/*
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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 <keymaster/km_openssl/symmetric_key.h>
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#include <assert.h>
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#include <openssl/err.h>
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#include <openssl/rand.h>
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#include <keymaster/android_keymaster_utils.h>
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#include <keymaster/keymaster_context.h>
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#include <keymaster/km_openssl/aes_key.h>
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#include <keymaster/km_openssl/hmac_key.h>
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#include <keymaster/km_openssl/openssl_err.h>
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#include <keymaster/logger.h>
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namespace keymaster {
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keymaster_error_t SymmetricKeyFactory::GenerateKey(const AuthorizationSet& key_description,
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KeymasterKeyBlob* key_blob,
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AuthorizationSet* hw_enforced,
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AuthorizationSet* sw_enforced) const {
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if (!key_blob || !hw_enforced || !sw_enforced)
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return KM_ERROR_OUTPUT_PARAMETER_NULL;
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uint32_t key_size_bits;
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if (!key_description.GetTagValue(TAG_KEY_SIZE, &key_size_bits) ||
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!key_size_supported(key_size_bits))
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return KM_ERROR_UNSUPPORTED_KEY_SIZE;
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keymaster_error_t error = validate_algorithm_specific_new_key_params(key_description);
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if (error != KM_ERROR_OK)
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return error;
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size_t key_data_size = key_size_bytes(key_size_bits);
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KeymasterKeyBlob key_material(key_data_size);
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if (!key_material.key_material)
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return KM_ERROR_MEMORY_ALLOCATION_FAILED;
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error = random_source_.GenerateRandom(key_material.writable_data(), key_data_size);
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if (error != KM_ERROR_OK) {
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LOG_E("Error generating %d bit symmetric key", key_size_bits);
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return error;
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}
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return blob_maker_.CreateKeyBlob(key_description, KM_ORIGIN_GENERATED, key_material, key_blob,
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hw_enforced, sw_enforced);
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}
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keymaster_error_t SymmetricKeyFactory::ImportKey(const AuthorizationSet& key_description,
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keymaster_key_format_t input_key_material_format,
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const KeymasterKeyBlob& input_key_material,
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KeymasterKeyBlob* output_key_blob,
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AuthorizationSet* hw_enforced,
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AuthorizationSet* sw_enforced) const {
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if (!output_key_blob || !hw_enforced || !sw_enforced)
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return KM_ERROR_OUTPUT_PARAMETER_NULL;
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AuthorizationSet authorizations(key_description);
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uint32_t key_bits;
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if (!authorizations.GetTagValue(TAG_KEY_SIZE, &key_bits)) {
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// Determine key size if not provided.
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key_bits = key_size_bits(input_key_material.key_material_size);
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authorizations.push_back(TAG_KEY_SIZE, key_bits);
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}
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keymaster_error_t error = validate_algorithm_specific_new_key_params(key_description);
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if (error != KM_ERROR_OK) return error;
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if (!key_size_supported(key_bits)) return KM_ERROR_UNSUPPORTED_KEY_SIZE;
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if (input_key_material_format != KM_KEY_FORMAT_RAW) return KM_ERROR_UNSUPPORTED_KEY_FORMAT;
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if (key_bits != key_size_bits(input_key_material.key_material_size)) {
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LOG_E("Expected %d-bit key data but got %d-bit key", key_bits,
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key_size_bits(input_key_material.key_material_size));
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return KM_ERROR_INVALID_KEY_BLOB;
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}
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return blob_maker_.CreateKeyBlob(authorizations, KM_ORIGIN_IMPORTED, input_key_material,
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output_key_blob, hw_enforced, sw_enforced);
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}
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static const keymaster_key_format_t supported_import_formats[] = {KM_KEY_FORMAT_RAW};
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const keymaster_key_format_t*
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SymmetricKeyFactory::SupportedImportFormats(size_t* format_count) const {
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*format_count = array_length(supported_import_formats);
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return supported_import_formats;
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}
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SymmetricKey::SymmetricKey(KeymasterKeyBlob&& key_material,
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AuthorizationSet&& hw_enforced, AuthorizationSet&& sw_enforced,
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const KeyFactory* key_factory)
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: Key(move(hw_enforced), move(sw_enforced), key_factory) {
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key_material_ = move(key_material);
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}
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SymmetricKey::~SymmetricKey() {}
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} // namespace keymaster
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