dropbear/libtommath/bn_mp_reduce_is_2k_l.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

42 lines
1.1 KiB
C

#include "tommath_private.h"
#ifdef BN_MP_REDUCE_IS_2K_L_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
*/
/* determines if reduce_2k_l can be used */
int mp_reduce_is_2k_l(const mp_int *a)
{
int ix, iy;
if (a->used == 0) {
return MP_NO;
} else if (a->used == 1) {
return MP_YES;
} else if (a->used > 1) {
/* if more than half of the digits are -1 we're sold */
for (iy = ix = 0; ix < a->used; ix++) {
if (a->dp[ix] == MP_MASK) {
++iy;
}
}
return (iy >= (a->used/2)) ? MP_YES : MP_NO;
}
return MP_NO;
}
#endif
/* ref: HEAD -> master, tag: v1.1.0 */
/* git commit: 08549ad6bc8b0cede0b357a9c341c5c6473a9c55 */
/* commit time: 2019-01-28 20:32:32 +0100 */