finalize multi-device

WASignalGroup/group.proto

@@ -0,0 +1,41 @@
+package groupproto;
+
+message SenderKeyMessage {
+	optional uint32 id         = 1;
+	optional uint32 iteration  = 2;
+	optional bytes  ciphertext = 3;
+  }
+  
+  message SenderKeyDistributionMessage {
+	optional uint32 id         = 1;
+	optional uint32 iteration  = 2;
+	optional bytes  chainKey   = 3;
+	optional bytes  signingKey = 4;
+  }
+  
+
+message SenderKeyStateStructure {
+    message SenderChainKey {
+        optional uint32 iteration = 1;
+        optional bytes  seed      = 2;
+    }
+
+    message SenderMessageKey {
+        optional uint32 iteration = 1;
+        optional bytes  seed      = 2;
+    }
+
+    message SenderSigningKey {
+        optional bytes public  = 1;
+        optional bytes private = 2;
+    }
+
+    optional uint32           senderKeyId       = 1;
+    optional SenderChainKey   senderChainKey    = 2;
+    optional SenderSigningKey senderSigningKey  = 3;
+    repeated SenderMessageKey senderMessageKeys = 4;
+}
+
+message SenderKeyRecordStructure {
+    repeated SenderKeyStateStructure senderKeyStates = 1;
+}