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