deon/gnuk
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

bug fix

Browse Source
This commit is contained in:
NIIBE Yutaka
2014-01-23 14:57:09 +09:00
parent 29e76d0ba7
commit 36541838f9
2 changed files with 7 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
ChangeLog
View File

@@ -1,3 +1,7 @@
2014-01-23 Niibe Yutaka <gniibe@fsij.org>
* src/ec_p256.c (ecdsa): Bug fix for k selection.
2014-01-22 Niibe Yutaka <gniibe@fsij.org>
* src/modp256.c (modp256_inv): Fix for constant time.

6
src/ec_p256.c
View File

@@ -514,11 +514,11 @@ ecdsa (bn256 *r, bn256 *s, const bn256 *z, const bn256 *d)
do
{
bn256_random (k);
if (bn256_sub (tmp_k, k, N) == 0) /* > N, it's too big. */
if (bn256_add_uint (k, k, 1))
continue;
if (bn256_add_uint (tmp_k, tmp_k, 2)) /* > N - 2, still big. */
if (bn256_sub (tmp_k, k, N) == 0) /* >= N, it's too big. */
continue;
bn256_add_uint (k, k, 1);
/* 1 <= k <= N - 1 */
compute_kG (KG, k);
borrow = bn256_sub (r, KG->x, N);
if (borrow)