crypto/openssl/crypto/srp/srp_vfy.c

   1 /* crypto/srp/srp_vfy.c */
   2 /* Written by Christophe Renou (christophe.renou@edelweb.fr) with
   3  * the precious help of Peter Sylvester (peter.sylvester@edelweb.fr)
   4  * for the EdelKey project and contributed to the OpenSSL project 2004.
   5  */
   6 /* ====================================================================
   7  * Copyright (c) 2004 The OpenSSL Project.  All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  *
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  *
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in
  18  *    the documentation and/or other materials provided with the
  19  *    distribution.
  20  *
  21  * 3. All advertising materials mentioning features or use of this
  22  *    software must display the following acknowledgment:
  23  *    "This product includes software developed by the OpenSSL Project
  24  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  25  *
  26  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  27  *    endorse or promote products derived from this software without
  28  *    prior written permission. For written permission, please contact
  29  *    licensing@OpenSSL.org.
  30  *
  31  * 5. Products derived from this software may not be called "OpenSSL"
  32  *    nor may "OpenSSL" appear in their names without prior written
  33  *    permission of the OpenSSL Project.
  34  *
  35  * 6. Redistributions of any form whatsoever must retain the following
  36  *    acknowledgment:
  37  *    "This product includes software developed by the OpenSSL Project
  38  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  41  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  43  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  44  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  45  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  46  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  47  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  49  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  50  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  51  * OF THE POSSIBILITY OF SUCH DAMAGE.
  52  * ====================================================================
  53  *
  54  * This product includes cryptographic software written by Eric Young
  55  * (eay@cryptsoft.com).  This product includes software written by Tim
  56  * Hudson (tjh@cryptsoft.com).
  57  *
  58  */
  59 #ifndef OPENSSL_NO_SRP
  60 #include "cryptlib.h"
  61 #include "srp_lcl.h"
  62 #include <openssl/srp.h>
  63 #include <openssl/evp.h>
  64 #include <openssl/buffer.h>
  65 #include <openssl/rand.h>
  66 #include <openssl/txt_db.h>
  67
  68 #define SRP_RANDOM_SALT_LEN 20
  69 #define MAX_LEN 2500
  70
  71 static char b64table[] =
  72   "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz./";
  73
  74 /* the following two conversion routines have been inspired by code from Stanford */
  75
  76 /*
  77  * Convert a base64 string into raw byte array representation.
  78  */
  79 static int t_fromb64(unsigned char *a, const char *src)
  80         {
  81         char *loc;
  82         int i, j;
  83         int size;
  84
  85         while(*src && (*src == ' ' || *src == '\t' || *src == '\n'))
  86                 ++src;
  87         size = strlen(src);
  88         i = 0;
  89         while(i < size)
  90                 {
  91                 loc = strchr(b64table, src[i]);
  92                 if(loc == (char *) 0) break;
  93                 else a[i] = loc - b64table;
  94                 ++i;
  95                 }
  96         /* if nothing valid to process we have a zero length response */
  97         if (i == 0)
  98                 return 0;
  99         size = i;
 100         i = size - 1;
 101         j = size;
 102         while(1)
 103                 {
 104                 a[j] = a[i];
 105                 if(--i < 0) break;
 106                 a[j] |= (a[i] & 3) << 6;
 107                 --j;
 108                 a[j] = (unsigned char) ((a[i] & 0x3c) >> 2);
 109                 if(--i < 0) break;
 110                 a[j] |= (a[i] & 0xf) << 4;
 111                 --j;
 112                 a[j] = (unsigned char) ((a[i] & 0x30) >> 4);
 113                 if(--i < 0) break;
 114                 a[j] |= (a[i] << 2);
 115
 116                 a[--j] = 0;
 117                 if(--i < 0) break;
 118                 }
 119         while(a[j] == 0 && j <= size) ++j;
 120         i = 0;
 121         while (j <= size) a[i++] = a[j++];
 122         return i;
 123         }
 124
 125
 126 /*
 127  * Convert a raw byte string into a null-terminated base64 ASCII string.
 128  */
 129 static char *t_tob64(char *dst, const unsigned char *src, int size)
 130         {
 131         int c, pos = size % 3;
 132         unsigned char b0 = 0, b1 = 0, b2 = 0, notleading = 0;
 133         char *olddst = dst;
 134
 135         switch(pos)
 136                 {
 137         case 1:
 138                 b2 = src[0];
 139                 break;
 140         case 2:
 141                 b1 = src[0];
 142                 b2 = src[1];
 143                 break;
 144                 }
 145
 146         while(1)
 147                 {
 148                 c = (b0 & 0xfc) >> 2;
 149                 if(notleading || c != 0)
 150                         {
 151                         *dst++ = b64table[c];
 152                         notleading = 1;
 153                         }
 154                 c = ((b0 & 3) << 4) | ((b1 & 0xf0) >> 4);
 155                 if(notleading || c != 0)
 156                         {
 157                         *dst++ = b64table[c];
 158                         notleading = 1;
 159                         }
 160                 c = ((b1 & 0xf) << 2) | ((b2 & 0xc0) >> 6);
 161                 if(notleading || c != 0)
 162                         {
 163                         *dst++ = b64table[c];
 164                         notleading = 1;
 165                         }
 166                 c = b2 & 0x3f;
 167                 if(notleading || c != 0)
 168                         {
 169                         *dst++ = b64table[c];
 170                         notleading = 1;
 171                         }
 172                 if(pos >= size) break;
 173                 else
 174                         {
 175                         b0 = src[pos++];
 176                         b1 = src[pos++];
 177                         b2 = src[pos++];
 178                         }
 179                 }
 180
 181         *dst++ = '\0';
 182         return olddst;
 183         }
 184
 185 static void SRP_user_pwd_free(SRP_user_pwd *user_pwd)
 186         {
 187         if (user_pwd == NULL)
 188                 return;
 189         BN_free(user_pwd->s);
 190         BN_clear_free(user_pwd->v);
 191         OPENSSL_free(user_pwd->id);
 192         OPENSSL_free(user_pwd->info);
 193         OPENSSL_free(user_pwd);
 194         }
 195
 196 static SRP_user_pwd *SRP_user_pwd_new()
 197         {
 198         SRP_user_pwd *ret = OPENSSL_malloc(sizeof(SRP_user_pwd));
 199         if (ret == NULL)
 200                 return NULL;
 201         ret->N = NULL;
 202         ret->g = NULL;
 203         ret->s = NULL;
 204         ret->v = NULL;
 205         ret->id = NULL ;
 206         ret->info = NULL;
 207         return ret;
 208         }
 209
 210 static void SRP_user_pwd_set_gN(SRP_user_pwd *vinfo, const BIGNUM *g,
 211                                 const BIGNUM *N)
 212         {
 213         vinfo->N = N;
 214         vinfo->g = g;
 215         }
 216
 217 static int SRP_user_pwd_set_ids(SRP_user_pwd *vinfo, const char *id,
 218                                 const char *info)
 219         {
 220         if (id != NULL && NULL == (vinfo->id = BUF_strdup(id)))
 221                 return 0;
 222         return (info == NULL || NULL != (vinfo->info = BUF_strdup(info))) ;
 223         }
 224
 225 static int SRP_user_pwd_set_sv(SRP_user_pwd *vinfo, const char *s,
 226                                const char *v)
 227         {
 228         unsigned char tmp[MAX_LEN];
 229         int len;
 230
 231         if (strlen(s) > MAX_LEN || strlen(v) > MAX_LEN)
 232                 return 0;
 233         len = t_fromb64(tmp, v);
 234         if (NULL == (vinfo->v = BN_bin2bn(tmp, len, NULL)) )
 235                 return 0;
 236         len = t_fromb64(tmp, s);
 237         return ((vinfo->s = BN_bin2bn(tmp, len, NULL)) != NULL) ;
 238         }
 239
 240 static int SRP_user_pwd_set_sv_BN(SRP_user_pwd *vinfo, BIGNUM *s, BIGNUM *v)
 241         {
 242         vinfo->v = v;
 243         vinfo->s = s;
 244         return (vinfo->s != NULL && vinfo->v != NULL) ;
 245         }
 246
 247 SRP_VBASE *SRP_VBASE_new(char *seed_key)
 248         {
 249         SRP_VBASE *vb = (SRP_VBASE *) OPENSSL_malloc(sizeof(SRP_VBASE));
 250
 251         if (vb == NULL)
 252                 return NULL;
 253         if (!(vb->users_pwd = sk_SRP_user_pwd_new_null()) ||
 254                 !(vb->gN_cache = sk_SRP_gN_cache_new_null()))
 255                 {
 256                 OPENSSL_free(vb);
 257                 return NULL;
 258                 }
 259         vb->default_g = NULL;
 260         vb->default_N = NULL;
 261         vb->seed_key = NULL;
 262         if ((seed_key != NULL) &&
 263                 (vb->seed_key = BUF_strdup(seed_key)) == NULL)
 264                 {
 265                 sk_SRP_user_pwd_free(vb->users_pwd);
 266                 sk_SRP_gN_cache_free(vb->gN_cache);
 267                 OPENSSL_free(vb);
 268                 return NULL;
 269                 }
 270         return vb;
 271         }
 272
 273
 274 int SRP_VBASE_free(SRP_VBASE *vb)
 275         {
 276         sk_SRP_user_pwd_pop_free(vb->users_pwd,SRP_user_pwd_free);
 277         sk_SRP_gN_cache_free(vb->gN_cache);
 278         OPENSSL_free(vb->seed_key);
 279         OPENSSL_free(vb);
 280         return 0;
 281         }
 282
 283
 284 static SRP_gN_cache *SRP_gN_new_init(const char *ch)
 285         {
 286         unsigned char tmp[MAX_LEN];
 287         int len;
 288
 289         SRP_gN_cache *newgN = (SRP_gN_cache *)OPENSSL_malloc(sizeof(SRP_gN_cache));
 290         if (newgN == NULL)
 291                 return NULL;
 292
 293         if ((newgN->b64_bn = BUF_strdup(ch)) == NULL)
 294                 goto err;
 295
 296         len = t_fromb64(tmp, ch);
 297         if ((newgN->bn = BN_bin2bn(tmp, len, NULL)))
 298                 return newgN;
 299
 300         OPENSSL_free(newgN->b64_bn);
 301 err:
 302         OPENSSL_free(newgN);
 303         return NULL;
 304         }
 305
 306
 307 static void SRP_gN_free(SRP_gN_cache *gN_cache)
 308         {
 309         if (gN_cache == NULL)
 310                 return;
 311         OPENSSL_free(gN_cache->b64_bn);
 312         BN_free(gN_cache->bn);
 313         OPENSSL_free(gN_cache);
 314         }
 315
 316 static SRP_gN *SRP_get_gN_by_id(const char *id, STACK_OF(SRP_gN) *gN_tab)
 317         {
 318         int i;
 319
 320         SRP_gN *gN;
 321         if (gN_tab != NULL)
 322         for(i = 0; i < sk_SRP_gN_num(gN_tab); i++)
 323                 {
 324                 gN = sk_SRP_gN_value(gN_tab, i);
 325                 if (gN && (id == NULL || strcmp(gN->id,id)==0))
 326                         return gN;
 327                 }
 328
 329         return SRP_get_default_gN(id);
 330         }
 331
 332 static BIGNUM *SRP_gN_place_bn(STACK_OF(SRP_gN_cache) *gN_cache, char *ch)
 333         {
 334         int i;
 335         if (gN_cache == NULL)
 336                 return NULL;
 337
 338         /* search if we have already one... */
 339         for(i = 0; i < sk_SRP_gN_cache_num(gN_cache); i++)
 340                 {
 341                 SRP_gN_cache *cache = sk_SRP_gN_cache_value(gN_cache, i);
 342                 if (strcmp(cache->b64_bn,ch)==0)
 343                         return cache->bn;
 344                 }
 345                 {               /* it is the first time that we find it */
 346                 SRP_gN_cache *newgN = SRP_gN_new_init(ch);
 347                 if (newgN)
 348                         {
 349                         if (sk_SRP_gN_cache_insert(gN_cache,newgN,0)>0)
 350                                 return newgN->bn;
 351                         SRP_gN_free(newgN);
 352                         }
 353                 }
 354         return NULL;
 355         }
 356
 357 /* this function parses verifier file. Format is:
 358  * string(index):base64(N):base64(g):0
 359  * string(username):base64(v):base64(salt):int(index)
 360  */
 361
 362
 363 int SRP_VBASE_init(SRP_VBASE *vb, char *verifier_file)
 364         {
 365         int error_code ;
 366         STACK_OF(SRP_gN) *SRP_gN_tab = sk_SRP_gN_new_null();
 367         char *last_index = NULL;
 368         int i;
 369         char **pp;
 370
 371         SRP_gN *gN = NULL;
 372         SRP_user_pwd *user_pwd = NULL ;
 373
 374         TXT_DB *tmpdb = NULL;
 375         BIO *in = BIO_new(BIO_s_file());
 376
 377         error_code = SRP_ERR_OPEN_FILE;
 378
 379         if (in == NULL || BIO_read_filename(in,verifier_file) <= 0)
 380                 goto err;
 381
 382         error_code = SRP_ERR_VBASE_INCOMPLETE_FILE;
 383
 384         if ((tmpdb =TXT_DB_read(in,DB_NUMBER)) == NULL)
 385                 goto err;
 386
 387         error_code = SRP_ERR_MEMORY;
 388
 389
 390         if (vb->seed_key)
 391                 {
 392                 last_index = SRP_get_default_gN(NULL)->id;
 393                 }
 394         for (i = 0; i < sk_OPENSSL_PSTRING_num(tmpdb->data); i++)
 395                 {
 396                 pp = sk_OPENSSL_PSTRING_value(tmpdb->data,i);
 397                 if (pp[DB_srptype][0] == DB_SRP_INDEX)
 398                         {
 399                         /*we add this couple in the internal Stack */
 400
 401                         if ((gN = (SRP_gN *)OPENSSL_malloc(sizeof(SRP_gN))) == NULL)
 402                                 goto err;
 403
 404                         if  (!(gN->id = BUF_strdup(pp[DB_srpid]))
 405                         ||  !(gN->N = SRP_gN_place_bn(vb->gN_cache,pp[DB_srpverifier]))
 406                         ||  !(gN->g = SRP_gN_place_bn(vb->gN_cache,pp[DB_srpsalt]))
 407                         ||  sk_SRP_gN_insert(SRP_gN_tab,gN,0) == 0)
 408                                 goto err;
 409
 410                         gN = NULL;
 411
 412                         if (vb->seed_key != NULL)
 413                                 {
 414                                 last_index = pp[DB_srpid];
 415                                 }
 416                         }
 417                 else if (pp[DB_srptype][0] == DB_SRP_VALID)
 418                         {
 419                         /* it is a user .... */
 420                         SRP_gN *lgN;
 421                         if ((lgN = SRP_get_gN_by_id(pp[DB_srpgN],SRP_gN_tab))!=NULL)
 422                                 {
 423                                 error_code = SRP_ERR_MEMORY;
 424                                 if ((user_pwd = SRP_user_pwd_new()) == NULL)
 425                                         goto err;
 426
 427                                 SRP_user_pwd_set_gN(user_pwd,lgN->g,lgN->N);
 428                                 if (!SRP_user_pwd_set_ids(user_pwd, pp[DB_srpid],pp[DB_srpinfo]))
 429                                         goto err;
 430
 431                                 error_code = SRP_ERR_VBASE_BN_LIB;
 432                                 if (!SRP_user_pwd_set_sv(user_pwd, pp[DB_srpsalt],pp[DB_srpverifier]))
 433                                         goto err;
 434
 435                                 if (sk_SRP_user_pwd_insert(vb->users_pwd, user_pwd, 0) == 0)
 436                                         goto err;
 437                                 user_pwd = NULL; /* abandon responsability */
 438                                 }
 439                         }
 440                 }
 441
 442         if (last_index != NULL)
 443                 {
 444                 /* this means that we want to simulate a default user */
 445
 446                 if (((gN = SRP_get_gN_by_id(last_index,SRP_gN_tab))==NULL))
 447                         {
 448                         error_code = SRP_ERR_VBASE_BN_LIB;
 449                         goto err;
 450                         }
 451                 vb->default_g = gN->g ;
 452                 vb->default_N = gN->N ;
 453                 gN = NULL ;
 454                 }
 455         error_code = SRP_NO_ERROR;
 456
 457  err:
 458         /* there may be still some leaks to fix, if this fails, the application terminates most likely */
 459
 460         if (gN != NULL)
 461                 {
 462                 OPENSSL_free(gN->id);
 463                 OPENSSL_free(gN);
 464                 }
 465
 466         SRP_user_pwd_free(user_pwd);
 467
 468         if (tmpdb) TXT_DB_free(tmpdb);
 469         if (in) BIO_free_all(in);
 470
 471         sk_SRP_gN_free(SRP_gN_tab);
 472
 473         return error_code;
 474
 475         }
 476
 477
 478 SRP_user_pwd *SRP_VBASE_get_by_user(SRP_VBASE *vb, char *username)
 479         {
 480         int i;
 481         SRP_user_pwd *user;
 482         unsigned char digv[SHA_DIGEST_LENGTH];
 483         unsigned char digs[SHA_DIGEST_LENGTH];
 484         EVP_MD_CTX ctxt;
 485
 486         if (vb == NULL)
 487                 return NULL;
 488         for(i = 0; i < sk_SRP_user_pwd_num(vb->users_pwd); i++)
 489                 {
 490                 user = sk_SRP_user_pwd_value(vb->users_pwd, i);
 491                 if (strcmp(user->id,username)==0)
 492                         return user;
 493                 }
 494         if ((vb->seed_key == NULL) ||
 495                 (vb->default_g == NULL) ||
 496                 (vb->default_N == NULL))
 497                 return NULL;
 498
 499 /* if the user is unknown we set parameters as well if we have a seed_key */
 500
 501         if ((user = SRP_user_pwd_new()) == NULL)
 502                 return NULL;
 503
 504         SRP_user_pwd_set_gN(user,vb->default_g,vb->default_N);
 505
 506         if (!SRP_user_pwd_set_ids(user,username,NULL))
 507                 goto err;
 508
 509         RAND_pseudo_bytes(digv, SHA_DIGEST_LENGTH);
 510         EVP_MD_CTX_init(&ctxt);
 511         EVP_DigestInit_ex(&ctxt, EVP_sha1(), NULL);
 512         EVP_DigestUpdate(&ctxt, vb->seed_key, strlen(vb->seed_key));
 513         EVP_DigestUpdate(&ctxt, username, strlen(username));
 514         EVP_DigestFinal_ex(&ctxt, digs, NULL);
 515         EVP_MD_CTX_cleanup(&ctxt);
 516         if (SRP_user_pwd_set_sv_BN(user, BN_bin2bn(digs,SHA_DIGEST_LENGTH,NULL), BN_bin2bn(digv,SHA_DIGEST_LENGTH, NULL)))
 517                 return user;
 518
 519 err:    SRP_user_pwd_free(user);
 520         return NULL;
 521         }
 522
 523
 524 /*
 525    create a verifier (*salt,*verifier,g and N are in base64)
 526 */
 527 char *SRP_create_verifier(const char *user, const char *pass, char **salt,
 528                           char **verifier, const char *N, const char *g)
 529         {
 530         int len;
 531         char * result=NULL;
 532         char *vf;
 533         BIGNUM *N_bn = NULL, *g_bn = NULL, *s = NULL, *v = NULL;
 534         unsigned char tmp[MAX_LEN];
 535         unsigned char tmp2[MAX_LEN];
 536         char * defgNid = NULL;
 537
 538         if ((user == NULL)||
 539                 (pass == NULL)||
 540                 (salt == NULL)||
 541                 (verifier == NULL))
 542                 goto err;
 543
 544         if (N)
 545                 {
 546                 if (!(len = t_fromb64(tmp, N))) goto err;
 547                 N_bn = BN_bin2bn(tmp, len, NULL);
 548                 if (!(len = t_fromb64(tmp, g))) goto err;
 549                 g_bn = BN_bin2bn(tmp, len, NULL);
 550                 defgNid = "*";
 551                 }
 552         else
 553                 {
 554                 SRP_gN * gN = SRP_get_gN_by_id(g, NULL) ;
 555                 if (gN == NULL)
 556                         goto err;
 557                 N_bn = gN->N;
 558                 g_bn = gN->g;
 559                 defgNid = gN->id;
 560                 }
 561
 562         if (*salt == NULL)
 563                 {
 564                 RAND_pseudo_bytes(tmp2, SRP_RANDOM_SALT_LEN);
 565
 566                 s = BN_bin2bn(tmp2, SRP_RANDOM_SALT_LEN, NULL);
 567                 }
 568         else
 569                 {
 570                 if (!(len = t_fromb64(tmp2, *salt)))
 571                         goto err;
 572                 s = BN_bin2bn(tmp2, len, NULL);
 573                 }
 574
 575
 576         if(!SRP_create_verifier_BN(user, pass, &s, &v, N_bn, g_bn)) goto err;
 577
 578         BN_bn2bin(v,tmp);
 579         if (((vf = OPENSSL_malloc(BN_num_bytes(v)*2)) == NULL))
 580                 goto err;
 581         t_tob64(vf, tmp, BN_num_bytes(v));
 582
 583         *verifier = vf;
 584         if (*salt == NULL)
 585                 {
 586                 char *tmp_salt;
 587
 588                 if ((tmp_salt = OPENSSL_malloc(SRP_RANDOM_SALT_LEN * 2)) == NULL)
 589                         {
 590                         OPENSSL_free(vf);
 591                         goto err;
 592                         }
 593                 t_tob64(tmp_salt, tmp2, SRP_RANDOM_SALT_LEN);
 594                 *salt = tmp_salt;
 595                 }
 596
 597         result=defgNid;
 598
 599 err:
 600         if(N)
 601                 {
 602                 BN_free(N_bn);
 603                 BN_free(g_bn);
 604                 }
 605         return result;
 606         }
 607
 608 /*
 609    create a verifier (*salt,*verifier,g and N are BIGNUMs)
 610 */
 611 int SRP_create_verifier_BN(const char *user, const char *pass, BIGNUM **salt, BIGNUM **verifier, BIGNUM *N, BIGNUM *g)
 612         {
 613         int result=0;
 614         BIGNUM *x = NULL;
 615         BN_CTX *bn_ctx = BN_CTX_new();
 616         unsigned char tmp2[MAX_LEN];
 617
 618         if ((user == NULL)||
 619                 (pass == NULL)||
 620                 (salt == NULL)||
 621                 (verifier == NULL)||
 622                 (N == NULL)||
 623                 (g == NULL)||
 624                 (bn_ctx == NULL))
 625                 goto err;
 626
 627         srp_bn_print(N);
 628         srp_bn_print(g);
 629
 630         if (*salt == NULL)
 631                 {
 632                 RAND_pseudo_bytes(tmp2, SRP_RANDOM_SALT_LEN);
 633
 634                 *salt = BN_bin2bn(tmp2,SRP_RANDOM_SALT_LEN,NULL);
 635                 }
 636
 637         x = SRP_Calc_x(*salt,user,pass);
 638
 639         *verifier = BN_new();
 640         if(*verifier == NULL) goto err;
 641
 642         if (!BN_mod_exp(*verifier,g,x,N,bn_ctx))
 643                 {
 644                 BN_clear_free(*verifier);
 645                 goto err;
 646                 }
 647
 648         srp_bn_print(*verifier);
 649
 650         result=1;
 651
 652 err:
 653
 654         BN_clear_free(x);
 655         BN_CTX_free(bn_ctx);
 656         return result;
 657         }
 658
 659
 660
 661 #endif