123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123 |
- // Copyright 2014 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 <stddef.h>
- #include <stdint.h>
- #include <memory>
- #include "base/check.h"
- #include "base/numerics/safe_math.h"
- #include "components/webcrypto/algorithms/aes.h"
- #include "components/webcrypto/algorithms/util.h"
- #include "components/webcrypto/blink_key_handle.h"
- #include "components/webcrypto/status.h"
- #include "crypto/openssl_util.h"
- #include "third_party/blink/public/platform/web_crypto_algorithm_params.h"
- #include "third_party/boringssl/src/include/openssl/aes.h"
- #include "third_party/boringssl/src/include/openssl/cipher.h"
- namespace webcrypto {
- namespace {
- const EVP_CIPHER* GetAESCipherByKeyLength(size_t key_length_bytes) {
- // 192-bit AES is intentionally unsupported (http://crbug.com/533699).
- switch (key_length_bytes) {
- case 16:
- return EVP_aes_128_cbc();
- case 32:
- return EVP_aes_256_cbc();
- default:
- return nullptr;
- }
- }
- Status AesCbcEncryptDecrypt(EncryptOrDecrypt cipher_operation,
- const blink::WebCryptoAlgorithm& algorithm,
- const blink::WebCryptoKey& key,
- base::span<const uint8_t> data,
- std::vector<uint8_t>* buffer) {
- crypto::OpenSSLErrStackTracer err_tracer(FROM_HERE);
- const blink::WebCryptoAesCbcParams* params = algorithm.AesCbcParams();
- const std::vector<uint8_t>& raw_key = GetSymmetricKeyData(key);
- if (params->Iv().size() != 16)
- return Status::ErrorIncorrectSizeAesCbcIv();
- // According to the openssl docs, the amount of data written may be as large
- // as (data_size + cipher_block_size - 1), constrained to a multiple of
- // cipher_block_size.
- base::CheckedNumeric<int> output_max_len = data.size();
- output_max_len += AES_BLOCK_SIZE - 1;
- if (!output_max_len.IsValid())
- return Status::ErrorDataTooLarge();
- const unsigned remainder =
- base::ValueOrDieForType<unsigned>(output_max_len % AES_BLOCK_SIZE);
- if (remainder != 0)
- output_max_len += AES_BLOCK_SIZE - remainder;
- if (!output_max_len.IsValid())
- return Status::ErrorDataTooLarge();
- // Note: PKCS padding is enabled by default
- const EVP_CIPHER* const cipher = GetAESCipherByKeyLength(raw_key.size());
- DCHECK(cipher);
- bssl::ScopedEVP_CIPHER_CTX context;
- if (!EVP_CipherInit_ex(context.get(), cipher, nullptr, &raw_key[0],
- params->Iv().data(), cipher_operation)) {
- return Status::OperationError();
- }
- buffer->resize(base::ValueOrDieForType<size_t>(output_max_len));
- int output_len = 0;
- if (!EVP_CipherUpdate(context.get(), buffer->data(), &output_len, data.data(),
- base::checked_cast<int>(data.size()))) {
- return Status::OperationError();
- }
- int final_output_chunk_len = 0;
- if (!EVP_CipherFinal_ex(context.get(), buffer->data() + output_len,
- &final_output_chunk_len)) {
- return Status::OperationError();
- }
- const unsigned int final_output_len =
- static_cast<unsigned int>(output_len) +
- static_cast<unsigned int>(final_output_chunk_len);
- buffer->resize(final_output_len);
- return Status::Success();
- }
- class AesCbcImplementation : public AesAlgorithm {
- public:
- AesCbcImplementation() : AesAlgorithm("CBC") {}
- Status Encrypt(const blink::WebCryptoAlgorithm& algorithm,
- const blink::WebCryptoKey& key,
- base::span<const uint8_t> data,
- std::vector<uint8_t>* buffer) const override {
- return AesCbcEncryptDecrypt(ENCRYPT, algorithm, key, data, buffer);
- }
- Status Decrypt(const blink::WebCryptoAlgorithm& algorithm,
- const blink::WebCryptoKey& key,
- base::span<const uint8_t> data,
- std::vector<uint8_t>* buffer) const override {
- return AesCbcEncryptDecrypt(DECRYPT, algorithm, key, data, buffer);
- }
- };
- } // namespace
- std::unique_ptr<AlgorithmImplementation> CreateAesCbcImplementation() {
- return std::make_unique<AesCbcImplementation>();
- }
- } // namespace webcrypto
|