1 /* 2 * Copyright 2015 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_KDF_H_ 18 #define SYSTEM_KEYMASTER_KDF_H_ 19 20 #include <hardware/keymaster_defs.h> 21 #include <keymaster/android_keymaster_utils.h> 22 #include <keymaster/serializable.h> 23 24 #include <keymaster/UniquePtr.h> 25 26 namespace keymaster { 27 28 /** 29 * A base class for wrapping different key derivation functions. 30 */ 31 class Kdf { 32 public: ~Kdf()33 virtual ~Kdf() { memset_s(secret_key_.get(), 0, secret_key_len_); }; 34 Kdf(); 35 bool Init(keymaster_digest_t digest_type, const uint8_t* secret, size_t secret_len, 36 const uint8_t* salt, size_t salt_len); 37 virtual bool GenerateKey(const uint8_t* info, size_t info_len, uint8_t* output, 38 size_t output_len) = 0; 39 40 protected: 41 bool Uint32ToBigEndianByteArray(uint32_t number, uint8_t* output); 42 UniquePtr<uint8_t[]> secret_key_; 43 size_t secret_key_len_; 44 UniquePtr<uint8_t[]> salt_; 45 size_t salt_len_; 46 bool is_initialized_; 47 keymaster_digest_t digest_type_; 48 size_t digest_size_; 49 }; 50 51 } // namespace keymaster 52 53 #endif // SYSTEM_KEYMASTER_KDF_H_ 54