1/* 2 * Copyright (c) 2000-2004,2006 Apple Computer, Inc. All Rights Reserved. 3 * 4 * @APPLE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. Please obtain a copy of the License at 10 * http://www.opensource.apple.com/apsl/ and read it before using this 11 * file. 12 * 13 * The Original Code and all software distributed under the License are 14 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 15 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 16 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 18 * Please see the License for the specific language governing rights and 19 * limitations under the License. 20 * 21 * @APPLE_LICENSE_HEADER_END@ 22 */ 23 24 25// 26// entropy - periodical to collect and seed entropy into /dev/random 27// 28#ifndef _H_ENTROPY 29#define _H_ENTROPY 30 31#include <security_utilities/machserver.h> 32#include <security_utilities/timeflow.h> 33#include <security_utilities/devrandom.h> 34 35using namespace Security; 36using MachPlusPlus::MachServer; 37 38 39// 40// A (one-off) timer object that manages system entropy 41// 42class EntropyManager : public MachServer::Timer, private DevRandomGenerator { 43 // all the parameters you ever (should) want to change :-) 44 static const int collectInterval = 600; // collect every 10 minutes 45 static const int updateInterval = 3600 * 6; // update file every 6 hours 46 static const int timingsToCollect = 40; // how many timings? 47 48public: 49 EntropyManager(MachPlusPlus::MachServer &srv, const char *entropyFile); 50 51 void action(); 52 53 MachPlusPlus::MachServer &server; // to which we do setTimer() 54 55private: 56 string mEntropyFilePath; // absolute path to entropy file 57 Time::Absolute mNextUpdate; // next time for entropy file update 58 59 void collectEntropy(); // collect system timings and seed RNG 60 void updateEntropyFile(); // update entropy file from RNG if it's time 61 62 static const size_t entropyFileSize = 20; // bytes (effectively one SHA-1 worth) 63}; 64 65#endif //_H_ENTROPY 66