Add fuzz tests for obfuscated2

mtglib/internal/obfuscated2/client_handshake_fuzz_internal_test.go

@@ -0,0 +1,32 @@
+package obfuscated2
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+var FuzzClientHandshakeSecret = []byte{1,2,3}
+
+func FuzzClientHandshake(f *testing.F) {
+	f.Add([]byte{1,2,3})
+
+	f.Fuzz(func(t *testing.T, frame []byte) {
+		data := bytes.NewReader(frame)
+
+		if _, _, _, err := ClientHandshake(FuzzClientHandshakeSecret, data); err != nil {
+			return
+		}
+
+		handshake := clientHandhakeFrame{}
+		require.Len(t, frame, handshakeFrameLen)
+
+		copy(handshake.data[:], frame)
+
+		decryptor := handshake.decryptor(FuzzClientHandshakeSecret)
+		decryptor.XORKeyStream(handshake.data[:], handshake.data[:])
+
+		require.Equal(t, handshakeConnectionType, handshake.connectionType())
+	})
+}