Add new x509 certificate chain validator in x509_verify.c

The new validator finds multiple validated chains to handle the modern
PKI cases which may frequently have multiple paths via different
intermediates to different roots. It is loosely based on golang's x509
validator

This includes integration so that the new validator can be used via
X509_verify_cert() as well as a new api x509_verify() which will
return multiple chains (similar to go).

The new validator is not enabled by default with this commit, this
will be changed in a follow on commit.

The new public API is not yet exposed, and will be finalized and
exposed with a man page and a library minor bump later.

ok tb@ inoguchi@ jsing@

1 files changed, 3 insertions, 2 deletions

diff --git a/src/lib/libcrypto/x509/x509_utl.c b/src/lib/libcrypto/x509/x509_utl.c
index 4641152f74..0fa6ea6d54 100644
--- a/src/lib/libcrypto/x509/x509_utl.c
+++ b/src/lib/libcrypto/x509/x509_utl.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: x509_utl.c,v 1.1 2020/06/04 15:19:32 jsing Exp $ */
+/* $OpenBSD: x509_utl.c,v 1.2 2020/09/13 15:06:17 beck Exp $ */
 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
  * project.
  */
@@ -988,7 +988,8 @@ do_x509_check(X509 *x, const char *chk, size_t chklen, unsigned int flags,
                 alt_type = V_ASN1_IA5STRING;
                 equal = equal_email;
         } else if (check_type == GEN_DNS) {
-                cnid = NID_commonName;
+                if (!(flags & X509_CHECK_FLAG_NEVER_CHECK_SUBJECT))
+                        cnid = NID_commonName;
                 /* Implicit client-side DNS sub-domain pattern */
                 if (chklen > 1 && chk[0] == '.')
                         flags |= _X509_CHECK_FLAG_DOT_SUBDOMAINS;