dropbear: libtommath/bn_mp_expt_d

annotate libtommath/bn_mp_expt_d_ex.c @ 1663:c795520269f9

Fallback for key gen without hard link support (#89) Add a non-atomic fallback for key generation on platforms where link() is not permitted (such as most stock Android installs) or on filesystems without hard link support (such as FAT).

author	Matt Robinson <git@nerdoftheherd.com>
date	Sat, 14 Mar 2020 14:37:35 +0000
parents	f52919ffd3b1
children

rev	line source
1655 f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	1 #include "tommath_private.h"
1436 60fc6476e044 Update to libtommath v1.0 Matt Johnston <matt@ucc.asn.au> parents: diff changeset	2 #ifdef BN_MP_EXPT_D_EX_C
60fc6476e044 Update to libtommath v1.0 Matt Johnston <matt@ucc.asn.au> parents: diff changeset	3 /* LibTomMath, multiple-precision integer library -- Tom St Denis
60fc6476e044 Update to libtommath v1.0 Matt Johnston <matt@ucc.asn.au> parents: diff changeset	4 *
60fc6476e044 Update to libtommath v1.0 Matt Johnston <matt@ucc.asn.au> parents: diff changeset	5 * LibTomMath is a library that provides multiple-precision
60fc6476e044 Update to libtommath v1.0 Matt Johnston <matt@ucc.asn.au> parents: diff changeset	6 * integer arithmetic as well as number theoretic functionality.
60fc6476e044 Update to libtommath v1.0 Matt Johnston <matt@ucc.asn.au> parents: diff changeset	7 *
60fc6476e044 Update to libtommath v1.0 Matt Johnston <matt@ucc.asn.au> parents: diff changeset	8 * The library was designed directly after the MPI library by
60fc6476e044 Update to libtommath v1.0 Matt Johnston <matt@ucc.asn.au> parents: diff changeset	9 * Michael Fromberger but has been written from scratch with
60fc6476e044 Update to libtommath v1.0 Matt Johnston <matt@ucc.asn.au> parents: diff changeset	10 * additional optimizations in place.
60fc6476e044 Update to libtommath v1.0 Matt Johnston <matt@ucc.asn.au> parents: diff changeset	11 *
1655 f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	12 * SPDX-License-Identifier: Unlicense
1436 60fc6476e044 Update to libtommath v1.0 Matt Johnston <matt@ucc.asn.au> parents: diff changeset	13 */
60fc6476e044 Update to libtommath v1.0 Matt Johnston <matt@ucc.asn.au> parents: diff changeset	14
60fc6476e044 Update to libtommath v1.0 Matt Johnston <matt@ucc.asn.au> parents: diff changeset	15 /* calculate c = a*b using a square-multiply algorithm /
1655 f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	16 int mp_expt_d_ex(const mp_int a, mp_digit b, mp_int c, int fast)
1436 60fc6476e044 Update to libtommath v1.0 Matt Johnston <matt@ucc.asn.au> parents: diff changeset	17 {
1655 f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	18 int res;
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	19 unsigned int x;
1436 60fc6476e044 Update to libtommath v1.0 Matt Johnston <matt@ucc.asn.au> parents: diff changeset	20
1655 f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	21 mp_int g;
1436 60fc6476e044 Update to libtommath v1.0 Matt Johnston <matt@ucc.asn.au> parents: diff changeset	22
1655 f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	23 if ((res = mp_init_copy(&g, a)) != MP_OKAY) {
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	24 return res;
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	25 }
1436 60fc6476e044 Update to libtommath v1.0 Matt Johnston <matt@ucc.asn.au> parents: diff changeset	26
1655 f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	27 /* set initial result */
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	28 mp_set(c, 1uL);
1436 60fc6476e044 Update to libtommath v1.0 Matt Johnston <matt@ucc.asn.au> parents: diff changeset	29
1655 f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	30 if (fast != 0) {
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	31 while (b > 0u) {
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	32 /* if the bit is set multiply */
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	33 if ((b & 1u) != 0u) {
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	34 if ((res = mp_mul(c, &g, c)) != MP_OKAY) {
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	35 mp_clear(&g);
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	36 return res;
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	37 }
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	38 }
1436 60fc6476e044 Update to libtommath v1.0 Matt Johnston <matt@ucc.asn.au> parents: diff changeset	39
1655 f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	40 /* square */
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	41 if (b > 1u) {
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	42 if ((res = mp_sqr(&g, &g)) != MP_OKAY) {
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	43 mp_clear(&g);
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	44 return res;
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	45 }
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	46 }
1436 60fc6476e044 Update to libtommath v1.0 Matt Johnston <matt@ucc.asn.au> parents: diff changeset	47
1655 f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	48 /* shift to next bit */
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	49 b >>= 1;
1436 60fc6476e044 Update to libtommath v1.0 Matt Johnston <matt@ucc.asn.au> parents: diff changeset	50 }
1655 f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	51 } else {
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	52 for (x = 0; x < (unsigned)DIGIT_BIT; x++) {
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	53 /* square */
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	54 if ((res = mp_sqr(c, c)) != MP_OKAY) {
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	55 mp_clear(&g);
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	56 return res;
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	57 }
1436 60fc6476e044 Update to libtommath v1.0 Matt Johnston <matt@ucc.asn.au> parents: diff changeset	58
1655 f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	59 /* if the bit is set multiply */
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	60 if ((b & ((mp_digit)1 << (DIGIT_BIT - 1))) != 0u) {
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	61 if ((res = mp_mul(c, &g, c)) != MP_OKAY) {
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	62 mp_clear(&g);
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	63 return res;
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	64 }
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	65 }
1436 60fc6476e044 Update to libtommath v1.0 Matt Johnston <matt@ucc.asn.au> parents: diff changeset	66
1655 f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	67 /* shift to next bit */
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	68 b <<= 1;
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	69 }
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	70 } /* if ... else */
1436 60fc6476e044 Update to libtommath v1.0 Matt Johnston <matt@ucc.asn.au> parents: diff changeset	71
1655 f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	72 mp_clear(&g);
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	73 return MP_OKAY;
1436 60fc6476e044 Update to libtommath v1.0 Matt Johnston <matt@ucc.asn.au> parents: diff changeset	74 }
60fc6476e044 Update to libtommath v1.0 Matt Johnston <matt@ucc.asn.au> parents: diff changeset	75 #endif
60fc6476e044 Update to libtommath v1.0 Matt Johnston <matt@ucc.asn.au> parents: diff changeset	76
1655 f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	77 /* ref: HEAD -> master, tag: v1.1.0 */
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	78 /* git commit: 08549ad6bc8b0cede0b357a9c341c5c6473a9c55 */
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1470 diff changeset	79 /* commit time: 2019-01-28 20:32:32 +0100 */

Mercurial > dropbear

annotate libtommath/bn_mp_expt_d_ex.c @ 1663:c795520269f9