fix location in tfm.c that could result in potential cache attack

This commit is contained in:
Jacob Barthelmeh
2017-01-10 15:00:00 -07:00
parent 8954de40ff
commit e3277c19b7

View File

@ -480,12 +480,11 @@ void fp_mul_comba(fp_int *A, fp_int *B, fp_int *C)
pa = FP_SIZE-1;
}
if (A == C || B == C) {
/* Always take branch to use tmp variable. This avoids a cache attack for
* determining if C equals A */
if (1) {
fp_init(&tmp);
dst = &tmp;
} else {
fp_zero(C);
dst = C;
}
for (ix = 0; ix < pa; ix++) {