1 /* 2 * Copyright 2014 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #pragma once 18 19 #include <utility> 20 21 #include "symmetric_key.h" 22 23 namespace keymaster { 24 25 const size_t kMinHmacLengthBits = 64; 26 const size_t kMinHmacKeyLengthBits = 64; 27 const size_t kMaxHmacKeyLengthBits = 2048; // Some RFC test cases require >1024-bit keys 28 29 class HmacKeyFactory : public SymmetricKeyFactory { 30 public: HmacKeyFactory(const SoftwareKeyBlobMaker & blob_maker,const RandomSource & random_source)31 explicit HmacKeyFactory(const SoftwareKeyBlobMaker& blob_maker, 32 const RandomSource& random_source) 33 : SymmetricKeyFactory(blob_maker, random_source) {} 34 35 keymaster_error_t LoadKey(KeymasterKeyBlob&& key_material, 36 const AuthorizationSet& additional_params, 37 AuthorizationSet&& hw_enforced, AuthorizationSet&& sw_enforced, 38 UniquePtr<Key>* key) const override; 39 40 OperationFactory* GetOperationFactory(keymaster_purpose_t purpose) const override; 41 42 private: key_size_supported(size_t key_size_bits)43 bool key_size_supported(size_t key_size_bits) const override { 44 return key_size_bits > 0 && key_size_bits % 8 == 00 && 45 key_size_bits >= kMinHmacKeyLengthBits && key_size_bits <= kMaxHmacKeyLengthBits; 46 } 47 keymaster_error_t validate_algorithm_specific_new_key_params( 48 const AuthorizationSet& key_description) const override; 49 }; 50 51 class HmacKey : public SymmetricKey { 52 public: HmacKey(KeymasterKeyBlob && key_material,AuthorizationSet && hw_enforced,AuthorizationSet && sw_enforced,const KeyFactory * key_factory)53 HmacKey(KeymasterKeyBlob&& key_material, AuthorizationSet&& hw_enforced, 54 AuthorizationSet&& sw_enforced, const KeyFactory* key_factory) 55 : SymmetricKey(std::move(key_material), std::move(hw_enforced), std::move(sw_enforced), 56 key_factory) {} 57 }; 58 59 } // namespace keymaster 60