PJSIP: Improve error handling in digest authenticator

Previously, regardless of whether failure to authenticate was due to
lacking any authentication or actually failing authentication, the
Digest Authenticator would simply return that a challenge was still
needed. It will continue to do that when no authentication information
is in the received SIP digest, but when authentication information
is present and does not pass authentication, that will be treated as
an authentication error. This is to ensure that PJSIP will issue
security events indicated failed auths.
........

Merged revisions 402537 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@402538 65c4cc65-6c06-0410-ace0-fbb531ad65f3

res/res_pjsip_authenticator_digest.c

@@ -290,6 +290,8 @@ enum digest_verify_result {
 	AUTH_SUCCESS,
 	/*! Authentication credentials correct but nonce mismatch */
 	AUTH_STALE,
+	/*! Authentication credentials were not provided */
+	AUTH_NOAUTH,
 };
 
 /*!
@@ -330,6 +332,11 @@ static int verify(struct ast_sip_auth *auth, pjsip_rx_data *rdata, pj_pool_t *po
 			return AUTH_SUCCESS;
 		}
 	}
+
+	if (authed == PJSIP_EAUTHNOAUTH) {
+		return AUTH_NOAUTH;
+	}
+
 	return AUTH_FAIL;
 }
 
@@ -376,6 +383,7 @@ static enum ast_sip_check_auth_result digest_check_auth(struct ast_sip_endpoint
 	enum digest_verify_result *verify_res;
 	enum ast_sip_check_auth_result res;
 	int i;
+	int failures = 0;
 
 	RAII_VAR(struct ast_sip_endpoint *, artificial_endpoint,
 		 ast_sip_get_artificial_endpoint(), ao2_cleanup);
@@ -403,13 +411,20 @@ static enum ast_sip_check_auth_result digest_check_auth(struct ast_sip_endpoint
 			res = AST_SIP_AUTHENTICATION_SUCCESS;
 			goto cleanup;
 		}
+		if (verify_res[i] == AUTH_FAIL) {
+			failures++;
+		}
 	}
 
 	for (i = 0; i < endpoint->inbound_auths.num; ++i) {
 		challenge(auths[i]->realm, tdata, rdata, verify_res[i] == AUTH_STALE);
 	}
 
-	res = AST_SIP_AUTHENTICATION_CHALLENGE;
+	if (failures == endpoint->inbound_auths.num) {
+		res = AST_SIP_AUTHENTICATION_FAILED;
+	} else {
+		res = AST_SIP_AUTHENTICATION_CHALLENGE;
+	}
 
 cleanup:
 	ast_sip_cleanup_auths(auths, endpoint->inbound_auths.num);