Index: crypto/encryptor_win.cc |
=================================================================== |
--- crypto/encryptor_win.cc (revision 0) |
+++ crypto/encryptor_win.cc (revision 0) |
@@ -0,0 +1,115 @@ |
+// 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 <vector> |
+ |
+#include "crypto/symmetric_key.h" |
+ |
+namespace crypto { |
+ |
+namespace { |
+ |
+// On success, returns the block size (in bytes) for the algorithm that |key| |
+// is for. On failure, returns 0. |
+DWORD GetCipherBlockSize(HCRYPTKEY key) { |
+ DWORD block_size_in_bits = 0; |
+ DWORD param_size = sizeof(block_size_in_bits); |
+ BOOL ok = CryptGetKeyParam(key, KP_BLOCKLEN, |
+ reinterpret_cast<BYTE*>(&block_size_in_bits), |
+ ¶m_size, 0); |
+ if (!ok) |
+ return 0; |
+ |
+ return block_size_in_bits / 8; |
+} |
+ |
+} // namespace |
+ |
+Encryptor::Encryptor() |
+ : key_(NULL), |
+ mode_(CBC), |
+ block_size_(0) { |
+} |
+ |
+Encryptor::~Encryptor() { |
+} |
+ |
+bool Encryptor::Init(SymmetricKey* key, Mode mode, const std::string& iv) { |
+ DCHECK(key); |
+ DCHECK_EQ(CBC, mode) << "Unsupported mode of operation"; |
+ |
+ // In CryptoAPI, the IV, padding mode, and feedback register (for a chaining |
+ // mode) are properties of a key, so we have to create a copy of the key for |
+ // the Encryptor. See the Remarks section of the CryptEncrypt MSDN page. |
+ BOOL ok = CryptDuplicateKey(key->key(), NULL, 0, capi_key_.receive()); |
+ if (!ok) |
+ return false; |
+ |
+ // CRYPT_MODE_CBC is the default for Microsoft Base Cryptographic Provider, |
+ // but we set it anyway to be safe. |
+ DWORD cipher_mode = CRYPT_MODE_CBC; |
+ ok = CryptSetKeyParam(capi_key_.get(), KP_MODE, |
+ reinterpret_cast<BYTE*>(&cipher_mode), 0); |
+ if (!ok) |
+ return false; |
+ |
+ block_size_ = GetCipherBlockSize(capi_key_.get()); |
+ if (block_size_ == 0) |
+ return false; |
+ |
+ if (iv.size() != block_size_) |
+ return false; |
+ |
+ ok = CryptSetKeyParam(capi_key_.get(), KP_IV, |
+ reinterpret_cast<const BYTE*>(iv.data()), 0); |
+ if (!ok) |
+ return false; |
+ |
+ DWORD padding_method = PKCS5_PADDING; |
+ ok = CryptSetKeyParam(capi_key_.get(), KP_PADDING, |
+ reinterpret_cast<BYTE*>(&padding_method), 0); |
+ if (!ok) |
+ return false; |
+ |
+ return true; |
+} |
+ |
+bool Encryptor::Encrypt(const std::string& plaintext, std::string* ciphertext) { |
+ DWORD data_len = plaintext.size(); |
+ DWORD total_len = data_len + block_size_; |
+ |
+ // CryptoAPI encrypts/decrypts in place. |
+ std::vector<BYTE> tmp(total_len); |
+ memcpy(&tmp[0], plaintext.data(), data_len); |
+ |
+ BOOL ok = CryptEncrypt(capi_key_.get(), NULL, TRUE, 0, &tmp[0], |
+ &data_len, total_len); |
+ if (!ok) |
+ return false; |
+ |
+ ciphertext->assign(reinterpret_cast<char*>(&tmp[0]), data_len); |
+ return true; |
+} |
+ |
+bool Encryptor::Decrypt(const std::string& ciphertext, std::string* plaintext) { |
+ DWORD data_len = ciphertext.size(); |
+ if (data_len == 0) |
+ return false; |
+ |
+ std::vector<BYTE> tmp(data_len); |
+ memcpy(&tmp[0], ciphertext.data(), data_len); |
+ |
+ BOOL ok = CryptDecrypt(capi_key_.get(), NULL, TRUE, 0, &tmp[0], &data_len); |
+ if (!ok) |
+ return false; |
+ |
+ DCHECK_GT(tmp.size(), data_len); |
+ |
+ plaintext->assign(reinterpret_cast<char*>(&tmp[0]), data_len); |
+ return true; |
+} |
+ |
+} // namespace crypto |
Property changes on: crypto\encryptor_win.cc |
___________________________________________________________________ |
Added: svn:eol-style |
+ LF |