-/* crypto/dsa/dsa_gen.c */
-/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
- * All rights reserved.
+/*
+ * Copyright 1995-2016 The OpenSSL Project Authors. 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.]
+ * Licensed under the OpenSSL license (the "License"). You may not use
+ * this file except in compliance with the License. You can obtain a copy
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
*/
-#undef GENUINE_DSA
-
-#ifdef GENUINE_DSA
-#define HASH SHA
-#else
-#define HASH SHA1
-#endif
+/*
+ * 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 xxxHASH EVP_sha1()
+#include <openssl/opensslconf.h>
#include <stdio.h>
-#include <time.h>
-#include "cryptlib.h"
-#include "sha.h"
-#include "bn.h"
-#include "dsa.h"
-#include "rand.h"
-
-DSA *DSA_generate_parameters(bits,seed_in,seed_len,counter_ret,h_ret,callback,
- cb_arg)
-int bits;
-unsigned char *seed_in;
-int seed_len;
-int *counter_ret;
-unsigned long *h_ret;
-void (*callback)();
-char *cb_arg;
- {
- int ok=0;
- unsigned char seed[SHA_DIGEST_LENGTH];
- unsigned char md[SHA_DIGEST_LENGTH];
- unsigned char buf[SHA_DIGEST_LENGTH],buf2[SHA_DIGEST_LENGTH];
- BIGNUM *r0,*W,*X,*c,*test;
- BIGNUM *g=NULL,*q=NULL,*p=NULL;
- BN_MONT_CTX *mont=NULL;
- int k,n=0,i,b,m=0;
- int counter=0;
- BN_CTX *ctx=NULL,*ctx2=NULL;
- unsigned int h=2;
- DSA *ret=NULL;
-
- if (bits < 512) bits=512;
- bits=(bits+63)/64*64;
-
- if ((seed_in != NULL) && (seed_len == 20))
- memcpy(seed,seed_in,seed_len);
-
- if ((ctx=BN_CTX_new()) == NULL) goto err;
- if ((ctx2=BN_CTX_new()) == NULL) goto err;
- if ((ret=DSA_new()) == NULL) goto err;
-
- if ((mont=BN_MONT_CTX_new()) == NULL) goto err;
-
- r0= &(ctx2->bn[0]);
- g= &(ctx2->bn[1]);
- W= &(ctx2->bn[2]);
- q= &(ctx2->bn[3]);
- X= &(ctx2->bn[4]);
- c= &(ctx2->bn[5]);
- p= &(ctx2->bn[6]);
- test= &(ctx2->bn[7]);
-
- BN_lshift(test,BN_value_one(),bits-1);
-
- for (;;)
- {
- for (;;)
- {
- /* step 1 */
- if (callback != NULL) callback(0,m++,cb_arg);
-
- if (!seed_len)
- RAND_bytes(seed,SHA_DIGEST_LENGTH);
- else
- seed_len=0;
-
- memcpy(buf,seed,SHA_DIGEST_LENGTH);
- memcpy(buf2,seed,SHA_DIGEST_LENGTH);
- for (i=SHA_DIGEST_LENGTH-1; i >= 0; i--)
- {
- buf[i]++;
- if (buf[i] != 0) break;
- }
-
- /* step 2 */
- HASH(seed,SHA_DIGEST_LENGTH,md);
- HASH(buf,SHA_DIGEST_LENGTH,buf2);
- for (i=0; i<SHA_DIGEST_LENGTH; i++)
- md[i]^=buf2[i];
-
- /* step 3 */
- md[0]|=0x80;
- md[SHA_DIGEST_LENGTH-1]|=0x01;
- if (!BN_bin2bn(md,SHA_DIGEST_LENGTH,q)) abort();
-
- /* step 4 */
- if (DSA_is_prime(q,callback,cb_arg) > 0) break;
- /* do a callback call */
- /* step 5 */
- }
-
- if (callback != NULL) callback(2,0,cb_arg);
- if (callback != NULL) callback(3,0,cb_arg);
-
- /* step 6 */
- counter=0;
-
- n=(bits-1)/160;
- b=(bits-1)-n*160;
-
- for (;;)
- {
- /* step 7 */
- BN_zero(W);
- for (k=0; k<=n; k++)
- {
- for (i=SHA_DIGEST_LENGTH-1; i >= 0; i--)
- {
- buf[i]++;
- if (buf[i] != 0) break;
- }
-
- HASH(buf,SHA_DIGEST_LENGTH,md);
-
- /* step 8 */
- if (!BN_bin2bn(md,SHA_DIGEST_LENGTH,r0)) abort();
- BN_lshift(r0,r0,160*k);
- BN_add(W,W,r0);
- }
-
- /* more of step 8 */
- BN_mask_bits(W,bits-1);
- BN_copy(X,W); /* this should be ok */
- BN_add(X,X,test); /* this should be ok */
-
- /* step 9 */
- BN_lshift1(r0,q);
- BN_mod(c,X,r0,ctx);
- BN_sub(r0,c,BN_value_one());
- BN_sub(p,X,r0);
-
- /* step 10 */
- if (BN_cmp(p,test) >= 0)
- {
- /* step 11 */
- if (DSA_is_prime(p,callback,cb_arg) > 0)
- goto end;
- }
-
- /* step 13 */
- counter++;
-
- /* step 14 */
- if (counter >= 4096) break;
-
- if (callback != NULL) callback(0,counter,cb_arg);
- }
- }
-end:
- if (callback != NULL) callback(2,1,cb_arg);
-
- /* We now need to gernerate g */
- /* Set r0=(p-1)/q */
- BN_sub(test,p,BN_value_one());
- BN_div(r0,NULL,test,q,ctx);
-
- BN_set_word(test,h);
- BN_MONT_CTX_set(mont,p,ctx);
-
- for (;;)
- {
- /* g=test^r0%p */
- BN_mod_exp_mont(g,test,r0,p,ctx,mont);
- if (!BN_is_one(g)) break;
- BN_add(test,test,BN_value_one());
- h++;
- }
-
- if (callback != NULL) callback(3,1,cb_arg);
-
- ok=1;
-err:
- if (!ok)
- {
- if (ret != NULL) DSA_free(ret);
- }
- else
- {
- ret->p=BN_dup(p);
- ret->q=BN_dup(q);
- ret->g=BN_dup(g);
- if ((m > 1) && (seed_in != NULL)) memcpy(seed_in,seed,20);
- if (counter_ret != NULL) *counter_ret=counter;
- if (h_ret != NULL) *h_ret=h;
- }
- if (ctx != NULL) BN_CTX_free(ctx);
- if (ctx != NULL) BN_CTX_free(ctx2);
- if (mont != NULL) BN_MONT_CTX_free(mont);
- return(ok?ret:NULL);
- }
-
-int DSA_is_prime(w, callback,cb_arg)
-BIGNUM *w;
-void (*callback)();
-char *cb_arg;
- {
- int ok= -1,j,i,n;
- BN_CTX *ctx=NULL,*ctx2=NULL;
- BIGNUM *w_1,*b,*m,*z,*tmp,*mont_1;
- int a;
- BN_MONT_CTX *mont=NULL;
-
- if (!BN_is_bit_set(w,0)) return(0);
-
- if ((ctx=BN_CTX_new()) == NULL) goto err;
- if ((ctx2=BN_CTX_new()) == NULL) goto err;
- if ((mont=BN_MONT_CTX_new()) == NULL) goto err;
-
- m= &(ctx2->bn[2]);
- b= &(ctx2->bn[3]);
- z= &(ctx2->bn[4]);
- w_1= &(ctx2->bn[5]);
- tmp= &(ctx2->bn[6]);
- mont_1= &(ctx2->bn[7]);
-
- /* step 1 */
- n=50;
-
- /* step 2 */
- if (!BN_sub(w_1,w,BN_value_one())) goto err;
- for (a=1; !BN_is_bit_set(w_1,a); a++)
- ;
- if (!BN_rshift(m,w_1,a)) goto err;
-
- BN_MONT_CTX_set(mont,w,ctx);
- BN_to_montgomery(mont_1,BN_value_one(),mont,ctx);
- BN_to_montgomery(w_1,w_1,mont,ctx);
- for (i=1; i < n; i++)
- {
- /* step 3 */
- BN_rand(b,BN_num_bits(w)-2/*-1*/,0,0);
- /* BN_set_word(b,0x10001L); */
-
- /* step 4 */
- j=0;
- if (!BN_mod_exp_mont(z,b,m,w,ctx,mont)) goto err;
-
- if (!BN_to_montgomery(z,z,mont,ctx)) goto err;
-
- /* step 5 */
- for (;;)
- {
- if (((j == 0) && (BN_cmp(z,mont_1) == 0)) ||
- (BN_cmp(z,w_1) == 0))
- break;
-
- /* step 6 */
- if ((j > 0) && (BN_cmp(z,mont_1) == 0))
- {
- ok=0;
- goto err;
- }
-
- j++;
- if (j >= a)
- {
- ok=0;
- goto err;
- }
-
- if (!BN_mod_mul_montgomery(z,z,z,mont,ctx)) goto err;
- if (callback != NULL) callback(1,j,cb_arg);
- }
- }
-
- ok=1;
-err:
- if (ok == -1) DSAerr(DSA_F_DSA_IS_PRIME,ERR_R_BN_LIB);
- BN_CTX_free(ctx);
- BN_CTX_free(ctx2);
-
- return(ok);
- }
+#include "internal/cryptlib.h"
+#include <openssl/evp.h>
+#include <openssl/bn.h>
+#include <openssl/rand.h>
+#include <openssl/sha.h>
+#include "dsa_locl.h"
+
+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)
+{
+ if (ret->meth->dsa_paramgen)
+ return ret->meth->dsa_paramgen(ret, bits, seed_in, seed_len,
+ counter_ret, h_ret, cb);
+ else {
+ const EVP_MD *evpmd = bits >= 2048 ? EVP_sha256() : EVP_sha1();
+ size_t qbits = EVP_MD_size(evpmd) * 8;
+
+ 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;
+
+ if (seed_in != NULL) {
+ if (seed_len < (size_t)qsize)
+ return 0;
+ if (seed_len > (size_t)qsize) {
+ /* Only consume as much seed as is expected. */
+ seed_len = qsize;
+ }
+ memcpy(seed, seed_in, seed_len);
+ }
+
+ if ((mont = BN_MONT_CTX_new()) == NULL)
+ goto err;
+
+ if ((ctx = BN_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 use_random_seed = (seed_in == NULL);
+
+ /* step 1 */
+ if (!BN_GENCB_call(cb, 0, m++))
+ goto err;
+
+ if (use_random_seed) {
+ if (RAND_bytes(seed, qsize) <= 0)
+ goto err;
+ } else {
+ /* If we come back through, use random seed next time. */
+ seed_in = NULL;
+ }
+ 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,
+ use_random_seed, 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) {
+ BN_free(ret->p);
+ BN_free(ret->q);
+ 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);
+ BN_MONT_CTX_free(mont);
+ return ok;
+}
+
+/*
+ * This is a parameter generation algorithm for the DSA2 algorithm as
+ * described in FIPS 186-3.
+ */
+int dsa_builtin_paramgen2(DSA *ret, size_t L, size_t N,
+ const EVP_MD *evpmd, const unsigned char *seed_in,
+ size_t seed_len, int idx, unsigned char *seed_out,
+ int *counter_ret, unsigned long *h_ret,
+ BN_GENCB *cb)
+{
+ int ok = -1;
+ unsigned char *seed = NULL, *seed_tmp = NULL;
+ unsigned char md[EVP_MAX_MD_SIZE];
+ int mdsize;
+ 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 = N >> 3;
+ int counter = 0;
+ int r = 0;
+ BN_CTX *ctx = NULL;
+ EVP_MD_CTX *mctx = EVP_MD_CTX_new();
+ unsigned int h = 2;
+
+ if (mctx == NULL)
+ goto err;
+
+ if (evpmd == NULL) {
+ if (N == 160)
+ evpmd = EVP_sha1();
+ else if (N == 224)
+ evpmd = EVP_sha224();
+ else
+ evpmd = EVP_sha256();
+ }
+
+ mdsize = EVP_MD_size(evpmd);
+ /* If unverifiable g generation only don't need seed */
+ if (!ret->p || !ret->q || idx >= 0) {
+ if (seed_len == 0)
+ seed_len = mdsize;
+
+ seed = OPENSSL_malloc(seed_len);
+
+ if (seed_out)
+ seed_tmp = seed_out;
+ else
+ seed_tmp = OPENSSL_malloc(seed_len);
+
+ if (seed == NULL || seed_tmp == NULL)
+ goto err;
+
+ if (seed_in)
+ 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);
+ X = BN_CTX_get(ctx);
+ c = BN_CTX_get(ctx);
+ test = BN_CTX_get(ctx);
+ if (test == NULL)
+ goto err;
+
+ /* if p, q already supplied generate g only */
+ if (ret->p && ret->q) {
+ p = ret->p;
+ q = ret->q;
+ if (idx >= 0)
+ memcpy(seed_tmp, seed, seed_len);
+ goto g_only;
+ } else {
+ p = BN_CTX_get(ctx);
+ q = BN_CTX_get(ctx);
+ }
+
+ if (!BN_lshift(test, BN_value_one(), L - 1))
+ goto err;
+ for (;;) {
+ for (;;) { /* find q */
+ unsigned char *pmd;
+ /* step 1 */
+ if (!BN_GENCB_call(cb, 0, m++))
+ goto err;
+
+ if (!seed_in) {
+ if (RAND_bytes(seed, seed_len) <= 0)
+ goto err;
+ }
+ /* step 2 */
+ if (!EVP_Digest(seed, seed_len, md, NULL, evpmd, NULL))
+ goto err;
+ /* Take least significant bits of md */
+ if (mdsize > qsize)
+ pmd = md + mdsize - qsize;
+ else
+ pmd = md;
+
+ if (mdsize < qsize)
+ memset(md + mdsize, 0, qsize - mdsize);
+
+ /* step 3 */
+ pmd[0] |= 0x80;
+ pmd[qsize - 1] |= 0x01;
+ if (!BN_bin2bn(pmd, qsize, q))
+ goto err;
+
+ /* step 4 */
+ r = BN_is_prime_fasttest_ex(q, DSS_prime_checks, ctx,
+ seed_in ? 1 : 0, cb);
+ if (r > 0)
+ break;
+ if (r != 0)
+ goto err;
+ /* Provided seed didn't produce a prime: error */
+ if (seed_in) {
+ ok = 0;
+ DSAerr(DSA_F_DSA_BUILTIN_PARAMGEN2, DSA_R_Q_NOT_PRIME);
+ goto err;
+ }
+
+ /* do a callback call */
+ /* step 5 */
+ }
+ /* Copy seed to seed_out before we mess with it */
+ if (seed_out)
+ memcpy(seed_out, seed, seed_len);
+
+ if (!BN_GENCB_call(cb, 2, 0))
+ goto err;
+ if (!BN_GENCB_call(cb, 3, 0))
+ goto err;
+
+ /* step 6 */
+ counter = 0;
+ /* "offset = 1" */
+
+ n = (L - 1) / (mdsize << 3);
+
+ 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 = seed_len - 1; i >= 0; i--) {
+ seed[i]++;
+ if (seed[i] != 0)
+ break;
+ }
+
+ if (!EVP_Digest(seed, seed_len, md, NULL, evpmd, NULL))
+ goto err;
+
+ /* step 8 */
+ if (!BN_bin2bn(md, mdsize, r0))
+ goto err;
+ if (!BN_lshift(r0, r0, (mdsize << 3) * k))
+ goto err;
+ if (!BN_add(W, W, r0))
+ goto err;
+ }
+
+ /* more of step 8 */
+ if (!BN_mask_bits(W, L - 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 >= (int)(4 * L))
+ break;
+ }
+ if (seed_in) {
+ ok = 0;
+ DSAerr(DSA_F_DSA_BUILTIN_PARAMGEN2, DSA_R_INVALID_PARAMETERS);
+ goto err;
+ }
+ }
+ end:
+ if (!BN_GENCB_call(cb, 2, 1))
+ goto err;
+
+ g_only:
+
+ /* 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 (idx < 0) {
+ if (!BN_set_word(test, h))
+ goto err;
+ } else
+ h = 1;
+ if (!BN_MONT_CTX_set(mont, p, ctx))
+ goto err;
+
+ for (;;) {
+ static const unsigned char ggen[4] = { 0x67, 0x67, 0x65, 0x6e };
+ if (idx >= 0) {
+ md[0] = idx & 0xff;
+ md[1] = (h >> 8) & 0xff;
+ md[2] = h & 0xff;
+ if (!EVP_DigestInit_ex(mctx, evpmd, NULL))
+ goto err;
+ if (!EVP_DigestUpdate(mctx, seed_tmp, seed_len))
+ goto err;
+ if (!EVP_DigestUpdate(mctx, ggen, sizeof(ggen)))
+ goto err;
+ if (!EVP_DigestUpdate(mctx, md, 3))
+ goto err;
+ if (!EVP_DigestFinal_ex(mctx, md, NULL))
+ goto err;
+ if (!BN_bin2bn(md, mdsize, test))
+ goto err;
+ }
+ /* g=test^r0%p */
+ if (!BN_mod_exp_mont(g, test, r0, p, ctx, mont))
+ goto err;
+ if (!BN_is_one(g))
+ break;
+ if (idx < 0 && !BN_add(test, test, BN_value_one()))
+ goto err;
+ h++;
+ if (idx >= 0 && h > 0xffff)
+ goto err;
+ }
+
+ if (!BN_GENCB_call(cb, 3, 1))
+ goto err;
+
+ ok = 1;
+ err:
+ if (ok == 1) {
+ if (p != ret->p) {
+ BN_free(ret->p);
+ ret->p = BN_dup(p);
+ }
+ if (q != ret->q) {
+ BN_free(ret->q);
+ ret->q = BN_dup(q);
+ }
+ BN_free(ret->g);
+ ret->g = BN_dup(g);
+ if (ret->p == NULL || ret->q == NULL || ret->g == NULL) {
+ ok = -1;
+ goto err;
+ }
+ if (counter_ret != NULL)
+ *counter_ret = counter;
+ if (h_ret != NULL)
+ *h_ret = h;
+ }
+ OPENSSL_free(seed);
+ if (seed_out != seed_tmp)
+ OPENSSL_free(seed_tmp);
+ if (ctx)
+ BN_CTX_end(ctx);
+ BN_CTX_free(ctx);
+ BN_MONT_CTX_free(mont);
+ EVP_MD_CTX_free(mctx);
+ return ok;
+}
projects / openssl.git / blobdiff