openssl/crypto/dsa/dsa_key.c
Rich Salz 74924dcb38 More secure storage of key material.
Add secure heap for storage of private keys (when possible).
Add BIO_s_secmem(), CBIGNUM, etc.
Add BIO_CTX_secure_new so all BIGNUM's in the context are secure.
Contributed by Akamai Technologies under the Corporate CLA.

Reviewed-by: Richard Levitte <levitte@openssl.org>
2015-06-23 17:09:35 -04:00

132 lines
4.7 KiB
C

/* crypto/dsa/dsa_key.c */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.]
*/
#include <stdio.h>
#include <time.h>
#include "internal/cryptlib.h"
#include <openssl/bn.h>
#include <openssl/dsa.h>
#include <openssl/rand.h>
static int dsa_builtin_keygen(DSA *dsa);
int DSA_generate_key(DSA *dsa)
{
if (dsa->meth->dsa_keygen)
return dsa->meth->dsa_keygen(dsa);
return dsa_builtin_keygen(dsa);
}
static int dsa_builtin_keygen(DSA *dsa)
{
int ok = 0;
BN_CTX *ctx = NULL;
BIGNUM *pub_key = NULL, *priv_key = NULL;
if ((ctx = BN_CTX_new()) == NULL)
goto err;
if (dsa->priv_key == NULL) {
if ((priv_key = BN_secure_new()) == NULL)
goto err;
} else
priv_key = dsa->priv_key;
do
if (!BN_rand_range(priv_key, dsa->q))
goto err;
while (BN_is_zero(priv_key)) ;
if (dsa->pub_key == NULL) {
if ((pub_key = BN_new()) == NULL)
goto err;
} else
pub_key = dsa->pub_key;
{
BIGNUM *local_prk = NULL;
BIGNUM *prk;
if ((dsa->flags & DSA_FLAG_NO_EXP_CONSTTIME) == 0) {
local_prk = prk = BN_new();
if (!local_prk)
goto err;
BN_with_flags(prk, priv_key, BN_FLG_CONSTTIME);
} else
prk = priv_key;
if (!BN_mod_exp(pub_key, dsa->g, prk, dsa->p, ctx)) {
BN_free(local_prk);
goto err;
}
BN_free(local_prk);
}
dsa->priv_key = priv_key;
dsa->pub_key = pub_key;
ok = 1;
err:
if (pub_key != dsa->pub_key)
BN_free(pub_key);
if (priv_key != dsa->priv_key)
BN_free(priv_key);
BN_CTX_free(ctx);
return (ok);
}