dropbear/libtommath/bn_mp_set_int.c
Steffen Jaeckel 615ed4e46a update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79)
* make key-generation compliant to FIPS 186.4

* fix includes in tommath_class.h

* update fuzzcorpus instead of error-out

* fixup fuzzing make-targets

* update Makefile.in

* apply necessary patches to ltm sources

* clean-up not required ltm files

* update to vanilla ltm 1.1.0

this already only contains the required files

* remove set/get double
2019-09-16 21:50:38 +08:00

46 lines
1.2 KiB
C

#include "tommath_private.h"
#ifdef BN_MP_SET_INT_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis
*
* LibTomMath is a library that provides multiple-precision
* integer arithmetic as well as number theoretic functionality.
*
* The library was designed directly after the MPI library by
* Michael Fromberger but has been written from scratch with
* additional optimizations in place.
*
* SPDX-License-Identifier: Unlicense
*/
/* set a 32-bit const */
int mp_set_int(mp_int *a, unsigned long b)
{
int x, res;
mp_zero(a);
/* set four bits at a time */
for (x = 0; x < 8; x++) {
/* shift the number up four bits */
if ((res = mp_mul_2d(a, 4, a)) != MP_OKAY) {
return res;
}
/* OR in the top four bits of the source */
a->dp[0] |= (mp_digit)(b >> 28) & 15uL;
/* shift the source up to the next four bits */
b <<= 4;
/* ensure that digits are not clamped off */
a->used += 1;
}
mp_clamp(a);
return MP_OKAY;
}
#endif
/* ref: HEAD -> master, tag: v1.1.0 */
/* git commit: 08549ad6bc8b0cede0b357a9c341c5c6473a9c55 */
/* commit time: 2019-01-28 20:32:32 +0100 */