asn1_string_to_utf8 test: appease coverity

Check for ASN_STRING_to_UTF8() failure before checking it matches our
expectations. This should convey clearly that test->want_len is never
negative.

CID 377011

Diagnosed by jsing

1 files changed, 8 insertions, 2 deletions

diff --git a/src/regress/lib/libcrypto/asn1/asn1_string_to_utf8.c b/src/regress/lib/libcrypto/asn1/asn1_string_to_utf8.c
index 2ead7b46c3..a87969d987 100644
--- a/src/regress/lib/libcrypto/asn1/asn1_string_to_utf8.c
+++ b/src/regress/lib/libcrypto/asn1/asn1_string_to_utf8.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: asn1_string_to_utf8.c,v 1.1 2022/05/16 20:53:20 tb Exp $ */
+/*      $OpenBSD: asn1_string_to_utf8.c,v 1.2 2022/11/23 08:51:05 tb Exp $ */
 /*
  * Copyright (c) 2022 Theo Buehler <tb@openbsd.org>
  *
@@ -86,12 +86,18 @@ asn1_string_to_utf8_test(const struct asn1_string_to_utf8_test_case *test)
                 goto err;
         }
 
-        if ((ret = ASN1_STRING_to_UTF8(&out, str)) != test->want_len) {
+        if ((ret = ASN1_STRING_to_UTF8(&out, str)) < 0) {
                 warnx("ASN1_STRING_to_UTF8 failed: got %d, want %d", ret,
                     test->want_len);
                 goto err;
         }
 
+        if (ret != test->want_len) {
+                warnx("ASN1_STRING_to_UTF8: got %d, want %d", ret,
+                    test->want_len);
+                goto err;
+        }
+
         if (memcmp(out, test->want, test->want_len) != 0) {
                 warnx("memcmp failed");
                 goto err;