06a325cfaf
This updates the repo to match the internal repo at commit: 521466f84993e273105bd41d930c00cf6d61008f
65 lines
1.7 KiB
C++
65 lines
1.7 KiB
C++
// Copyright 2020 Google LLC. All Rights Reserved.
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#include "crypto_utils/aes_cbc_decryptor.h"
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#include <cstddef>
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#include <cstdint>
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#include <vector>
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#include "base/check.h"
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#include "base/logging.h"
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namespace widevine {
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namespace {
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constexpr size_t kAesBlockSize = 16;
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} // namespace
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AesCbcDecryptor::~AesCbcDecryptor() {}
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bool AesCbcDecryptor::SetKey(const uint8_t* key, size_t key_size) {
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DCHECK(key);
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if (key_size != kAesBlockSize && key_size != kAesBlockSize * 2) {
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LOG(WARNING) << "Incorrect key size " << key_size;
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return false;
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}
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if (AES_set_decrypt_key(key, key_size * 8, &aes_key_) != 0) {
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LOG(WARNING) << "Invalid AES key.";
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return false;
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}
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aes_key_size_ = key_size;
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return true;
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}
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bool AesCbcDecryptor::Decrypt(const uint8_t* iv,
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size_t iv_size,
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const uint8_t* input_data,
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size_t input_data_size,
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uint8_t* output_data) {
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DCHECK(iv);
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DCHECK(input_data);
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DCHECK(output_data);
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if (aes_key_size_ == 0) {
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LOG(WARNING) << "This class has not been initialized.";
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return false;
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}
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// IV is allowed to be either AES BLOCK size or half of it.
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if (iv_size != kAesBlockSize && iv_size != kAesBlockSize / 2) {
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LOG(WARNING) << "Invalid IV size " << iv_size;
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return false;
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}
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if ((input_data_size % kAesBlockSize) != 0) {
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LOG(WARNING) << "Input data size must be multiple of 16: "
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<< input_data_size;
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return false;
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}
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std::vector<uint8_t> local_iv(iv, iv + iv_size);
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local_iv.resize(kAesBlockSize);
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AES_cbc_encrypt(input_data, output_data, input_data_size, &aes_key_,
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local_iv.data(), AES_DECRYPT);
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return true;
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}
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} // namespace widevine
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