From da989402f22d44bab2e920ec4872e711991e0047 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Bodo=20M=C3=B6ller?= Date: Fri, 16 Nov 2007 13:01:14 +0000 Subject: [PATCH] The hash length check wasn't strict enough, as pointed out by Ernst G Giessmann --- crypto/ecdsa/ecs_ossl.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/crypto/ecdsa/ecs_ossl.c b/crypto/ecdsa/ecs_ossl.c index 32d66a9774..f8b5d4ed6a 100644 --- a/crypto/ecdsa/ecs_ossl.c +++ b/crypto/ecdsa/ecs_ossl.c @@ -251,8 +251,16 @@ static ECDSA_SIG *ecdsa_do_sign(const unsigned char *dgst, int dgst_len, ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_EC_LIB); goto err; } - if (dgst_len > BN_num_bytes(order)) + if (8 * dgst_len > BN_num_bits(order)) { + /* XXX + * + * Should provide for optional hash truncation: + * Keep the BN_num_bits(order) leftmost bits of dgst + * (see March 2006 FIPS 186-3 draft, which has a few + * confusing errors in this part though) + */ + ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ECDSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE); goto err; -- 2.34.1