Name constraints with excluded names but no permitted names should allow names not matching the exc…

net/cert/internal/name_constraints.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/cert/internal/name_constraints.h"
 
 #include <limits.h>
 
 #include "base/strings/string_util.h"
 #include "net/cert/internal/verify_name_match.h"
@@ skipping 478 matching lines @@
   // empty subject in such a case.
   if (subject_alt_name_extnvalue_tlv.Length() &&
       subject_rdn_sequence.Length() == 0) {
     return true;
   }
 
   return IsPermittedDirectoryName(subject_rdn_sequence);
 }
 
 bool NameConstraints::IsPermittedDNSName(const std::string& name) const {
-  // If there are no name constraints for DNS names, all names are accepted.
-  if (!(ConstrainedNameTypes() & GENERAL_NAME_DNS_NAME))
-    return true;
-
   for (const std::string& excluded_name : excluded_subtrees_.dns_names) {
     // When matching wildcard hosts against excluded subtrees, consider it a
     // match if the constraint would match any expansion of the wildcard. Eg,
     // *.bar.com should match a constraint of foo.bar.com.
     if (DNSNameMatches(name, excluded_name, WILDCARD_PARTIAL_MATCH))
       return false;
   }
+
+  // If permitted subtrees are not constrained, any name that is not excluded is
+  // allowed.
+  if (!(permitted_subtrees_.present_name_types & GENERAL_NAME_DNS_NAME))
+    return true;
+
   for (const std::string& permitted_name : permitted_subtrees_.dns_names) {
     // When matching wildcard hosts against permitted subtrees, consider it a
     // match only if the constraint would match all expansions of the wildcard.
     // Eg, *.bar.com should match a constraint of bar.com, but not foo.bar.com.
     if (DNSNameMatches(name, permitted_name, WILDCARD_FULL_MATCH))
       return true;
   }
 
   return false;
 }
 
 bool NameConstraints::IsPermittedDirectoryName(
     const der::Input& name_rdn_sequence) const {
-  // If there are no name constraints for directory names, all names are
-  // accepted.
-  if (!(ConstrainedNameTypes() & GENERAL_NAME_DIRECTORY_NAME))
-    return true;
-
   for (const auto& excluded_name : excluded_subtrees_.directory_names) {
     if (VerifyNameInSubtree(
             name_rdn_sequence,
             der::Input(excluded_name.data(), excluded_name.size()))) {
       return false;
     }
   }
+
+  // If permitted subtrees are not constrained, any name that is not excluded is
+  // allowed.
+  if (!(permitted_subtrees_.present_name_types & GENERAL_NAME_DIRECTORY_NAME))
+    return true;
+
   for (const auto& permitted_name : permitted_subtrees_.directory_names) {
     if (VerifyNameInSubtree(
             name_rdn_sequence,
             der::Input(permitted_name.data(), permitted_name.size()))) {
       return true;
     }
   }
 
   return false;
 }
 
 bool NameConstraints::IsPermittedIP(const IPAddressNumber& ip) const {
-  // If there are no name constraints for IP Address names, all names are
-  // accepted.
-  if (!(ConstrainedNameTypes() & GENERAL_NAME_IP_ADDRESS))
-    return true;
-
   for (const auto& excluded_ip : excluded_subtrees_.ip_address_ranges) {
     if (IPNumberMatchesPrefix(ip, excluded_ip.first, excluded_ip.second))
       return false;
   }
+
+  // If permitted subtrees are not constrained, any name that is not excluded is
+  // allowed.
+  if (!(permitted_subtrees_.present_name_types & GENERAL_NAME_IP_ADDRESS))
+    return true;
+
   for (const auto& permitted_ip : permitted_subtrees_.ip_address_ranges) {
     if (IPNumberMatchesPrefix(ip, permitted_ip.first, permitted_ip.second))
       return true;
   }
 
   return false;
 }
 
 int NameConstraints::ConstrainedNameTypes() const {
   return (permitted_subtrees_.present_name_types |
           excluded_subtrees_.present_name_types);
 }
 
 }  // namespace net