e2e: get_id_keys

Parse the output of olm_account_identity_keys to get a list of
algorithms and the keys for them.

There really should be a better way; the algorithm names in here
match what we need in the keys section, but we have to append
the device id later, so it's a pain that it returns (undocumented)
JSON.

Signed-off-by: Dr. David Alan Gilbert <dave@treblig.org>

1 files changed, 58 insertions, 0 deletions

diff --git a/matrix-e2e.c b/matrix-e2e.c
index 2e3acd9..792c580 100644
--- a/matrix-e2e.c
+++ b/matrix-e2e.c
@@ -238,6 +238,64 @@ out:
     return ret;
 }
 
+/* Returns the list of algorithms and our keys for those algorithms on the current account */
+static int get_id_keys(PurpleConnection *pc, OlmAccount *account, gchar ***algorithms, gchar ***keys)
+{
+    /* There has to be an easier way than this.... */
+    size_t id_key_len = olm_account_identity_keys_length(account);
+    gchar *id_keys = g_malloc0(id_key_len+1);
+    if (olm_account_identity_keys(account, id_keys, id_key_len) ==
+        olm_error()) {
+        purple_connection_error_reason(pc,
+                PURPLE_CONNECTION_ERROR_OTHER_ERROR,
+                olm_account_last_error(account));
+        g_free(id_keys);
+        return -1;
+    }
+
+    /* We get back a json string, something like:
+     * {"curve25519":"encodedkey...","ed25519":"encodedkey...."}'
+     */
+    JsonParser *json_parser = json_parser_new();
+    GError *err = NULL;
+    if (!json_parser_load_from_data(json_parser,
+            id_keys, strlen(id_keys), &err)) {
+        purple_connection_error_reason(pc,
+                PURPLE_CONNECTION_ERROR_OTHER_ERROR,
+                "Failed to parse olm account ID keys");
+        purple_debug_info("matrixprpl",
+                "unable to parse olm account ID keys: %s",
+                err->message);
+        g_error_free(err);
+        g_free(id_keys);
+        g_object_unref(json_parser);
+        return -1;
+    }
+    /* We have one object with a series of string members where
+     * each member is named after the algorithm.
+     */
+    JsonNode *id_node = json_parser_get_root(json_parser);
+    JsonObject *id_body = matrix_json_node_get_object(id_node);
+    guint n_keys = json_object_get_size(id_body);
+    *algorithms = g_new(gchar *, n_keys);
+    *keys = g_new(gchar *, n_keys);
+    JsonObjectIter iter;
+    const gchar *key_algo;
+    JsonNode *key_node;
+    guint i = 0;
+    json_object_iter_init(&iter, id_body);
+    while (json_object_iter_next(&iter, &key_algo, &key_node)) {
+        (*algorithms)[i] = g_strdup(key_algo);
+        (*keys)[i] = g_strdup(matrix_json_object_get_string_member(id_body, key_algo));
+        i++;
+    }
+
+    g_free(id_keys);
+    g_object_unref(json_parser);
+
+    return n_keys;
+}
+
 #else
 /* ==== Stubs for when e2e is configured out of the build === */
 #endif