mirror of
https://github.com/henrydcase/pqc.git
synced 2024-11-26 17:31:38 +00:00
4ea4b478ba
* Update NTRU version: https://github.com/jschanck/ntru/tree/485dde03 * Fixed ntruhrss701/clean/Makefile.Microsoft_nmake
27 lines
699 B
C
27 lines
699 B
C
#include "sample.h"
|
|
|
|
static uint16_t mod3(uint16_t a) {
|
|
uint16_t r;
|
|
int16_t t, c;
|
|
|
|
r = (a >> 8) + (a & 0xff); // r mod 255 == a mod 255
|
|
r = (r >> 4) + (r & 0xf); // r' mod 15 == r mod 15
|
|
r = (r >> 2) + (r & 0x3); // r' mod 3 == r mod 3
|
|
r = (r >> 2) + (r & 0x3); // r' mod 3 == r mod 3
|
|
|
|
t = r - 3;
|
|
c = t >> 15;
|
|
|
|
return (c & r) ^ (~c & t);
|
|
}
|
|
|
|
void PQCLEAN_NTRUHRSS701_CLEAN_sample_iid(poly *r, const unsigned char uniformbytes[NTRU_SAMPLE_IID_BYTES]) {
|
|
int i;
|
|
/* {0,1,...,255} -> {0,1,2}; Pr[0] = 86/256, Pr[1] = Pr[-1] = 85/256 */
|
|
for (i = 0; i < NTRU_N - 1; i++) {
|
|
r->coeffs[i] = mod3(uniformbytes[i]);
|
|
}
|
|
|
|
r->coeffs[NTRU_N - 1] = 0;
|
|
}
|