386 lines
12 KiB
C
386 lines
12 KiB
C
/* crypto/dsa/dsa_gen.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.]
|
|
*/
|
|
|
|
#undef GENUINE_DSA
|
|
|
|
#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)
|
|
*/
|
|
# define HASH EVP_sha()
|
|
#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)
|
|
*/
|
|
# define HASH EVP_sha1()
|
|
#endif
|
|
|
|
#include <openssl/opensslconf.h> /* To see if OPENSSL_NO_SHA is defined */
|
|
|
|
#ifndef OPENSSL_NO_SHA
|
|
|
|
# include <stdio.h>
|
|
# include "cryptlib.h"
|
|
# include <openssl/evp.h>
|
|
# include <openssl/bn.h>
|
|
# include <openssl/rand.h>
|
|
# include <openssl/sha.h>
|
|
# include "dsa_locl.h"
|
|
|
|
# ifdef OPENSSL_FIPS
|
|
# include <openssl/fips.h>
|
|
# endif
|
|
|
|
int DSA_generate_parameters_ex(DSA *ret, int bits,
|
|
const unsigned char *seed_in, int seed_len,
|
|
int *counter_ret, unsigned long *h_ret,
|
|
BN_GENCB *cb)
|
|
{
|
|
# ifdef OPENSSL_FIPS
|
|
if (FIPS_mode() && !(ret->meth->flags & DSA_FLAG_FIPS_METHOD)
|
|
&& !(ret->flags & DSA_FLAG_NON_FIPS_ALLOW)) {
|
|
DSAerr(DSA_F_DSA_GENERATE_PARAMETERS_EX, DSA_R_NON_FIPS_DSA_METHOD);
|
|
return 0;
|
|
}
|
|
# endif
|
|
if (ret->meth->dsa_paramgen)
|
|
return ret->meth->dsa_paramgen(ret, bits, seed_in, seed_len,
|
|
counter_ret, h_ret, cb);
|
|
# ifdef OPENSSL_FIPS
|
|
else if (FIPS_mode()) {
|
|
return FIPS_dsa_generate_parameters_ex(ret, bits,
|
|
seed_in, seed_len,
|
|
counter_ret, h_ret, cb);
|
|
}
|
|
# endif
|
|
else {
|
|
const EVP_MD *evpmd;
|
|
size_t qbits = bits >= 2048 ? 256 : 160;
|
|
|
|
if (bits >= 2048) {
|
|
qbits = 256;
|
|
evpmd = EVP_sha256();
|
|
} else {
|
|
qbits = 160;
|
|
evpmd = EVP_sha1();
|
|
}
|
|
|
|
return dsa_builtin_paramgen(ret, bits, qbits, evpmd,
|
|
seed_in, seed_len, NULL, counter_ret,
|
|
h_ret, cb);
|
|
}
|
|
}
|
|
|
|
int dsa_builtin_paramgen(DSA *ret, size_t bits, size_t qbits,
|
|
const EVP_MD *evpmd, const unsigned char *seed_in,
|
|
size_t seed_len, unsigned char *seed_out,
|
|
int *counter_ret, unsigned long *h_ret, BN_GENCB *cb)
|
|
{
|
|
int ok = 0;
|
|
unsigned char seed[SHA256_DIGEST_LENGTH];
|
|
unsigned char md[SHA256_DIGEST_LENGTH];
|
|
unsigned char buf[SHA256_DIGEST_LENGTH], buf2[SHA256_DIGEST_LENGTH];
|
|
BIGNUM *r0, *W, *X, *c, *test;
|
|
BIGNUM *g = NULL, *q = NULL, *p = NULL;
|
|
BN_MONT_CTX *mont = NULL;
|
|
int i, k, n = 0, m = 0, qsize = qbits >> 3;
|
|
int counter = 0;
|
|
int r = 0;
|
|
BN_CTX *ctx = NULL;
|
|
unsigned int h = 2;
|
|
|
|
if (qsize != SHA_DIGEST_LENGTH && qsize != SHA224_DIGEST_LENGTH &&
|
|
qsize != SHA256_DIGEST_LENGTH)
|
|
/* invalid q size */
|
|
return 0;
|
|
|
|
if (evpmd == NULL)
|
|
/* use SHA1 as default */
|
|
evpmd = EVP_sha1();
|
|
|
|
if (bits < 512)
|
|
bits = 512;
|
|
|
|
bits = (bits + 63) / 64 * 64;
|
|
|
|
/*
|
|
* NB: seed_len == 0 is special case: copy generated seed to seed_in if
|
|
* it is not NULL.
|
|
*/
|
|
if (seed_len && (seed_len < (size_t)qsize))
|
|
seed_in = NULL; /* seed buffer too small -- ignore */
|
|
if (seed_len > (size_t)qsize)
|
|
seed_len = qsize; /* App. 2.2 of FIPS PUB 186 allows larger
|
|
* SEED, but our internal buffers are
|
|
* restricted to 160 bits */
|
|
if (seed_in != NULL)
|
|
memcpy(seed, seed_in, seed_len);
|
|
|
|
if ((ctx = BN_CTX_new()) == NULL)
|
|
goto err;
|
|
|
|
if ((mont = BN_MONT_CTX_new()) == NULL)
|
|
goto err;
|
|
|
|
BN_CTX_start(ctx);
|
|
r0 = BN_CTX_get(ctx);
|
|
g = BN_CTX_get(ctx);
|
|
W = BN_CTX_get(ctx);
|
|
q = BN_CTX_get(ctx);
|
|
X = BN_CTX_get(ctx);
|
|
c = BN_CTX_get(ctx);
|
|
p = BN_CTX_get(ctx);
|
|
test = BN_CTX_get(ctx);
|
|
|
|
if (!BN_lshift(test, BN_value_one(), bits - 1))
|
|
goto err;
|
|
|
|
for (;;) {
|
|
for (;;) { /* find q */
|
|
int seed_is_random;
|
|
|
|
/* step 1 */
|
|
if (!BN_GENCB_call(cb, 0, m++))
|
|
goto err;
|
|
|
|
if (!seed_len) {
|
|
RAND_pseudo_bytes(seed, qsize);
|
|
seed_is_random = 1;
|
|
} else {
|
|
seed_is_random = 0;
|
|
seed_len = 0; /* use random seed if 'seed_in' turns out to
|
|
* be bad */
|
|
}
|
|
memcpy(buf, seed, qsize);
|
|
memcpy(buf2, seed, qsize);
|
|
/* precompute "SEED + 1" for step 7: */
|
|
for (i = qsize - 1; i >= 0; i--) {
|
|
buf[i]++;
|
|
if (buf[i] != 0)
|
|
break;
|
|
}
|
|
|
|
/* step 2 */
|
|
if (!EVP_Digest(seed, qsize, md, NULL, evpmd, NULL))
|
|
goto err;
|
|
if (!EVP_Digest(buf, qsize, buf2, NULL, evpmd, NULL))
|
|
goto err;
|
|
for (i = 0; i < qsize; i++)
|
|
md[i] ^= buf2[i];
|
|
|
|
/* step 3 */
|
|
md[0] |= 0x80;
|
|
md[qsize - 1] |= 0x01;
|
|
if (!BN_bin2bn(md, qsize, q))
|
|
goto err;
|
|
|
|
/* step 4 */
|
|
r = BN_is_prime_fasttest_ex(q, DSS_prime_checks, ctx,
|
|
seed_is_random, cb);
|
|
if (r > 0)
|
|
break;
|
|
if (r != 0)
|
|
goto err;
|
|
|
|
/* do a callback call */
|
|
/* step 5 */
|
|
}
|
|
|
|
if (!BN_GENCB_call(cb, 2, 0))
|
|
goto err;
|
|
if (!BN_GENCB_call(cb, 3, 0))
|
|
goto err;
|
|
|
|
/* step 6 */
|
|
counter = 0;
|
|
/* "offset = 2" */
|
|
|
|
n = (bits - 1) / 160;
|
|
|
|
for (;;) {
|
|
if ((counter != 0) && !BN_GENCB_call(cb, 0, counter))
|
|
goto err;
|
|
|
|
/* 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 = qsize - 1; i >= 0; i--) {
|
|
buf[i]++;
|
|
if (buf[i] != 0)
|
|
break;
|
|
}
|
|
|
|
if (!EVP_Digest(buf, qsize, md, NULL, evpmd, NULL))
|
|
goto err;
|
|
|
|
/* step 8 */
|
|
if (!BN_bin2bn(md, qsize, r0))
|
|
goto err;
|
|
if (!BN_lshift(r0, r0, (qsize << 3) * k))
|
|
goto err;
|
|
if (!BN_add(W, W, r0))
|
|
goto err;
|
|
}
|
|
|
|
/* more of step 8 */
|
|
if (!BN_mask_bits(W, bits - 1))
|
|
goto err;
|
|
if (!BN_copy(X, W))
|
|
goto err;
|
|
if (!BN_add(X, X, test))
|
|
goto err;
|
|
|
|
/* step 9 */
|
|
if (!BN_lshift1(r0, q))
|
|
goto err;
|
|
if (!BN_mod(c, X, r0, ctx))
|
|
goto err;
|
|
if (!BN_sub(r0, c, BN_value_one()))
|
|
goto err;
|
|
if (!BN_sub(p, X, r0))
|
|
goto err;
|
|
|
|
/* step 10 */
|
|
if (BN_cmp(p, test) >= 0) {
|
|
/* step 11 */
|
|
r = BN_is_prime_fasttest_ex(p, DSS_prime_checks, ctx, 1, cb);
|
|
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:
|
|
if (!BN_GENCB_call(cb, 2, 1))
|
|
goto err;
|
|
|
|
/* We now need to generate g */
|
|
/* Set r0=(p-1)/q */
|
|
if (!BN_sub(test, p, BN_value_one()))
|
|
goto err;
|
|
if (!BN_div(r0, NULL, test, q, ctx))
|
|
goto err;
|
|
|
|
if (!BN_set_word(test, h))
|
|
goto err;
|
|
if (!BN_MONT_CTX_set(mont, p, ctx))
|
|
goto err;
|
|
|
|
for (;;) {
|
|
/* g=test^r0%p */
|
|
if (!BN_mod_exp_mont(g, test, r0, p, ctx, mont))
|
|
goto err;
|
|
if (!BN_is_one(g))
|
|
break;
|
|
if (!BN_add(test, test, BN_value_one()))
|
|
goto err;
|
|
h++;
|
|
}
|
|
|
|
if (!BN_GENCB_call(cb, 3, 1))
|
|
goto err;
|
|
|
|
ok = 1;
|
|
err:
|
|
if (ok) {
|
|
if (ret->p)
|
|
BN_free(ret->p);
|
|
if (ret->q)
|
|
BN_free(ret->q);
|
|
if (ret->g)
|
|
BN_free(ret->g);
|
|
ret->p = BN_dup(p);
|
|
ret->q = BN_dup(q);
|
|
ret->g = BN_dup(g);
|
|
if (ret->p == NULL || ret->q == NULL || ret->g == NULL) {
|
|
ok = 0;
|
|
goto err;
|
|
}
|
|
if (counter_ret != NULL)
|
|
*counter_ret = counter;
|
|
if (h_ret != NULL)
|
|
*h_ret = h;
|
|
if (seed_out)
|
|
memcpy(seed_out, seed, qsize);
|
|
}
|
|
if (ctx) {
|
|
BN_CTX_end(ctx);
|
|
BN_CTX_free(ctx);
|
|
}
|
|
if (mont != NULL)
|
|
BN_MONT_CTX_free(mont);
|
|
return ok;
|
|
}
|
|
#endif
|