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pqcrypto/crypto_kem/ledakemlt12/leaktime/utils.c
2019-08-23 12:41:58 +02:00

22 lines
610 B
C

#include "gf2x_arith.h"
#include "utils.h"
/* compares DIGIT sequences, returns 0 if they are equal */
int PQCLEAN_LEDAKEMLT12_LEAKTIME_gf2x_verify(const DIGIT *a, const DIGIT *b, size_t len) {
DIGIT x = 0;
for (size_t i = 0; i < len; i++) {
x |= a[i] ^ b[i];
}
x = (~x) + 1;
x >>= (DIGIT_SIZE_b - 1);
return (int)x;
}
/* conditionally move a into r if cond */
void PQCLEAN_LEDAKEMLT12_LEAKTIME_cmov(uint8_t *r, const uint8_t *a, size_t len, int cond) {
uint8_t mask = (uint8_t)(-cond);
for (size_t i = 0; i < len; i++) {
r[i] ^= mask & (r[i] ^ a[i]);
}
}