Files
whitebox/crypto_utils/aes_cbc_decryptor.cc
Aaron Vaage 69ea909ff5 Multiple Renewal Keys and Logging
In this code update we add a test to ensure that the White-box API
implementation handle seeing multiple renewal keys correctly. Since
there should be no more than one renewal key in a license response, upon
seeing a second renewal key, the implementation should return a
WB_RESULT_INVALID_PARAMETER code.

Due to changes in how Chrome manages CHECKS and DCHECKS, this code has
been updated to use the new headers.
2020-08-21 17:18:28 -07:00

63 lines
1.7 KiB
C++

// Copyright 2020 Google LLC. All Rights Reserved.
#include "crypto_utils/aes_cbc_decryptor.h"
#include <cstddef>
#include <cstdint>
#include <vector>
#include "base/check.h"
#include "base/logging.h"
namespace widevine {
namespace {
constexpr size_t kAesBlockSize = 16;
} // namespace
bool AesCbcDecryptor::SetKey(const uint8_t* key, size_t key_size) {
DCHECK(key);
if (key_size != kAesBlockSize && key_size != kAesBlockSize * 2) {
LOG(WARNING) << "Incorrect key size " << key_size;
return false;
}
if (AES_set_decrypt_key(key, key_size * 8, &aes_key_) != 0) {
LOG(WARNING) << "Invalid AES key.";
return false;
}
aes_key_size_ = key_size;
return true;
}
bool AesCbcDecryptor::Decrypt(const uint8_t* iv,
size_t iv_size,
const uint8_t* input_data,
size_t input_data_size,
uint8_t* output_data) {
DCHECK(iv);
DCHECK(input_data);
DCHECK(output_data);
if (aes_key_size_ == 0) {
LOG(WARNING) << "This class has not been initialized.";
return false;
}
// IV is allowed to be either AES BLOCK size or half of it.
if (iv_size != kAesBlockSize && iv_size != kAesBlockSize / 2) {
LOG(WARNING) << "Invalid IV size " << iv_size;
return false;
}
if ((input_data_size % kAesBlockSize) != 0) {
LOG(WARNING) << "Input data size must be multiple of 16: "
<< input_data_size;
return false;
}
std::vector<uint8_t> local_iv(iv, iv + iv_size);
local_iv.resize(kAesBlockSize);
AES_cbc_encrypt(input_data, output_data, input_data_size, &aes_key_,
local_iv.data(), AES_DECRYPT);
return true;
}
} // namespace widevine