Direct proxy works

obfuscated2/telegram_protocol.go

@@ -0,0 +1,78 @@
+package obfuscated2
+
+import (
+	"crypto/rand"
+
+	"github.com/juju/errors"
+
+	"github.com/9seconds/mtg/protocol"
+	"github.com/9seconds/mtg/telegram"
+	"github.com/9seconds/mtg/utils"
+	"github.com/9seconds/mtg/wrappers"
+)
+
+type TelegramProtocol struct {
+	protocol.BaseProtocol
+
+	dialer telegram.Telegram
+}
+
+func (t *TelegramProtocol) Handshake(req *protocol.TelegramRequest) (wrappers.Wrap, error) {
+	socket, err := t.dialer.Dial(req.Ctx,
+		req.Cancel,
+		req.ClientProtocol.GetDC(),
+		req.ClientProtocol.GetConnectionProtocol())
+	if err != nil {
+		return nil, errors.Annotate(err, "Cannot dial to Telegram")
+	}
+	fm := generateFrame(req.ClientProtocol)
+	data := fm.Bytes()
+
+	encryptor := utils.MakeStreamCipher(fm.Key(), fm.IV())
+	decryptedFrame := fm.Invert()
+	decryptor := utils.MakeStreamCipher(decryptedFrame.Key(), decryptedFrame.IV())
+
+	copyFrame := make([]byte, frameLen)
+	copy(copyFrame[:frameOffsetIV], data[:frameOffsetIV])
+	encryptor.XORKeyStream(data, data)
+	copy(data[:frameOffsetIV], copyFrame[:frameOffsetIV])
+
+	if _, err := socket.Write(data); err != nil {
+		return nil, errors.Annotate(err, "Cannot write handshate frame to Telegram")
+	}
+
+	return wrappers.NewObfuscated2(socket, encryptor, decryptor), nil
+}
+
+func MakeTelegramProtocol(dialer telegram.Telegram) protocol.TelegramProtocol {
+	return &TelegramProtocol{
+		dialer: dialer,
+	}
+}
+
+func generateFrame(cp protocol.ClientProtocol) (fm Frame) {
+	data := fm.Bytes()
+
+	for {
+		if _, err := rand.Read(data); err != nil {
+			continue
+		}
+		if data[0] == 0xef {
+			continue
+		}
+
+		val := (uint32(data[3]) << 24) | (uint32(data[2]) << 16) | (uint32(data[1]) << 8) | uint32(data[0])
+		if val == 0x44414548 || val == 0x54534f50 || val == 0x20544547 || val == 0x4954504f || val == 0xeeeeeeee {
+			continue
+		}
+
+		val = (uint32(data[7]) << 24) | (uint32(data[6]) << 16) | (uint32(data[5]) << 8) | uint32(data[4])
+		if val == 0x00000000 {
+			continue
+		}
+
+		copy(fm.Magic(), cp.GetConnectionType().Tag())
+
+		return
+	}
+}