mirror of
https://github.com/XLabsProject/s1x-client.git
synced 2023-08-02 15:02:12 +02:00
35 lines
801 B
C
35 lines
801 B
C
|
#include "tommath_private.h"
|
||
|
|
#ifdef MP_REDUCE_IS_2K_C
|
||
|
|
/* LibTomMath, multiple-precision integer library -- Tom St Denis */
|
||
|
|
/* SPDX-License-Identifier: Unlicense */
|
||
|
|
|
||
|
|
/* determines if mp_reduce_2k can be used */
|
||
|
|
bool mp_reduce_is_2k(const mp_int *a)
|
||
|
|
{
|
||
|
|
if (mp_iszero(a)) {
|
||
|
|
return false;
|
||
|
|
} else if (a->used == 1) {
|
||
|
|
return true;
|
||
|
|
} else if (a->used > 1) {
|
||
|
|
int ix, iy = mp_count_bits(a), iw = 1;
|
||
|
|
mp_digit iz = 1;
|
||
|
|
|
||
|
|
/* Test every bit from the second digit up, must be 1 */
|
||
|
|
for (ix = MP_DIGIT_BIT; ix < iy; ix++) {
|
||
|
|
if ((a->dp[iw] & iz) == 0u) {
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
iz <<= 1;
|
||
|
|
if (iz > MP_DIGIT_MAX) {
|
||
|
|
++iw;
|
||
|
|
iz = 1;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return true;
|
||
|
|
} else {
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
#endif
|