1 /* crypto/dsa/dsa_gen.c */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
5 * This package is an SSL implementation written
6 * by Eric Young (eay@cryptsoft.com).
7 * The implementation was written so as to conform with Netscapes SSL.
9 * This library is free for commercial and non-commercial use as long as
10 * the following conditions are aheared to. The following conditions
11 * apply to all code found in this distribution, be it the RC4, RSA,
12 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
13 * included with this distribution is covered by the same copyright terms
14 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
16 * Copyright remains Eric Young's, and as such any Copyright notices in
17 * the code are not to be removed.
18 * If this package is used in a product, Eric Young should be given attribution
19 * as the author of the parts of the library used.
20 * This can be in the form of a textual message at program startup or
21 * in documentation (online or textual) provided with the package.
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
26 * 1. Redistributions of source code must retain the copyright
27 * notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 * notice, this list of conditions and the following disclaimer in the
30 * documentation and/or other materials provided with the distribution.
31 * 3. All advertising materials mentioning features or use of this software
32 * must display the following acknowledgement:
33 * "This product includes cryptographic software written by
34 * Eric Young (eay@cryptsoft.com)"
35 * The word 'cryptographic' can be left out if the rouines from the library
36 * being used are not cryptographic related :-).
37 * 4. If you include any Windows specific code (or a derivative thereof) from
38 * the apps directory (application code) you must include an acknowledgement:
39 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
53 * The licence and distribution terms for any publically available version or
54 * derivative of this code cannot be changed. i.e. this code cannot simply be
55 * copied and put under another distribution licence
56 * [including the GNU Public Licence.]
63 * Parameter generation follows the original release of FIPS PUB 186,
64 * Appendix 2.2 (i.e. use SHA as defined in FIPS PUB 180)
66 # define HASH EVP_sha()
69 * Parameter generation follows the updated Appendix 2.2 for FIPS PUB 186,
70 * also Appendix 2.2 of FIPS PUB 186-1 (i.e. use SHA as defined in FIPS PUB
73 # define HASH EVP_sha1()
76 #include <openssl/opensslconf.h> /* To see if OPENSSL_NO_SHA is defined */
78 #ifndef OPENSSL_NO_SHA
81 # include "cryptlib.h"
82 # include <openssl/evp.h>
83 # include <openssl/bn.h>
84 # include <openssl/rand.h>
85 # include <openssl/sha.h>
86 # include "dsa_locl.h"
89 /* Workaround bug in prototype */
90 # define fips_dsa_builtin_paramgen2 fips_dsa_paramgen_bad
91 # include <openssl/fips.h>
94 int DSA_generate_parameters_ex(DSA *ret, int bits,
95 const unsigned char *seed_in, int seed_len,
96 int *counter_ret, unsigned long *h_ret,
100 if (FIPS_mode() && !(ret->meth->flags & DSA_FLAG_FIPS_METHOD)
101 && !(ret->flags & DSA_FLAG_NON_FIPS_ALLOW)) {
102 DSAerr(DSA_F_DSA_GENERATE_PARAMETERS_EX, DSA_R_NON_FIPS_DSA_METHOD);
106 if (ret->meth->dsa_paramgen)
107 return ret->meth->dsa_paramgen(ret, bits, seed_in, seed_len,
108 counter_ret, h_ret, cb);
110 else if (FIPS_mode()) {
111 return FIPS_dsa_generate_parameters_ex(ret, bits,
113 counter_ret, h_ret, cb);
118 size_t qbits = bits >= 2048 ? 256 : 160;
122 evpmd = EVP_sha256();
128 return dsa_builtin_paramgen(ret, bits, qbits, evpmd,
129 seed_in, seed_len, NULL, counter_ret,
134 int dsa_builtin_paramgen(DSA *ret, size_t bits, size_t qbits,
135 const EVP_MD *evpmd, const unsigned char *seed_in,
136 size_t seed_len, unsigned char *seed_out,
137 int *counter_ret, unsigned long *h_ret, BN_GENCB *cb)
140 unsigned char seed[SHA256_DIGEST_LENGTH];
141 unsigned char md[SHA256_DIGEST_LENGTH];
142 unsigned char buf[SHA256_DIGEST_LENGTH], buf2[SHA256_DIGEST_LENGTH];
143 BIGNUM *r0, *W, *X, *c, *test;
144 BIGNUM *g = NULL, *q = NULL, *p = NULL;
145 BN_MONT_CTX *mont = NULL;
146 int i, k, n = 0, m = 0, qsize = qbits >> 3;
152 if (qsize != SHA_DIGEST_LENGTH && qsize != SHA224_DIGEST_LENGTH &&
153 qsize != SHA256_DIGEST_LENGTH)
158 /* use SHA1 as default */
164 bits = (bits + 63) / 64 * 64;
167 * NB: seed_len == 0 is special case: copy generated seed to seed_in if
170 if (seed_len && (seed_len < (size_t)qsize))
171 seed_in = NULL; /* seed buffer too small -- ignore */
172 if (seed_len > (size_t)qsize)
173 seed_len = qsize; /* App. 2.2 of FIPS PUB 186 allows larger
174 * SEED, but our internal buffers are
175 * restricted to 160 bits */
177 memcpy(seed, seed_in, seed_len);
179 if ((ctx = BN_CTX_new()) == NULL)
182 if ((mont = BN_MONT_CTX_new()) == NULL)
186 r0 = BN_CTX_get(ctx);
193 test = BN_CTX_get(ctx);
195 if (!BN_lshift(test, BN_value_one(), bits - 1))
199 for (;;) { /* find q */
203 if (!BN_GENCB_call(cb, 0, m++))
207 if(RAND_pseudo_bytes(seed, qsize) < 0)
212 seed_len = 0; /* use random seed if 'seed_in' turns out to
215 memcpy(buf, seed, qsize);
216 memcpy(buf2, seed, qsize);
217 /* precompute "SEED + 1" for step 7: */
218 for (i = qsize - 1; i >= 0; i--) {
225 if (!EVP_Digest(seed, qsize, md, NULL, evpmd, NULL))
227 if (!EVP_Digest(buf, qsize, buf2, NULL, evpmd, NULL))
229 for (i = 0; i < qsize; i++)
234 md[qsize - 1] |= 0x01;
235 if (!BN_bin2bn(md, qsize, q))
239 r = BN_is_prime_fasttest_ex(q, DSS_prime_checks, ctx,
246 /* do a callback call */
250 if (!BN_GENCB_call(cb, 2, 0))
252 if (!BN_GENCB_call(cb, 3, 0))
259 n = (bits - 1) / 160;
262 if ((counter != 0) && !BN_GENCB_call(cb, 0, counter))
267 /* now 'buf' contains "SEED + offset - 1" */
268 for (k = 0; k <= n; k++) {
270 * obtain "SEED + offset + k" by incrementing:
272 for (i = qsize - 1; i >= 0; i--) {
278 if (!EVP_Digest(buf, qsize, md, NULL, evpmd, NULL))
282 if (!BN_bin2bn(md, qsize, r0))
284 if (!BN_lshift(r0, r0, (qsize << 3) * k))
286 if (!BN_add(W, W, r0))
291 if (!BN_mask_bits(W, bits - 1))
295 if (!BN_add(X, X, test))
299 if (!BN_lshift1(r0, q))
301 if (!BN_mod(c, X, r0, ctx))
303 if (!BN_sub(r0, c, BN_value_one()))
305 if (!BN_sub(p, X, r0))
309 if (BN_cmp(p, test) >= 0) {
311 r = BN_is_prime_fasttest_ex(p, DSS_prime_checks, ctx, 1, cb);
313 goto end; /* found it */
320 /* "offset = offset + n + 1" */
328 if (!BN_GENCB_call(cb, 2, 1))
331 /* We now need to generate g */
333 if (!BN_sub(test, p, BN_value_one()))
335 if (!BN_div(r0, NULL, test, q, ctx))
338 if (!BN_set_word(test, h))
340 if (!BN_MONT_CTX_set(mont, p, ctx))
345 if (!BN_mod_exp_mont(g, test, r0, p, ctx, mont))
349 if (!BN_add(test, test, BN_value_one()))
354 if (!BN_GENCB_call(cb, 3, 1))
369 if (ret->p == NULL || ret->q == NULL || ret->g == NULL) {
373 if (counter_ret != NULL)
374 *counter_ret = counter;
378 memcpy(seed_out, seed, qsize);
385 BN_MONT_CTX_free(mont);
390 # undef fips_dsa_builtin_paramgen2
391 extern int fips_dsa_builtin_paramgen2(DSA *ret, size_t L, size_t N,
393 const unsigned char *seed_in,
394 size_t seed_len, int idx,
395 unsigned char *seed_out,
396 int *counter_ret, unsigned long *h_ret,
401 * This is a parameter generation algorithm for the DSA2 algorithm as
402 * described in FIPS 186-3.
405 int dsa_builtin_paramgen2(DSA *ret, size_t L, size_t N,
406 const EVP_MD *evpmd, const unsigned char *seed_in,
407 size_t seed_len, int idx, unsigned char *seed_out,
408 int *counter_ret, unsigned long *h_ret,
412 unsigned char *seed = NULL, *seed_tmp = NULL;
413 unsigned char md[EVP_MAX_MD_SIZE];
415 BIGNUM *r0, *W, *X, *c, *test;
416 BIGNUM *g = NULL, *q = NULL, *p = NULL;
417 BN_MONT_CTX *mont = NULL;
418 int i, k, n = 0, m = 0, qsize = N >> 3;
428 return fips_dsa_builtin_paramgen2(ret, L, N, evpmd,
429 seed_in, seed_len, idx,
430 seed_out, counter_ret, h_ret, cb);
433 EVP_MD_CTX_init(&mctx);
439 evpmd = EVP_sha224();
441 evpmd = EVP_sha256();
444 mdsize = EVP_MD_size(evpmd);
445 /* If unverificable g generation only don't need seed */
446 if (!ret->p || !ret->q || idx >= 0) {
450 seed = OPENSSL_malloc(seed_len);
455 seed_tmp = OPENSSL_malloc(seed_len);
457 if (!seed || !seed_tmp)
461 memcpy(seed, seed_in, seed_len);
465 if ((ctx = BN_CTX_new()) == NULL)
468 if ((mont = BN_MONT_CTX_new()) == NULL)
472 r0 = BN_CTX_get(ctx);
477 test = BN_CTX_get(ctx);
479 /* if p, q already supplied generate g only */
480 if (ret->p && ret->q) {
484 memcpy(seed_tmp, seed, seed_len);
491 if (!BN_lshift(test, BN_value_one(), L - 1))
494 for (;;) { /* find q */
497 if (!BN_GENCB_call(cb, 0, m++))
501 if (RAND_pseudo_bytes(seed, seed_len) < 0)
505 if (!EVP_Digest(seed, seed_len, md, NULL, evpmd, NULL))
507 /* Take least significant bits of md */
509 pmd = md + mdsize - qsize;
514 memset(md + mdsize, 0, qsize - mdsize);
518 pmd[qsize - 1] |= 0x01;
519 if (!BN_bin2bn(pmd, qsize, q))
523 r = BN_is_prime_fasttest_ex(q, DSS_prime_checks, ctx,
524 seed_in ? 1 : 0, cb);
529 /* Provided seed didn't produce a prime: error */
532 DSAerr(DSA_F_DSA_BUILTIN_PARAMGEN2, DSA_R_Q_NOT_PRIME);
536 /* do a callback call */
539 /* Copy seed to seed_out before we mess with it */
541 memcpy(seed_out, seed, seed_len);
543 if (!BN_GENCB_call(cb, 2, 0))
545 if (!BN_GENCB_call(cb, 3, 0))
552 n = (L - 1) / (mdsize << 3);
555 if ((counter != 0) && !BN_GENCB_call(cb, 0, counter))
560 /* now 'buf' contains "SEED + offset - 1" */
561 for (k = 0; k <= n; k++) {
563 * obtain "SEED + offset + k" by incrementing:
565 for (i = seed_len - 1; i >= 0; i--) {
571 if (!EVP_Digest(seed, seed_len, md, NULL, evpmd, NULL))
575 if (!BN_bin2bn(md, mdsize, r0))
577 if (!BN_lshift(r0, r0, (mdsize << 3) * k))
579 if (!BN_add(W, W, r0))
584 if (!BN_mask_bits(W, L - 1))
588 if (!BN_add(X, X, test))
592 if (!BN_lshift1(r0, q))
594 if (!BN_mod(c, X, r0, ctx))
596 if (!BN_sub(r0, c, BN_value_one()))
598 if (!BN_sub(p, X, r0))
602 if (BN_cmp(p, test) >= 0) {
604 r = BN_is_prime_fasttest_ex(p, DSS_prime_checks, ctx, 1, cb);
606 goto end; /* found it */
613 /* "offset = offset + n + 1" */
616 if (counter >= (int)(4 * L))
621 DSAerr(DSA_F_DSA_BUILTIN_PARAMGEN2, DSA_R_INVALID_PARAMETERS);
626 if (!BN_GENCB_call(cb, 2, 1))
631 /* We now need to generate g */
633 if (!BN_sub(test, p, BN_value_one()))
635 if (!BN_div(r0, NULL, test, q, ctx))
639 if (!BN_set_word(test, h))
643 if (!BN_MONT_CTX_set(mont, p, ctx))
647 static const unsigned char ggen[4] = { 0x67, 0x67, 0x65, 0x6e };
650 md[1] = (h >> 8) & 0xff;
652 if (!EVP_DigestInit_ex(&mctx, evpmd, NULL))
654 if (!EVP_DigestUpdate(&mctx, seed_tmp, seed_len))
656 if (!EVP_DigestUpdate(&mctx, ggen, sizeof(ggen)))
658 if (!EVP_DigestUpdate(&mctx, md, 3))
660 if (!EVP_DigestFinal_ex(&mctx, md, NULL))
662 if (!BN_bin2bn(md, mdsize, test))
666 if (!BN_mod_exp_mont(g, test, r0, p, ctx, mont))
670 if (idx < 0 && !BN_add(test, test, BN_value_one()))
673 if (idx >= 0 && h > 0xffff)
677 if (!BN_GENCB_call(cb, 3, 1))
696 if (ret->p == NULL || ret->q == NULL || ret->g == NULL) {
700 if (counter_ret != NULL)
701 *counter_ret = counter;
707 if (seed_out != seed_tmp)
708 OPENSSL_free(seed_tmp);
714 BN_MONT_CTX_free(mont);
715 EVP_MD_CTX_cleanup(&mctx);
719 int dsa_paramgen_check_g(DSA *dsa)
723 BN_MONT_CTX *mont = NULL;
729 if (BN_cmp(dsa->g, BN_value_one()) <= 0)
731 if (BN_cmp(dsa->g, dsa->p) >= 0)
733 tmp = BN_CTX_get(ctx);
736 if ((mont = BN_MONT_CTX_new()) == NULL)
738 if (!BN_MONT_CTX_set(mont, dsa->p, ctx))
740 /* Work out g^q mod p */
741 if (!BN_mod_exp_mont(tmp, dsa->g, dsa->q, dsa->p, ctx, mont))
743 if (!BN_cmp(tmp, BN_value_one()))
750 BN_MONT_CTX_free(mont);