SRTCP unprotect failed because of unable to perform desired validation

Asterisk Asterisk Support
2

The nearest I can find to that message has this description:

if (res != err_status_ok && res != err_status_replay_fail ) {
		/*
		 * Authentication failures happen when an active attacker tries to
		 * insert malicious RTP packets. Furthermore, authentication failures
		 * happen, when the other party encrypts the sRTP data in an unexpected
		 * way. This happens quite often with RTCP. Therefore, when you see
		 * authentication failures, try to identify the implementation
		 * (author and product name) used by your other party. Try to investigate
		 * whether they use a custom library or an outdated version of libSRTP.
		 */
		if (rtcp) {
			ast_verb(2, "SRTCP unprotect failed on SSRC %u because of %s\n",
				ast_rtp_instance_get_ssrc(srtp->rtp), srtp_errstr(res));

The specific, “unable to perform desired validation”, diagnostic is a result of a cant_check error from the, presumably third party, lib_srtp implementation.

1 Like