--- /dev/null
+/* 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
projects / cassiopeia.git / blobdiff