Fix an off-by-one error where the most significant digit was not initialized leading to signature verification failures by the testmgr. Example: If a curve requires ndigits (=9) and diff (=2) indicates that 2 digits need to be set to zero then start with digit 'ndigits - diff' (=7) and clear 'diff' digits starting from there, so 7 and 8. Reported-by: Venkat Rao Bagalkote <venkat88@xxxxxxxxxxxxxxxxxx> Closes: https://lore.kernel.org/linux-crypto/619bc2de-b18a-4939-a652-9ca886bf6349@xxxxxxxxxxxxx/T/#m045d8812409ce233c17fcdb8b88b6629c671f9f4 Fixes: 2fd2a82ccbfc ("crypto: ecdsa - Use ecc_digits_from_bytes to create hash digits array") Signed-off-by: Stefan Berger <stefanb@xxxxxxxxxxxxx> --- crypto/ecc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/crypto/ecc.c b/crypto/ecc.c index fe761256e335..dd48d9928a21 100644 --- a/crypto/ecc.c +++ b/crypto/ecc.c @@ -78,7 +78,7 @@ void ecc_digits_from_bytes(const u8 *in, unsigned int nbytes, /* diff > 0: not enough input bytes: set most significant digits to 0 */ if (diff > 0) { ndigits -= diff; - memset(&out[ndigits - 1], 0, diff * sizeof(u64)); + memset(&out[ndigits], 0, diff * sizeof(u64)); } if (o) { -- 2.44.0
