155714Skris/* crypto/dsa/dsa_gen.c */ 255714Skris/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 355714Skris * All rights reserved. 455714Skris * 555714Skris * This package is an SSL implementation written 655714Skris * by Eric Young (eay@cryptsoft.com). 755714Skris * The implementation was written so as to conform with Netscapes SSL. 8296465Sdelphij * 955714Skris * This library is free for commercial and non-commercial use as long as 1055714Skris * the following conditions are aheared to. The following conditions 1155714Skris * apply to all code found in this distribution, be it the RC4, RSA, 1255714Skris * lhash, DES, etc., code; not just the SSL code. The SSL documentation 1355714Skris * included with this distribution is covered by the same copyright terms 1455714Skris * except that the holder is Tim Hudson (tjh@cryptsoft.com). 15296465Sdelphij * 1655714Skris * Copyright remains Eric Young's, and as such any Copyright notices in 1755714Skris * the code are not to be removed. 1855714Skris * If this package is used in a product, Eric Young should be given attribution 1955714Skris * as the author of the parts of the library used. 2055714Skris * This can be in the form of a textual message at program startup or 2155714Skris * in documentation (online or textual) provided with the package. 22296465Sdelphij * 2355714Skris * Redistribution and use in source and binary forms, with or without 2455714Skris * modification, are permitted provided that the following conditions 2555714Skris * are met: 2655714Skris * 1. Redistributions of source code must retain the copyright 2755714Skris * notice, this list of conditions and the following disclaimer. 2855714Skris * 2. Redistributions in binary form must reproduce the above copyright 2955714Skris * notice, this list of conditions and the following disclaimer in the 3055714Skris * documentation and/or other materials provided with the distribution. 3155714Skris * 3. All advertising materials mentioning features or use of this software 3255714Skris * must display the following acknowledgement: 3355714Skris * "This product includes cryptographic software written by 3455714Skris * Eric Young (eay@cryptsoft.com)" 3555714Skris * The word 'cryptographic' can be left out if the rouines from the library 3655714Skris * being used are not cryptographic related :-). 37296465Sdelphij * 4. If you include any Windows specific code (or a derivative thereof) from 3855714Skris * the apps directory (application code) you must include an acknowledgement: 3955714Skris * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 40296465Sdelphij * 4155714Skris * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 4255714Skris * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 4355714Skris * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 4455714Skris * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 4555714Skris * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 4655714Skris * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 4755714Skris * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 4855714Skris * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 4955714Skris * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 5055714Skris * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 5155714Skris * SUCH DAMAGE. 52296465Sdelphij * 5355714Skris * The licence and distribution terms for any publically available version or 5455714Skris * derivative of this code cannot be changed. i.e. this code cannot simply be 5555714Skris * copied and put under another distribution licence 5655714Skris * [including the GNU Public Licence.] 5755714Skris */ 5855714Skris 5955714Skris#undef GENUINE_DSA 6055714Skris 6155714Skris#ifdef GENUINE_DSA 62296465Sdelphij/* 63296465Sdelphij * Parameter generation follows the original release of FIPS PUB 186, 64296465Sdelphij * Appendix 2.2 (i.e. use SHA as defined in FIPS PUB 180) 65296465Sdelphij */ 66296465Sdelphij# define HASH EVP_sha() 6755714Skris#else 68296465Sdelphij/* 69296465Sdelphij * Parameter generation follows the updated Appendix 2.2 for FIPS PUB 186, 70296465Sdelphij * also Appendix 2.2 of FIPS PUB 186-1 (i.e. use SHA as defined in FIPS PUB 71296465Sdelphij * 180-1) 72296465Sdelphij */ 73296465Sdelphij# define HASH EVP_sha1() 74296465Sdelphij#endif 7555714Skris 76160814Ssimon#include <openssl/opensslconf.h> /* To see if OPENSSL_NO_SHA is defined */ 77160814Ssimon 78109998Smarkm#ifndef OPENSSL_NO_SHA 7959191Skris 80296465Sdelphij# include <stdio.h> 81296465Sdelphij# include <time.h> 82296465Sdelphij# include "cryptlib.h" 83296465Sdelphij# include <openssl/evp.h> 84296465Sdelphij# include <openssl/bn.h> 85296465Sdelphij# include <openssl/dsa.h> 86296465Sdelphij# include <openssl/rand.h> 87296465Sdelphij# include <openssl/sha.h> 8855714Skris 89296465Sdelphij# ifndef OPENSSL_FIPS 90194206Ssimon 91160814Ssimonstatic int dsa_builtin_paramgen(DSA *ret, int bits, 92296465Sdelphij unsigned char *seed_in, int seed_len, 93296465Sdelphij int *counter_ret, unsigned long *h_ret, 94296465Sdelphij BN_GENCB *cb); 95160814Ssimon 96160814Ssimonint DSA_generate_parameters_ex(DSA *ret, int bits, 97296465Sdelphij unsigned char *seed_in, int seed_len, 98296465Sdelphij int *counter_ret, unsigned long *h_ret, 99296465Sdelphij BN_GENCB *cb) 100296465Sdelphij{ 101296465Sdelphij if (ret->meth->dsa_paramgen) 102296465Sdelphij return ret->meth->dsa_paramgen(ret, bits, seed_in, seed_len, 103296465Sdelphij counter_ret, h_ret, cb); 104296465Sdelphij return dsa_builtin_paramgen(ret, bits, seed_in, seed_len, 105296465Sdelphij counter_ret, h_ret, cb); 106296465Sdelphij} 107160814Ssimon 108160814Ssimonstatic int dsa_builtin_paramgen(DSA *ret, int bits, 109296465Sdelphij unsigned char *seed_in, int seed_len, 110296465Sdelphij int *counter_ret, unsigned long *h_ret, 111296465Sdelphij BN_GENCB *cb) 112296465Sdelphij{ 113296465Sdelphij int ok = 0; 114296465Sdelphij unsigned char seed[SHA_DIGEST_LENGTH]; 115296465Sdelphij unsigned char md[SHA_DIGEST_LENGTH]; 116296465Sdelphij unsigned char buf[SHA_DIGEST_LENGTH], buf2[SHA_DIGEST_LENGTH]; 117296465Sdelphij BIGNUM *r0, *W, *X, *c, *test; 118296465Sdelphij BIGNUM *g = NULL, *q = NULL, *p = NULL; 119296465Sdelphij BN_MONT_CTX *mont = NULL; 120296465Sdelphij int k, n = 0, i, m = 0; 121296465Sdelphij int counter = 0; 122296465Sdelphij int r = 0; 123296465Sdelphij BN_CTX *ctx = NULL; 124296465Sdelphij unsigned int h = 2; 12555714Skris 126296465Sdelphij if (bits < 512) 127296465Sdelphij bits = 512; 128296465Sdelphij bits = (bits + 63) / 64 * 64; 12955714Skris 130296465Sdelphij /* 131296465Sdelphij * NB: seed_len == 0 is special case: copy generated seed to seed_in if 132296465Sdelphij * it is not NULL. 133296465Sdelphij */ 134296465Sdelphij if (seed_len && (seed_len < 20)) 135296465Sdelphij seed_in = NULL; /* seed buffer too small -- ignore */ 136296465Sdelphij if (seed_len > 20) 137296465Sdelphij seed_len = 20; /* App. 2.2 of FIPS PUB 186 allows larger 138296465Sdelphij * SEED, but our internal buffers are 139296465Sdelphij * restricted to 160 bits */ 140296465Sdelphij if ((seed_in != NULL) && (seed_len == 20)) { 141296465Sdelphij memcpy(seed, seed_in, seed_len); 142296465Sdelphij /* set seed_in to NULL to avoid it being copied back */ 143296465Sdelphij seed_in = NULL; 144296465Sdelphij } 14555714Skris 146296465Sdelphij if ((ctx = BN_CTX_new()) == NULL) 147296465Sdelphij goto err; 14855714Skris 149296465Sdelphij if ((mont = BN_MONT_CTX_new()) == NULL) 150296465Sdelphij goto err; 15155714Skris 152296465Sdelphij BN_CTX_start(ctx); 153296465Sdelphij r0 = BN_CTX_get(ctx); 154296465Sdelphij g = BN_CTX_get(ctx); 155296465Sdelphij W = BN_CTX_get(ctx); 156296465Sdelphij q = BN_CTX_get(ctx); 157296465Sdelphij X = BN_CTX_get(ctx); 158296465Sdelphij c = BN_CTX_get(ctx); 159296465Sdelphij p = BN_CTX_get(ctx); 160296465Sdelphij test = BN_CTX_get(ctx); 16155714Skris 162296465Sdelphij if (!BN_lshift(test, BN_value_one(), bits - 1)) 163296465Sdelphij goto err; 16455714Skris 165296465Sdelphij for (;;) { 166296465Sdelphij for (;;) { /* find q */ 167296465Sdelphij int seed_is_random; 16859191Skris 169296465Sdelphij /* step 1 */ 170296465Sdelphij if (!BN_GENCB_call(cb, 0, m++)) 171296465Sdelphij goto err; 17255714Skris 173296465Sdelphij if (!seed_len) { 174296465Sdelphij RAND_pseudo_bytes(seed, SHA_DIGEST_LENGTH); 175296465Sdelphij seed_is_random = 1; 176296465Sdelphij } else { 177296465Sdelphij seed_is_random = 0; 178296465Sdelphij seed_len = 0; /* use random seed if 'seed_in' turns out to 179296465Sdelphij * be bad */ 180296465Sdelphij } 181296465Sdelphij memcpy(buf, seed, SHA_DIGEST_LENGTH); 182296465Sdelphij memcpy(buf2, seed, SHA_DIGEST_LENGTH); 183296465Sdelphij /* precompute "SEED + 1" for step 7: */ 184296465Sdelphij for (i = SHA_DIGEST_LENGTH - 1; i >= 0; i--) { 185296465Sdelphij buf[i]++; 186296465Sdelphij if (buf[i] != 0) 187296465Sdelphij break; 188296465Sdelphij } 18955714Skris 190296465Sdelphij /* step 2 */ 191296465Sdelphij EVP_Digest(seed, SHA_DIGEST_LENGTH, md, NULL, HASH, NULL); 192296465Sdelphij EVP_Digest(buf, SHA_DIGEST_LENGTH, buf2, NULL, HASH, NULL); 193296465Sdelphij for (i = 0; i < SHA_DIGEST_LENGTH; i++) 194296465Sdelphij md[i] ^= buf2[i]; 19555714Skris 196296465Sdelphij /* step 3 */ 197296465Sdelphij md[0] |= 0x80; 198296465Sdelphij md[SHA_DIGEST_LENGTH - 1] |= 0x01; 199296465Sdelphij if (!BN_bin2bn(md, SHA_DIGEST_LENGTH, q)) 200296465Sdelphij goto err; 20155714Skris 202296465Sdelphij /* step 4 */ 203296465Sdelphij r = BN_is_prime_fasttest_ex(q, DSS_prime_checks, ctx, 204296465Sdelphij seed_is_random, cb); 205296465Sdelphij if (r > 0) 206296465Sdelphij break; 207296465Sdelphij if (r != 0) 208296465Sdelphij goto err; 20959191Skris 210296465Sdelphij /* do a callback call */ 211296465Sdelphij /* step 5 */ 212296465Sdelphij } 21355714Skris 214296465Sdelphij if (!BN_GENCB_call(cb, 2, 0)) 215296465Sdelphij goto err; 216296465Sdelphij if (!BN_GENCB_call(cb, 3, 0)) 217296465Sdelphij goto err; 21855714Skris 219296465Sdelphij /* step 6 */ 220296465Sdelphij counter = 0; 221296465Sdelphij /* "offset = 2" */ 22255714Skris 223296465Sdelphij n = (bits - 1) / 160; 22455714Skris 225296465Sdelphij for (;;) { 226296465Sdelphij if ((counter != 0) && !BN_GENCB_call(cb, 0, counter)) 227296465Sdelphij goto err; 22859191Skris 229296465Sdelphij /* step 7 */ 230296465Sdelphij BN_zero(W); 231296465Sdelphij /* now 'buf' contains "SEED + offset - 1" */ 232296465Sdelphij for (k = 0; k <= n; k++) { 233296465Sdelphij /* 234296465Sdelphij * obtain "SEED + offset + k" by incrementing: 235296465Sdelphij */ 236296465Sdelphij for (i = SHA_DIGEST_LENGTH - 1; i >= 0; i--) { 237296465Sdelphij buf[i]++; 238296465Sdelphij if (buf[i] != 0) 239296465Sdelphij break; 240296465Sdelphij } 24155714Skris 242296465Sdelphij EVP_Digest(buf, SHA_DIGEST_LENGTH, md, NULL, HASH, NULL); 24355714Skris 244296465Sdelphij /* step 8 */ 245296465Sdelphij if (!BN_bin2bn(md, SHA_DIGEST_LENGTH, r0)) 246296465Sdelphij goto err; 247296465Sdelphij if (!BN_lshift(r0, r0, 160 * k)) 248296465Sdelphij goto err; 249296465Sdelphij if (!BN_add(W, W, r0)) 250296465Sdelphij goto err; 251296465Sdelphij } 25255714Skris 253296465Sdelphij /* more of step 8 */ 254296465Sdelphij if (!BN_mask_bits(W, bits - 1)) 255296465Sdelphij goto err; 256296465Sdelphij if (!BN_copy(X, W)) 257296465Sdelphij goto err; 258296465Sdelphij if (!BN_add(X, X, test)) 259296465Sdelphij goto err; 26055714Skris 261296465Sdelphij /* step 9 */ 262296465Sdelphij if (!BN_lshift1(r0, q)) 263296465Sdelphij goto err; 264296465Sdelphij if (!BN_mod(c, X, r0, ctx)) 265296465Sdelphij goto err; 266296465Sdelphij if (!BN_sub(r0, c, BN_value_one())) 267296465Sdelphij goto err; 268296465Sdelphij if (!BN_sub(p, X, r0)) 269296465Sdelphij goto err; 27055714Skris 271296465Sdelphij /* step 10 */ 272296465Sdelphij if (BN_cmp(p, test) >= 0) { 273296465Sdelphij /* step 11 */ 274296465Sdelphij r = BN_is_prime_fasttest_ex(p, DSS_prime_checks, ctx, 1, cb); 275296465Sdelphij if (r > 0) 276296465Sdelphij goto end; /* found it */ 277296465Sdelphij if (r != 0) 278296465Sdelphij goto err; 279296465Sdelphij } 28055714Skris 281296465Sdelphij /* step 13 */ 282296465Sdelphij counter++; 283296465Sdelphij /* "offset = offset + n + 1" */ 28455714Skris 285296465Sdelphij /* step 14 */ 286296465Sdelphij if (counter >= 4096) 287296465Sdelphij break; 288296465Sdelphij } 289296465Sdelphij } 290296465Sdelphij end: 291296465Sdelphij if (!BN_GENCB_call(cb, 2, 1)) 292296465Sdelphij goto err; 29355714Skris 294296465Sdelphij /* We now need to generate g */ 295296465Sdelphij /* Set r0=(p-1)/q */ 296296465Sdelphij if (!BN_sub(test, p, BN_value_one())) 297296465Sdelphij goto err; 298296465Sdelphij if (!BN_div(r0, NULL, test, q, ctx)) 299296465Sdelphij goto err; 30055714Skris 301296465Sdelphij if (!BN_set_word(test, h)) 302296465Sdelphij goto err; 303296465Sdelphij if (!BN_MONT_CTX_set(mont, p, ctx)) 304296465Sdelphij goto err; 30555714Skris 306296465Sdelphij for (;;) { 307296465Sdelphij /* g=test^r0%p */ 308296465Sdelphij if (!BN_mod_exp_mont(g, test, r0, p, ctx, mont)) 309296465Sdelphij goto err; 310296465Sdelphij if (!BN_is_one(g)) 311296465Sdelphij break; 312296465Sdelphij if (!BN_add(test, test, BN_value_one())) 313296465Sdelphij goto err; 314296465Sdelphij h++; 315296465Sdelphij } 31655714Skris 317296465Sdelphij if (!BN_GENCB_call(cb, 3, 1)) 318296465Sdelphij goto err; 31955714Skris 320296465Sdelphij ok = 1; 321296465Sdelphij err: 322296465Sdelphij if (ok) { 323296465Sdelphij if (ret->p) 324296465Sdelphij BN_free(ret->p); 325296465Sdelphij if (ret->q) 326296465Sdelphij BN_free(ret->q); 327296465Sdelphij if (ret->g) 328296465Sdelphij BN_free(ret->g); 329296465Sdelphij ret->p = BN_dup(p); 330296465Sdelphij ret->q = BN_dup(q); 331296465Sdelphij ret->g = BN_dup(g); 332296465Sdelphij if (ret->p == NULL || ret->q == NULL || ret->g == NULL) { 333296465Sdelphij ok = 0; 334296465Sdelphij goto err; 335296465Sdelphij } 336296465Sdelphij if (seed_in != NULL) 337296465Sdelphij memcpy(seed_in, seed, 20); 338296465Sdelphij if (counter_ret != NULL) 339296465Sdelphij *counter_ret = counter; 340296465Sdelphij if (h_ret != NULL) 341296465Sdelphij *h_ret = h; 342296465Sdelphij } 343296465Sdelphij if (ctx) { 344296465Sdelphij BN_CTX_end(ctx); 345296465Sdelphij BN_CTX_free(ctx); 346296465Sdelphij } 347296465Sdelphij if (mont != NULL) 348296465Sdelphij BN_MONT_CTX_free(mont); 349296465Sdelphij return ok; 350296465Sdelphij} 351296465Sdelphij# endif 352160814Ssimon#endif 353