[crypto] Allow for X.509 certificates with no common name

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/crypto/cms.c

 	/* Verify using all signerInfos */
 	list_for_each_entry ( info, &sig->info, list ) {
 		cert = x509_first ( info->chain );
-		if ( name && ( strcmp ( name, cert->subject.name ) != 0 ) )
+		if ( name && ( ( cert->subject.name == NULL ) ||
+			       ( strcmp ( cert->subject.name, name ) != 0 ) ) )
 			continue;
 		if ( ( rc = cms_verify_signer_info ( sig, info, data, len,
 						     time, root ) ) != 0 )

src/crypto/x509.c

 			return rc;
 		}
 
-		/* Allocate name */
+		/* Allocate and copy name */
 		*name = zalloc ( name_cursor.len + 1 /* NUL */ );
 		if ( ! *name )
 			return -ENOMEM;
 		return 0;
 	}
 
+	/* Certificates may not have a commonName */
 	DBGC ( cert, "X509 %p no commonName found:\n", cert );
-	DBGC_HDA ( cert, 0, raw->data, raw->len );
-	return -ENOENT;
+	return 0;
 }
 
 /**

src/net/tls.c

 	assert ( cert != NULL );
 
 	/* Verify server name */
-	if ( strcmp ( tls->name, cert->subject.name ) != 0 ) {
+	if ( ( cert->subject.name == NULL ) ||
+	     ( strcmp ( cert->subject.name, tls->name ) != 0 ) ) {
 		DBGC ( tls, "TLS %p server name incorrect (expected %s, got "
 		       "%s)\n", tls, tls->name, cert->subject.name );
 		return -EACCES_WRONG_NAME;