diff options
| -rw-r--r-- | networking/tls_sp_c32.c | 23 |
1 files changed, 9 insertions, 14 deletions
diff --git a/networking/tls_sp_c32.c b/networking/tls_sp_c32.c index ffcb83d..c151eea 100644 --- a/networking/tls_sp_c32.c +++ b/networking/tls_sp_c32.c @@ -159,17 +159,20 @@ static void sp_256_point_from_bin2x32(sp_point* p, const uint8_t *bin2x32) p->z[0] = 1; } -/* Compare a with b in constant time. +/* Compare a with b. * * return -ve, 0 or +ve if a is less than, equal to or greater than b * respectively. */ static sp_digit sp_256_cmp_10(const sp_digit* a, const sp_digit* b) { - sp_digit r = 0; + sp_digit r; int i; - for (i = 9; i >= 0; i--) - r |= (a[i] - b[i]) & (0 - !r); + for (i = 9; i >= 0; i--) { + r = a[i] - b[i]; + if (r != 0) + break; + } return r; } @@ -179,15 +182,7 @@ static sp_digit sp_256_cmp_10(const sp_digit* a, const sp_digit* b) */ static int sp_256_cmp_equal_10(const sp_digit* a, const sp_digit* b) { -#if 1 - sp_digit r = 0; - int i; - for (i = 0; i < 10; i++) - r |= (a[i] ^ b[i]); - return r == 0; -#else return sp_256_cmp_10(a, b) == 0; -#endif } /* Normalize the values in each word to 26 bits. */ @@ -710,8 +705,8 @@ static void sp_256_proj_point_add_10(sp_point* r, sp_point* p, sp_point* q, sp_256_sub_10(t1, p256_mod, q->y); sp_256_norm_10(t1); if (sp_256_cmp_equal_10(p->x, q->x) - & sp_256_cmp_equal_10(p->z, q->z) - & (sp_256_cmp_equal_10(p->y, q->y) | sp_256_cmp_equal_10(p->y, t1)) + && sp_256_cmp_equal_10(p->z, q->z) + && (sp_256_cmp_equal_10(p->y, q->y) || sp_256_cmp_equal_10(p->y, t1)) ) { sp_256_proj_point_dbl_10(r, p, t); } |