From f6385248f6dbca423aa7b9a1e1dadadd15cb4f9b Mon Sep 17 00:00:00 2001 From: "Dr. Stephen Henson" Date: Sat, 19 Nov 2011 17:03:44 +0000 Subject: [PATCH] Add flag to support cofactor ECDH --- CHANGES | 3 +++ crypto/ecdh/ecdh.h | 2 ++ crypto/ecdh/ech_ossl.c | 12 ++++++++++++ fips/ecdh/fips_ecdh_selftest.c | 2 ++ fips/ecdh/fips_ecdhvs.c | 1 + 5 files changed, 20 insertions(+) diff --git a/CHANGES b/CHANGES index 795ada567e..0e9afd12ed 100644 --- a/CHANGES +++ b/CHANGES @@ -4,6 +4,9 @@ Changes between 1.0.1 and 1.1.0 [xx XXX xxxx] + *) Add flag to EC_KEY to use cofactor ECDH if set. + [Steve Henson] + *) Update fips_test_suite to support multiple command line options. New test to induce all self test errors in sequence and check expected failures. 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); diff --git a/fips/ecdh/fips_ecdh_selftest.c b/fips/ecdh/fips_ecdh_selftest.c index 2b21ceaf48..0b16c57aae 100644 --- a/fips/ecdh/fips_ecdh_selftest.c +++ b/fips/ecdh/fips_ecdh_selftest.c @@ -166,6 +166,7 @@ int FIPS_selftest_ecdh(void) rv = -1; goto err; } + EC_KEY_set_flags(ec1, EC_FLAG_COFACTOR_ECDH); if (!EC_KEY_set_public_key_affine_coordinates(ec1, x, y)) { @@ -194,6 +195,7 @@ int FIPS_selftest_ecdh(void) rv = -1; goto err; } + EC_KEY_set_flags(ec1, EC_FLAG_COFACTOR_ECDH); if (!EC_KEY_set_public_key_affine_coordinates(ec2, x, y)) { diff --git a/fips/ecdh/fips_ecdhvs.c b/fips/ecdh/fips_ecdhvs.c index 099285aac3..61d216d1b7 100644 --- a/fips/ecdh/fips_ecdhvs.c +++ b/fips/ecdh/fips_ecdhvs.c @@ -261,6 +261,7 @@ static void ec_output_Zhash(FILE *out, int exout, EC_GROUP *group, unsigned char chash[EVP_MAX_MD_SIZE]; int Zlen; ec = EC_KEY_new(); + EC_KEY_set_flags(ec, EC_FLAG_COFACTOR_ECDH); EC_KEY_set_group(ec, group); peerkey = make_peer(group, cx, cy); if (rhash == NULL) -- 2.25.1