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, 1 deletions

diff --git a/src/lib/libcrypto/x509/x509v3.h b/src/lib/libcrypto/x509/x509v3.h
index 8f7f5c5794..d2754fa624 100644
--- a/src/lib/libcrypto/x509/x509v3.h
+++ b/src/lib/libcrypto/x509/x509v3.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: x509v3.h,v 1.1 2020/06/04 15:19:32 jsing Exp $ */
+/* $OpenBSD: x509v3.h,v 1.2 2020/09/13 15:06:17 beck Exp $ */
 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
  * project 1999.
  */
@@ -815,6 +815,8 @@ STACK_OF(OPENSSL_STRING) *X509_get1_ocsp(X509 *x);
 #define X509_CHECK_FLAG_MULTI_LABEL_WILDCARDS 0x8
 /* Constraint verifier subdomain patterns to match a single labels. */
 #define X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS 0x10
+/* Disable checking the CN for a hostname, to support modern validation */
+#define X509_CHECK_FLAG_NEVER_CHECK_SUBJECT 0x20
 
 /*
  * Match reference identifiers starting with "." to any sub-domain.