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 "symmetric_key.h" 20 21 namespace keymaster { 22 23 const size_t kMinHmacLengthBits = 64; 24 const size_t kMinHmacKeyLengthBits = 64; 25 const size_t kMaxHmacKeyLengthBits = 2048; // Some RFC test cases require >1024-bit keys 26 27 class HmacKeyFactory : public SymmetricKeyFactory { 28 public: HmacKeyFactory(const SoftwareKeyBlobMaker & blob_maker,const RandomSource & random_source)29 explicit HmacKeyFactory(const SoftwareKeyBlobMaker& blob_maker, 30 const RandomSource& random_source) 31 : SymmetricKeyFactory(blob_maker, random_source) {} 32 33 keymaster_error_t LoadKey(KeymasterKeyBlob&& key_material, 34 const AuthorizationSet& additional_params, 35 AuthorizationSet&& hw_enforced, AuthorizationSet&& sw_enforced, 36 UniquePtr<Key>* key) const override; 37 38 OperationFactory* GetOperationFactory(keymaster_purpose_t purpose) const override; 39 40 private: key_size_supported(size_t key_size_bits)41 bool key_size_supported(size_t key_size_bits) const override { 42 return key_size_bits > 0 && key_size_bits % 8 == 00 && 43 key_size_bits >= kMinHmacKeyLengthBits && key_size_bits <= kMaxHmacKeyLengthBits; 44 } 45 keymaster_error_t validate_algorithm_specific_new_key_params( 46 const AuthorizationSet& key_description) const override; 47 }; 48 49 class HmacKey : public SymmetricKey { 50 public: HmacKey(KeymasterKeyBlob && key_material,AuthorizationSet && hw_enforced,AuthorizationSet && sw_enforced,const KeyFactory * key_factory)51 HmacKey(KeymasterKeyBlob&& key_material, AuthorizationSet&& hw_enforced, 52 AuthorizationSet&& sw_enforced, const KeyFactory* key_factory) 53 : SymmetricKey(move(key_material), move(hw_enforced), move(sw_enforced), key_factory) {} 54 }; 55 56 } // namespace keymaster 57