Fix DoS attack vulnerability in VMess Option Processing

This commit is contained in:
Shelikhoo 2022-06-12 23:29:09 +01:00 committed by yuhan6665
parent ba4ce4c24f
commit d4f18b1342
4 changed files with 72 additions and 45 deletions

View File

@ -136,31 +136,35 @@ func (c *ClientSession) EncodeRequestHeader(header *protocol.RequestHeader, writ
return nil
}
func (c *ClientSession) EncodeRequestBody(request *protocol.RequestHeader, writer io.Writer) buf.Writer {
func (c *ClientSession) EncodeRequestBody(request *protocol.RequestHeader, writer io.Writer) (buf.Writer, error) {
var sizeParser crypto.ChunkSizeEncoder = crypto.PlainChunkSizeParser{}
if request.Option.Has(protocol.RequestOptionChunkMasking) {
sizeParser = NewShakeSizeParser(c.requestBodyIV[:])
}
var padding crypto.PaddingLengthGenerator
if request.Option.Has(protocol.RequestOptionGlobalPadding) {
padding = sizeParser.(crypto.PaddingLengthGenerator)
var ok bool
padding, ok = sizeParser.(crypto.PaddingLengthGenerator)
if !ok {
return nil, newError("invalid option: RequestOptionGlobalPadding")
}
}
switch request.Security {
case protocol.SecurityType_NONE:
if request.Option.Has(protocol.RequestOptionChunkStream) {
if request.Command.TransferType() == protocol.TransferTypeStream {
return crypto.NewChunkStreamWriter(sizeParser, writer)
return crypto.NewChunkStreamWriter(sizeParser, writer), nil
}
auth := &crypto.AEADAuthenticator{
AEAD: new(NoOpAuthenticator),
NonceGenerator: crypto.GenerateEmptyBytes(),
AdditionalDataGenerator: crypto.GenerateEmptyBytes(),
}
return crypto.NewAuthenticationWriter(auth, sizeParser, writer, protocol.TransferTypePacket, padding)
return crypto.NewAuthenticationWriter(auth, sizeParser, writer, protocol.TransferTypePacket, padding), nil
}
return buf.NewWriter(writer)
return buf.NewWriter(writer), nil
case protocol.SecurityType_LEGACY:
aesStream := crypto.NewAesEncryptionStream(c.requestBodyKey[:], c.requestBodyIV[:])
cryptionWriter := crypto.NewCryptionWriter(aesStream, writer)
@ -170,10 +174,10 @@ func (c *ClientSession) EncodeRequestBody(request *protocol.RequestHeader, write
NonceGenerator: crypto.GenerateEmptyBytes(),
AdditionalDataGenerator: crypto.GenerateEmptyBytes(),
}
return crypto.NewAuthenticationWriter(auth, sizeParser, cryptionWriter, request.Command.TransferType(), padding)
return crypto.NewAuthenticationWriter(auth, sizeParser, cryptionWriter, request.Command.TransferType(), padding), nil
}
return &buf.SequentialWriter{Writer: cryptionWriter}
return &buf.SequentialWriter{Writer: cryptionWriter}, nil
case protocol.SecurityType_AES128_GCM:
aead := crypto.NewAesGcm(c.requestBodyKey[:])
auth := &crypto.AEADAuthenticator{
@ -192,7 +196,7 @@ func (c *ClientSession) EncodeRequestBody(request *protocol.RequestHeader, write
}
sizeParser = NewAEADSizeParser(lengthAuth)
}
return crypto.NewAuthenticationWriter(auth, sizeParser, writer, request.Command.TransferType(), padding)
return crypto.NewAuthenticationWriter(auth, sizeParser, writer, request.Command.TransferType(), padding), nil
case protocol.SecurityType_CHACHA20_POLY1305:
aead, err := chacha20poly1305.New(GenerateChacha20Poly1305Key(c.requestBodyKey[:]))
common.Must(err)
@ -214,9 +218,9 @@ func (c *ClientSession) EncodeRequestBody(request *protocol.RequestHeader, write
}
sizeParser = NewAEADSizeParser(lengthAuth)
}
return crypto.NewAuthenticationWriter(auth, sizeParser, writer, request.Command.TransferType(), padding)
return crypto.NewAuthenticationWriter(auth, sizeParser, writer, request.Command.TransferType(), padding), nil
default:
panic("Unknown security type.")
return nil, newError("invalid option: Security")
}
}
@ -305,21 +309,25 @@ func (c *ClientSession) DecodeResponseHeader(reader io.Reader) (*protocol.Respon
return header, nil
}
func (c *ClientSession) DecodeResponseBody(request *protocol.RequestHeader, reader io.Reader) buf.Reader {
func (c *ClientSession) DecodeResponseBody(request *protocol.RequestHeader, reader io.Reader) (buf.Reader, error) {
var sizeParser crypto.ChunkSizeDecoder = crypto.PlainChunkSizeParser{}
if request.Option.Has(protocol.RequestOptionChunkMasking) {
sizeParser = NewShakeSizeParser(c.responseBodyIV[:])
}
var padding crypto.PaddingLengthGenerator
if request.Option.Has(protocol.RequestOptionGlobalPadding) {
padding = sizeParser.(crypto.PaddingLengthGenerator)
var ok bool
padding, ok = sizeParser.(crypto.PaddingLengthGenerator)
if !ok {
return nil, newError("invalid option: RequestOptionGlobalPadding")
}
}
switch request.Security {
case protocol.SecurityType_NONE:
if request.Option.Has(protocol.RequestOptionChunkStream) {
if request.Command.TransferType() == protocol.TransferTypeStream {
return crypto.NewChunkStreamReader(sizeParser, reader)
return crypto.NewChunkStreamReader(sizeParser, reader), nil
}
auth := &crypto.AEADAuthenticator{
@ -328,10 +336,10 @@ func (c *ClientSession) DecodeResponseBody(request *protocol.RequestHeader, read
AdditionalDataGenerator: crypto.GenerateEmptyBytes(),
}
return crypto.NewAuthenticationReader(auth, sizeParser, reader, protocol.TransferTypePacket, padding)
return crypto.NewAuthenticationReader(auth, sizeParser, reader, protocol.TransferTypePacket, padding), nil
}
return buf.NewReader(reader)
return buf.NewReader(reader), nil
case protocol.SecurityType_LEGACY:
if request.Option.Has(protocol.RequestOptionChunkStream) {
auth := &crypto.AEADAuthenticator{
@ -339,10 +347,10 @@ func (c *ClientSession) DecodeResponseBody(request *protocol.RequestHeader, read
NonceGenerator: crypto.GenerateEmptyBytes(),
AdditionalDataGenerator: crypto.GenerateEmptyBytes(),
}
return crypto.NewAuthenticationReader(auth, sizeParser, c.responseReader, request.Command.TransferType(), padding)
return crypto.NewAuthenticationReader(auth, sizeParser, c.responseReader, request.Command.TransferType(), padding), nil
}
return buf.NewReader(c.responseReader)
return buf.NewReader(c.responseReader), nil
case protocol.SecurityType_AES128_GCM:
aead := crypto.NewAesGcm(c.responseBodyKey[:])
@ -362,7 +370,7 @@ func (c *ClientSession) DecodeResponseBody(request *protocol.RequestHeader, read
}
sizeParser = NewAEADSizeParser(lengthAuth)
}
return crypto.NewAuthenticationReader(auth, sizeParser, reader, request.Command.TransferType(), padding)
return crypto.NewAuthenticationReader(auth, sizeParser, reader, request.Command.TransferType(), padding), nil
case protocol.SecurityType_CHACHA20_POLY1305:
aead, _ := chacha20poly1305.New(GenerateChacha20Poly1305Key(c.responseBodyKey[:]))
@ -383,9 +391,9 @@ func (c *ClientSession) DecodeResponseBody(request *protocol.RequestHeader, read
}
sizeParser = NewAEADSizeParser(lengthAuth)
}
return crypto.NewAuthenticationReader(auth, sizeParser, reader, request.Command.TransferType(), padding)
return crypto.NewAuthenticationReader(auth, sizeParser, reader, request.Command.TransferType(), padding), nil
default:
panic("Unknown security type.")
return nil, newError("invalid option: Security")
}
}

View File

@ -310,21 +310,25 @@ func (s *ServerSession) DecodeRequestHeader(reader io.Reader, isDrain bool) (*pr
}
// DecodeRequestBody returns Reader from which caller can fetch decrypted body.
func (s *ServerSession) DecodeRequestBody(request *protocol.RequestHeader, reader io.Reader) buf.Reader {
func (s *ServerSession) DecodeRequestBody(request *protocol.RequestHeader, reader io.Reader) (buf.Reader, error) {
var sizeParser crypto.ChunkSizeDecoder = crypto.PlainChunkSizeParser{}
if request.Option.Has(protocol.RequestOptionChunkMasking) {
sizeParser = NewShakeSizeParser(s.requestBodyIV[:])
}
var padding crypto.PaddingLengthGenerator
if request.Option.Has(protocol.RequestOptionGlobalPadding) {
padding = sizeParser.(crypto.PaddingLengthGenerator)
var ok bool
padding, ok = sizeParser.(crypto.PaddingLengthGenerator)
if !ok {
return nil, newError("invalid option: RequestOptionGlobalPadding")
}
}
switch request.Security {
case protocol.SecurityType_NONE:
if request.Option.Has(protocol.RequestOptionChunkStream) {
if request.Command.TransferType() == protocol.TransferTypeStream {
return crypto.NewChunkStreamReader(sizeParser, reader)
return crypto.NewChunkStreamReader(sizeParser, reader), nil
}
auth := &crypto.AEADAuthenticator{
@ -332,9 +336,9 @@ func (s *ServerSession) DecodeRequestBody(request *protocol.RequestHeader, reade
NonceGenerator: crypto.GenerateEmptyBytes(),
AdditionalDataGenerator: crypto.GenerateEmptyBytes(),
}
return crypto.NewAuthenticationReader(auth, sizeParser, reader, protocol.TransferTypePacket, padding)
return crypto.NewAuthenticationReader(auth, sizeParser, reader, protocol.TransferTypePacket, padding), nil
}
return buf.NewReader(reader)
return buf.NewReader(reader), nil
case protocol.SecurityType_LEGACY:
aesStream := crypto.NewAesDecryptionStream(s.requestBodyKey[:], s.requestBodyIV[:])
@ -345,9 +349,9 @@ func (s *ServerSession) DecodeRequestBody(request *protocol.RequestHeader, reade
NonceGenerator: crypto.GenerateEmptyBytes(),
AdditionalDataGenerator: crypto.GenerateEmptyBytes(),
}
return crypto.NewAuthenticationReader(auth, sizeParser, cryptionReader, request.Command.TransferType(), padding)
return crypto.NewAuthenticationReader(auth, sizeParser, cryptionReader, request.Command.TransferType(), padding), nil
}
return buf.NewReader(cryptionReader)
return buf.NewReader(cryptionReader), nil
case protocol.SecurityType_AES128_GCM:
aead := crypto.NewAesGcm(s.requestBodyKey[:])
@ -367,7 +371,7 @@ func (s *ServerSession) DecodeRequestBody(request *protocol.RequestHeader, reade
}
sizeParser = NewAEADSizeParser(lengthAuth)
}
return crypto.NewAuthenticationReader(auth, sizeParser, reader, request.Command.TransferType(), padding)
return crypto.NewAuthenticationReader(auth, sizeParser, reader, request.Command.TransferType(), padding), nil
case protocol.SecurityType_CHACHA20_POLY1305:
aead, _ := chacha20poly1305.New(GenerateChacha20Poly1305Key(s.requestBodyKey[:]))
@ -389,10 +393,10 @@ func (s *ServerSession) DecodeRequestBody(request *protocol.RequestHeader, reade
}
sizeParser = NewAEADSizeParser(lengthAuth)
}
return crypto.NewAuthenticationReader(auth, sizeParser, reader, request.Command.TransferType(), padding)
return crypto.NewAuthenticationReader(auth, sizeParser, reader, request.Command.TransferType(), padding), nil
default:
panic("Unknown security type.")
return nil, newError("invalid option: Security")
}
}
@ -453,21 +457,25 @@ func (s *ServerSession) EncodeResponseHeader(header *protocol.ResponseHeader, wr
}
// EncodeResponseBody returns a Writer that auto-encrypt content written by caller.
func (s *ServerSession) EncodeResponseBody(request *protocol.RequestHeader, writer io.Writer) buf.Writer {
func (s *ServerSession) EncodeResponseBody(request *protocol.RequestHeader, writer io.Writer) (buf.Writer, error) {
var sizeParser crypto.ChunkSizeEncoder = crypto.PlainChunkSizeParser{}
if request.Option.Has(protocol.RequestOptionChunkMasking) {
sizeParser = NewShakeSizeParser(s.responseBodyIV[:])
}
var padding crypto.PaddingLengthGenerator
if request.Option.Has(protocol.RequestOptionGlobalPadding) {
padding = sizeParser.(crypto.PaddingLengthGenerator)
var ok bool
padding, ok = sizeParser.(crypto.PaddingLengthGenerator)
if !ok {
return nil, newError("invalid option: RequestOptionGlobalPadding")
}
}
switch request.Security {
case protocol.SecurityType_NONE:
if request.Option.Has(protocol.RequestOptionChunkStream) {
if request.Command.TransferType() == protocol.TransferTypeStream {
return crypto.NewChunkStreamWriter(sizeParser, writer)
return crypto.NewChunkStreamWriter(sizeParser, writer), nil
}
auth := &crypto.AEADAuthenticator{
@ -475,9 +483,9 @@ func (s *ServerSession) EncodeResponseBody(request *protocol.RequestHeader, writ
NonceGenerator: crypto.GenerateEmptyBytes(),
AdditionalDataGenerator: crypto.GenerateEmptyBytes(),
}
return crypto.NewAuthenticationWriter(auth, sizeParser, writer, protocol.TransferTypePacket, padding)
return crypto.NewAuthenticationWriter(auth, sizeParser, writer, protocol.TransferTypePacket, padding), nil
}
return buf.NewWriter(writer)
return buf.NewWriter(writer), nil
case protocol.SecurityType_LEGACY:
if request.Option.Has(protocol.RequestOptionChunkStream) {
@ -486,9 +494,9 @@ func (s *ServerSession) EncodeResponseBody(request *protocol.RequestHeader, writ
NonceGenerator: crypto.GenerateEmptyBytes(),
AdditionalDataGenerator: crypto.GenerateEmptyBytes(),
}
return crypto.NewAuthenticationWriter(auth, sizeParser, s.responseWriter, request.Command.TransferType(), padding)
return crypto.NewAuthenticationWriter(auth, sizeParser, s.responseWriter, request.Command.TransferType(), padding), nil
}
return &buf.SequentialWriter{Writer: s.responseWriter}
return &buf.SequentialWriter{Writer: s.responseWriter}, nil
case protocol.SecurityType_AES128_GCM:
aead := crypto.NewAesGcm(s.responseBodyKey[:])
@ -508,7 +516,7 @@ func (s *ServerSession) EncodeResponseBody(request *protocol.RequestHeader, writ
}
sizeParser = NewAEADSizeParser(lengthAuth)
}
return crypto.NewAuthenticationWriter(auth, sizeParser, writer, request.Command.TransferType(), padding)
return crypto.NewAuthenticationWriter(auth, sizeParser, writer, request.Command.TransferType(), padding), nil
case protocol.SecurityType_CHACHA20_POLY1305:
aead, _ := chacha20poly1305.New(GenerateChacha20Poly1305Key(s.responseBodyKey[:]))
@ -530,9 +538,9 @@ func (s *ServerSession) EncodeResponseBody(request *protocol.RequestHeader, writ
}
sizeParser = NewAEADSizeParser(lengthAuth)
}
return crypto.NewAuthenticationWriter(auth, sizeParser, writer, request.Command.TransferType(), padding)
return crypto.NewAuthenticationWriter(auth, sizeParser, writer, request.Command.TransferType(), padding), nil
default:
panic("Unknown security type.")
return nil, newError("invalid option: Security")
}
}

View File

@ -184,8 +184,10 @@ func (h *Handler) RemoveUser(ctx context.Context, email string) error {
func transferResponse(timer signal.ActivityUpdater, session *encoding.ServerSession, request *protocol.RequestHeader, response *protocol.ResponseHeader, input buf.Reader, output *buf.BufferedWriter) error {
session.EncodeResponseHeader(response, output)
bodyWriter := session.EncodeResponseBody(request, output)
bodyWriter, err := session.EncodeResponseBody(request, output)
if err != nil {
return newError("failed to start decoding response").Base(err)
}
{
// Optimize for small response packet
data, err := input.ReadMultiBuffer()
@ -301,7 +303,10 @@ func (h *Handler) Process(ctx context.Context, network net.Network, connection s
requestDone := func() error {
defer timer.SetTimeout(sessionPolicy.Timeouts.DownlinkOnly)
bodyReader := svrSession.DecodeRequestBody(request, reader)
bodyReader, err := svrSession.DecodeRequestBody(request, reader)
if err != nil {
return newError("failed to start decoding").Base(err)
}
if err := buf.Copy(bodyReader, link.Writer, buf.UpdateActivity(timer)); err != nil {
return newError("failed to transfer request").Base(err)
}

View File

@ -158,7 +158,10 @@ func (h *Handler) Process(ctx context.Context, link *transport.Link, dialer inte
return newError("failed to encode request").Base(err).AtWarning()
}
bodyWriter := session.EncodeRequestBody(request, writer)
bodyWriter, err := session.EncodeRequestBody(request, writer)
if err != nil {
return newError("failed to start encoding").Base(err)
}
bodyWriter2 := bodyWriter
if request.Command == protocol.RequestCommandMux && request.Port == 666 {
bodyWriter = xudp.NewPacketWriter(bodyWriter, target)
@ -194,7 +197,10 @@ func (h *Handler) Process(ctx context.Context, link *transport.Link, dialer inte
}
h.handleCommand(rec.Destination(), header.Command)
bodyReader := session.DecodeResponseBody(request, reader)
bodyReader, err := session.DecodeResponseBody(request, reader)
if err != nil {
return newError("failed to start encoding response").Base(err)
}
if request.Command == protocol.RequestCommandMux && request.Port == 666 {
bodyReader = xudp.NewPacketReader(&buf.BufferedReader{Reader: bodyReader})
}