Mercurial > dropbear

comparison libtommath/bn_s_mp_rand_jenkins.c @ 1739:13d834efc376 fuzz

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
merge from main
author Matt Johnston <matt@ucc.asn.au>
date Thu, 15 Oct 2020 19:55:15 +0800
parents 1051e4eea25a
children
comparison
equal deleted inserted replaced
1562:768ebf737aa0 1739:13d834efc376
1 #include "tommath_private.h"
2 #ifdef BN_S_MP_RAND_JENKINS_C
3 /* LibTomMath, multiple-precision integer library -- Tom St Denis */
4 /* SPDX-License-Identifier: Unlicense */
5
6 /* Bob Jenkins' http://burtleburtle.net/bob/rand/smallprng.html */
7 /* Chosen for speed and a good "mix" */
8 typedef struct {
9 uint64_t a;
10 uint64_t b;
11 uint64_t c;
12 uint64_t d;
13 } ranctx;
14
15 static ranctx jenkins_x;
16
17 #define rot(x,k) (((x)<<(k))|((x)>>(64-(k))))
18 static uint64_t s_rand_jenkins_val(void)
19 {
20 uint64_t e = jenkins_x.a - rot(jenkins_x.b, 7);
21 jenkins_x.a = jenkins_x.b ^ rot(jenkins_x.c, 13);
22 jenkins_x.b = jenkins_x.c + rot(jenkins_x.d, 37);
23 jenkins_x.c = jenkins_x.d + e;
24 jenkins_x.d = e + jenkins_x.a;
25 return jenkins_x.d;
26 }
27
28 void s_mp_rand_jenkins_init(uint64_t seed)
29 {
30 uint64_t i;
31 jenkins_x.a = 0xf1ea5eedULL;
32 jenkins_x.b = jenkins_x.c = jenkins_x.d = seed;
33 for (i = 0uLL; i < 20uLL; ++i) {
34 (void)s_rand_jenkins_val();
35 }
36 }
37
38 mp_err s_mp_rand_jenkins(void *p, size_t n)
39 {
40 char *q = (char *)p;
41 while (n > 0u) {
42 int i;
43 uint64_t x = s_rand_jenkins_val();
44 for (i = 0; (i < 8) && (n > 0u); ++i, --n) {
45 *q++ = (char)(x & 0xFFuLL);
46 x >>= 8;
47 }
48 }
49 return MP_OKAY;
50 }
51
52 #endif