Adding OCSP Parser

net/cert/internal/signature_algorithm.h

 // 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.
 
 #ifndef NET_CERT_INTERNAL_SIGNATURE_ALGORITHM_H_
 #define NET_CERT_INTERNAL_SIGNATURE_ALGORITHM_H_
 
 #include <stdint.h>
 
 #include "base/compiler_specific.h"
@@ skipping 16 matching lines @@
 };
 
 // The signature scheme used within a signature. Parameters are specified
 // separately.
 enum class SignatureAlgorithmId {
   RsaPkcs1,  // RSA PKCS#1 v1.5
   RsaPss,    // RSASSA-PSS
   Ecdsa,     // ECDSA
 };
 
+// Parses a HashAlgorithm as defined by RFC 5912:
+//
+//     HashAlgorithm  ::=  AlgorithmIdentifier{DIGEST-ALGORITHM,
+//                             {HashAlgorithms}}
+//
+//     HashAlgorithms DIGEST-ALGORITHM ::=  {
+//         { IDENTIFIER id-sha1 PARAMS TYPE NULL ARE preferredPresent } |
+//         { IDENTIFIER id-sha224 PARAMS TYPE NULL ARE preferredPresent } |
+//         { IDENTIFIER id-sha256 PARAMS TYPE NULL ARE preferredPresent } |
+//         { IDENTIFIER id-sha384 PARAMS TYPE NULL ARE preferredPresent } |
+//         { IDENTIFIER id-sha512 PARAMS TYPE NULL ARE preferredPresent }
+//     }
+WARN_UNUSED_RESULT bool ParseHashAlgorithm(const der::Input input,
+                                           DigestAlgorithm* out);
+
 // Base class for describing algorithm parameters.
 class NET_EXPORT SignatureAlgorithmParameters {
  public:
   SignatureAlgorithmParameters() {}
   virtual ~SignatureAlgorithmParameters(){};
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SignatureAlgorithmParameters);
 };
 
@@ skipping 52 matching lines @@
   const SignatureAlgorithmId algorithm_;
   const DigestAlgorithm digest_;
   const scoped_ptr<SignatureAlgorithmParameters> params_;
 
   DISALLOW_COPY_AND_ASSIGN(SignatureAlgorithm);
 };
 
 }  // namespace net
 
 #endif  // NET_CERT_INTERNAL_SIGNATURE_ALGORITHM_H_