30 lines
708 B
C
30 lines
708 B
C
|
#include <stdint.h>
|
||
|
|
#include <stdlib.h>
|
||
|
|
|
||
|
|
#include "verify.h"
|
||
|
|
|
||
|
|
/* returns 0 for equal strings, 1 for non-equal strings */
|
||
|
|
unsigned char PQCLEAN_NTRUHPS2048677_CLEAN_verify(const unsigned char *a, const unsigned char *b, size_t len) {
|
||
|
|
uint64_t r;
|
||
|
|
size_t i;
|
||
|
|
|
||
|
|
r = 0;
|
||
|
|
for (i = 0; i < len; i++) {
|
||
|
|
r |= a[i] ^ b[i];
|
||
|
|
}
|
||
|
|
|
||
|
|
r = (~r + 1); // Two's complement
|
||
|
|
r >>= 63;
|
||
|
|
return (unsigned char)r;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* b = 1 means mov, b = 0 means don't mov*/
|
||
|
|
void PQCLEAN_NTRUHPS2048677_CLEAN_cmov(unsigned char *r, const unsigned char *x, size_t len, unsigned char b) {
|
||
|
|
size_t i;
|
||
|
|
|
||
|
|
b = (~b + 1); // Two's complement
|
||
|
|
for (i = 0; i < len; i++) {
|
||
|
|
r[i] ^= b & (x[i] ^ r[i]);
|
||
|
|
}
|
||
|
|
}
|