mirror of
https://github.com/henrydcase/pqc.git
synced 2024-11-27 01:41:40 +00:00
431dbada45
Exported from SUPERCOP-20200826 using the scripts at: https://github.com/jschanck/pqclean-package-ntruprime
26 lines
576 B
C
26 lines
576 B
C
#include "crypto_encode_857xfreeze3.h"
|
|
|
|
#define int16 int16_t
|
|
|
|
#define p 857
|
|
|
|
/* valid inputs: -16384 <= x < 16384 */
|
|
/* then 3 divides x-F3_freeze(x) */
|
|
/* and F3_freeze(x) is in {-1,0,1} */
|
|
|
|
/* all inputs: 3 divides x-F3_freeze(x) */
|
|
/* and F3_freeze(x) is in {-2,-1,0,1,2} */
|
|
|
|
static inline unsigned char F3_freeze(int16 x) {
|
|
return x - 3 * ((10923 * x + 16384) >> 15);
|
|
}
|
|
|
|
void PQCLEAN_SNTRUP857_CLEAN_crypto_encode_857xfreeze3(unsigned char *s, const void *v) {
|
|
const int16 *r = v;
|
|
|
|
int i;
|
|
for (i = 0; i < p; ++i) {
|
|
s[i] = F3_freeze(r[i]);
|
|
}
|
|
}
|