+ Identity *id;
+ Idlist agent, files, *preferred;
+ Key *key;
+ AuthenticationConnection *ac;
+ char *comment;
+ int i, found;
+
+ TAILQ_INIT(&agent); /* keys from the agent */
+ TAILQ_INIT(&files); /* keys from the config file */
+ preferred = &authctxt->keys;
+ TAILQ_INIT(preferred); /* preferred order of keys */
+
+ /* list of keys stored in the filesystem */
+ for (i = 0; i < options.num_identity_files; i++) {
+ key = options.identity_keys[i];
+ if (key && key->type == KEY_RSA1)
+ continue;
+ options.identity_keys[i] = NULL;
+ id = xmalloc(sizeof(*id));
+ memset(id, 0, sizeof(*id));
+ id->key = key;
+ id->filename = xstrdup(options.identity_files[i]);
+ TAILQ_INSERT_TAIL(&files, id, next);
+ }
+ /* list of keys supported by the agent */
+ if ((ac = ssh_get_authentication_connection())) {
+ for (key = ssh_get_first_identity(ac, &comment, 2);
+ key != NULL;
+ key = ssh_get_next_identity(ac, &comment, 2)) {
+ found = 0;
+ TAILQ_FOREACH(id, &files, next) {
+ /* agent keys from the config file are preferred */
+ if (key_equal(key, id->key)) {
+ key_free(key);
+ xfree(comment);
+ TAILQ_REMOVE(&files, id, next);
+ TAILQ_INSERT_TAIL(preferred, id, next);
+ id->ac = ac;
+ found = 1;
+ break;
+ }
+ }
+ if (!found) {
+ id = xmalloc(sizeof(*id));
+ memset(id, 0, sizeof(*id));
+ id->key = key;
+ id->filename = comment;
+ id->ac = ac;
+ TAILQ_INSERT_TAIL(&agent, id, next);
+ }
+ }
+ /* append remaining agent keys */
+ for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
+ TAILQ_REMOVE(&agent, id, next);
+ TAILQ_INSERT_TAIL(preferred, id, next);
+ }
+ authctxt->agent = ac;
+ }
+ /* append remaining keys from the config file */
+ for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
+ TAILQ_REMOVE(&files, id, next);
+ TAILQ_INSERT_TAIL(preferred, id, next);
+ }
+ TAILQ_FOREACH(id, preferred, next) {
+ debug2("key: %s (%p)", id->filename, id->key);
+ }