| /* |
| * 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 "symmetric_key.h" |
| |
| #include <assert.h> |
| |
| #include <openssl/err.h> |
| #include <openssl/rand.h> |
| |
| #include <keymaster/android_keymaster_utils.h> |
| #include <keymaster/logger.h> |
| #include <keymaster/keymaster_context.h> |
| |
| #include "aes_key.h" |
| #include "hmac_key.h" |
| #include "openssl_err.h" |
| |
| namespace keymaster { |
| |
| keymaster_error_t SymmetricKeyFactory::GenerateKey(const AuthorizationSet& key_description, |
| KeymasterKeyBlob* key_blob, |
| AuthorizationSet* hw_enforced, |
| AuthorizationSet* sw_enforced) const { |
| if (!key_blob || !hw_enforced || !sw_enforced) |
| return KM_ERROR_OUTPUT_PARAMETER_NULL; |
| |
| uint32_t key_size_bits; |
| if (!key_description.GetTagValue(TAG_KEY_SIZE, &key_size_bits) || |
| !key_size_supported(key_size_bits)) |
| return KM_ERROR_UNSUPPORTED_KEY_SIZE; |
| |
| keymaster_error_t error = validate_algorithm_specific_new_key_params(key_description); |
| if (error != KM_ERROR_OK) |
| return error; |
| |
| size_t key_data_size = key_size_bits / 8; |
| KeymasterKeyBlob key_material(key_data_size); |
| if (!key_material.key_material) |
| return KM_ERROR_MEMORY_ALLOCATION_FAILED; |
| |
| error = context_->GenerateRandom(key_material.writable_data(), key_data_size); |
| if (error != KM_ERROR_OK) { |
| LOG_E("Error generating %d bit symmetric key", key_size_bits); |
| return error; |
| } |
| |
| return context_->CreateKeyBlob(key_description, KM_ORIGIN_GENERATED, key_material, key_blob, |
| hw_enforced, sw_enforced); |
| } |
| |
| keymaster_error_t SymmetricKeyFactory::ImportKey(const AuthorizationSet& key_description, |
| keymaster_key_format_t input_key_material_format, |
| const KeymasterKeyBlob& input_key_material, |
| KeymasterKeyBlob* output_key_blob, |
| AuthorizationSet* hw_enforced, |
| AuthorizationSet* sw_enforced) const { |
| if (!output_key_blob || !hw_enforced || !sw_enforced) |
| return KM_ERROR_OUTPUT_PARAMETER_NULL; |
| |
| AuthorizationSet authorizations(key_description); |
| |
| uint32_t key_size_bits; |
| if (!authorizations.GetTagValue(TAG_KEY_SIZE, &key_size_bits)) { |
| // Default key size if not specified. |
| key_size_bits = input_key_material.key_material_size * 8; |
| authorizations.push_back(TAG_KEY_SIZE, key_size_bits); |
| } |
| |
| keymaster_error_t error = validate_algorithm_specific_new_key_params(key_description); |
| if (error != KM_ERROR_OK) |
| return error; |
| |
| if (!key_size_supported(key_size_bits)) |
| return KM_ERROR_UNSUPPORTED_KEY_SIZE; |
| |
| if (input_key_material_format != KM_KEY_FORMAT_RAW) |
| return KM_ERROR_UNSUPPORTED_KEY_FORMAT; |
| |
| if (key_size_bits != input_key_material.key_material_size * 8) { |
| LOG_E("Expected %d-bit key data but got %d bits", key_size_bits, |
| input_key_material.key_material_size * 8); |
| return KM_ERROR_INVALID_KEY_BLOB; |
| } |
| |
| return context_->CreateKeyBlob(authorizations, KM_ORIGIN_IMPORTED, input_key_material, |
| output_key_blob, hw_enforced, sw_enforced); |
| } |
| |
| static const keymaster_key_format_t supported_import_formats[] = {KM_KEY_FORMAT_RAW}; |
| const keymaster_key_format_t* |
| SymmetricKeyFactory::SupportedImportFormats(size_t* format_count) const { |
| *format_count = array_length(supported_import_formats); |
| return supported_import_formats; |
| } |
| |
| SymmetricKey::SymmetricKey(const KeymasterKeyBlob& key_material, |
| const AuthorizationSet& hw_enforced, const AuthorizationSet& sw_enforced, |
| keymaster_error_t* error) |
| : Key(hw_enforced, sw_enforced, error) { |
| if (*error != KM_ERROR_OK) |
| return; |
| |
| uint8_t* tmp = dup_buffer(key_material.key_material, key_material.key_material_size); |
| if (tmp) { |
| key_data_.reset(tmp); |
| key_data_size_ = key_material.key_material_size; |
| *error = KM_ERROR_OK; |
| } else { |
| *error = KM_ERROR_MEMORY_ALLOCATION_FAILED; |
| } |
| } |
| |
| SymmetricKey::~SymmetricKey() { |
| memset_s(key_data_.get(), 0, key_data_size_); |
| } |
| |
| keymaster_error_t SymmetricKey::key_material(UniquePtr<uint8_t[]>* key_material, |
| size_t* size) const { |
| *size = key_data_size_; |
| key_material->reset(new (std::nothrow) uint8_t[*size]); |
| if (!key_material->get()) |
| return KM_ERROR_MEMORY_ALLOCATION_FAILED; |
| memcpy(key_material->get(), key_data_.get(), *size); |
| return KM_ERROR_OK; |
| } |
| |
| } // namespace keymaster |