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 #ifndef SYSTEM_KEYMASTER_HMAC_KEY_H_ 18 #define SYSTEM_KEYMASTER_HMAC_KEY_H_ 19 20 #include "symmetric_key.h" 21 22 namespace keymaster { 23 24 const size_t kMinHmacLengthBits = 64; 25 const size_t kMinHmacKeyLengthBits = 64; 26 const size_t kMaxHmacKeyLengthBits = 2048; // Some RFC test cases require >1024-bit keys 27 28 class HmacKeyFactory : public SymmetricKeyFactory { 29 public: 30 explicit HmacKeyFactory(const SoftwareKeyBlobMaker* blob_maker, 31 const RandomSource* random_source) : 32 SymmetricKeyFactory(blob_maker, random_source) {} 33 34 keymaster_error_t LoadKey(KeymasterKeyBlob&& key_material, 35 const AuthorizationSet& additional_params, 36 AuthorizationSet&& hw_enforced, 37 AuthorizationSet&& sw_enforced, 38 UniquePtr<Key>* key) const override; 39 40 OperationFactory* GetOperationFactory(keymaster_purpose_t purpose) const override; 41 42 private: 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: 53 HmacKey(KeymasterKeyBlob&& key_material, AuthorizationSet&& hw_enforced, 54 AuthorizationSet&& sw_enforced, const KeyFactory* key_factory) 55 : SymmetricKey(move(key_material), move(hw_enforced), move(sw_enforced), key_factory) {} 56 }; 57 58 } // namespace keymaster 59 60 #endif // SYSTEM_KEYMASTER_HMAC_KEY_H_ 61
