| // Copyright (c) 2011 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 "crypto/hmac.h" |
| |
| #include <openssl/hmac.h> |
| #include <stddef.h> |
| |
| #include <algorithm> |
| #include <memory> |
| #include <vector> |
| |
| #include "base/logging.h" |
| #include "base/stl_util.h" |
| #include "crypto/openssl_util.h" |
| |
| namespace crypto { |
| |
| struct HMACPlatformData { |
| std::vector<unsigned char> key; |
| }; |
| |
| HMAC::HMAC(HashAlgorithm hash_alg) : hash_alg_(hash_alg) { |
| // Only SHA-1 and SHA-256 hash algorithms are supported now. |
| DCHECK(hash_alg_ == SHA1 || hash_alg_ == SHA256); |
| } |
| |
| bool HMAC::Init(const unsigned char* key, size_t key_length) { |
| // Init must not be called more than once on the same HMAC object. |
| DCHECK(!plat_); |
| plat_.reset(new HMACPlatformData()); |
| plat_->key.assign(key, key + key_length); |
| return true; |
| } |
| |
| HMAC::~HMAC() { |
| if (plat_) { |
| // Zero out key copy. |
| plat_->key.assign(plat_->key.size(), 0); |
| STLClearObject(&plat_->key); |
| } |
| } |
| |
| bool HMAC::Sign(const base::StringPiece& data, |
| unsigned char* digest, |
| size_t digest_length) const { |
| DCHECK(plat_); // Init must be called before Sign. |
| |
| ScopedOpenSSLSafeSizeBuffer<EVP_MAX_MD_SIZE> result(digest, digest_length); |
| return !!::HMAC(hash_alg_ == SHA1 ? EVP_sha1() : EVP_sha256(), |
| plat_->key.data(), plat_->key.size(), |
| reinterpret_cast<const unsigned char*>(data.data()), |
| data.size(), result.safe_buffer(), NULL); |
| } |
| |
| } // namespace crypto |