mirror of
https://github.com/henrydcase/pqc.git
synced 2024-11-30 03:11:43 +00:00
52 lines
1.5 KiB
C
52 lines
1.5 KiB
C
|
#include "SABER_params.h"
|
|||
|
|
#include "api.h"
|
|||
|
|
#include "cbd.h"
|
|||
|
|
#include <stdint.h>
|
|||
|
|
/*---------------------------------------------------------------------
|
|||
|
|
This file has been adapted from the implementation
|
|||
|
|
(available at, Public Domain https://github.com/pq-crystals/kyber)
|
|||
|
|
of "CRYSTALS – Kyber: a CCA-secure module-lattice-based KEM"
|
|||
|
|
by : Joppe Bos, Leo Ducas, Eike Kiltz, Tancrede Lepoint,
|
|||
|
|
Vadim Lyubashevsky, John M. Schanck, Peter Schwabe & Damien stehle
|
|||
|
|
----------------------------------------------------------------------*/
|
|||
|
|
|
|||
|
|
|
|||
|
|
static uint64_t load_littleendian(const unsigned char *x, int bytes) {
|
|||
|
|
int i;
|
|||
|
|
uint64_t r = x[0];
|
|||
|
|
for (i = 1; i < bytes; i++) {
|
|||
|
|
r |= (uint64_t)x[i] << (8 * i);
|
|||
|
|
}
|
|||
|
|
return r;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
|
|||
|
|
void PQCLEAN_SABER_AVX2_cbd(uint16_t *r, const unsigned char *buf) {
|
|||
|
|
uint16_t Qmod_minus1 = SABER_Q - 1;
|
|||
|
|
|
|||
|
|
uint32_t t, d, a[4], b[4];
|
|||
|
|
int i, j;
|
|||
|
|
|
|||
|
|
for (i = 0; i < SABER_N / 4; i++) {
|
|||
|
|
t = load_littleendian(buf + 4 * i, 4);
|
|||
|
|
d = 0;
|
|||
|
|
for (j = 0; j < 4; j++) {
|
|||
|
|
d += (t >> j) & 0x11111111;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
a[0] = d & 0xf;
|
|||
|
|
b[0] = (d >> 4) & 0xf;
|
|||
|
|
a[1] = (d >> 8) & 0xf;
|
|||
|
|
b[1] = (d >> 12) & 0xf;
|
|||
|
|
a[2] = (d >> 16) & 0xf;
|
|||
|
|
b[2] = (d >> 20) & 0xf;
|
|||
|
|
a[3] = (d >> 24) & 0xf;
|
|||
|
|
b[3] = (d >> 28);
|
|||
|
|
|
|||
|
|
r[4 * i + 0] = (uint16_t)(a[0] - b[0]) & Qmod_minus1;
|
|||
|
|
r[4 * i + 1] = (uint16_t)(a[1] - b[1]) & Qmod_minus1;
|
|||
|
|
r[4 * i + 2] = (uint16_t)(a[2] - b[2]) & Qmod_minus1;
|
|||
|
|
r[4 * i + 3] = (uint16_t)(a[3] - b[3]) & Qmod_minus1;
|
|||
|
|
}
|
|||
|
|
}
|