package encoding import ( "crypto/md5" "errors" "hash/fnv" "io" "v2ray.com/core/common/crypto" "v2ray.com/core/common/log" v2net "v2ray.com/core/common/net" "v2ray.com/core/common/protocol" "v2ray.com/core/common/serial" "v2ray.com/core/proxy/vmess" ) type ServerSession struct { userValidator protocol.UserValidator requestBodyKey []byte requestBodyIV []byte responseBodyKey []byte responseBodyIV []byte responseHeader byte responseWriter io.Writer } // NewServerSession creates a new ServerSession, using the given UserValidator. // The ServerSession instance doesn't take ownership of the validator. func NewServerSession(validator protocol.UserValidator) *ServerSession { return &ServerSession{ userValidator: validator, } } // Release implements common.Releaseable. func (v *ServerSession) Release() { v.userValidator = nil v.requestBodyIV = nil v.requestBodyKey = nil v.responseBodyIV = nil v.responseBodyKey = nil v.responseWriter = nil } func (v *ServerSession) DecodeRequestHeader(reader io.Reader) (*protocol.RequestHeader, error) { buffer := make([]byte, 512) _, err := io.ReadFull(reader, buffer[:protocol.IDBytesLen]) if err != nil { log.Info("Raw: Failed to read request header: ", err) return nil, io.EOF } user, timestamp, valid := v.userValidator.Get(buffer[:protocol.IDBytesLen]) if !valid { return nil, protocol.ErrInvalidUser } timestampHash := md5.New() timestampHash.Write(hashTimestamp(timestamp)) iv := timestampHash.Sum(nil) account, err := user.GetTypedAccount() if err != nil { return nil, errors.New("VMess|Server: Failed to get user account: " + err.Error()) } aesStream := crypto.NewAesDecryptionStream(account.(*vmess.InternalAccount).ID.CmdKey(), iv) decryptor := crypto.NewCryptionReader(aesStream, reader) nBytes, err := io.ReadFull(decryptor, buffer[:41]) if err != nil { return nil, errors.New("VMess|Server: Failed to read request header: " + err.Error()) } bufferLen := nBytes request := &protocol.RequestHeader{ User: user, Version: buffer[0], } if request.Version != Version { log.Info("VMess|Server: Invalid protocol version ", request.Version) return nil, protocol.ErrInvalidVersion } v.requestBodyIV = append([]byte(nil), buffer[1:17]...) // 16 bytes v.requestBodyKey = append([]byte(nil), buffer[17:33]...) // 16 bytes v.responseHeader = buffer[33] // 1 byte request.Option = protocol.RequestOption(buffer[34]) // 1 byte + 2 bytes reserved request.Command = protocol.RequestCommand(buffer[37]) request.Port = v2net.PortFromBytes(buffer[38:40]) switch buffer[40] { case AddrTypeIPv4: nBytes, err = io.ReadFull(decryptor, buffer[41:45]) // 4 bytes bufferLen += 4 if err != nil { return nil, errors.New("VMess|Server: Failed to read IPv4: " + err.Error()) } request.Address = v2net.IPAddress(buffer[41:45]) case AddrTypeIPv6: nBytes, err = io.ReadFull(decryptor, buffer[41:57]) // 16 bytes bufferLen += 16 if err != nil { return nil, errors.New("VMess|Server: Failed to read IPv6 address: " + err.Error()) } request.Address = v2net.IPAddress(buffer[41:57]) case AddrTypeDomain: _, err = io.ReadFull(decryptor, buffer[41:42]) if err != nil { return nil, errors.New("VMess:Server: Failed to read domain: " + err.Error()) } domainLength := int(buffer[41]) if domainLength == 0 { return nil, errors.New("VMess|Server: Zero domain length.") } nBytes, err = io.ReadFull(decryptor, buffer[42:42+domainLength]) if err != nil { return nil, errors.New("VMess|Server: Failed to read domain: " + err.Error()) } bufferLen += 1 + domainLength request.Address = v2net.DomainAddress(string(buffer[42 : 42+domainLength])) } nBytes, err = io.ReadFull(decryptor, buffer[bufferLen:bufferLen+4]) if err != nil { return nil, errors.New("VMess|Server: Failed to read checksum: " + err.Error()) } fnv1a := fnv.New32a() fnv1a.Write(buffer[:bufferLen]) actualHash := fnv1a.Sum32() expectedHash := serial.BytesToUint32(buffer[bufferLen : bufferLen+4]) if actualHash != expectedHash { return nil, errors.New("VMess|Server: Invalid auth.") } return request, nil } func (v *ServerSession) DecodeRequestBody(reader io.Reader) io.Reader { aesStream := crypto.NewAesDecryptionStream(v.requestBodyKey, v.requestBodyIV) return crypto.NewCryptionReader(aesStream, reader) } func (v *ServerSession) EncodeResponseHeader(header *protocol.ResponseHeader, writer io.Writer) { responseBodyKey := md5.Sum(v.requestBodyKey) responseBodyIV := md5.Sum(v.requestBodyIV) v.responseBodyKey = responseBodyKey[:] v.responseBodyIV = responseBodyIV[:] aesStream := crypto.NewAesEncryptionStream(v.responseBodyKey, v.responseBodyIV) encryptionWriter := crypto.NewCryptionWriter(aesStream, writer) v.responseWriter = encryptionWriter encryptionWriter.Write([]byte{v.responseHeader, byte(header.Option)}) err := MarshalCommand(header.Command, encryptionWriter) if err != nil { encryptionWriter.Write([]byte{0x00, 0x00}) } } func (v *ServerSession) EncodeResponseBody(writer io.Writer) io.Writer { return v.responseWriter }