Update stir_shaken.c - enforce verifier pvar error reason

- more explicit SET_VERIFY_ERR_VARS.
- stir_shaken_verify generic err_reason pvar is now more explicit to easily reflect the real reason.

- replace verifier generic "Internal Server Error" by dedicated internal error like "Failed to parse headers", "Failed to parse identity header", "Failed to get current time", "Failed to get UNIX time from Date header", "Failed to load certificate", "Error validating certificate", "Error while verifying signature".

Author: Integration-IT

modules/stir_shaken/stir_shaken.c

@@ -1999,7 +1999,7 @@ static int w_stir_verify(struct sip_msg *msg, str *cert_buf,
 	if ((rc = get_parsed_identity( msg, &parsed)) < 0) {
 		if (rc == -1) {
 			LM_ERR("Failed to parse identity header\n");
-			SET_VERIFY_ERR_VARS(IERROR_CODE, IERROR_REASON);
+			SET_VERIFY_ERR_VARS(IERROR_CODE, IERROR_REASON_PARSE_IDENTITY);
 		} else {  /* rc == -4 */
 			LM_INFO("Invalid identity header\n");
 			SET_VERIFY_ERR_VARS(INVALID_IDENTITY_CODE, INVALID_IDENTITY_REASON);
@@ -2028,7 +2028,7 @@ static int w_stir_verify(struct sip_msg *msg, str *cert_buf,
 
 	if ((now = time(0)) == -1) {
 		LM_ERR("Failed to get current time\n");
-		SET_VERIFY_ERR_VARS(IERROR_CODE, IERROR_REASON);
+		SET_VERIFY_ERR_VARS(IERROR_CODE, IERROR_REASON_GET_CURRENT_TIME);
 		rc = -1;
 		goto error;
 	}
@@ -2045,7 +2045,7 @@ static int w_stir_verify(struct sip_msg *msg, str *cert_buf,
 
 		if (get_date_ts(date_hf, &date_ts) < 0) {
 			LM_ERR("Failed to get UNIX time from Date header\n");
-			SET_VERIFY_ERR_VARS(IERROR_CODE, IERROR_REASON);
+			SET_VERIFY_ERR_VARS(IERROR_CODE, IERROR_REASON_GET_TIME_FROM_DATE_HEADER);
 			rc = -1;
 			goto error;
 		}
@@ -2095,7 +2095,7 @@ static int w_stir_verify(struct sip_msg *msg, str *cert_buf,
 
 	if (load_cert(&cert, &certchain, cert_buf) < 0) {
 		LM_ERR("Failed to load certificate\n");
-		SET_VERIFY_ERR_VARS(IERROR_CODE, IERROR_REASON);
+		SET_VERIFY_ERR_VARS(IERROR_CODE, IERROR_REASON_LOAD_CERTIFICATE);
 		rc = -1;
 		goto error;
 	}
@@ -2119,7 +2119,7 @@ static int w_stir_verify(struct sip_msg *msg, str *cert_buf,
 	if ((rc = validate_certificate(cert, certchain)) < 0) {
 		if (rc == -1) {
 			LM_ERR("Error validating certificate\n");
-			SET_VERIFY_ERR_VARS(IERROR_CODE, IERROR_REASON);
+			SET_VERIFY_ERR_VARS(IERROR_CODE, IERROR_REASON_VALIDATE_CERTIFICATE);
 			goto error;
 		} else {  /* rc == -8 */
 			LM_INFO("Invalid certificate\n");
@@ -2135,7 +2135,7 @@ static int w_stir_verify(struct sip_msg *msg, str *cert_buf,
 	if ((rc = verify_signature(cert, parsed, iat_ts, orig_tn_p, dest_tn_p)) <= 0) {
 		if (rc < 0) {
 			LM_ERR("Error while verifying signature\n");
-			SET_VERIFY_ERR_VARS(IERROR_CODE, IERROR_REASON);
+			SET_VERIFY_ERR_VARS(IERROR_CODE, IERROR_REASON_VERIFY_SIGNATURE);
 			rc = -1;
 			goto error;
 		} else {