fips_dsa_gen.c revision 193645
1/* crypto/dsa/dsa_gen.c */ 2/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 3 * All rights reserved. 4 * 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. 8 * 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). 15 * 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. 22 * 23 * Redistribution and use in source and binary forms, with or without 24 * modification, are permitted provided that the following conditions 25 * are met: 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)" 40 * 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 51 * SUCH DAMAGE. 52 * 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.] 57 */ 58 59#undef GENUINE_DSA 60 61#ifdef GENUINE_DSA 62/* Parameter generation follows the original release of FIPS PUB 186, 63 * Appendix 2.2 (i.e. use SHA as defined in FIPS PUB 180) */ 64#define HASH EVP_sha() 65#else 66/* Parameter generation follows the updated Appendix 2.2 for FIPS PUB 186, 67 * also Appendix 2.2 of FIPS PUB 186-1 (i.e. use SHA as defined in 68 * FIPS PUB 180-1) */ 69#define HASH EVP_sha1() 70#endif 71 72#include <openssl/opensslconf.h> /* To see if OPENSSL_NO_SHA is defined */ 73 74#ifndef OPENSSL_NO_SHA 75 76#include <stdio.h> 77#include <time.h> 78#include <string.h> 79#include <openssl/evp.h> 80#include <openssl/bn.h> 81#include <openssl/dsa.h> 82#include <openssl/rand.h> 83#include <openssl/sha.h> 84#include <openssl/err.h> 85 86#ifdef OPENSSL_FIPS 87 88static int dsa_builtin_paramgen(DSA *ret, int bits, 89 unsigned char *seed_in, int seed_len, 90 int *counter_ret, unsigned long *h_ret, BN_GENCB *cb); 91 92int DSA_generate_parameters_ex(DSA *ret, int bits, 93 unsigned char *seed_in, int seed_len, 94 int *counter_ret, unsigned long *h_ret, BN_GENCB *cb) 95 { 96 if(ret->meth->dsa_paramgen) 97 return ret->meth->dsa_paramgen(ret, bits, seed_in, seed_len, 98 counter_ret, h_ret, cb); 99 return dsa_builtin_paramgen(ret, bits, seed_in, seed_len, 100 counter_ret, h_ret, cb); 101 } 102 103static int dsa_builtin_paramgen(DSA *ret, int bits, 104 unsigned char *seed_in, int seed_len, 105 int *counter_ret, unsigned long *h_ret, BN_GENCB *cb) 106 { 107 int ok=0; 108 unsigned char seed[SHA_DIGEST_LENGTH]; 109 unsigned char md[SHA_DIGEST_LENGTH]; 110 unsigned char buf[SHA_DIGEST_LENGTH],buf2[SHA_DIGEST_LENGTH]; 111 BIGNUM *r0,*W,*X,*c,*test; 112 BIGNUM *g=NULL,*q=NULL,*p=NULL; 113 BN_MONT_CTX *mont=NULL; 114 int k,n=0,i,b,m=0; 115 int counter=0; 116 int r=0; 117 BN_CTX *ctx=NULL; 118 unsigned int h=2; 119 120 if(FIPS_selftest_failed()) 121 { 122 FIPSerr(FIPS_F_DSA_BUILTIN_PARAMGEN, 123 FIPS_R_FIPS_SELFTEST_FAILED); 124 goto err; 125 } 126 127 if (FIPS_mode() && (bits < OPENSSL_DSA_FIPS_MIN_MODULUS_BITS)) 128 { 129 DSAerr(DSA_F_DSA_BUILTIN_PARAMGEN, DSA_R_KEY_SIZE_TOO_SMALL); 130 goto err; 131 } 132 133 if (bits < 512) bits=512; 134 bits=(bits+63)/64*64; 135 136 /* NB: seed_len == 0 is special case: copy generated seed to 137 * seed_in if it is not NULL. 138 */ 139 if (seed_len && (seed_len < 20)) 140 seed_in = NULL; /* seed buffer too small -- ignore */ 141 if (seed_len > 20) 142 seed_len = 20; /* App. 2.2 of FIPS PUB 186 allows larger SEED, 143 * but our internal buffers are restricted to 160 bits*/ 144 if ((seed_in != NULL) && (seed_len == 20)) 145 { 146 memcpy(seed,seed_in,seed_len); 147 /* set seed_in to NULL to avoid it being copied back */ 148 seed_in = NULL; 149 } 150 151 if ((ctx=BN_CTX_new()) == NULL) goto err; 152 153 if ((mont=BN_MONT_CTX_new()) == NULL) goto err; 154 155 BN_CTX_start(ctx); 156 r0 = BN_CTX_get(ctx); 157 g = BN_CTX_get(ctx); 158 W = BN_CTX_get(ctx); 159 q = BN_CTX_get(ctx); 160 X = BN_CTX_get(ctx); 161 c = BN_CTX_get(ctx); 162 p = BN_CTX_get(ctx); 163 test = BN_CTX_get(ctx); 164 165 if (!BN_lshift(test,BN_value_one(),bits-1)) 166 goto err; 167 168 for (;;) 169 { 170 for (;;) /* find q */ 171 { 172 int seed_is_random; 173 174 /* step 1 */ 175 if(!BN_GENCB_call(cb, 0, m++)) 176 goto err; 177 178 if (!seed_len) 179 { 180 RAND_pseudo_bytes(seed,SHA_DIGEST_LENGTH); 181 seed_is_random = 1; 182 } 183 else 184 { 185 seed_is_random = 0; 186 seed_len=0; /* use random seed if 'seed_in' turns out to be bad*/ 187 } 188 memcpy(buf,seed,SHA_DIGEST_LENGTH); 189 memcpy(buf2,seed,SHA_DIGEST_LENGTH); 190 /* precompute "SEED + 1" for step 7: */ 191 for (i=SHA_DIGEST_LENGTH-1; i >= 0; i--) 192 { 193 buf[i]++; 194 if (buf[i] != 0) break; 195 } 196 197 /* step 2 */ 198 EVP_Digest(seed,SHA_DIGEST_LENGTH,md,NULL,HASH, NULL); 199 EVP_Digest(buf,SHA_DIGEST_LENGTH,buf2,NULL,HASH, NULL); 200 for (i=0; i<SHA_DIGEST_LENGTH; i++) 201 md[i]^=buf2[i]; 202 203 /* step 3 */ 204 md[0]|=0x80; 205 md[SHA_DIGEST_LENGTH-1]|=0x01; 206 if (!BN_bin2bn(md,SHA_DIGEST_LENGTH,q)) goto err; 207 208 /* step 4 */ 209 r = BN_is_prime_fasttest_ex(q, DSS_prime_checks, ctx, 210 seed_is_random, cb); 211 if (r > 0) 212 break; 213 if (r != 0) 214 goto err; 215 216 /* do a callback call */ 217 /* step 5 */ 218 } 219 220 if(!BN_GENCB_call(cb, 2, 0)) goto err; 221 if(!BN_GENCB_call(cb, 3, 0)) goto err; 222 223 /* step 6 */ 224 counter=0; 225 /* "offset = 2" */ 226 227 n=(bits-1)/160; 228 b=(bits-1)-n*160; 229 230 for (;;) 231 { 232 if ((counter != 0) && !BN_GENCB_call(cb, 0, counter)) 233 goto err; 234 235 /* step 7 */ 236 BN_zero(W); 237 /* now 'buf' contains "SEED + offset - 1" */ 238 for (k=0; k<=n; k++) 239 { 240 /* obtain "SEED + offset + k" by incrementing: */ 241 for (i=SHA_DIGEST_LENGTH-1; i >= 0; i--) 242 { 243 buf[i]++; 244 if (buf[i] != 0) break; 245 } 246 247 EVP_Digest(buf,SHA_DIGEST_LENGTH,md,NULL,HASH, NULL); 248 249 /* step 8 */ 250 if (!BN_bin2bn(md,SHA_DIGEST_LENGTH,r0)) 251 goto err; 252 if (!BN_lshift(r0,r0,160*k)) goto err; 253 if (!BN_add(W,W,r0)) goto err; 254 } 255 256 /* more of step 8 */ 257 if (!BN_mask_bits(W,bits-1)) goto err; 258 if (!BN_copy(X,W)) goto err; 259 if (!BN_add(X,X,test)) goto err; 260 261 /* step 9 */ 262 if (!BN_lshift1(r0,q)) goto err; 263 if (!BN_mod(c,X,r0,ctx)) goto err; 264 if (!BN_sub(r0,c,BN_value_one())) goto err; 265 if (!BN_sub(p,X,r0)) goto err; 266 267 /* step 10 */ 268 if (BN_cmp(p,test) >= 0) 269 { 270 /* step 11 */ 271 r = BN_is_prime_fasttest_ex(p, DSS_prime_checks, 272 ctx, 1, cb); 273 if (r > 0) 274 goto end; /* found it */ 275 if (r != 0) 276 goto err; 277 } 278 279 /* step 13 */ 280 counter++; 281 /* "offset = offset + n + 1" */ 282 283 /* step 14 */ 284 if (counter >= 4096) break; 285 } 286 } 287end: 288 if(!BN_GENCB_call(cb, 2, 1)) 289 goto err; 290 291 /* We now need to generate g */ 292 /* Set r0=(p-1)/q */ 293 if (!BN_sub(test,p,BN_value_one())) goto err; 294 if (!BN_div(r0,NULL,test,q,ctx)) goto err; 295 296 if (!BN_set_word(test,h)) goto err; 297 if (!BN_MONT_CTX_set(mont,p,ctx)) goto err; 298 299 for (;;) 300 { 301 /* g=test^r0%p */ 302 if (!BN_mod_exp_mont(g,test,r0,p,ctx,mont)) goto err; 303 if (!BN_is_one(g)) break; 304 if (!BN_add(test,test,BN_value_one())) goto err; 305 h++; 306 } 307 308 if(!BN_GENCB_call(cb, 3, 1)) 309 goto err; 310 311 ok=1; 312err: 313 if (ok) 314 { 315 if(ret->p) BN_free(ret->p); 316 if(ret->q) BN_free(ret->q); 317 if(ret->g) BN_free(ret->g); 318 ret->p=BN_dup(p); 319 ret->q=BN_dup(q); 320 ret->g=BN_dup(g); 321 if (ret->p == NULL || ret->q == NULL || ret->g == NULL) 322 { 323 ok=0; 324 goto err; 325 } 326 if (seed_in != NULL) memcpy(seed_in,seed,20); 327 if (counter_ret != NULL) *counter_ret=counter; 328 if (h_ret != NULL) *h_ret=h; 329 } 330 if(ctx) 331 { 332 BN_CTX_end(ctx); 333 BN_CTX_free(ctx); 334 } 335 if (mont != NULL) BN_MONT_CTX_free(mont); 336 return ok; 337 } 338#endif 339#endif 340