Add dependencies/vendor (whatsapp)

vendor/go.mau.fi/libsignal/protocol/CiphertextMessage.go

@@ -0,0 +1,19 @@
+package protocol
+
+type CiphertextMessage interface {
+	Serialize() []byte
+	Type() uint32
+}
+
+type GroupCiphertextMessage interface {
+	CiphertextMessage
+	SignedSerialize() []byte
+}
+
+const UnsupportedVersion = 1
+const CurrentVersion = 3
+
+const WHISPER_TYPE = 2
+const PREKEY_TYPE = 3
+const SENDERKEY_TYPE = 4
+const SENDERKEY_DISTRIBUTION_TYPE = 5