dsa_gen.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/* 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
* 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.]
*/
#ifdef GENUINE_DSA
/* Parameter generation follows the original release of FIPS PUB 186,
* Appendix 2.2 (i.e. use SHA as defined in FIPS PUB 180) */
#else
/* Parameter generation follows the updated Appendix 2.2 for FIPS PUB 186,
* also Appendix 2.2 of FIPS PUB 186-1 (i.e. use SHA as defined in
* FIPS PUB 180-1) */
#endif
#ifndef OPENSSL_NO_SHA
#include <stdio.h>
#include <time.h>
#include "cryptlib.h"
int *counter_ret, unsigned long *h_ret,
void (*callback)(int, int, void *),
void *cb_arg)
{
int ok=0;
unsigned char seed[SHA_DIGEST_LENGTH];
unsigned char md[SHA_DIGEST_LENGTH];
int k,n=0,i,b,m=0;
int counter=0;
int r=0;
unsigned int h=2;
if (seed_len < 20)
if (seed_len > 20)
* but our internal buffers are restricted to 160 bits*/
g = BN_CTX_get(ctx2);
W = BN_CTX_get(ctx2);
q = BN_CTX_get(ctx2);
X = BN_CTX_get(ctx2);
c = BN_CTX_get(ctx2);
p = BN_CTX_get(ctx2);
for (;;)
{
for (;;) /* find q */
{
int seed_is_random;
/* step 1 */
if (!seed_len)
{
seed_is_random = 1;
}
else
{
seed_is_random = 0;
seed_len=0; /* use random seed if 'seed_in' turns out to be bad*/
}
/* precompute "SEED + 1" for step 7: */
for (i=SHA_DIGEST_LENGTH-1; i >= 0; i--)
{
buf[i]++;
if (buf[i] != 0) break;
}
/* step 2 */
for (i=0; i<SHA_DIGEST_LENGTH; i++)
/* step 3 */
md[0]|=0x80;
/* step 4 */
if (r > 0)
break;
if (r != 0)
goto err;
/* do a callback call */
/* step 5 */
}
/* step 6 */
counter=0;
/* "offset = 2" */
for (;;)
{
/* step 7 */
BN_zero(W);
/* now 'buf' contains "SEED + offset - 1" */
for (k=0; k<=n; k++)
{
/* obtain "SEED + offset + k" by incrementing: */
for (i=SHA_DIGEST_LENGTH-1; i >= 0; i--)
{
buf[i]++;
if (buf[i] != 0) break;
}
/* step 8 */
goto err;
}
/* more of step 8 */
BN_copy(X,W); /* this should be ok */
/* step 9 */
BN_lshift1(r0,q);
/* step 10 */
{
/* step 11 */
if (r > 0)
goto end; /* found it */
if (r != 0)
goto err;
}
/* step 13 */
counter++;
/* "offset = offset + n + 1" */
/* step 14 */
if (counter >= 4096) break;
}
}
end:
/* We now need to generate g */
/* Set r0=(p-1)/q */
BN_set_word(test,h);
for (;;)
{
/* g=test^r0%p */
if (!BN_is_one(g)) break;
h++;
}
ok=1;
err:
if (!ok)
{
}
else
{
}
{
}
}
#endif