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authorKristian Monsen <kristianm@google.com>2011-06-28 21:49:31 +0100
committerKristian Monsen <kristianm@google.com>2011-07-08 17:55:00 +0100
commitddb351dbec246cf1fab5ec20d2d5520909041de1 (patch)
tree158e3fb57bdcac07c7f1e767fde3c70687c9fbb1 /crypto/encryptor_win.cc
parent6b92e04f5f151c896e3088e86f70db7081009308 (diff)
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Merge Chromium at r12.0.742.93: Initial merge by git
Change-Id: Ic5ee2fec31358bbee305f7e915442377bfa6cda6
Diffstat (limited to 'crypto/encryptor_win.cc')
-rw-r--r--crypto/encryptor_win.cc115
1 files changed, 115 insertions, 0 deletions
diff --git a/crypto/encryptor_win.cc b/crypto/encryptor_win.cc
new file mode 100644
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+++ b/crypto/encryptor_win.cc
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+// 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),
+ &param_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