initial commit

listener/obfs/tls/conn.go

@@ -0,0 +1,161 @@
+package tls
+
+import (
+	"bytes"
+	"crypto/rand"
+	"crypto/tls"
+	"net"
+	"sync"
+	"time"
+
+	dissector "github.com/go-gost/tls-dissector"
+)
+
+const (
+	maxTLSDataLen = 16384
+)
+
+type obfsTLSConn struct {
+	net.Conn
+	rbuf           bytes.Buffer
+	wbuf           bytes.Buffer
+	handshaked     bool
+	handshakeMutex sync.Mutex
+}
+
+func (c *obfsTLSConn) Handshake() (err error) {
+	c.handshakeMutex.Lock()
+	defer c.handshakeMutex.Unlock()
+
+	if c.handshaked {
+		return
+	}
+
+	if err = c.handshake(); err != nil {
+		return
+	}
+
+	c.handshaked = true
+	return nil
+}
+
+func (c *obfsTLSConn) handshake() error {
+	record := &dissector.Record{}
+	if _, err := record.ReadFrom(c.Conn); err != nil {
+		// log.Log(err)
+		return err
+	}
+	if record.Type != dissector.Handshake {
+		return dissector.ErrBadType
+	}
+
+	clientMsg := &dissector.ClientHelloMsg{}
+	if err := clientMsg.Decode(record.Opaque); err != nil {
+		// log.Log(err)
+		return err
+	}
+
+	for _, ext := range clientMsg.Extensions {
+		if ext.Type() == dissector.ExtSessionTicket {
+			b, err := ext.Encode()
+			if err != nil {
+				// log.Log(err)
+				return err
+			}
+			c.rbuf.Write(b)
+			break
+		}
+	}
+
+	serverMsg := &dissector.ServerHelloMsg{
+		Version:           tls.VersionTLS12,
+		SessionID:         clientMsg.SessionID,
+		CipherSuite:       0xcca8,
+		CompressionMethod: 0x00,
+		Extensions: []dissector.Extension{
+			&dissector.RenegotiationInfoExtension{},
+			&dissector.ExtendedMasterSecretExtension{},
+			&dissector.ECPointFormatsExtension{
+				Formats: []uint8{0x00},
+			},
+		},
+	}
+
+	serverMsg.Random.Time = uint32(time.Now().Unix())
+	rand.Read(serverMsg.Random.Opaque[:])
+	b, err := serverMsg.Encode()
+	if err != nil {
+		return err
+	}
+
+	record = &dissector.Record{
+		Type:    dissector.Handshake,
+		Version: tls.VersionTLS10,
+		Opaque:  b,
+	}
+
+	if _, err := record.WriteTo(&c.wbuf); err != nil {
+		return err
+	}
+
+	record = &dissector.Record{
+		Type:    dissector.ChangeCipherSpec,
+		Version: tls.VersionTLS12,
+		Opaque:  []byte{0x01},
+	}
+	if _, err := record.WriteTo(&c.wbuf); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (c *obfsTLSConn) Read(b []byte) (n int, err error) {
+	if err = c.Handshake(); err != nil {
+		return
+	}
+
+	if c.rbuf.Len() > 0 {
+		return c.rbuf.Read(b)
+	}
+	record := &dissector.Record{}
+	if _, err = record.ReadFrom(c.Conn); err != nil {
+		return
+	}
+	n = copy(b, record.Opaque)
+	_, err = c.rbuf.Write(record.Opaque[n:])
+	return
+}
+
+func (c *obfsTLSConn) Write(b []byte) (n int, err error) {
+	if err = c.Handshake(); err != nil {
+		return
+	}
+	n = len(b)
+
+	for len(b) > 0 {
+		data := b
+		if len(b) > maxTLSDataLen {
+			data = b[:maxTLSDataLen]
+			b = b[maxTLSDataLen:]
+		} else {
+			b = b[:0]
+		}
+		record := &dissector.Record{
+			Type:    dissector.AppData,
+			Version: tls.VersionTLS12,
+			Opaque:  data,
+		}
+
+		if c.wbuf.Len() > 0 {
+			record.Type = dissector.Handshake
+			record.WriteTo(&c.wbuf)
+			_, err = c.wbuf.WriteTo(c.Conn)
+			return
+		}
+
+		if _, err = record.WriteTo(c.Conn); err != nil {
+			return
+		}
+	}
+	return
+}

listener/obfs/tls/listener.go

@@ -0,0 +1,61 @@
+package tls
+
+import (
+	"net"
+
+	"github.com/go-gost/gost/v3/pkg/common/admission"
+	"github.com/go-gost/gost/v3/pkg/common/metrics"
+	"github.com/go-gost/gost/v3/pkg/listener"
+	"github.com/go-gost/gost/v3/pkg/logger"
+	md "github.com/go-gost/gost/v3/pkg/metadata"
+	"github.com/go-gost/gost/v3/pkg/registry"
+)
+
+func init() {
+	registry.ListenerRegistry().Register("otls", NewListener)
+}
+
+type obfsListener struct {
+	net.Listener
+	logger  logger.Logger
+	md      metadata
+	options listener.Options
+}
+
+func NewListener(opts ...listener.Option) listener.Listener {
+	options := listener.Options{}
+	for _, opt := range opts {
+		opt(&options)
+	}
+	return &obfsListener{
+		logger:  options.Logger,
+		options: options,
+	}
+}
+
+func (l *obfsListener) Init(md md.Metadata) (err error) {
+	if err = l.parseMetadata(md); err != nil {
+		return
+	}
+
+	ln, err := net.Listen("tcp", l.options.Addr)
+	if err != nil {
+		return
+	}
+	ln = metrics.WrapListener(l.options.Service, ln)
+	ln = admission.WrapListener(l.options.Admission, ln)
+
+	l.Listener = ln
+	return
+}
+
+func (l *obfsListener) Accept() (net.Conn, error) {
+	c, err := l.Listener.Accept()
+	if err != nil {
+		return nil, err
+	}
+
+	return &obfsTLSConn{
+		Conn: c,
+	}, nil
+}

listener/obfs/tls/metadata.go

@@ -0,0 +1,12 @@
+package tls
+
+import (
+	md "github.com/go-gost/gost/v3/pkg/metadata"
+)
+
+type metadata struct {
+}
+
+func (l *obfsListener) parseMetadata(md md.Metadata) (err error) {
+	return
+}