| /* |
| * 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_key.h" |
| |
| #include <assert.h> |
| |
| #include <openssl/err.h> |
| #include <openssl/rand.h> |
| |
| #include "aes_operation.h" |
| #include "unencrypted_key_blob.h" |
| |
| namespace keymaster { |
| |
| Operation* AesKey::CreateOperation(keymaster_purpose_t purpose, keymaster_error_t* error) { |
| keymaster_block_mode_t block_mode; |
| if (!authorizations().GetTagValue(TAG_BLOCK_MODE, &block_mode)) { |
| *error = KM_ERROR_UNSUPPORTED_BLOCK_MODE; |
| return NULL; |
| } |
| |
| switch (block_mode) { |
| case KM_MODE_OCB: |
| return CreateOcbOperation(purpose, error); |
| default: |
| *error = KM_ERROR_UNSUPPORTED_BLOCK_MODE; |
| return NULL; |
| } |
| } |
| |
| Operation* AesKey::CreateOcbOperation(keymaster_purpose_t purpose, keymaster_error_t* error) { |
| *error = KM_ERROR_OK; |
| |
| if (key_data_size() != 16 && key_data_size() != 24 && key_data_size() != 32) |
| *error = KM_ERROR_UNSUPPORTED_KEY_SIZE; |
| |
| uint32_t chunk_length; |
| if (!authorizations().GetTagValue(TAG_CHUNK_LENGTH, &chunk_length)) |
| // TODO(swillden): Create and use a better return code. |
| *error = KM_ERROR_INVALID_ARGUMENT; |
| |
| uint32_t tag_length; |
| if (!authorizations().GetTagValue(TAG_MAC_LENGTH, &tag_length)) |
| // TODO(swillden): Create and use a better return code. |
| *error = KM_ERROR_INVALID_ARGUMENT; |
| |
| keymaster_padding_t padding; |
| if (authorizations().GetTagValue(TAG_PADDING, &padding) && padding != KM_PAD_NONE) { |
| *error = KM_ERROR_UNSUPPORTED_PADDING_MODE; |
| } |
| |
| if (*error != KM_ERROR_OK) |
| return NULL; |
| |
| keymaster_blob_t additional_data = {0, 0}; |
| authorizations().GetTagValue(TAG_ASSOCIATED_DATA, &additional_data); |
| |
| UniquePtr<Operation> op; |
| switch (purpose) { |
| case KM_PURPOSE_ENCRYPT: |
| case KM_PURPOSE_DECRYPT: |
| op.reset(new AesOcbOperation(purpose, logger_, key_data(), key_data_size(), chunk_length, |
| tag_length, additional_data)); |
| break; |
| default: |
| *error = KM_ERROR_UNSUPPORTED_PURPOSE; |
| return NULL; |
| } |
| |
| if (!op.get()) |
| *error = KM_ERROR_MEMORY_ALLOCATION_FAILED; |
| |
| return op.release(); |
| } |
| |
| } // namespace keymaster |