Add parsing code for RFC 5280 PolicyConstraints.

net/cert/internal/parse_certificate.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/parse_certificate.h"
 
 #include <utility>
 
 #include "base/strings/string_util.h"
 #include "net/cert/internal/cert_errors.h"
@@ skipping 620 matching lines @@
     // the broken encoding.
   }
 
   //         pathLenConstraint       INTEGER (0..MAX) OPTIONAL }
   der::Input encoded_path_len;
   if (!sequence_parser.ReadOptionalTag(der::kInteger, &encoded_path_len,
                                        &out->has_path_len)) {
     return false;
   }
   if (out->has_path_len) {
+    // TODO(eroman): Surface reason for failure if length was longer than uint8.
     if (!der::ParseUint8(encoded_path_len, &out->path_len))
       return false;
   } else {
     // Default initialize to 0 as a precaution.
     out->path_len = 0;
   }
 
   // There shouldn't be any unconsumed data in the extension.
   if (sequence_parser.HasMore())
     return false;
@@ skipping 72 matching lines @@
         out_ca_issuers_uris->push_back(uri);
       else if (access_method_oid == AdOcspOid())
         out_ocsp_uris->push_back(uri);
     }
   }
 
   return true;
 }
 
 }  // namespace net