| // Copyright (c) 2006-2008 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. |
| |
| // Utility class for calculating the HMAC for a given message. We currently |
| // only support SHA1 for the hash algorithm, but this can be extended easily. |
| |
| #ifndef BASE_HMAC_H_ |
| #define BASE_HMAC_H_ |
| #pragma once |
| |
| #include <string> |
| |
| #include "base/basictypes.h" |
| #include "base/scoped_ptr.h" |
| |
| namespace base { |
| |
| // Simplify the interface and reduce includes by abstracting out the internals. |
| struct HMACPlatformData; |
| |
| class HMAC { |
| public: |
| // The set of supported hash functions. Extend as required. |
| enum HashAlgorithm { |
| SHA1, |
| SHA256, |
| }; |
| |
| explicit HMAC(HashAlgorithm hash_alg); |
| ~HMAC(); |
| |
| // Initializes this instance using |key| of the length |key_length|. Call Init |
| // only once. It returns false on the second or later calls. |
| bool Init(const unsigned char* key, int key_length); |
| |
| // Initializes this instance using |key|. Call Init only once. It returns |
| // false on the second or later calls. |
| bool Init(const std::string& key) { |
| return Init(reinterpret_cast<const unsigned char*>(key.data()), |
| static_cast<int>(key.size())); |
| } |
| |
| // Calculates the HMAC for the message in |data| using the algorithm supplied |
| // to the constructor and the key supplied to the Init method. The HMAC is |
| // returned in |digest|, which has |digest_length| bytes of storage available. |
| bool Sign(const std::string& data, unsigned char* digest, int digest_length); |
| |
| // TODO(albertb): Add a Verify method. |
| |
| private: |
| HashAlgorithm hash_alg_; |
| scoped_ptr<HMACPlatformData> plat_; |
| |
| DISALLOW_COPY_AND_ASSIGN(HMAC); |
| }; |
| |
| } // namespace base |
| |
| #endif // BASE_HMAC_H_ |