Index: crypto/encryptor_openssl.cc |
=================================================================== |
--- crypto/encryptor_openssl.cc (revision 0) |
+++ crypto/encryptor_openssl.cc (revision 0) |
@@ -0,0 +1,127 @@ |
+// 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/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 24: return EVP_aes_192_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 std::string& iv) { |
+ DCHECK(key); |
+ DCHECK_EQ(CBC, mode); |
+ |
+ EnsureOpenSSLInit(); |
+ if (iv.size() != AES_BLOCK_SIZE) |
+ return false; |
+ |
+ if (GetCipherForKey(key) == NULL) |
+ return false; |
+ |
+ key_ = key; |
+ mode_ = mode; |
+ iv_ = iv; |
+ return true; |
+} |
+ |
+bool Encryptor::Encrypt(const std::string& plaintext, std::string* ciphertext) { |
+ return Crypt(true, plaintext, ciphertext); |
+} |
+ |
+bool Encryptor::Decrypt(const std::string& ciphertext, std::string* plaintext) { |
+ return Crypt(false, ciphertext, plaintext); |
+} |
+ |
+bool Encryptor::Crypt(bool do_encrypt, |
+ const std::string& 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->swap(result); |
+ |
+ 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), static_cast<int>(iv_.length())); |
+ DCHECK_EQ(EVP_CIPHER_key_length(cipher), static_cast<int>(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); |
+ 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; |
+} |
+ |
+} // namespace crypto |
Property changes on: crypto\encryptor_openssl.cc |
___________________________________________________________________ |
Added: svn:eol-style |
+ LF |