| // 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/symmetric_key.h" |
| |
| #include <stddef.h> |
| #include <stdint.h> |
| |
| #include <algorithm> |
| #include <utility> |
| |
| #include "base/logging.h" |
| #include "base/strings/string_util.h" |
| #include "crypto/openssl_util.h" |
| #include "third_party/boringssl/src/include/openssl/evp.h" |
| #include "third_party/boringssl/src/include/openssl/rand.h" |
| |
| namespace crypto { |
| |
| SymmetricKey::~SymmetricKey() { |
| std::fill(key_.begin(), key_.end(), '\0'); // Zero out the confidential key. |
| } |
| |
| // static |
| std::unique_ptr<SymmetricKey> SymmetricKey::GenerateRandomKey( |
| Algorithm algorithm, |
| size_t key_size_in_bits) { |
| DCHECK_EQ(AES, algorithm); |
| |
| // Whitelist supported key sizes to avoid accidentaly relying on |
| // algorithms available in NSS but not BoringSSL and vice |
| // versa. Note that BoringSSL does not support AES-192. |
| if (key_size_in_bits != 128 && key_size_in_bits != 256) |
| return nullptr; |
| |
| size_t key_size_in_bytes = key_size_in_bits / 8; |
| DCHECK_EQ(key_size_in_bits, key_size_in_bytes * 8); |
| |
| if (key_size_in_bytes == 0) |
| return nullptr; |
| |
| OpenSSLErrStackTracer err_tracer(FROM_HERE); |
| std::unique_ptr<SymmetricKey> key(new SymmetricKey); |
| uint8_t* key_data = reinterpret_cast<uint8_t*>( |
| base::WriteInto(&key->key_, key_size_in_bytes + 1)); |
| |
| int rv = RAND_bytes(key_data, static_cast<int>(key_size_in_bytes)); |
| return rv == 1 ? std::move(key) : nullptr; |
| } |
| |
| // static |
| std::unique_ptr<SymmetricKey> SymmetricKey::DeriveKeyFromPassword( |
| Algorithm algorithm, |
| const std::string& password, |
| const std::string& salt, |
| size_t iterations, |
| size_t key_size_in_bits) { |
| DCHECK(algorithm == AES || algorithm == HMAC_SHA1); |
| |
| if (algorithm == AES) { |
| // Whitelist supported key sizes to avoid accidentaly relying on |
| // algorithms available in NSS but not BoringSSL and vice |
| // versa. Note that BoringSSL does not support AES-192. |
| if (key_size_in_bits != 128 && key_size_in_bits != 256) |
| return nullptr; |
| } |
| |
| size_t key_size_in_bytes = key_size_in_bits / 8; |
| DCHECK_EQ(key_size_in_bits, key_size_in_bytes * 8); |
| |
| if (key_size_in_bytes == 0) |
| return nullptr; |
| |
| OpenSSLErrStackTracer err_tracer(FROM_HERE); |
| std::unique_ptr<SymmetricKey> key(new SymmetricKey); |
| uint8_t* key_data = reinterpret_cast<uint8_t*>( |
| base::WriteInto(&key->key_, key_size_in_bytes + 1)); |
| int rv = PKCS5_PBKDF2_HMAC_SHA1( |
| password.data(), password.length(), |
| reinterpret_cast<const uint8_t*>(salt.data()), salt.length(), |
| static_cast<unsigned>(iterations), |
| key_size_in_bytes, key_data); |
| return rv == 1 ? std::move(key) : nullptr; |
| } |
| |
| // static |
| std::unique_ptr<SymmetricKey> SymmetricKey::Import(Algorithm algorithm, |
| const std::string& raw_key) { |
| if (algorithm == AES) { |
| // Whitelist supported key sizes to avoid accidentaly relying on |
| // algorithms available in NSS but not BoringSSL and vice |
| // versa. Note that BoringSSL does not support AES-192. |
| if (raw_key.size() != 128/8 && raw_key.size() != 256/8) |
| return nullptr; |
| } |
| |
| std::unique_ptr<SymmetricKey> key(new SymmetricKey); |
| key->key_ = raw_key; |
| return key; |
| } |
| |
| SymmetricKey::SymmetricKey() = default; |
| |
| } // namespace crypto |