diff --git a/tests/suites/test_suite_x509write.data b/tests/suites/test_suite_x509write.data
index 5ac7200..1aca306 100644
--- a/tests/suites/test_suite_x509write.data
+++ b/tests/suites/test_suite_x509write.data
@@ -167,108 +167,104 @@
 x509_crt_check:"data_files/server1.key":"":"C=NL,O=PolarSSL,CN=PolarSSL Server 1":"data_files/test-ca.key":"PolarSSLTest":"C=NL,O=PolarSSL,CN=PolarSSL Test CA":"01":"20190210144406":"20290210144406":MBEDTLS_MD_SHA1:0:0:"NULL":0:0:1:-1:"data_files/server1.allSubjectAltNames.crt":0:0:"data_files/test-ca.crt":1
 
 X509 String to Names #1
-mbedtls_x509_string_to_names:"C=NL,O=Offspark\\, Inc., OU=PolarSSL":"C=NL, O=Offspark\\, Inc., OU=PolarSSL":0
+mbedtls_x509_string_to_names:"C=NL,O=Offspark\\, Inc., OU=PolarSSL":"C=NL, O=Offspark\\, Inc., OU=PolarSSL":0:0
 
 X509 String to Names #2
-mbedtls_x509_string_to_names:"C=NL, O=Offspark, Inc., OU=PolarSSL":"":MBEDTLS_ERR_X509_INVALID_NAME
+mbedtls_x509_string_to_names:"C=NL, O=Offspark, Inc., OU=PolarSSL":"":MBEDTLS_ERR_X509_INVALID_NAME:0
 
 X509 String to Names #3 (Name precisely 255 bytes)
-mbedtls_x509_string_to_names:"C=NL, O=123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345,OU=PolarSSL":"C=NL, O=123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345, OU=PolarSSL":0
+mbedtls_x509_string_to_names:"C=NL, O=123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345,OU=PolarSSL":"C=NL, O=123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345, OU=PolarSSL":0:0
 
 X509 String to Names #4 (Name larger than 255 bytes)
-mbedtls_x509_string_to_names:"C=NL, O=1234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456, OU=PolarSSL":"":MBEDTLS_ERR_X509_INVALID_NAME
+mbedtls_x509_string_to_names:"C=NL, O=1234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456, OU=PolarSSL":"":MBEDTLS_ERR_X509_INVALID_NAME:0
 
 X509 String to Names #5 (Escape non-allowed characters)
-mbedtls_x509_string_to_names:"C=NL, O=Offspark\\a Inc., OU=PolarSSL":"":MBEDTLS_ERR_X509_INVALID_NAME
+mbedtls_x509_string_to_names:"C=NL, O=Offspark\\a Inc., OU=PolarSSL":"":MBEDTLS_ERR_X509_INVALID_NAME:0
 
 X509 String to Names #6 (Escape at end)
-mbedtls_x509_string_to_names:"C=NL, O=Offspark\\":"":MBEDTLS_ERR_X509_INVALID_NAME
+mbedtls_x509_string_to_names:"C=NL, O=Offspark\\":"":MBEDTLS_ERR_X509_INVALID_NAME:0
 
 X509 String to Names #7 (Invalid, no '=' or ',')
-mbedtls_x509_string_to_names:"ABC123":"":MBEDTLS_ERR_X509_INVALID_NAME
+mbedtls_x509_string_to_names:"ABC123":"":MBEDTLS_ERR_X509_INVALID_NAME:0
 
 X509 String to Names #8 (Escaped valid characters)
-mbedtls_x509_string_to_names:"C=NL, O=Offspark\\+ \\> \\=, OU=PolarSSL":"C=NL, O=Offspark\\+ \\> \\=, OU=PolarSSL":0
+mbedtls_x509_string_to_names:"C=NL, O=Offspark\\+ \\> \\=, OU=PolarSSL":"C=NL, O=Offspark\\+ \\> \\=, OU=PolarSSL":0:0
 
 X509 String to Names #9 (Escaped ascii hexpairs uppercase encoded)
-mbedtls_x509_string_to_names:"C=NL, O=\\4F\\66\\66\\73\\70\\61\\72\\6B, OU=PolarSSL":"C=NL, O=Offspark, OU=PolarSSL":0
+mbedtls_x509_string_to_names:"C=NL, O=\\4F\\66\\66\\73\\70\\61\\72\\6B, OU=PolarSSL":"C=NL, O=Offspark, OU=PolarSSL":0:0
 
 X509 String to Names #10 (Escaped ascii hexpairs lowercase encoded)
-mbedtls_x509_string_to_names:"C=NL, O=\\4f\\66\\66\\73\\70\\61\\72\\6b, OU=PolarSSL":"C=NL, O=Offspark, OU=PolarSSL":0
+mbedtls_x509_string_to_names:"C=NL, O=\\4f\\66\\66\\73\\70\\61\\72\\6b, OU=PolarSSL":"C=NL, O=Offspark, OU=PolarSSL":0:0
 
 X509 String to Names #11 (Invalid hexpair escape at end of string)
-mbedtls_x509_string_to_names:"C=NL, O=\\4f\\66\\66\\73\\70\\61\\72\\6, OU=PolarSSL":"":MBEDTLS_ERR_X509_INVALID_NAME
+mbedtls_x509_string_to_names:"C=NL, O=\\4f\\66\\66\\73\\70\\61\\72\\6, OU=PolarSSL":"":MBEDTLS_ERR_X509_INVALID_NAME:0
 
 X509 String to Names #12 (Reject escaped null hexpair)
-mbedtls_x509_string_to_names:"C=NL, O=Of\\00spark, OU=PolarSSL":"":MBEDTLS_ERR_X509_INVALID_NAME
+mbedtls_x509_string_to_names:"C=NL, O=Of\\00spark, OU=PolarSSL":"":MBEDTLS_ERR_X509_INVALID_NAME:0
 
 X509 String to Names #13 (Invalid hexpairs)
-mbedtls_x509_string_to_names:"C=NL, O=Of\\flspark, OU=PolarSSL":"":MBEDTLS_ERR_X509_INVALID_NAME
+mbedtls_x509_string_to_names:"C=NL, O=Of\\flspark, OU=PolarSSL":"":MBEDTLS_ERR_X509_INVALID_NAME:0
 
 X509 String to Names #14 (Accept numercoid/hexstring)
-mbedtls_x509_string_to_names:"C=NL, 2.5.4.10=#0C084F6666737061726B, OU=PolarSSL":"C=NL, O=Offspark, OU=PolarSSL":0
+mbedtls_x509_string_to_names:"C=NL, 2.5.4.10=#0C084F6666737061726B, OU=PolarSSL":"C=NL, O=Offspark, OU=PolarSSL":0:0
 
 # TODO: Should the trailing garbage be ignored?
 X509 String to Names (hexstring: trailing garbage after DER is ignored)
-mbedtls_x509_string_to_names:"C=NL, 2.5.4.10=#0C084F6666737061726Baa, OU=PolarSSL":"C=NL, O=Offspark, OU=PolarSSL":0
+mbedtls_x509_string_to_names:"C=NL, 2.5.4.10=#0C084F6666737061726Baa, OU=PolarSSL":"C=NL, O=Offspark, OU=PolarSSL":0:0
 
-# TODO: this passes mbedtls_x509_string_to_names() but fails the
-# round-trip test: mbedtls_x509_dn_gets() returns MBEDTLS_ERR_X509_INVALID_NAME.
-# X509 String to Names: long hexstring (DER=256 bytes, too long)
-# mbedtls_x509_string_to_names:"C=NL, 2.5.4.10=#0C81fdaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa, OU=PolarSSL":"C=NL, O=Offspark, OU=PolarSSL":0
+X509 String to Names: long hexstring (DER=256 bytes, too long)
+mbedtls_x509_string_to_names:"C=NL, 2.5.4.10=#0C81fdaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa, OU=PolarSSL":"C=NL, O=Offspark, OU=PolarSSL":0:MAY_FAIL_DN_GETS
 
 X509 String to Names: long hexstring (DER=257 bytes, too long)
-mbedtls_x509_string_to_names:"C=NL, 2.5.4.10=#0C81feaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa, OU=PolarSSL":"C=NL, O=Offspark, OU=PolarSSL":MBEDTLS_ERR_X509_INVALID_NAME
+mbedtls_x509_string_to_names:"C=NL, 2.5.4.10=#0C81feaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa, OU=PolarSSL":"C=NL, O=Offspark, OU=PolarSSL":MBEDTLS_ERR_X509_INVALID_NAME:0
 
 X509 String to Names: long hexstring (DER=258 bytes, too long)
-mbedtls_x509_string_to_names:"C=NL, 2.5.4.10=#0C81ffaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa, OU=PolarSSL":"C=NL, O=Offspark, OU=PolarSSL":MBEDTLS_ERR_X509_INVALID_NAME
+mbedtls_x509_string_to_names:"C=NL, 2.5.4.10=#0C81ffaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa, OU=PolarSSL":"C=NL, O=Offspark, OU=PolarSSL":MBEDTLS_ERR_X509_INVALID_NAME:0
 
 X509 String to Names #15 (Odd length DER hexstring)
-mbedtls_x509_string_to_names:"C=NL, 2.5.4.10=#0C084F6666737061726, OU=PolarSSL":"":MBEDTLS_ERR_X509_INVALID_NAME
+mbedtls_x509_string_to_names:"C=NL, 2.5.4.10=#0C084F6666737061726, OU=PolarSSL":"":MBEDTLS_ERR_X509_INVALID_NAME:0
 
 X509 String to Names (empty DER hexstring)
-mbedtls_x509_string_to_names:"C=NL, 2.5.4.10=#, OU=PolarSSL":"":MBEDTLS_ERR_X509_INVALID_NAME
+mbedtls_x509_string_to_names:"C=NL, 2.5.4.10=#, OU=PolarSSL":"":MBEDTLS_ERR_X509_INVALID_NAME:0
 
 X509 String to Names (empty DER hexstring at end)
-mbedtls_x509_string_to_names:"C=NL, 2.5.4.10=#":"":MBEDTLS_ERR_X509_INVALID_NAME
+mbedtls_x509_string_to_names:"C=NL, 2.5.4.10=#":"":MBEDTLS_ERR_X509_INVALID_NAME:0
 
 X509 String to Names (1-byte DER hexstring)
-mbedtls_x509_string_to_names:"C=NL, 2.5.4.10=#0C, OU=PolarSSL":"":MBEDTLS_ERR_X509_INVALID_NAME
+mbedtls_x509_string_to_names:"C=NL, 2.5.4.10=#0C, OU=PolarSSL":"":MBEDTLS_ERR_X509_INVALID_NAME:0
 
 X509 String to Names (1-byte DER hexstring at end)
-mbedtls_x509_string_to_names:"C=NL, 2.5.4.10=#0C":"":MBEDTLS_ERR_X509_INVALID_NAME
+mbedtls_x509_string_to_names:"C=NL, 2.5.4.10=#0C":"":MBEDTLS_ERR_X509_INVALID_NAME:0
 
 X509 String to Names #16 (hexstring: DER length exceeds available data)
-mbedtls_x509_string_to_names:"C=NL, 2.5.4.10=#0C0B4F6666737061726B, OU=PolarSSL":"":MBEDTLS_ERR_X509_INVALID_NAME
+mbedtls_x509_string_to_names:"C=NL, 2.5.4.10=#0C0B4F6666737061726B, OU=PolarSSL":"":MBEDTLS_ERR_X509_INVALID_NAME:0
 
 X509 String to Names #17 (hexstring: Invalid OID)
-mbedtls_x509_string_to_names:"C=NL, 10.5.4.10=#0C084F6666737061726B, OU=PolarSSL":"":MBEDTLS_ERR_X509_INVALID_NAME
+mbedtls_x509_string_to_names:"C=NL, 10.5.4.10=#0C084F6666737061726B, OU=PolarSSL":"":MBEDTLS_ERR_X509_INVALID_NAME:0
 
 X509 String to Names #18 (short name and hexstring)
-mbedtls_x509_string_to_names:"C=NL, O=#0C084F6666737061726B, OU=PolarSSL":"C=NL, O=Offspark, OU=PolarSSL":0
+mbedtls_x509_string_to_names:"C=NL, O=#0C084F6666737061726B, OU=PolarSSL":"C=NL, O=Offspark, OU=PolarSSL":0:0
 
 X509 String to Names #18 (null byte in hexstring with string type)
-mbedtls_x509_string_to_names:"C=NL, O=#0C0100, OU=PolarSSL":"C=NL, O=Offspark, OU=PolarSSL":MBEDTLS_ERR_X509_INVALID_NAME
+mbedtls_x509_string_to_names:"C=NL, O=#0C0100, OU=PolarSSL":"C=NL, O=Offspark, OU=PolarSSL":MBEDTLS_ERR_X509_INVALID_NAME:0
 
-# TODO: this passes mbedtls_x509_string_to_names() but fails the
-# round-trip test: mbedtls_x509_get_name() returns MBEDTLS_ERR_X509_INVALID_NAME.
-# X509 String to Names #18 (null byte in hexstring with non-string type)
-# mbedtls_x509_string_to_names:"C=NL, O=#040100, OU=PolarSSL":"C=NL, O=Offspark, OU=PolarSSL":0
+X509 String to Names #18 (null byte in hexstring with non-string type)
+mbedtls_x509_string_to_names:"C=NL, O=#040100, OU=PolarSSL":"C=NL, O=Offspark, OU=PolarSSL":0:MAY_FAIL_GET_NAME
 
 X509 String to Names #19 (Accept non-ascii hexpairs)
-mbedtls_x509_string_to_names:"C=NL, O=Of\\CCspark, OU=PolarSSL":"C=NL, O=Of\\CCspark, OU=PolarSSL":0
+mbedtls_x509_string_to_names:"C=NL, O=Of\\CCspark, OU=PolarSSL":"C=NL, O=Of\\CCspark, OU=PolarSSL":0:0
 
 X509 String to Names #20 (Reject empty AttributeValue)
-mbedtls_x509_string_to_names:"C=NL, O=, OU=PolarSSL":"":MBEDTLS_ERR_X509_INVALID_NAME
+mbedtls_x509_string_to_names:"C=NL, O=, OU=PolarSSL":"":MBEDTLS_ERR_X509_INVALID_NAME:0
 
 X509 Round trip test (Escaped characters)
-mbedtls_x509_string_to_names:"CN=Lu\\C4\\8Di\\C4\\87, O=Offspark, OU=PolarSSL":"CN=Lu\\C4\\8Di\\C4\\87, O=Offspark, OU=PolarSSL":0
+mbedtls_x509_string_to_names:"CN=Lu\\C4\\8Di\\C4\\87, O=Offspark, OU=PolarSSL":"CN=Lu\\C4\\8Di\\C4\\87, O=Offspark, OU=PolarSSL":0:0
 
 X509 Round trip test (hexstring output for non string input)
-mbedtls_x509_string_to_names:"C=NL, 2.5.4.10=#03084F6666737061726B, OU=PolarSSL":"C=NL, O=#03084F6666737061726B, OU=PolarSSL":0
+mbedtls_x509_string_to_names:"C=NL, 2.5.4.10=#03084F6666737061726B, OU=PolarSSL":"C=NL, O=#03084F6666737061726B, OU=PolarSSL":0:0
 
 X509 Round trip test (numercoid hexstring output for unknown OID)
-mbedtls_x509_string_to_names:"C=NL, 2.5.4.10.234.532=#0C084F6666737061726B, OU=PolarSSL":"C=NL, 2.5.4.10.234.532=#0C084F6666737061726B, OU=PolarSSL":0
+mbedtls_x509_string_to_names:"C=NL, 2.5.4.10.234.532=#0C084F6666737061726B, OU=PolarSSL":"C=NL, 2.5.4.10.234.532=#0C084F6666737061726B, OU=PolarSSL":0:0
 
 Check max serial length
 x509_set_serial_check:
diff --git a/tests/suites/test_suite_x509write.function b/tests/suites/test_suite_x509write.function
index 6ce7f54..a7ed262 100644
--- a/tests/suites/test_suite_x509write.function
+++ b/tests/suites/test_suite_x509write.function
@@ -125,6 +125,12 @@
     return ret;
 }
 #endif  /* MBEDTLS_X509_CSR_WRITE_C */
+
+/* Due to inconsistencies in the input size limits applied by different
+ * library functions, some write-parse tests may fail. */
+#define MAY_FAIL_GET_NAME       0x0001
+#define MAY_FAIL_DN_GETS        0x0002
+
 /* END_HEADER */
 
 /* BEGIN_DEPENDENCIES
@@ -687,8 +693,8 @@
 /* END_CASE */
 
 /* BEGIN_CASE depends_on:MBEDTLS_X509_CREATE_C:MBEDTLS_X509_USE_C */
-void mbedtls_x509_string_to_names(char *name, char *parsed_name, int result
-                                  )
+void mbedtls_x509_string_to_names(char *name, char *parsed_name,
+                                  int result, int may_fail)
 {
     int ret;
     size_t len = 0;
@@ -715,11 +721,21 @@
 
     TEST_EQUAL(mbedtls_asn1_get_tag(&c, buf + sizeof(buf), &len,
                                     MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE), 0);
-    TEST_EQUAL(mbedtls_x509_get_name(&c, buf + sizeof(buf), &parsed), 0);
+    ret = mbedtls_x509_get_name(&c, buf + sizeof(buf), &parsed);
+    if ((may_fail & MAY_FAIL_GET_NAME) && ret < 0) {
+        /* Validation inconsistency between mbedtls_x509_string_to_names() and
+         * mbedtls_x509_get_name(). Accept it for now. */
+        goto exit;
+    }
+    TEST_EQUAL(ret, 0);
 
     ret = mbedtls_x509_dn_gets((char *) out, sizeof(out), &parsed);
+    if ((may_fail & MAY_FAIL_DN_GETS) && ret < 0) {
+        /* Validation inconsistency between mbedtls_x509_string_to_names() and
+         * mbedtls_x509_dn_gets(). Accept it for now. */
+        goto exit;
+    }
     TEST_LE_S(1, ret);
-
     TEST_ASSERT(strcmp((char *) out, parsed_name) == 0);
 
 exit: