diff options
| author | Vadim Sukhomlinov <sukhomlinov@google.com> | 2019-08-22 11:12:43 -0700 |
|---|---|---|
| committer | Commit Bot <commit-bot@chromium.org> | 2019-08-23 18:22:49 +0000 |
| commit | a06dc0b52c6415eabc3a5d46357894bbe6416a17 (patch) | |
| tree | c4eb82a24467928cd0d7fc26fc1584ec388c62c8 | |
| parent | 5b3ef3d1d46f84aa20b36d4d4e92e5bbb46bc2b0 (diff) | |
| download | chrome-ec-a06dc0b52c6415eabc3a5d46357894bbe6416a17.tar.gz | |
g: corrected division algorithm in DCRYPTO_bn_div
Long division algorithm computes incorrect answer in rare cases causing
valid RSA signatures to be rejected.
BRANCH=cr50
BUG=b:137973895
TEST=tpm_test passes
Change-Id: Ie8f39eed21443978734adbbf60b72d7701154c18
Signed-off-by: Vadim Sukhomlinov <sukhomlinov@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1766088
Reviewed-by: Vadim Bendebury <vbendeb@chromium.org>
Reviewed-by: Andrey Pronin <apronin@chromium.org>
| -rw-r--r-- | chip/g/dcrypto/bn.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/chip/g/dcrypto/bn.c b/chip/g/dcrypto/bn.c index 3131139f89..94aafa1799 100644 --- a/chip/g/dcrypto/bn.c +++ b/chip/g/dcrypto/bn.c @@ -610,6 +610,7 @@ static int bn_div_ex(struct LITE_BIGNUM *q, /* If borrowed, add one back and adjust estimate */ if (t < 0) { + k = 0; qd = qd - 1; for (i = 0; i < n; i++) { t = (uint64_t)un[i + j] + vn[i] + k; |