1 /* 2 * util/random.c - thread safe random generator, which is reasonably secure. 3 * 4 * Copyright (c) 2007, NLnet Labs. All rights reserved. 5 * 6 * This software is open source. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * Redistributions of source code must retain the above copyright notice, 13 * this list of conditions and the following disclaimer. 14 * 15 * Redistributions in binary form must reproduce the above copyright notice, 16 * this list of conditions and the following disclaimer in the documentation 17 * and/or other materials provided with the distribution. 18 * 19 * Neither the name of the NLNET LABS nor the names of its contributors may 20 * be used to endorse or promote products derived from this software without 21 * specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 24 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 25 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 26 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 27 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 28 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 29 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 30 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 31 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 32 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 33 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 34 */ 35 36 /** 37 * \file 38 * Thread safe random functions. Similar to arc4random() with an explicit 39 * initialisation routine. 40 * 41 * The code in this file is based on arc4random from 42 * openssh-4.0p1/openbsd-compat/bsd-arc4random.c 43 * That code is also BSD licensed. Here is their statement: 44 * 45 * Copyright (c) 1996, David Mazieres <dm@uun.org> 46 * Copyright (c) 2008, Damien Miller <djm@openbsd.org> 47 * 48 * Permission to use, copy, modify, and distribute this software for any 49 * purpose with or without fee is hereby granted, provided that the above 50 * copyright notice and this permission notice appear in all copies. 51 * 52 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 53 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 54 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 55 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 56 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 57 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 58 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 59 */ 60 #include "config.h" 61 #include "util/random.h" 62 #include "util/log.h" 63 #include <time.h> 64 65 /** 66 * Max random value. Similar to RAND_MAX, but more portable 67 * (mingw uses only 15 bits random). 68 */ 69 #define MAX_VALUE 0x7fffffff 70 71 void 72 ub_systemseed(unsigned int seed) 73 { 74 } 75 76 struct ub_randstate* 77 ub_initstate(unsigned int seed, struct ub_randstate* from) 78 { 79 struct ub_randstate* s = (struct ub_randstate*)malloc(0); 80 if(!s) { 81 log_err("malloc failure in random init"); 82 return NULL; 83 } 84 return s; 85 } 86 87 long int 88 ub_random(struct ub_randstate* s) 89 { 90 /* This relies on MAX_VALUE being 0x7fffffff. */ 91 return (long)arc4random() & MAX_VALUE; 92 } 93 94 long int 95 ub_random_max(struct ub_randstate* state, long int x) 96 { 97 return (long)arc4random_uniform(x); 98 } 99 100 void 101 ub_randfree(struct ub_randstate* s) 102 { 103 if(s) 104 free(s); 105 } 106