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Diffstat (limited to 'external/unbound/util/random.c')
| -rw-r--r-- | external/unbound/util/random.c | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/external/unbound/util/random.c b/external/unbound/util/random.c new file mode 100644 index 000000000..71f0ba53e --- /dev/null +++ b/external/unbound/util/random.c @@ -0,0 +1,166 @@ +/* + * util/random.c - thread safe random generator, which is reasonably secure. + * + * Copyright (c) 2007, NLnet Labs. All rights reserved. + * + * This software is open source. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * Neither the name of the NLNET LABS nor the names of its contributors may + * be used to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED + * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/** + * \file + * Thread safe random functions. Similar to arc4random() with an explicit + * initialisation routine. + * + * The code in this file is based on arc4random from + * openssh-4.0p1/openbsd-compat/bsd-arc4random.c + * That code is also BSD licensed. Here is their statement: + * + * Copyright (c) 1996, David Mazieres <dm@uun.org> + * Copyright (c) 2008, Damien Miller <djm@openbsd.org> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ +#include "config.h" +#include "util/random.h" +#include "util/log.h" +#include <time.h> + +#ifdef HAVE_NSS +/* nspr4 */ +#include "prerror.h" +/* nss3 */ +#include "secport.h" +#include "pk11pub.h" +#endif + +/** + * Max random value. Similar to RAND_MAX, but more portable + * (mingw uses only 15 bits random). + */ +#define MAX_VALUE 0x7fffffff + +#ifndef HAVE_NSS +void +ub_systemseed(unsigned int ATTR_UNUSED(seed)) +{ + /* arc4random_uniform does not need seeds, it gets kernel entropy */ +} + +struct ub_randstate* +ub_initstate(unsigned int ATTR_UNUSED(seed), + struct ub_randstate* ATTR_UNUSED(from)) +{ + struct ub_randstate* s = (struct ub_randstate*)malloc(1); + if(!s) { + log_err("malloc failure in random init"); + return NULL; + } + return s; +} + +long int +ub_random(struct ub_randstate* ATTR_UNUSED(s)) +{ + /* This relies on MAX_VALUE being 0x7fffffff. */ + return (long)arc4random() & MAX_VALUE; +} + +long int +ub_random_max(struct ub_randstate* state, long int x) +{ + (void)state; + /* on OpenBSD, this does not need _seed(), or _stir() calls */ + return (long)arc4random_uniform((uint32_t)x); +} + +#else + +/* not much to remember for NSS since we use its pk11_random, placeholder */ +struct ub_randstate { + int ready; +}; + +void ub_systemseed(unsigned int ATTR_UNUSED(seed)) +{ +} + +struct ub_randstate* ub_initstate(unsigned int ATTR_UNUSED(seed), + struct ub_randstate* ATTR_UNUSED(from)) +{ + struct ub_randstate* s = (struct ub_randstate*)calloc(1, sizeof(*s)); + if(!s) { + log_err("malloc failure in random init"); + return NULL; + } + return s; +} + +long int ub_random(struct ub_randstate* ATTR_UNUSED(state)) +{ + long int x; + /* random 31 bit value. */ + SECStatus s = PK11_GenerateRandom((unsigned char*)&x, (int)sizeof(x)); + if(s != SECSuccess) { + log_err("PK11_GenerateRandom error: %s", + PORT_ErrorToString(PORT_GetError())); + } + return x & MAX_VALUE; +} + +long int +ub_random_max(struct ub_randstate* state, long int x) +{ + /* make sure we fetch in a range that is divisible by x. ignore + * values from d .. MAX_VALUE, instead draw a new number */ + long int d = MAX_VALUE - (MAX_VALUE % x); /* d is divisible by x */ + long int v = ub_random(state); + while(d <= v) + v = ub_random(state); + return (v % x); +} +#endif /* HAVE_NSS */ + +void +ub_randfree(struct ub_randstate* s) +{ + if(s) + free(s); + /* user app must do RAND_cleanup(); */ +} |