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

crypto/encryptor_openssl.cc

-// 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/encryptor.h"
-
-#include <openssl/aes.h>
-#include <openssl/evp.h>
-
-#include "base/logging.h"
-#include "base/strings/string_util.h"
-#include "crypto/openssl_util.h"
-#include "crypto/symmetric_key.h"
-
-namespace crypto {
-
-namespace {
-
-const EVP_CIPHER* GetCipherForKey(SymmetricKey* key) {
-  switch (key->key().length()) {
-    case 16: return EVP_aes_128_cbc();
-    case 32: return EVP_aes_256_cbc();
-    default: return NULL;
-  }
-}
-
-// On destruction this class will cleanup the ctx, and also clear the OpenSSL
-// ERR stack as a convenience.
-class ScopedCipherCTX {
- public:
-  explicit ScopedCipherCTX() {
-    EVP_CIPHER_CTX_init(&ctx_);
-  }
-  ~ScopedCipherCTX() {
-    EVP_CIPHER_CTX_cleanup(&ctx_);
-    ClearOpenSSLERRStack(FROM_HERE);
-  }
-  EVP_CIPHER_CTX* get() { return &ctx_; }
-
- private:
-  EVP_CIPHER_CTX ctx_;
-};
-
-}  // namespace
-
-Encryptor::Encryptor()
-    : key_(NULL),
-      mode_(CBC) {
-}
-
-Encryptor::~Encryptor() {
-}
-
-bool Encryptor::Init(SymmetricKey* key,
-                     Mode mode,
-                     const base::StringPiece& iv) {
-  DCHECK(key);
-  DCHECK(mode == CBC || mode == CTR);
-
-  EnsureOpenSSLInit();
-  if (mode == CBC && iv.size() != AES_BLOCK_SIZE)
-    return false;
-
-  if (GetCipherForKey(key) == NULL)
-    return false;
-
-  key_ = key;
-  mode_ = mode;
-  iv.CopyToString(&iv_);
-  return true;
-}
-
-bool Encryptor::Encrypt(const base::StringPiece& plaintext,
-                        std::string* ciphertext) {
-  CHECK(!plaintext.empty() || (mode_ == CBC));
-  return (mode_ == CTR) ?
-      CryptCTR(true, plaintext, ciphertext) :
-      Crypt(true, plaintext, ciphertext);
-}
-
-bool Encryptor::Decrypt(const base::StringPiece& ciphertext,
-                        std::string* plaintext) {
-  CHECK(!ciphertext.empty());
-  return (mode_ == CTR) ?
-      CryptCTR(false, ciphertext, plaintext) :
-      Crypt(false, ciphertext, plaintext);
-}
-
-bool Encryptor::Crypt(bool do_encrypt,
-                      const base::StringPiece& input,
-                      std::string* output) {
-  DCHECK(key_);  // Must call Init() before En/De-crypt.
-  // Work on the result in a local variable, and then only transfer it to
-  // |output| on success to ensure no partial data is returned.
-  std::string result;
-  output->clear();
-
-  const EVP_CIPHER* cipher = GetCipherForKey(key_);
-  DCHECK(cipher);  // Already handled in Init();
-
-  const std::string& key = key_->key();
-  DCHECK_EQ(EVP_CIPHER_iv_length(cipher), iv_.length());
-  DCHECK_EQ(EVP_CIPHER_key_length(cipher), key.length());
-
-  ScopedCipherCTX ctx;
-  if (!EVP_CipherInit_ex(ctx.get(), cipher, NULL,
-                         reinterpret_cast<const uint8*>(key.data()),
-                         reinterpret_cast<const uint8*>(iv_.data()),
-                         do_encrypt))
-    return false;
-
-  // When encrypting, add another block size of space to allow for any padding.
-  const size_t output_size = input.size() + (do_encrypt ? iv_.size() : 0);
-  CHECK_GT(output_size, 0u);
-  CHECK_GT(output_size + 1, input.size());
-  uint8* out_ptr = reinterpret_cast<uint8*>(WriteInto(&result,
-                                                      output_size + 1));
-  int out_len;
-  if (!EVP_CipherUpdate(ctx.get(), out_ptr, &out_len,
-                        reinterpret_cast<const uint8*>(input.data()),
-                        input.length()))
-    return false;
-
-  // Write out the final block plus padding (if any) to the end of the data
-  // just written.
-  int tail_len;
-  if (!EVP_CipherFinal_ex(ctx.get(), out_ptr + out_len, &tail_len))
-    return false;
-
-  out_len += tail_len;
-  DCHECK_LE(out_len, static_cast<int>(output_size));
-  result.resize(out_len);
-
-  output->swap(result);
-  return true;
-}
-
-bool Encryptor::CryptCTR(bool do_encrypt,
-                         const base::StringPiece& input,
-                         std::string* output) {
-  if (!counter_.get()) {
-    LOG(ERROR) << "Counter value not set in CTR mode.";
-    return false;
-  }
-
-  AES_KEY aes_key;
-  if (AES_set_encrypt_key(reinterpret_cast<const uint8*>(key_->key().data()),
-                          key_->key().size() * 8, &aes_key) != 0) {
-    return false;
-  }
-
-  const size_t out_size = input.size();
-  CHECK_GT(out_size, 0u);
-  CHECK_GT(out_size + 1, input.size());
-
-  std::string result;
-  uint8* out_ptr = reinterpret_cast<uint8*>(WriteInto(&result, out_size + 1));
-
-  uint8_t ivec[AES_BLOCK_SIZE] = { 0 };
-  uint8_t ecount_buf[AES_BLOCK_SIZE] = { 0 };
-  unsigned int block_offset = 0;
-
-  counter_->Write(ivec);
-
-  AES_ctr128_encrypt(reinterpret_cast<const uint8*>(input.data()), out_ptr,
-                     input.size(), &aes_key, ivec, ecount_buf, &block_offset);
-
-  // AES_ctr128_encrypt() updates |ivec|. Update the |counter_| here.
-  SetCounter(base::StringPiece(reinterpret_cast<const char*>(ivec),
-                               AES_BLOCK_SIZE));
-
-  output->swap(result);
-  return true;
-}
-
-}  // namespace crypto