| Index: crypto/encryptor_openssl.cc
|
| diff --git a/crypto/encryptor_openssl.cc b/crypto/encryptor_openssl.cc
|
| new file mode 100644
|
| index 0000000000000000000000000000000000000000..4f0e51137d76d67b8c9d8c1a332a2c166bf44bd5
|
| --- /dev/null
|
| +++ b/crypto/encryptor_openssl.cc
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| @@ -0,0 +1,177 @@
|
| +// 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>
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| +#include <openssl/evp.h>
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| +
|
| +#include "base/logging.h"
|
| +#include "base/strings/string_util.h"
|
| +#include "crypto/openssl_util.h"
|
| +#include "crypto/symmetric_key.h"
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| +
|
| +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;
|
| + }
|
| +}
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| +
|
| +// On destruction this class will cleanup the ctx, and also clear the OpenSSL
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| +// ERR stack as a convenience.
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| +class ScopedCipherCTX {
|
| + public:
|
| + explicit ScopedCipherCTX() {
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| + EVP_CIPHER_CTX_init(&ctx_);
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| + }
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| + ~ScopedCipherCTX() {
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| + EVP_CIPHER_CTX_cleanup(&ctx_);
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| + ClearOpenSSLERRStack(FROM_HERE);
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| + }
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| + EVP_CIPHER_CTX* get() { return &ctx_; }
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| +
|
| + private:
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| + EVP_CIPHER_CTX ctx_;
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| +};
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| +
|
| +} // namespace
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| +
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| +Encryptor::Encryptor()
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| + : key_(NULL),
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| + mode_(CBC) {
|
| +}
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| +
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| +Encryptor::~Encryptor() {
|
| +}
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| +
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| +bool Encryptor::Init(SymmetricKey* key,
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| + Mode mode,
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| + const base::StringPiece& iv) {
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| + DCHECK(key);
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| + DCHECK(mode == CBC || mode == CTR);
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| +
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| + EnsureOpenSSLInit();
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| + if (mode == CBC && iv.size() != AES_BLOCK_SIZE)
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| + return false;
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| +
|
| + if (GetCipherForKey(key) == NULL)
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| + return false;
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| +
|
| + key_ = key;
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| + mode_ = mode;
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| + iv.CopyToString(&iv_);
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| + return true;
|
| +}
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| +
|
| +bool Encryptor::Encrypt(const base::StringPiece& plaintext,
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| + std::string* ciphertext) {
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| + CHECK(!plaintext.empty() || (mode_ == CBC));
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| + return (mode_ == CTR) ?
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| + CryptCTR(true, plaintext, ciphertext) :
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| + Crypt(true, plaintext, ciphertext);
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| +}
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| +
|
| +bool Encryptor::Decrypt(const base::StringPiece& ciphertext,
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| + std::string* plaintext) {
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| + CHECK(!ciphertext.empty());
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| + return (mode_ == CTR) ?
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| + CryptCTR(false, ciphertext, plaintext) :
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| + Crypt(false, ciphertext, plaintext);
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| +}
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| +
|
| +bool Encryptor::Crypt(bool do_encrypt,
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| + const base::StringPiece& input,
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| + std::string* output) {
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| + DCHECK(key_); // Must call Init() before En/De-crypt.
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| + // Work on the result in a local variable, and then only transfer it to
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| + // |output| on success to ensure no partial data is returned.
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| + std::string result;
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| + output->clear();
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| +
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| + const EVP_CIPHER* cipher = GetCipherForKey(key_);
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| + DCHECK(cipher); // Already handled in Init();
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| +
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| + const std::string& key = key_->key();
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| + DCHECK_EQ(EVP_CIPHER_iv_length(cipher), iv_.length());
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| + DCHECK_EQ(EVP_CIPHER_key_length(cipher), key.length());
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| +
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| + ScopedCipherCTX ctx;
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| + if (!EVP_CipherInit_ex(ctx.get(), cipher, NULL,
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| + reinterpret_cast<const uint8*>(key.data()),
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| + reinterpret_cast<const uint8*>(iv_.data()),
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| + do_encrypt))
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| + return false;
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| +
|
| + // When encrypting, add another block size of space to allow for any padding.
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| + const size_t output_size = input.size() + (do_encrypt ? iv_.size() : 0);
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| + CHECK_GT(output_size, 0u);
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| + CHECK_GT(output_size + 1, input.size());
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| + uint8* out_ptr =
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| + reinterpret_cast<uint8*>(base::WriteInto(&result, output_size + 1));
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| + int out_len;
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| + if (!EVP_CipherUpdate(ctx.get(), out_ptr, &out_len,
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| + reinterpret_cast<const uint8*>(input.data()),
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| + input.length()))
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| + return false;
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| +
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| + // Write out the final block plus padding (if any) to the end of the data
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| + // just written.
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| + int tail_len;
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| + if (!EVP_CipherFinal_ex(ctx.get(), out_ptr + out_len, &tail_len))
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| + return false;
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| +
|
| + out_len += tail_len;
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| + DCHECK_LE(out_len, static_cast<int>(output_size));
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| + result.resize(out_len);
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| +
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| + output->swap(result);
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| + return true;
|
| +}
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| +
|
| +bool Encryptor::CryptCTR(bool do_encrypt,
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| + const base::StringPiece& input,
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| + std::string* output) {
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| + if (!counter_.get()) {
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| + LOG(ERROR) << "Counter value not set in CTR mode.";
|
| + return false;
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| + }
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| +
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| + AES_KEY aes_key;
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| + if (AES_set_encrypt_key(reinterpret_cast<const uint8*>(key_->key().data()),
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| + key_->key().size() * 8, &aes_key) != 0) {
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| + return false;
|
| + }
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| +
|
| + const size_t out_size = input.size();
|
| + CHECK_GT(out_size, 0u);
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| + CHECK_GT(out_size + 1, input.size());
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| +
|
| + std::string result;
|
| + uint8* out_ptr =
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| + reinterpret_cast<uint8*>(base::WriteInto(&result, out_size + 1));
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| +
|
| + uint8_t ivec[AES_BLOCK_SIZE] = { 0 };
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| + uint8_t ecount_buf[AES_BLOCK_SIZE] = { 0 };
|
| + unsigned int block_offset = 0;
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| +
|
| + counter_->Write(ivec);
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| +
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| + AES_ctr128_encrypt(reinterpret_cast<const uint8*>(input.data()), out_ptr,
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| + input.size(), &aes_key, ivec, ecount_buf, &block_offset);
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| +
|
| + // AES_ctr128_encrypt() updates |ivec|. Update the |counter_| here.
|
| + SetCounter(base::StringPiece(reinterpret_cast<const char*>(ivec),
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| + AES_BLOCK_SIZE));
|
| +
|
| + output->swap(result);
|
| + return true;
|
| +}
|
| +
|
| +} // namespace crypto
|
|
|