1 // Copyright 2013 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #include "chrome/browser/profile_resetter/jtl_foundation.h" 6 7 #include "base/logging.h" 8 #include "base/strings/string_number_conversions.h" 9 #include "base/strings/string_util.h" 10 11 namespace jtl_foundation { 12 Hasher(const std::string & seed)13Hasher::Hasher(const std::string& seed) : hmac_(crypto::HMAC::SHA256) { 14 if (!hmac_.Init(seed)) 15 NOTREACHED(); 16 } 17 ~Hasher()18Hasher::~Hasher() {} 19 GetHash(const std::string & input) const20std::string Hasher::GetHash(const std::string& input) const { 21 if (cached_hashes_.find(input) == cached_hashes_.end()) { 22 // Calculate value. 23 unsigned char digest[kHashSizeInBytes]; 24 if (!hmac_.Sign(input, digest, arraysize(digest))) { 25 NOTREACHED(); 26 return std::string(); 27 } 28 // Instead of using the full SHA256, we only use the hex encoding of the 29 // first 16 bytes. 30 cached_hashes_[input] = base::HexEncode(digest, kHashSizeInBytes / 2); 31 DCHECK_EQ(kHashSizeInBytes, cached_hashes_[input].size()); 32 } 33 return cached_hashes_[input]; 34 } 35 36 // static IsHash(const std::string & maybe_hash)37bool Hasher::IsHash(const std::string& maybe_hash) { 38 if (maybe_hash.size() != kHashSizeInBytes) 39 return false; 40 for (std::string::const_iterator it = maybe_hash.begin(); 41 it != maybe_hash.end(); ++it) { 42 if (!IsHexDigit(*it)) 43 return false; 44 } 45 return true; 46 } 47 48 } // namespace jtl_foundation 49