| /* |
| * 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 <keymaster/km_openssl/aes_key.h> |
| |
| #include <assert.h> |
| |
| #include <keymaster/new> |
| |
| #include <openssl/err.h> |
| #include <openssl/rand.h> |
| |
| #include "aes_operation.h" |
| |
| namespace keymaster { |
| |
| static AesOperationFactory encrypt_factory(KM_PURPOSE_ENCRYPT); |
| static AesOperationFactory decrypt_factory(KM_PURPOSE_DECRYPT); |
| |
| OperationFactory* AesKeyFactory::GetOperationFactory(keymaster_purpose_t purpose) const { |
| switch (purpose) { |
| case KM_PURPOSE_ENCRYPT: |
| return &encrypt_factory; |
| case KM_PURPOSE_DECRYPT: |
| return &decrypt_factory; |
| default: |
| return nullptr; |
| } |
| } |
| |
| keymaster_error_t AesKeyFactory::LoadKey(KeymasterKeyBlob&& key_material, |
| const AuthorizationSet& /* additional_params */, |
| AuthorizationSet&& hw_enforced, |
| AuthorizationSet&& sw_enforced, |
| UniquePtr<Key>* key) const { |
| if (!key) |
| return KM_ERROR_OUTPUT_PARAMETER_NULL; |
| |
| uint32_t min_mac_length = 0; |
| if (hw_enforced.Contains(TAG_BLOCK_MODE, KM_MODE_GCM) || |
| sw_enforced.Contains(TAG_BLOCK_MODE, KM_MODE_GCM)) { |
| |
| if (!hw_enforced.GetTagValue(TAG_MIN_MAC_LENGTH, &min_mac_length) && |
| !sw_enforced.GetTagValue(TAG_MIN_MAC_LENGTH, &min_mac_length)) { |
| |
| LOG_E("AES-GCM key must have KM_TAG_MIN_MAC_LENGTH", 0); |
| return KM_ERROR_INVALID_KEY_BLOB; |
| } |
| } |
| |
| keymaster_error_t error = KM_ERROR_OK; |
| key->reset(new (std::nothrow) AesKey(move(key_material), move(hw_enforced), move(sw_enforced), |
| this)); |
| if (!key->get()) |
| error = KM_ERROR_MEMORY_ALLOCATION_FAILED; |
| return error; |
| } |
| |
| keymaster_error_t AesKeyFactory::validate_algorithm_specific_new_key_params( |
| const AuthorizationSet& key_description) const { |
| if (key_description.Contains(TAG_BLOCK_MODE, KM_MODE_GCM)) { |
| uint32_t min_tag_length; |
| if (!key_description.GetTagValue(TAG_MIN_MAC_LENGTH, &min_tag_length)) |
| return KM_ERROR_MISSING_MIN_MAC_LENGTH; |
| |
| if (min_tag_length % 8 != 0) |
| return KM_ERROR_UNSUPPORTED_MIN_MAC_LENGTH; |
| |
| if (min_tag_length < kMinGcmTagLength || min_tag_length > kMaxGcmTagLength) |
| return KM_ERROR_UNSUPPORTED_MIN_MAC_LENGTH; |
| } else { |
| // Not GCM |
| if (key_description.find(TAG_MIN_MAC_LENGTH) != -1) { |
| LOG_W("KM_TAG_MIN_MAC_LENGTH found for non AES-GCM key", 0); |
| return KM_ERROR_INVALID_TAG; |
| } |
| } |
| |
| return KM_ERROR_OK; |
| } |
| |
| } // namespace keymaster |