Rework name verification code so that a match is indicated via an argument,

rather than return codes. More strictly follow RFC 6125, in particular only
check the CN if there are no SAN identifiers present in the certificate
(per section 6.4.4).

Previous behaviour questioned by Daniel Stenberg <daniel at haxx dot se>.

ok beck@ jca@

1 files changed, 7 insertions, 7 deletions

diff --git a/src/lib/libtls/tls_client.c b/src/lib/libtls/tls_client.c
index a1e2caa717..0e519684ef 100644
--- a/src/lib/libtls/tls_client.c
+++ b/src/lib/libtls/tls_client.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tls_client.c,v 1.40 2017/01/26 12:56:37 jsing Exp $ */
+/* $OpenBSD: tls_client.c,v 1.41 2017/04/10 17:11:13 jsing Exp $ */
 /*
  * Copyright (c) 2014 Joel Sing <jsing@openbsd.org>
  *
@@ -289,7 +289,7 @@ int
 tls_handshake_client(struct tls *ctx)
 {
         X509 *cert = NULL;
-        int ssl_ret;
+        int match, ssl_ret;
         int rv = -1;
 
         if ((ctx->flags & TLS_CLIENT) == 0) {
@@ -311,11 +311,11 @@ tls_handshake_client(struct tls *ctx)
                         tls_set_errorx(ctx, "no server certificate");
                         goto err;
                 }
-                if ((rv = tls_check_name(ctx, cert,
-                    ctx->servername)) != 0) {
-                        if (rv != -2)
-                                tls_set_errorx(ctx, "name `%s' not present in"
-                                    " server certificate", ctx->servername);
+                if (tls_check_name(ctx, cert, ctx->servername, &match) == -1)
+                        goto err;
+                if (!match) {
+                        tls_set_errorx(ctx, "name `%s' not present in"
+                            " server certificate", ctx->servername);
                         goto err;
                 }
         }