From a3a2e3a43d13d8486c5e100e1bef7fec8e61b27b Mon Sep 17 00:00:00 2001 From: "Dr. Stephen Henson" Date: Sat, 10 Dec 2011 13:35:11 +0000 Subject: [PATCH] add cofactor ECDH support from fips branch --- crypto/ecdh/ecdh.h | 2 ++ crypto/ecdh/ech_ossl.c | 12 ++++++++++++ 2 files changed, 14 insertions(+) diff --git a/crypto/ecdh/ecdh.h b/crypto/ecdh/ecdh.h index b4b58ee65b..8ac82b8cbd 100644 --- a/crypto/ecdh/ecdh.h +++ b/crypto/ecdh/ecdh.h @@ -85,6 +85,8 @@ extern "C" { #endif +#define EC_FLAG_COFACTOR_ECDH 0x1000 + const ECDH_METHOD *ECDH_OpenSSL(void); void ECDH_set_default_method(const ECDH_METHOD *); diff --git a/crypto/ecdh/ech_ossl.c b/crypto/ecdh/ech_ossl.c index 94a8f4b696..2656797449 100644 --- a/crypto/ecdh/ech_ossl.c +++ b/crypto/ecdh/ech_ossl.c @@ -146,6 +146,18 @@ static int ecdh_compute_key(void *out, size_t outlen, const EC_POINT *pub_key, } group = EC_KEY_get0_group(ecdh); + + if (EC_KEY_get_flags(ecdh) & EC_FLAG_COFACTOR_ECDH) + { + if (!EC_GROUP_get_cofactor(group, x, ctx) || + !BN_mul(x, x, priv_key, ctx)) + { + ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ERR_R_MALLOC_FAILURE); + goto err; + } + priv_key = x; + } + if ((tmp=EC_POINT_new(group)) == NULL) { ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,ERR_R_MALLOC_FAILURE); -- 2.25.1