Test optional fields in authorityKeyId

Signed-off-by: Przemek Stekiel <przemyslaw.stekiel@mobica.com>
diff --git a/tests/suites/test_suite_x509parse.function b/tests/suites/test_suite_x509parse.function
index 89155e9..71ab32c 100644
--- a/tests/suites/test_suite_x509parse.function
+++ b/tests/suites/test_suite_x509parse.function
@@ -1595,34 +1595,43 @@
 
     if (ref_ret == 0) {
         /* KeyId test */
-        TEST_ASSERT(crt.authority_key_id.keyIdentifier.tag == MBEDTLS_ASN1_OCTET_STRING);
-        TEST_ASSERT(memcmp(crt.authority_key_id.keyIdentifier.p, keyId->x, keyId->len) == 0);
-        TEST_ASSERT(crt.authority_key_id.keyIdentifier.len == keyId->len);
+        if (crt.authority_key_id.keyIdentifier.len > 0)
+        {
+            TEST_ASSERT(crt.authority_key_id.keyIdentifier.tag == MBEDTLS_ASN1_OCTET_STRING);
+            TEST_ASSERT(memcmp(crt.authority_key_id.keyIdentifier.p, keyId->x, keyId->len) == 0);
+            TEST_ASSERT(crt.authority_key_id.keyIdentifier.len == keyId->len);
+        }
 
         /* Issuer test */
-        mbedtls_x509_sequence *issuerPtr = &crt.authority_key_id.authorityCertIssuer;
+        if (crt.authority_key_id.authorityCertIssuer.buf.len > 0)
+        {
+            mbedtls_x509_sequence *issuerPtr = &crt.authority_key_id.authorityCertIssuer;
 
-        TEST_ASSERT(mbedtls_x509_parse_subject_alt_name(&issuerPtr->buf, &san) == 0);
+            TEST_ASSERT(mbedtls_x509_parse_subject_alt_name(&issuerPtr->buf, &san) == 0);
 
-        pname = &san.san.directory_name;
+            pname = &san.san.directory_name;
 
-        while (pname != NULL) {
-            for (issuerCounter = 0; issuerCounter < pname->val.len; issuerCounter++) {
-                result |=
-                    (authorityKeyId_issuer[bufferCounter++] != pname->val.p[issuerCounter]);
+            while (pname != NULL) {
+                for (issuerCounter = 0; issuerCounter < pname->val.len; issuerCounter++) {
+                    result |=
+                        (authorityKeyId_issuer[bufferCounter++] != pname->val.p[issuerCounter]);
+                }
+                bufferCounter++; /* Skipping the slash */
+                pname = pname->next;
             }
-            bufferCounter++; /* Skipping the slash */
-            pname = pname->next;
+            mbedtls_x509_free_subject_alt_name(&san);
+            TEST_ASSERT(result == 0);
         }
-        mbedtls_x509_free_subject_alt_name(&san);
-        TEST_ASSERT(result == 0);
 
         /* Serial test */
-        TEST_ASSERT(crt.authority_key_id.authorityCertSerialNumber.tag ==
-                    MBEDTLS_ASN1_INTEGER);
-        TEST_ASSERT(memcmp(crt.authority_key_id.authorityCertSerialNumber.p,
-                           serial->x, serial->len) == 0);
-        TEST_ASSERT(crt.authority_key_id.authorityCertSerialNumber.len == serial->len);
+        if (crt.authority_key_id.authorityCertSerialNumber.len > 0)
+        {
+            TEST_ASSERT(crt.authority_key_id.authorityCertSerialNumber.tag ==
+                        MBEDTLS_ASN1_INTEGER);
+            TEST_ASSERT(memcmp(crt.authority_key_id.authorityCertSerialNumber.p,
+                            serial->x, serial->len) == 0);
+            TEST_ASSERT(crt.authority_key_id.authorityCertSerialNumber.len == serial->len);
+        }
 
     } else {
         TEST_ASSERT(crt.authority_key_id.keyIdentifier.tag == 0);