| /* |
| * Copyright 2014 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include "aes_operation.h" |
| |
| namespace keymaster { |
| |
| static const keymaster_block_mode_t supported_block_modes[] = {KM_MODE_ECB, KM_MODE_CBC, |
| KM_MODE_CTR, KM_MODE_GCM}; |
| |
| const keymaster_block_mode_t* |
| AesEvpCipherDescription::SupportedBlockModes(size_t* block_mode_count) const { |
| *block_mode_count = array_length(supported_block_modes); |
| return supported_block_modes; |
| } |
| |
| const EVP_CIPHER* AesEvpCipherDescription::GetCipherInstance(size_t key_size, |
| keymaster_block_mode_t block_mode, |
| keymaster_error_t* error) const { |
| *error = KM_ERROR_OK; |
| |
| switch (block_mode) { |
| case KM_MODE_ECB: |
| switch (key_size) { |
| case 16: |
| return EVP_aes_128_ecb(); |
| case 24: |
| return EVP_aes_192_ecb(); |
| case 32: |
| return EVP_aes_256_ecb(); |
| }; |
| *error = KM_ERROR_UNSUPPORTED_KEY_SIZE; |
| break; |
| |
| case KM_MODE_CBC: |
| switch (key_size) { |
| case 16: |
| return EVP_aes_128_cbc(); |
| case 24: |
| return EVP_aes_192_cbc(); |
| case 32: |
| return EVP_aes_256_cbc(); |
| }; |
| *error = KM_ERROR_UNSUPPORTED_KEY_SIZE; |
| break; |
| |
| case KM_MODE_CTR: |
| switch (key_size) { |
| case 16: |
| return EVP_aes_128_ctr(); |
| case 24: |
| return EVP_aes_192_ctr(); |
| case 32: |
| return EVP_aes_256_ctr(); |
| } |
| *error = KM_ERROR_UNSUPPORTED_KEY_SIZE; |
| break; |
| |
| case KM_MODE_GCM: |
| switch (key_size) { |
| case 16: |
| return EVP_aes_128_gcm(); |
| case 24: |
| return EVP_aes_192_gcm(); |
| case 32: |
| return EVP_aes_256_gcm(); |
| } |
| *error = KM_ERROR_UNSUPPORTED_KEY_SIZE; |
| break; |
| |
| default: |
| *error = KM_ERROR_UNSUPPORTED_BLOCK_MODE; |
| break; |
| } |
| |
| assert(*error != KM_ERROR_OK); |
| return nullptr; |
| } |
| |
| static AesEvpCipherDescription description; |
| const EvpCipherDescription& AesOperationFactory::GetCipherDescription() const { |
| return description; |
| } |
| |
| } // namespace keymaster |