Move crypto_helpers from sync to base

chrome/browser/sync/util/crypto_helpers.cc

-// Copyright (c) 2010 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 "chrome/browser/sync/util/crypto_helpers.h"
-
-#include <string>
-#include <vector>
-
-#include "base/basictypes.h"
-#include "base/format_macros.h"
-#include "base/logging.h"
-#include "base/base64.h"
-#include "base/rand_util.h"
-#include "base/string_number_conversions.h"
-#include "base/string_util.h"
-
-using std::string;
-using std::vector;
-
-MD5Calculator::MD5Calculator() {
-  MD5Init(&context_);
-}
-
-MD5Calculator::~MD5Calculator() {}
-
-void MD5Calculator::AddData(const unsigned char* data, int length) {
-  CHECK(bin_digest_.empty());
-  MD5Update(&context_, data, length);
-}
-
-void MD5Calculator::CalcDigest() {
-  if (bin_digest_.empty()) {
-    MD5Digest digest;
-    MD5Final(&digest, &context_);
-    bin_digest_.assign(digest.a, digest.a + arraysize(digest.a));
-  }
-}
-
-const vector<uint8>& MD5Calculator::GetDigest() {
-  CalcDigest();
-  return bin_digest_;
-}
-
-std::string MD5Calculator::GetHexDigest() {
-  CalcDigest();
-  string hex = base::HexEncode(reinterpret_cast<char*>(&bin_digest_.front()),
-                               bin_digest_.size());
-  StringToLowerASCII(&hex);
-  return hex;
-}
-
-void GetRandomBytes(char* output, int output_length) {
-  uint64 random_int;
-  const char* random_int_bytes = reinterpret_cast<const char*>(&random_int);
-  int random_int_size = sizeof(random_int);
-  for (int i = 0; i < output_length; i += random_int_size) {
-    random_int = base::RandUint64();
-    int copy_count = std::min(output_length - i, random_int_size);
-    memcpy(output + i, random_int_bytes, copy_count);
-  }
-}
-
-string Generate128BitRandomHexString() {
-  const int kNumberBytes = 128 / 8;
-  std::string random_bytes(kNumberBytes, ' ');
-  GetRandomBytes(&random_bytes[0], kNumberBytes);
-  std::string base64_encoded_bytes;
-  base::Base64Encode(random_bytes, &base64_encoded_bytes);
-  return base64_encoded_bytes;
-}