| // Copyright 2015 The Chromium Authors | 
 | // Use of this source code is governed by a BSD-style license that can be | 
 | // found in the LICENSE file. | 
 |  | 
 | #include "extended_key_usage.h" | 
 |  | 
 | #include "input.h" | 
 | #include "parser.h" | 
 | #include "tag.h" | 
 |  | 
 | namespace bssl { | 
 |  | 
 | bool ParseEKUExtension(const der::Input& extension_value, | 
 |                        std::vector<der::Input>* eku_oids) { | 
 |   der::Parser extension_parser(extension_value); | 
 |   der::Parser sequence_parser; | 
 |   if (!extension_parser.ReadSequence(&sequence_parser)) | 
 |     return false; | 
 |  | 
 |   // Section 4.2.1.12 of RFC 5280 defines ExtKeyUsageSyntax as: | 
 |   // ExtKeyUsageSyntax ::= SEQUENCE SIZE (1..MAX) OF KeyPurposeId | 
 |   // | 
 |   // Therefore, the sequence must contain at least one KeyPurposeId. | 
 |   if (!sequence_parser.HasMore()) | 
 |     return false; | 
 |   while (sequence_parser.HasMore()) { | 
 |     der::Input eku_oid; | 
 |     if (!sequence_parser.ReadTag(der::kOid, &eku_oid)) | 
 |       // The SEQUENCE OF must contain only KeyPurposeIds (OIDs). | 
 |       return false; | 
 |     eku_oids->push_back(eku_oid); | 
 |   } | 
 |   if (extension_parser.HasMore()) | 
 |     // The extension value must follow ExtKeyUsageSyntax - there is no way that | 
 |     // it could be extended to allow for something after the SEQUENCE OF. | 
 |     return false; | 
 |   return true; | 
 | } | 
 |  | 
 | }  // namespace net |