OSX/libsecurity_apple_csp/open_ssl/dsa/dsa_gen.c

   1 /*
   2  * Copyright (c) 2000-2001,2011,2014 Apple Inc. All Rights Reserved.
   3  *
   4  * The contents of this file constitute Original Code as defined in and are
   5  * subject to the Apple Public Source License Version 1.2 (the 'License').
   6  * You may not use this file except in compliance with the License. Please obtain
   7  * a copy of the License at http://www.apple.com/publicsource and read it before
   8  * using this file.
   9  *
  10  * This Original Code and all software distributed under the License are
  11  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS
  12  * OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, INCLUDING WITHOUT
  13  * LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
  14  * PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. Please see the License for the
  15  * specific language governing rights and limitations under the License.
  16  */
  17
  18
  19 /* crypto/dsa/dsa_gen.c */
  20 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  21  * All rights reserved.
  22  *
  23  * This package is an SSL implementation written
  24  * by Eric Young (eay@cryptsoft.com).
  25  * The implementation was written so as to conform with Netscapes SSL.
  26  *
  27  * This library is free for commercial and non-commercial use as long as
  28  * the following conditions are aheared to.  The following conditions
  29  * apply to all code found in this distribution, be it the RC4, RSA,
  30  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  31  * included with this distribution is covered by the same copyright terms
  32  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  33  *
  34  * Copyright remains Eric Young's, and as such any Copyright notices in
  35  * the code are not to be removed.
  36  * If this package is used in a product, Eric Young should be given attribution
  37  * as the author of the parts of the library used.
  38  * This can be in the form of a textual message at program startup or
  39  * in documentation (online or textual) provided with the package.
  40  *
  41  * Redistribution and use in source and binary forms, with or without
  42  * modification, are permitted provided that the following conditions
  43  * are met:
  44  * 1. Redistributions of source code must retain the copyright
  45  *    notice, this list of conditions and the following disclaimer.
  46  * 2. Redistributions in binary form must reproduce the above copyright
  47  *    notice, this list of conditions and the following disclaimer in the
  48  *    documentation and/or other materials provided with the distribution.
  49  * 3. All advertising materials mentioning features or use of this software
  50  *    must display the following acknowledgement:
  51  *    "This product includes cryptographic software written by
  52  *     Eric Young (eay@cryptsoft.com)"
  53  *    The word 'cryptographic' can be left out if the rouines from the library
  54  *    being used are not cryptographic related :-).
  55  * 4. If you include any Windows specific code (or a derivative thereof) from
  56  *    the apps directory (application code) you must include an acknowledgement:
  57  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  58  *
  59  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  60  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  61  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  62  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  63  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  64  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  65  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  66  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  67  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  68  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  69  * SUCH DAMAGE.
  70  *
  71  * The licence and distribution terms for any publically available version or
  72  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  73  * copied and put under another distribution licence
  74  * [including the GNU Public Licence.]
  75  */
  76
  77 #undef GENUINE_DSA
  78
  79 #ifdef GENUINE_DSA
  80 /* Parameter generation follows the original release of FIPS PUB 186,
  81  * Appendix 2.2 (i.e. use SHA as defined in FIPS PUB 180) */
  82 #define HASH    SHA
  83 #else
  84 /* Parameter generation follows the updated Appendix 2.2 for FIPS PUB 186,
  85  * also Appendix 2.2 of FIPS PUB 186-1 (i.e. use SHA as defined in
  86  * FIPS PUB 180-1) */
  87 #define HASH    SHA1
  88 #endif
  89
  90 #ifndef NO_SHA
  91
  92 #include <stdio.h>
  93 #include <time.h>
  94 #include "cryptlib.h"
  95 #include <openssl/sha.h>
  96 #include <openssl/bn_legacy.h>
  97 #include <openssl/dsa_legacy.h>
  98 #include <openssl/rand.h>
  99
 100 DSA *DSA_generate_parameters(int bits, unsigned char *seed_in, int seed_len,
 101                 int *counter_ret, unsigned long *h_ret,
 102                 void (*callback)(int, int, void *),
 103                 void *cb_arg)
 104         {
 105         int ok=0;
 106         unsigned char seed[SHA_DIGEST_LENGTH];
 107         unsigned char md[SHA_DIGEST_LENGTH];
 108         unsigned char buf[SHA_DIGEST_LENGTH],buf2[SHA_DIGEST_LENGTH];
 109         BIGNUM *r0,*W,*X,*c,*test;
 110         BIGNUM *g=NULL,*q=NULL,*p=NULL;
 111         BN_MONT_CTX *mont=NULL;
 112         int k,n=0,i,b,m=0;
 113         int counter=0;
 114         int r=0;
 115         BN_CTX *ctx=NULL,*ctx2=NULL,*ctx3=NULL;
 116         unsigned int h=2;
 117         DSA *ret=NULL;
 118
 119         if (bits < 512) bits=512;
 120         bits=(bits+63)/64*64;
 121
 122         if (seed_len < 20)
 123                 seed_in = NULL; /* seed buffer too small -- ignore */
 124         if (seed_len > 20)
 125                 seed_len = 20; /* App. 2.2 of FIPS PUB 186 allows larger SEED,
 126                                 * but our internal buffers are restricted to 160 bits*/
 127         if ((seed_in != NULL) && (seed_len == 20))
 128                 memcpy(seed,seed_in,seed_len);
 129
 130         if ((ctx=BN_CTX_new()) == NULL) goto err;
 131         if ((ctx2=BN_CTX_new()) == NULL) goto err;
 132         if ((ctx3=BN_CTX_new()) == NULL) goto err;
 133         if ((ret=DSA_new()) == NULL) goto err;
 134
 135         if ((mont=BN_MONT_CTX_new()) == NULL) goto err;
 136
 137         BN_CTX_start(ctx2);
 138         r0 = BN_CTX_get(ctx2);
 139         g = BN_CTX_get(ctx2);
 140         W = BN_CTX_get(ctx2);
 141         q = BN_CTX_get(ctx2);
 142         X = BN_CTX_get(ctx2);
 143         c = BN_CTX_get(ctx2);
 144         p = BN_CTX_get(ctx2);
 145         test = BN_CTX_get(ctx2);
 146
 147         BN_lshift(test,BN_value_one(),bits-1);
 148
 149         for (;;)
 150                 {
 151                 for (;;) /* find q */
 152                         {
 153                         int seed_is_random;
 154
 155                         /* step 1 */
 156                         if (callback != NULL) callback(0,m++,cb_arg);
 157
 158                         if (!seed_len)
 159                                 {
 160                                 RAND_pseudo_bytes(seed,SHA_DIGEST_LENGTH);
 161                                 seed_is_random = 1;
 162                                 }
 163                         else
 164                                 {
 165                                 seed_is_random = 0;
 166                                 seed_len=0; /* use random seed if 'seed_in' turns out to be bad*/
 167                                 }
 168                         memcpy(buf,seed,SHA_DIGEST_LENGTH);
 169                         memcpy(buf2,seed,SHA_DIGEST_LENGTH);
 170                         /* precompute "SEED + 1" for step 7: */
 171                         for (i=SHA_DIGEST_LENGTH-1; i >= 0; i--)
 172                                 {
 173                                 buf[i]++;
 174                                 if (buf[i] != 0) break;
 175                                 }
 176
 177                         /* step 2 */
 178                         HASH(seed,SHA_DIGEST_LENGTH,md);
 179                         HASH(buf,SHA_DIGEST_LENGTH,buf2);
 180                         for (i=0; i<SHA_DIGEST_LENGTH; i++)
 181                                 md[i]^=buf2[i];
 182
 183                         /* step 3 */
 184                         md[0]|=0x80;
 185                         md[SHA_DIGEST_LENGTH-1]|=0x01;
 186                         if (!BN_bin2bn(md,SHA_DIGEST_LENGTH,q)) goto err;
 187
 188                         /* step 4 */
 189                         r = BN_is_prime_fasttest(q, DSS_prime_checks, callback, ctx3, cb_arg, seed_is_random);
 190                         if (r > 0)
 191                                 break;
 192                         if (r != 0)
 193                                 goto err;
 194
 195                         /* do a callback call */
 196                         /* step 5 */
 197                         }
 198
 199                 if (callback != NULL) callback(2,0,cb_arg);
 200                 if (callback != NULL) callback(3,0,cb_arg);
 201
 202                 /* step 6 */
 203                 counter=0;
 204                 /* "offset = 2" */
 205
 206                 n=(bits-1)/160;
 207                 b=(bits-1)-n*160;
 208
 209                 for (;;)
 210                         {
 211                         if (callback != NULL && counter != 0)
 212                                 callback(0,counter,cb_arg);
 213
 214                         /* step 7 */
 215                         BN_zero(W);
 216                         /* now 'buf' contains "SEED + offset - 1" */
 217                         for (k=0; k<=n; k++)
 218                                 {
 219                                 /* obtain "SEED + offset + k" by incrementing: */
 220                                 for (i=SHA_DIGEST_LENGTH-1; i >= 0; i--)
 221                                         {
 222                                         buf[i]++;
 223                                         if (buf[i] != 0) break;
 224                                         }
 225
 226                                 HASH(buf,SHA_DIGEST_LENGTH,md);
 227
 228                                 /* step 8 */
 229                                 if (!BN_bin2bn(md,SHA_DIGEST_LENGTH,r0))
 230                                         goto err;
 231                                 BN_lshift(r0,r0,160*k);
 232                                 BN_add(W,W,r0);
 233                                 }
 234
 235                         /* more of step 8 */
 236                         BN_mask_bits(W,bits-1);
 237                         BN_copy(X,W); /* this should be ok */
 238                         BN_add(X,X,test); /* this should be ok */
 239
 240                         /* step 9 */
 241                         BN_lshift1(r0,q);
 242                         BN_mod(c,X,r0,ctx);
 243                         BN_sub(r0,c,BN_value_one());
 244                         BN_sub(p,X,r0);
 245
 246                         /* step 10 */
 247                         if (BN_cmp(p,test) >= 0)
 248                                 {
 249                                 /* step 11 */
 250                                 r = BN_is_prime_fasttest(p, DSS_prime_checks, callback, ctx3, cb_arg, 1);
 251                                 if (r > 0)
 252                                                 goto end; /* found it */
 253                                 if (r != 0)
 254                                         goto err;
 255                                 }
 256
 257                         /* step 13 */
 258                         counter++;
 259                         /* "offset = offset + n + 1" */
 260
 261                         /* step 14 */
 262                         if (counter >= 4096) break;
 263                         }
 264                 }
 265 end:
 266         if (callback != NULL) callback(2,1,cb_arg);
 267
 268         /* We now need to generate g */
 269         /* Set r0=(p-1)/q */
 270         BN_sub(test,p,BN_value_one());
 271         BN_div(r0,NULL,test,q,ctx);
 272
 273         BN_set_word(test,h);
 274         BN_MONT_CTX_set(mont,p,ctx);
 275
 276         for (;;)
 277                 {
 278                 /* g=test^r0%p */
 279                 BN_mod_exp_mont(g,test,r0,p,ctx,mont);
 280                 if (!BN_is_one(g)) break;
 281                 BN_add(test,test,BN_value_one());
 282                 h++;
 283                 }
 284
 285         if (callback != NULL) callback(3,1,cb_arg);
 286
 287         ok=1;
 288 err:
 289         if (!ok)
 290                 {
 291                 if (ret != NULL) DSA_free(ret);
 292                 }
 293         else
 294                 {
 295                 ret->p=BN_dup(p);
 296                 ret->q=BN_dup(q);
 297                 ret->g=BN_dup(g);
 298                 if ((m > 1) && (seed_in != NULL)) memcpy(seed_in,seed,20);
 299                 if (counter_ret != NULL) *counter_ret=counter;
 300                 if (h_ret != NULL) *h_ret=h;
 301                 }
 302         if (ctx != NULL) BN_CTX_free(ctx);
 303         if (ctx2 != NULL)
 304                 {
 305                 BN_CTX_end(ctx2);
 306                 BN_CTX_free(ctx2);
 307                 }
 308         if (ctx3 != NULL) BN_CTX_free(ctx3);
 309         if (mont != NULL) BN_MONT_CTX_free(mont);
 310         return(ok?ret:NULL);
 311         }
 312 #endif