From bb315ca716656b7aff89f86d35988062952ccb21 Mon Sep 17 00:00:00 2001 From: Shane Lontis Date: Fri, 22 Mar 2019 14:10:31 +1000 Subject: [PATCH] EC keygen updates + changed ecdsa_sign to use BN_secure_new Reviewed-by: Nicola Tuveri Reviewed-by: Paul Dale (Merged from https://github.com/openssl/openssl/pull/8557) --- crypto/ec/ec_key.c | 61 +++++++++++++++++++++++++++++++----------- crypto/ec/ecdsa_ossl.c | 2 +- 2 files changed, 47 insertions(+), 16 deletions(-) diff --git a/crypto/ec/ec_key.c b/crypto/ec/ec_key.c index 637ba141ab..416c0e08fc 100644 --- a/crypto/ec/ec_key.c +++ b/crypto/ec/ec_key.c @@ -1,5 +1,5 @@ /* - * Copyright 2002-2018 The OpenSSL Project Authors. All Rights Reserved. + * Copyright 2002-2019 The OpenSSL Project Authors. All Rights Reserved. * Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved * * Licensed under the Apache License 2.0 (the "License"). You may not use @@ -195,59 +195,90 @@ int ossl_ec_key_gen(EC_KEY *eckey) return eckey->group->meth->keygen(eckey); } +/* + * ECC Key generation. + * See SP800-56AR3 5.6.1.2.2 "Key Pair Generation by Testing Candidates" + * + * Params: + * eckey An EC key object that contains domain params. The generated keypair + * is stored in this object. + * Returns 1 if the keypair was generated or 0 otherwise. + */ int ec_key_simple_generate_key(EC_KEY *eckey) { int ok = 0; - BN_CTX *ctx = NULL; BIGNUM *priv_key = NULL; const BIGNUM *order = NULL; EC_POINT *pub_key = NULL; - - if ((ctx = BN_CTX_new()) == NULL) - goto err; + const EC_GROUP *group = eckey->group; if (eckey->priv_key == NULL) { - priv_key = BN_new(); + priv_key = BN_secure_new(); if (priv_key == NULL) goto err; } else priv_key = eckey->priv_key; - order = EC_GROUP_get0_order(eckey->group); + /* + * Steps (1-2): Check domain parameters and security strength. + * These steps must be done by the user. This would need to be + * stated in the security policy. + */ + + order = EC_GROUP_get0_order(group); if (order == NULL) goto err; + /* + * Steps (3-7): priv_key = DRBG_RAND(order_n_bits) (range [1, n-1]). + * Although this is slightly different from the standard, it is effectively + * equivalent as it gives an unbiased result ranging from 1..n-1. It is also + * faster as the standard needs to retry more often. Also doing + * 1 + rand[0..n-2] would effect the way that tests feed dummy entropy into + * rand so the simpler backward compatible method has been used here. + */ do if (!BN_priv_rand_range(priv_key, order)) goto err; while (BN_is_zero(priv_key)) ; if (eckey->pub_key == NULL) { - pub_key = EC_POINT_new(eckey->group); + pub_key = EC_POINT_new(group); if (pub_key == NULL) goto err; } else pub_key = eckey->pub_key; - if (!EC_POINT_mul(eckey->group, pub_key, priv_key, NULL, NULL, ctx)) + /* Step (8) : pub_key = priv_key * G (where G is a point on the curve) */ + if (!EC_POINT_mul(group, pub_key, priv_key, NULL, NULL, NULL)) goto err; eckey->priv_key = priv_key; eckey->pub_key = pub_key; + priv_key = NULL; + pub_key = NULL; ok = 1; - err: - if (eckey->pub_key == NULL) - EC_POINT_free(pub_key); - if (eckey->priv_key != priv_key) - BN_free(priv_key); - BN_CTX_free(ctx); +err: + /* Step (9): If there is an error return an invalid keypair. */ + if (!ok) { + BN_clear(eckey->priv_key); + if (eckey->pub_key != NULL) + EC_POINT_set_to_infinity(group, eckey->pub_key); + } + + EC_POINT_free(pub_key); + BN_clear_free(priv_key); return ok; } int ec_key_simple_generate_public_key(EC_KEY *eckey) { + /* + * See SP800-56AR3 5.6.1.2.2: Step (8) + * pub_key = priv_key * G (where G is a point on the curve) + */ return EC_POINT_mul(eckey->group, eckey->pub_key, eckey->priv_key, NULL, NULL, NULL); } diff --git a/crypto/ec/ecdsa_ossl.c b/crypto/ec/ecdsa_ossl.c index a790e0adea..a488d5c86d 100644 --- a/crypto/ec/ecdsa_ossl.c +++ b/crypto/ec/ecdsa_ossl.c @@ -59,7 +59,7 @@ static int ecdsa_sign_setup(EC_KEY *eckey, BN_CTX *ctx_in, } } - k = BN_new(); /* this value is later returned in *kinvp */ + k = BN_secure_new(); /* this value is later returned in *kinvp */ r = BN_new(); /* this value is later returned in *rp */ X = BN_new(); if (k == NULL || r == NULL || X == NULL) { -- 2.34.1