Reland "Cut down /crypto and switch what is left of it to boringssl".

crypto/encryptor.cc

-// Copyright (c) 2012 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/encryptor.h"
-
-#include "base/logging.h"
-#include "base/sys_byteorder.h"
-
-namespace crypto {
-
-/////////////////////////////////////////////////////////////////////////////
-// Encyptor::Counter Implementation.
-Encryptor::Counter::Counter(const base::StringPiece& counter) {
-  CHECK(sizeof(counter_) == counter.length());
-
-  memcpy(&counter_, counter.data(), sizeof(counter_));
-}
-
-Encryptor::Counter::~Counter() {
-}
-
-bool Encryptor::Counter::Increment() {
-  uint64 low_num = base::NetToHost64(counter_.components64[1]);
-  uint64 new_low_num = low_num + 1;
-  counter_.components64[1] = base::HostToNet64(new_low_num);
-
-  // If overflow occured then increment the most significant component.
-  if (new_low_num < low_num) {
-    counter_.components64[0] =
-        base::HostToNet64(base::NetToHost64(counter_.components64[0]) + 1);
-  }
-
-  // TODO(hclam): Return false if counter value overflows.
-  return true;
-}
-
-void Encryptor::Counter::Write(void* buf) {
-  uint8* buf_ptr = reinterpret_cast<uint8*>(buf);
-  memcpy(buf_ptr, &counter_, sizeof(counter_));
-}
-
-size_t Encryptor::Counter::GetLengthInBytes() const {
-  return sizeof(counter_);
-}
-
-/////////////////////////////////////////////////////////////////////////////
-// Partial Encryptor Implementation.
-
-bool Encryptor::SetCounter(const base::StringPiece& counter) {
-  if (mode_ != CTR)
-    return false;
-  if (counter.length() != 16u)
-    return false;
-
-  counter_.reset(new Counter(counter));
-  return true;
-}
-
-bool Encryptor::GenerateCounterMask(size_t plaintext_len,
-                                    uint8* mask,
-                                    size_t* mask_len) {
-  DCHECK_EQ(CTR, mode_);
-  CHECK(mask);
-  CHECK(mask_len);
-
-  const size_t kBlockLength = counter_->GetLengthInBytes();
-  size_t blocks = (plaintext_len + kBlockLength - 1) / kBlockLength;
-  CHECK(blocks);
-
-  *mask_len = blocks * kBlockLength;
-
-  for (size_t i = 0; i < blocks; ++i) {
-    counter_->Write(mask);
-    mask += kBlockLength;
-
-    bool ret = counter_->Increment();
-    if (!ret)
-      return false;
-  }
-  return true;
-}
-
-void Encryptor::MaskMessage(const void* plaintext,
-                            size_t plaintext_len,
-                            const void* mask,
-                            void* ciphertext) const {
-  DCHECK_EQ(CTR, mode_);
-  const uint8* plaintext_ptr = reinterpret_cast<const uint8*>(plaintext);
-  const uint8* mask_ptr = reinterpret_cast<const uint8*>(mask);
-  uint8* ciphertext_ptr = reinterpret_cast<uint8*>(ciphertext);
-
-  for (size_t i = 0; i < plaintext_len; ++i)
-    ciphertext_ptr[i] = plaintext_ptr[i] ^ mask_ptr[i];
-}
-
-}  // namespace crypto