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_HKDF_H_ 18 #define SYSTEM_KEYMASTER_HKDF_H_ 19 20 #include "kdf.h" 21 22 #include <keymaster/serializable.h> 23 24 #include <keymaster/UniquePtr.h> 25 26 namespace keymaster { 27 28 /** 29 * Rfc5869Sha256Kdf implements the key derivation function specified in RFC 5869 (using SHA256) and 30 * outputs key material, as needed by ECIES. See https://tools.ietf.org/html/rfc5869 for details. 31 */ 32 class Rfc5869Sha256Kdf : public Kdf { 33 public: 34 ~Rfc5869Sha256Kdf() {} 35 bool Init(Buffer& secret, Buffer& salt) { 36 return Init(secret.peek_read(), secret.available_read(), salt.peek_read(), 37 salt.available_read()); 38 } 39 40 bool Init(const uint8_t* secret, size_t secret_len, const uint8_t* salt, size_t salt_len) { 41 return Kdf::Init(KM_DIGEST_SHA_2_256, secret, secret_len, salt, salt_len); 42 } 43 44 bool GenerateKey(const uint8_t* info, size_t info_len, uint8_t* output, 45 size_t output_len) override; 46 }; 47 48 } // namespace keymaster 49 50 #endif // SYSTEM_KEYMASTER_HKDF_H_ 51
