Mercurial > dropbear
diff libtommath/bn_s_mp_rand_jenkins.c @ 1739:13d834efc376 fuzz
merge from main
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Thu, 15 Oct 2020 19:55:15 +0800 |
parents | 1051e4eea25a |
children |
line wrap: on
line diff
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/libtommath/bn_s_mp_rand_jenkins.c Thu Oct 15 19:55:15 2020 +0800 @@ -0,0 +1,52 @@ +#include "tommath_private.h" +#ifdef BN_S_MP_RAND_JENKINS_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis */ +/* SPDX-License-Identifier: Unlicense */ + +/* Bob Jenkins' http://burtleburtle.net/bob/rand/smallprng.html */ +/* Chosen for speed and a good "mix" */ +typedef struct { + uint64_t a; + uint64_t b; + uint64_t c; + uint64_t d; +} ranctx; + +static ranctx jenkins_x; + +#define rot(x,k) (((x)<<(k))|((x)>>(64-(k)))) +static uint64_t s_rand_jenkins_val(void) +{ + uint64_t e = jenkins_x.a - rot(jenkins_x.b, 7); + jenkins_x.a = jenkins_x.b ^ rot(jenkins_x.c, 13); + jenkins_x.b = jenkins_x.c + rot(jenkins_x.d, 37); + jenkins_x.c = jenkins_x.d + e; + jenkins_x.d = e + jenkins_x.a; + return jenkins_x.d; +} + +void s_mp_rand_jenkins_init(uint64_t seed) +{ + uint64_t i; + jenkins_x.a = 0xf1ea5eedULL; + jenkins_x.b = jenkins_x.c = jenkins_x.d = seed; + for (i = 0uLL; i < 20uLL; ++i) { + (void)s_rand_jenkins_val(); + } +} + +mp_err s_mp_rand_jenkins(void *p, size_t n) +{ + char *q = (char *)p; + while (n > 0u) { + int i; + uint64_t x = s_rand_jenkins_val(); + for (i = 0; (i < 8) && (n > 0u); ++i, --n) { + *q++ = (char)(x & 0xFFuLL); + x >>= 8; + } + } + return MP_OKAY; +} + +#endif