add identifier.proto

schema/identifier.proto

@@ -0,0 +1,38 @@
+//
+// Copyright 2022 Anysphere, Inc.
+// SPDX-License-Identifier: GPL-3.0-only
+//
+
+/*
+identifier.proto contains the protobuf for the public identifier.
+this schema should be kept backwards-compatible at all costs.
+*/
+
+syntax = "proto3";
+
+package asphrclient;
+
+// We want the identifier to contain as little information as possible, but still
+// enough such that it can be used both for the one-way asynchronous friend adding method (which requires
+// a public-key crypto public key) as well as the two-way friend adding method (which requires
+// a key-exchange public key). We also include the index allocation.
+//
+// The string-based public ID takes the following format:
+//
+//      [public-id] = base58(bytes(PublicID) || checksum(bytes(PublicID)))
+//
+// In public, it is always displayed in link format:
+//
+//      [public-id-link] = anysphere.id/#[public-id]
+//
+message PublicID {
+    // index is the database index of the person.
+    // if, in the future, a person has access to several indices, this is the index that is used
+    // in the friend-adding process. two people who can already communicate may tell each other about
+    // other indices. this is just for bootstrapping.
+    uint32 index = 1;
+    // the public-key crypto public key, used for handling friend requests.
+    bytes friend_request_public_key = 2;
+    // the key-exchange public key, used for adding a friend in the two-way situation.
+    bytes kx_public_key = 3;
+}