2 * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
12 #include "internal/cryptlib.h"
13 #include <openssl/bn.h>
16 static int dsa_builtin_keygen(DSA *dsa);
18 int DSA_generate_key(DSA *dsa)
20 if (dsa->meth->dsa_keygen)
21 return dsa->meth->dsa_keygen(dsa);
22 return dsa_builtin_keygen(dsa);
25 static int dsa_builtin_keygen(DSA *dsa)
29 BIGNUM *pub_key = NULL, *priv_key = NULL;
31 if ((ctx = BN_CTX_new()) == NULL)
34 if (dsa->priv_key == NULL) {
35 if ((priv_key = BN_secure_new()) == NULL)
38 priv_key = dsa->priv_key;
41 if (!BN_rand_range(priv_key, dsa->q))
43 while (BN_is_zero(priv_key)) ;
45 if (dsa->pub_key == NULL) {
46 if ((pub_key = BN_new()) == NULL)
49 pub_key = dsa->pub_key;
52 BIGNUM *prk = BN_new();
56 BN_with_flags(prk, priv_key, BN_FLG_CONSTTIME);
58 if (!BN_mod_exp(pub_key, dsa->g, prk, dsa->p, ctx)) {
62 /* We MUST free prk before any further use of priv_key */
66 dsa->priv_key = priv_key;
67 dsa->pub_key = pub_key;
71 if (pub_key != dsa->pub_key)
73 if (priv_key != dsa->priv_key)