(hash)
encryptionBegin := buffer.Len()
buffer.AppendBytes(request.Version)
buffer.Append(request.RequestIV)
buffer.Append(request.RequestKey)
buffer.Append(request.ResponseHeader)
buffer.AppendBytes(request.Command)
buffer.Append(request.Address.PortBytes())
switch {
case request.Address.IsIPv4():
buffer.AppendBytes(addrTypeIPv4)
buffer.Append(request.Address.IP())
case request.Address.IsIPv6():
buffer.AppendBytes(addrTypeIPv6)
buffer.Append(request.Address.IP())
case request.Address.IsDomain():
buffer.AppendBytes(addrTypeDomain, byte(len(request.Address.Domain())))
buffer.Append([]byte(request.Address.Domain()))
}
encryptionEnd := buffer.Len()
fnv1a := fnv.New32a()
fnv1a.Write(buffer.Value[encryptionBegin:encryptionEnd])
fnvHash := fnv1a.Sum32()
buffer.AppendBytes(byte(fnvHash>>24), byte(fnvHash>>16), byte(fnvHash>>8), byte(fnvHash))
encryptionEnd += 4
aesCipher, err := aes.NewCipher(request.UserId.CmdKey())
if err != nil {
return nil, err
}
aesStream := cipher.NewCFBEncrypter(aesCipher, user.Int64Hash(counter))
aesStream.XORKeyStream(buffer.Value[encryptionBegin:encryptionEnd], buffer.Value[encryptionBegin:encryptionEnd])
return buffer, nil
}
func (r *VMessRequestReader) Read(reader io.Reader) (*VMessRequest, error) {
buffer := make([]byte, 256)
nBytes, err := reader.Read(buffer[:user.IDBytesLen])
if err != nil {
return nil, err
}
log.Debug("Read user hash: %v", buffer[:nBytes])
userId, timeSec, valid := r.vUserSet.GetUser(buffer[:nBytes])
if !valid {
return nil, ErrorInvalidUser
}
aesCipher, err := aes.NewCipher(userId.CmdKey())
if err != nil {
return nil, err
}
aesStream := cipher.NewCFBDecrypter(aesCipher, user.Int64Hash(timeSec))
decryptor := v2io.NewCryptionReader(aesStream, reader)
if err != nil {
return nil, err
}
nBytes, err = decryptor.Read(buffer[0:1])
if err != nil {
return nil, err
}
randomLength := buffer[0]
if randomLength <= 0 || randomLength > 32 {
return nil, fmt.Errorf("Unexpected random length %d", randomLength)
}
_, err = decryptor.Read(buffer[:randomLength])
if err != nil {
return nil, err
}
nBytes, err = decryptor.Read(buffer[0:1])
if err != nil {
return nil, err
}
request := &VMessRequest{
UserId: *userId,
Version: buffer[0],
}
if request.Version != Version {
log.Error("Unknown VMess version %d", request.Version)
return nil, ErrorInvalidVerion
}
// TODO: check number of bytes returned
_, err = decryptor.Read(request.RequestIV[:])
if err != nil {
return nil, err
}
_, err = decryptor.Read(request.RequestKey[:])
if err != nil {
return nil, err
}
_, err = decryptor.Read(request.ResponseHeader[:])
if err != nil {
return nil, err
}
_, err = decryptor.Read(buffer[0:1])
if err != nil {
return nil, err
}
request.Command = buffer[0]
_, err = decryptor.Read(buffer[0:2])
if err != nil {
return nil, err
}
port := binary.BigEndian.Uint16(buffer[0:2])
_, err = decryptor.Read(buffer[0:1])
if err != nil {
return nil, err
}
switch buffer[0] {
case addrTypeIPv4:
_, err = decryptor.Read(buffer[1:5])
if err != nil {
return nil, err
}
request.Address = v2net.IPAddress(buffer[1:5], port)
case addrTypeIPv6:
_, err = decryptor.Read(buffer[1:17])
if err != nil {
return nil, err
}
request.Address = v2net.IPAddress(buffer[1:17], port)
case addrTypeDomain:
_, err = decryptor.Read(buffer[1:2])
if err != nil {
return nil, err
}
domainLength := buffer[1]
_, err = decryptor.Read(buffer[2 : 2+domainLength])
if err != nil {
return nil, err
}
request.Address = v2net.DomainAddress(string(buffer[2:2+domainLength]), port)
}
_, err = decryptor.Read(buffer[0:1])
if err != nil {
return nil, err
}
randomLength = buffer[0]
_, err = decryptor.Read(buffer[:randomLength])
if err != nil {
return nil, err
}
return request, nil
}
// Read reads a VMessRequest from a byte stream.
func (r *VMessRequestReader) Read(reader io.Reader) (*VMessRequest, error) {
buffer := alloc.NewSmallBuffer()
nBytes, err := v2net.ReadAllBytes(reader, buffer.Value[:config.IDBytesLen])
if err != nil {
return nil, err
}
userId, timeSec, valid := r.vUserSet.GetUser(buffer.Value[:nBytes])
if !valid {
return nil, proxy.InvalidAuthentication
}
aesCipher, err := aes.NewCipher(userId.CmdKey())
if err != nil {
return nil, err
}
aesStream := cipher.NewCFBDecrypter(aesCipher, user.Int64Hash(timeSec))
decryptor := v2io.NewCryptionReader(aesStream, reader)
if err != nil {
return nil, err
}
nBytes, err = v2net.ReadAllBytes(decryptor, buffer.Value[:41])
if err != nil {
return nil, err
}
bufferLen := nBytes
request := &VMessRequest{
UserId: *userId,
Version: buffer.Value[0],
}
if request.Version != Version {
log.Warning("Invalid protocol version %d", request.Version)
return nil, proxy.InvalidProtocolVersion
}
request.RequestIV = buffer.Value[1:17] // 16 bytes
request.RequestKey = buffer.Value[17:33] // 16 bytes
request.ResponseHeader = buffer.Value[33:37] // 4 bytes
request.Command = buffer.Value[37]
port := binary.BigEndian.Uint16(buffer.Value[38:40])
switch buffer.Value[40] {
case addrTypeIPv4:
_, err = v2net.ReadAllBytes(decryptor, buffer.Value[41:45]) // 4 bytes
bufferLen += 4
if err != nil {
return nil, err
}
request.Address = v2net.IPAddress(buffer.Value[41:45], port)
case addrTypeIPv6:
_, err = v2net.ReadAllBytes(decryptor, buffer.Value[41:57]) // 16 bytes
bufferLen += 16
if err != nil {
return nil, err
}
request.Address = v2net.IPAddress(buffer.Value[41:57], port)
case addrTypeDomain:
_, err = v2net.ReadAllBytes(decryptor, buffer.Value[41:42])
if err != nil {
return nil, err
}
domainLength := int(buffer.Value[41])
_, err = v2net.ReadAllBytes(decryptor, buffer.Value[42:42+domainLength])
if err != nil {
return nil, err
}
bufferLen += 1 + domainLength
request.Address = v2net.DomainAddress(string(buffer.Value[42:42+domainLength]), port)
}
_, err = v2net.ReadAllBytes(decryptor, buffer.Value[bufferLen:bufferLen+4])
if err != nil {
return nil, err
}
fnv1a := fnv.New32a()
fnv1a.Write(buffer.Value[:bufferLen])
actualHash := fnv1a.Sum32()
expectedHash := binary.BigEndian.Uint32(buffer.Value[bufferLen : bufferLen+4])
if actualHash != expectedHash {
return nil, transport.CorruptedPacket
}
return request, nil
}
// Read reads a VMessRequest from a byte stream.
func (r *VMessRequestReader) Read(reader io.Reader) (*VMessRequest, error) {
buffer := make([]byte, 256)
nBytes, err := reader.Read(buffer[:user.IDBytesLen])
if err != nil {
return nil, err
}
log.Debug("Read user hash: %v", buffer[:nBytes])
userId, timeSec, valid := r.vUserSet.GetUser(buffer[:nBytes])
if !valid {
return nil, errors.NewAuthenticationError(buffer[:nBytes])
}
aesCipher, err := aes.NewCipher(userId.CmdKey())
if err != nil {
return nil, err
}
aesStream := cipher.NewCFBDecrypter(aesCipher, user.Int64Hash(timeSec))
decryptor := v2io.NewCryptionReader(aesStream, reader)
if err != nil {
return nil, err
}
nBytes, err = decryptor.Read(buffer[:41])
if err != nil {
return nil, err
}
bufferLen := nBytes
request := &VMessRequest{
UserId: *userId,
Version: buffer[0],
}
if request.Version != Version {
return nil, errors.NewProtocolVersionError(int(request.Version))
}
copy(request.RequestIV[:], buffer[1:17]) // 16 bytes
copy(request.RequestKey[:], buffer[17:33]) // 16 bytes
copy(request.ResponseHeader[:], buffer[33:37]) // 4 bytes
request.Command = buffer[37]
port := binary.BigEndian.Uint16(buffer[38:40])
switch buffer[40] {
case addrTypeIPv4:
_, err = decryptor.Read(buffer[41:45]) // 4 bytes
bufferLen += 4
if err != nil {
return nil, err
}
request.Address = v2net.IPAddress(buffer[41:45], port)
case addrTypeIPv6:
_, err = decryptor.Read(buffer[41:57]) // 16 bytes
bufferLen += 16
if err != nil {
return nil, err
}
request.Address = v2net.IPAddress(buffer[41:57], port)
case addrTypeDomain:
_, err = decryptor.Read(buffer[41:42])
if err != nil {
return nil, err
}
domainLength := int(buffer[41])
_, err = decryptor.Read(buffer[42 : 42+domainLength])
if err != nil {
return nil, err
}
bufferLen += 1 + domainLength
request.Address = v2net.DomainAddress(string(buffer[42:42+domainLength]), port)
}
_, err = decryptor.Read(buffer[bufferLen : bufferLen+4])
if err != nil {
return nil, err
}
fnv1a := fnv.New32a()
fnv1a.Write(buffer[:bufferLen])
actualHash := fnv1a.Sum32()
expectedHash := binary.BigEndian.Uint32(buffer[bufferLen : bufferLen+4])
if actualHash != expectedHash {
return nil, errors.NewCorruptedPacketError()
}
return request, nil
}
// Read reads a VMessRequest from a byte stream.
func (this *VMessRequestReader) Read(reader io.Reader) (*VMessRequest, error) {
buffer := alloc.NewSmallBuffer()
defer buffer.Release()
nBytes, err := v2net.ReadAllBytes(reader, buffer.Value[:vmess.IDBytesLen])
if err != nil {
log.Debug("VMess: Failed to read request ID (%d bytes): %v", nBytes, err)
return nil, err
}
userObj, timeSec, valid := this.vUserSet.GetUser(buffer.Value[:nBytes])
if !valid {
return nil, proxy.InvalidAuthentication
}
aesStream, err := v2crypto.NewAesDecryptionStream(userObj.ID().CmdKey(), user.Int64Hash(timeSec))
if err != nil {
log.Debug("VMess: Failed to create AES stream: %v", err)
return nil, err
}
decryptor := v2crypto.NewCryptionReader(aesStream, reader)
nBytes, err = v2net.ReadAllBytes(decryptor, buffer.Value[:41])
if err != nil {
log.Debug("VMess: Failed to read request header (%d bytes): %v", nBytes, err)
return nil, err
}
bufferLen := nBytes
request := &VMessRequest{
User: userObj,
Version: buffer.Value[0],
}
if request.Version != Version {
log.Warning("VMess: Invalid protocol version %d", request.Version)
return nil, proxy.InvalidProtocolVersion
}
request.RequestIV = append([]byte(nil), buffer.Value[1:17]...) // 16 bytes
request.RequestKey = append([]byte(nil), buffer.Value[17:33]...) // 16 bytes
request.ResponseHeader = append([]byte(nil), buffer.Value[33:37]...) // 4 bytes
request.Command = buffer.Value[37]
request.Port = v2net.PortFromBytes(buffer.Value[38:40])
switch buffer.Value[40] {
case addrTypeIPv4:
nBytes, err = v2net.ReadAllBytes(decryptor, buffer.Value[41:45]) // 4 bytes
bufferLen += 4
if err != nil {
log.Debug("VMess: Failed to read target IPv4 (%d bytes): %v", nBytes, err)
return nil, err
}
request.Address = v2net.IPAddress(buffer.Value[41:45])
case addrTypeIPv6:
nBytes, err = v2net.ReadAllBytes(decryptor, buffer.Value[41:57]) // 16 bytes
bufferLen += 16
if err != nil {
log.Debug("VMess: Failed to read target IPv6 (%d bytes): %v", nBytes, err)
return nil, err
}
request.Address = v2net.IPAddress(buffer.Value[41:57])
case addrTypeDomain:
nBytes, err = v2net.ReadAllBytes(decryptor, buffer.Value[41:42])
if err != nil {
log.Debug("VMess: Failed to read target domain (%d bytes): %v", nBytes, err)
return nil, err
}
domainLength := int(buffer.Value[41])
if domainLength == 0 {
return nil, transport.CorruptedPacket
}
nBytes, err = v2net.ReadAllBytes(decryptor, buffer.Value[42:42+domainLength])
if err != nil {
log.Debug("VMess: Failed to read target domain (%d bytes): %v", nBytes, err)
return nil, err
}
bufferLen += 1 + domainLength
domainBytes := append([]byte(nil), buffer.Value[42:42+domainLength]...)
request.Address = v2net.DomainAddress(string(domainBytes))
}
nBytes, err = v2net.ReadAllBytes(decryptor, buffer.Value[bufferLen:bufferLen+4])
if err != nil {
log.Debug("VMess: Failed to read checksum (%d bytes): %v", nBytes, err)
return nil, err
}
fnv1a := fnv.New32a()
fnv1a.Write(buffer.Value[:bufferLen])
actualHash := fnv1a.Sum32()
expectedHash := binary.BigEndian.Uint32(buffer.Value[bufferLen : bufferLen+4])
if actualHash != expectedHash {
return nil, transport.CorruptedPacket
}
return request, nil
}