diff --git a/crypto/ecdh/ecdh.h b/crypto/ecdh/ecdh.h index b4b58ee65ba2caee7a968e7a8d7070ea9d94ea01..8ac82b8cbdb6d86b8d8b18bfbfcd9b36fe250a69 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 94a8f4b696a5fcb97c3cd08ab4c471d8dc696210..2656797449e7075cd910bd69deaf4c6c8012b3f5 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);