1 /* crypto/srp/srp_vfy.c */
2 /*
3 * Written by Christophe Renou (christophe.renou@edelweb.fr) with the
4 * precious help of Peter Sylvester (peter.sylvester@edelweb.fr) for the
5 * EdelKey project and contributed to the OpenSSL project 2004.
6 */
7 /* ====================================================================
8 * Copyright (c) 2004 The OpenSSL Project. All rights reserved.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 *
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 *
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in
19 * the documentation and/or other materials provided with the
20 * distribution.
21 *
22 * 3. All advertising materials mentioning features or use of this
23 * software must display the following acknowledgment:
24 * "This product includes software developed by the OpenSSL Project
25 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
26 *
27 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
28 * endorse or promote products derived from this software without
29 * prior written permission. For written permission, please contact
30 * licensing@OpenSSL.org.
31 *
32 * 5. Products derived from this software may not be called "OpenSSL"
33 * nor may "OpenSSL" appear in their names without prior written
34 * permission of the OpenSSL Project.
35 *
36 * 6. Redistributions of any form whatsoever must retain the following
37 * acknowledgment:
38 * "This product includes software developed by the OpenSSL Project
39 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
40 *
41 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
42 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
44 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
45 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
46 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
47 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
48 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
49 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
50 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
51 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
52 * OF THE POSSIBILITY OF SUCH DAMAGE.
53 * ====================================================================
54 *
55 * This product includes cryptographic software written by Eric Young
56 * (eay@cryptsoft.com). This product includes software written by Tim
57 * Hudson (tjh@cryptsoft.com).
58 *
59 */
60 #ifndef OPENSSL_NO_SRP
61 # include "cryptlib.h"
62 # include "srp_lcl.h"
63 # include <openssl/srp.h>
64 # include <openssl/evp.h>
65 # include <openssl/buffer.h>
66 # include <openssl/rand.h>
67 # include <openssl/txt_db.h>
68
69 # define SRP_RANDOM_SALT_LEN 20
70 # define MAX_LEN 2500
71
72 static char b64table[] =
73 "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz./";
74
75 /*
76 * the following two conversion routines have been inspired by code from
77 * Stanford
78 */
79
80 /*
81 * Convert a base64 string into raw byte array representation.
82 */
t_fromb64(unsigned char * a,size_t alen,const char * src)83 static int t_fromb64(unsigned char *a, size_t alen, const char *src)
84 {
85 char *loc;
86 int i, j;
87 int size;
88
89 if (alen == 0 || alen > INT_MAX)
90 return -1;
91
92 while (*src && (*src == ' ' || *src == '\t' || *src == '\n'))
93 ++src;
94 size = strlen(src);
95 if (size < 0 || size >= (int)alen)
96 return -1;
97
98 i = 0;
99 while (i < size) {
100 loc = strchr(b64table, src[i]);
101 if (loc == (char *)0)
102 break;
103 else
104 a[i] = loc - b64table;
105 ++i;
106 }
107 /* if nothing valid to process we have a zero length response */
108 if (i == 0)
109 return 0;
110 size = i;
111 i = size - 1;
112 j = size;
113 while (1) {
114 a[j] = a[i];
115 if (--i < 0)
116 break;
117 a[j] |= (a[i] & 3) << 6;
118 --j;
119 a[j] = (unsigned char)((a[i] & 0x3c) >> 2);
120 if (--i < 0)
121 break;
122 a[j] |= (a[i] & 0xf) << 4;
123 --j;
124 a[j] = (unsigned char)((a[i] & 0x30) >> 4);
125 if (--i < 0)
126 break;
127 a[j] |= (a[i] << 2);
128
129 a[--j] = 0;
130 if (--i < 0)
131 break;
132 }
133 while (j <= size && a[j] == 0)
134 ++j;
135 i = 0;
136 while (j <= size)
137 a[i++] = a[j++];
138 return i;
139 }
140
141 /*
142 * Convert a raw byte string into a null-terminated base64 ASCII string.
143 */
t_tob64(char * dst,const unsigned char * src,int size)144 static char *t_tob64(char *dst, const unsigned char *src, int size)
145 {
146 int c, pos = size % 3;
147 unsigned char b0 = 0, b1 = 0, b2 = 0, notleading = 0;
148 char *olddst = dst;
149
150 switch (pos) {
151 case 1:
152 b2 = src[0];
153 break;
154 case 2:
155 b1 = src[0];
156 b2 = src[1];
157 break;
158 }
159
160 while (1) {
161 c = (b0 & 0xfc) >> 2;
162 if (notleading || c != 0) {
163 *dst++ = b64table[c];
164 notleading = 1;
165 }
166 c = ((b0 & 3) << 4) | ((b1 & 0xf0) >> 4);
167 if (notleading || c != 0) {
168 *dst++ = b64table[c];
169 notleading = 1;
170 }
171 c = ((b1 & 0xf) << 2) | ((b2 & 0xc0) >> 6);
172 if (notleading || c != 0) {
173 *dst++ = b64table[c];
174 notleading = 1;
175 }
176 c = b2 & 0x3f;
177 if (notleading || c != 0) {
178 *dst++ = b64table[c];
179 notleading = 1;
180 }
181 if (pos >= size)
182 break;
183 else {
184 b0 = src[pos++];
185 b1 = src[pos++];
186 b2 = src[pos++];
187 }
188 }
189
190 *dst++ = '\0';
191 return olddst;
192 }
193
SRP_user_pwd_free(SRP_user_pwd * user_pwd)194 void SRP_user_pwd_free(SRP_user_pwd *user_pwd)
195 {
196 if (user_pwd == NULL)
197 return;
198 BN_free(user_pwd->s);
199 BN_clear_free(user_pwd->v);
200 OPENSSL_free(user_pwd->id);
201 OPENSSL_free(user_pwd->info);
202 OPENSSL_free(user_pwd);
203 }
204
SRP_user_pwd_new()205 static SRP_user_pwd *SRP_user_pwd_new()
206 {
207 SRP_user_pwd *ret = OPENSSL_malloc(sizeof(SRP_user_pwd));
208 if (ret == NULL)
209 return NULL;
210 ret->N = NULL;
211 ret->g = NULL;
212 ret->s = NULL;
213 ret->v = NULL;
214 ret->id = NULL;
215 ret->info = NULL;
216 return ret;
217 }
218
SRP_user_pwd_set_gN(SRP_user_pwd * vinfo,const BIGNUM * g,const BIGNUM * N)219 static void SRP_user_pwd_set_gN(SRP_user_pwd *vinfo, const BIGNUM *g,
220 const BIGNUM *N)
221 {
222 vinfo->N = N;
223 vinfo->g = g;
224 }
225
SRP_user_pwd_set_ids(SRP_user_pwd * vinfo,const char * id,const char * info)226 static int SRP_user_pwd_set_ids(SRP_user_pwd *vinfo, const char *id,
227 const char *info)
228 {
229 if (id != NULL && NULL == (vinfo->id = BUF_strdup(id)))
230 return 0;
231 return (info == NULL || NULL != (vinfo->info = BUF_strdup(info)));
232 }
233
SRP_user_pwd_set_sv(SRP_user_pwd * vinfo,const char * s,const char * v)234 static int SRP_user_pwd_set_sv(SRP_user_pwd *vinfo, const char *s,
235 const char *v)
236 {
237 unsigned char tmp[MAX_LEN];
238 int len;
239
240 vinfo->v = NULL;
241 vinfo->s = NULL;
242
243 len = t_fromb64(tmp, sizeof(tmp), v);
244 if (len < 0)
245 return 0;
246 if (NULL == (vinfo->v = BN_bin2bn(tmp, len, NULL)))
247 return 0;
248 len = t_fromb64(tmp, sizeof(tmp), s);
249 if (len < 0)
250 goto err;
251 vinfo->s = BN_bin2bn(tmp, len, NULL);
252 if (vinfo->s == NULL)
253 goto err;
254 return 1;
255 err:
256 BN_free(vinfo->v);
257 vinfo->v = NULL;
258 return 0;
259 }
260
SRP_user_pwd_set_sv_BN(SRP_user_pwd * vinfo,BIGNUM * s,BIGNUM * v)261 static int SRP_user_pwd_set_sv_BN(SRP_user_pwd *vinfo, BIGNUM *s, BIGNUM *v)
262 {
263 vinfo->v = v;
264 vinfo->s = s;
265 return (vinfo->s != NULL && vinfo->v != NULL);
266 }
267
srp_user_pwd_dup(SRP_user_pwd * src)268 static SRP_user_pwd *srp_user_pwd_dup(SRP_user_pwd *src)
269 {
270 SRP_user_pwd *ret;
271
272 if (src == NULL)
273 return NULL;
274 if ((ret = SRP_user_pwd_new()) == NULL)
275 return NULL;
276
277 SRP_user_pwd_set_gN(ret, src->g, src->N);
278 if (!SRP_user_pwd_set_ids(ret, src->id, src->info)
279 || !SRP_user_pwd_set_sv_BN(ret, BN_dup(src->s), BN_dup(src->v))) {
280 SRP_user_pwd_free(ret);
281 return NULL;
282 }
283 return ret;
284 }
285
SRP_VBASE_new(char * seed_key)286 SRP_VBASE *SRP_VBASE_new(char *seed_key)
287 {
288 SRP_VBASE *vb = (SRP_VBASE *)OPENSSL_malloc(sizeof(SRP_VBASE));
289
290 if (vb == NULL)
291 return NULL;
292 if (!(vb->users_pwd = sk_SRP_user_pwd_new_null()) ||
293 !(vb->gN_cache = sk_SRP_gN_cache_new_null())) {
294 OPENSSL_free(vb);
295 return NULL;
296 }
297 vb->default_g = NULL;
298 vb->default_N = NULL;
299 vb->seed_key = NULL;
300 if ((seed_key != NULL) && (vb->seed_key = BUF_strdup(seed_key)) == NULL) {
301 sk_SRP_user_pwd_free(vb->users_pwd);
302 sk_SRP_gN_cache_free(vb->gN_cache);
303 OPENSSL_free(vb);
304 return NULL;
305 }
306 return vb;
307 }
308
SRP_VBASE_free(SRP_VBASE * vb)309 int SRP_VBASE_free(SRP_VBASE *vb)
310 {
311 sk_SRP_user_pwd_pop_free(vb->users_pwd, SRP_user_pwd_free);
312 sk_SRP_gN_cache_free(vb->gN_cache);
313 OPENSSL_free(vb->seed_key);
314 OPENSSL_free(vb);
315 return 0;
316 }
317
SRP_gN_new_init(const char * ch)318 static SRP_gN_cache *SRP_gN_new_init(const char *ch)
319 {
320 unsigned char tmp[MAX_LEN];
321 int len;
322
323 SRP_gN_cache *newgN =
324 (SRP_gN_cache *)OPENSSL_malloc(sizeof(SRP_gN_cache));
325 if (newgN == NULL)
326 return NULL;
327
328 len = t_fromb64(tmp, sizeof(tmp), ch);
329 if (len < 0)
330 goto err;
331
332 if ((newgN->b64_bn = BUF_strdup(ch)) == NULL)
333 goto err;
334
335 if ((newgN->bn = BN_bin2bn(tmp, len, NULL)))
336 return newgN;
337
338 OPENSSL_free(newgN->b64_bn);
339 err:
340 OPENSSL_free(newgN);
341 return NULL;
342 }
343
SRP_gN_free(SRP_gN_cache * gN_cache)344 static void SRP_gN_free(SRP_gN_cache *gN_cache)
345 {
346 if (gN_cache == NULL)
347 return;
348 OPENSSL_free(gN_cache->b64_bn);
349 BN_free(gN_cache->bn);
350 OPENSSL_free(gN_cache);
351 }
352
SRP_get_gN_by_id(const char * id,STACK_OF (SRP_gN)* gN_tab)353 static SRP_gN *SRP_get_gN_by_id(const char *id, STACK_OF(SRP_gN) *gN_tab)
354 {
355 int i;
356
357 SRP_gN *gN;
358 if (gN_tab != NULL)
359 for (i = 0; i < sk_SRP_gN_num(gN_tab); i++) {
360 gN = sk_SRP_gN_value(gN_tab, i);
361 if (gN && (id == NULL || strcmp(gN->id, id) == 0))
362 return gN;
363 }
364
365 return SRP_get_default_gN(id);
366 }
367
SRP_gN_place_bn(STACK_OF (SRP_gN_cache)* gN_cache,char * ch)368 static BIGNUM *SRP_gN_place_bn(STACK_OF(SRP_gN_cache) *gN_cache, char *ch)
369 {
370 int i;
371 if (gN_cache == NULL)
372 return NULL;
373
374 /* search if we have already one... */
375 for (i = 0; i < sk_SRP_gN_cache_num(gN_cache); i++) {
376 SRP_gN_cache *cache = sk_SRP_gN_cache_value(gN_cache, i);
377 if (strcmp(cache->b64_bn, ch) == 0)
378 return cache->bn;
379 }
380 { /* it is the first time that we find it */
381 SRP_gN_cache *newgN = SRP_gN_new_init(ch);
382 if (newgN) {
383 if (sk_SRP_gN_cache_insert(gN_cache, newgN, 0) > 0)
384 return newgN->bn;
385 SRP_gN_free(newgN);
386 }
387 }
388 return NULL;
389 }
390
391 /*
392 * this function parses verifier file. Format is:
393 * string(index):base64(N):base64(g):0
394 * string(username):base64(v):base64(salt):int(index)
395 */
396
SRP_VBASE_init(SRP_VBASE * vb,char * verifier_file)397 int SRP_VBASE_init(SRP_VBASE *vb, char *verifier_file)
398 {
399 int error_code;
400 STACK_OF(SRP_gN) *SRP_gN_tab = sk_SRP_gN_new_null();
401 char *last_index = NULL;
402 int i;
403 char **pp;
404
405 SRP_gN *gN = NULL;
406 SRP_user_pwd *user_pwd = NULL;
407
408 TXT_DB *tmpdb = NULL;
409 BIO *in = BIO_new(BIO_s_file());
410
411 error_code = SRP_ERR_OPEN_FILE;
412
413 if (in == NULL || BIO_read_filename(in, verifier_file) <= 0)
414 goto err;
415
416 error_code = SRP_ERR_VBASE_INCOMPLETE_FILE;
417
418 if ((tmpdb = TXT_DB_read(in, DB_NUMBER)) == NULL)
419 goto err;
420
421 error_code = SRP_ERR_MEMORY;
422
423 if (vb->seed_key) {
424 last_index = SRP_get_default_gN(NULL)->id;
425 }
426 for (i = 0; i < sk_OPENSSL_PSTRING_num(tmpdb->data); i++) {
427 pp = sk_OPENSSL_PSTRING_value(tmpdb->data, i);
428 if (pp[DB_srptype][0] == DB_SRP_INDEX) {
429 /*
430 * we add this couple in the internal Stack
431 */
432
433 if ((gN = (SRP_gN *) OPENSSL_malloc(sizeof(SRP_gN))) == NULL)
434 goto err;
435
436 if (!(gN->id = BUF_strdup(pp[DB_srpid]))
437 || !(gN->N =
438 SRP_gN_place_bn(vb->gN_cache, pp[DB_srpverifier]))
439 || !(gN->g = SRP_gN_place_bn(vb->gN_cache, pp[DB_srpsalt]))
440 || sk_SRP_gN_insert(SRP_gN_tab, gN, 0) == 0)
441 goto err;
442
443 gN = NULL;
444
445 if (vb->seed_key != NULL) {
446 last_index = pp[DB_srpid];
447 }
448 } else if (pp[DB_srptype][0] == DB_SRP_VALID) {
449 /* it is a user .... */
450 SRP_gN *lgN;
451 if ((lgN = SRP_get_gN_by_id(pp[DB_srpgN], SRP_gN_tab)) != NULL) {
452 error_code = SRP_ERR_MEMORY;
453 if ((user_pwd = SRP_user_pwd_new()) == NULL)
454 goto err;
455
456 SRP_user_pwd_set_gN(user_pwd, lgN->g, lgN->N);
457 if (!SRP_user_pwd_set_ids
458 (user_pwd, pp[DB_srpid], pp[DB_srpinfo]))
459 goto err;
460
461 error_code = SRP_ERR_VBASE_BN_LIB;
462 if (!SRP_user_pwd_set_sv
463 (user_pwd, pp[DB_srpsalt], pp[DB_srpverifier]))
464 goto err;
465
466 if (sk_SRP_user_pwd_insert(vb->users_pwd, user_pwd, 0) == 0)
467 goto err;
468 user_pwd = NULL; /* abandon responsability */
469 }
470 }
471 }
472
473 if (last_index != NULL) {
474 /* this means that we want to simulate a default user */
475
476 if (((gN = SRP_get_gN_by_id(last_index, SRP_gN_tab)) == NULL)) {
477 error_code = SRP_ERR_VBASE_BN_LIB;
478 goto err;
479 }
480 vb->default_g = gN->g;
481 vb->default_N = gN->N;
482 gN = NULL;
483 }
484 error_code = SRP_NO_ERROR;
485
486 err:
487 /*
488 * there may be still some leaks to fix, if this fails, the application
489 * terminates most likely
490 */
491
492 if (gN != NULL) {
493 OPENSSL_free(gN->id);
494 OPENSSL_free(gN);
495 }
496
497 SRP_user_pwd_free(user_pwd);
498
499 if (tmpdb)
500 TXT_DB_free(tmpdb);
501 if (in)
502 BIO_free_all(in);
503
504 sk_SRP_gN_free(SRP_gN_tab);
505
506 return error_code;
507
508 }
509
find_user(SRP_VBASE * vb,char * username)510 static SRP_user_pwd *find_user(SRP_VBASE *vb, char *username)
511 {
512 int i;
513 SRP_user_pwd *user;
514
515 if (vb == NULL)
516 return NULL;
517
518 for (i = 0; i < sk_SRP_user_pwd_num(vb->users_pwd); i++) {
519 user = sk_SRP_user_pwd_value(vb->users_pwd, i);
520 if (strcmp(user->id, username) == 0)
521 return user;
522 }
523
524 return NULL;
525 }
526
527 /*
528 * This method ignores the configured seed and fails for an unknown user.
529 * Ownership of the returned pointer is not released to the caller.
530 * In other words, caller must not free the result.
531 */
SRP_VBASE_get_by_user(SRP_VBASE * vb,char * username)532 SRP_user_pwd *SRP_VBASE_get_by_user(SRP_VBASE *vb, char *username)
533 {
534 return find_user(vb, username);
535 }
536
537 /*
538 * Ownership of the returned pointer is released to the caller.
539 * In other words, caller must free the result once done.
540 */
SRP_VBASE_get1_by_user(SRP_VBASE * vb,char * username)541 SRP_user_pwd *SRP_VBASE_get1_by_user(SRP_VBASE *vb, char *username)
542 {
543 SRP_user_pwd *user;
544 unsigned char digv[SHA_DIGEST_LENGTH];
545 unsigned char digs[SHA_DIGEST_LENGTH];
546 EVP_MD_CTX ctxt;
547
548 if (vb == NULL)
549 return NULL;
550
551 if ((user = find_user(vb, username)) != NULL)
552 return srp_user_pwd_dup(user);
553
554 if ((vb->seed_key == NULL) ||
555 (vb->default_g == NULL) || (vb->default_N == NULL))
556 return NULL;
557
558 /* if the user is unknown we set parameters as well if we have a seed_key */
559
560 if ((user = SRP_user_pwd_new()) == NULL)
561 return NULL;
562
563 SRP_user_pwd_set_gN(user, vb->default_g, vb->default_N);
564
565 if (!SRP_user_pwd_set_ids(user, username, NULL))
566 goto err;
567
568 if (RAND_bytes(digv, SHA_DIGEST_LENGTH) <= 0)
569 goto err;
570 EVP_MD_CTX_init(&ctxt);
571 EVP_DigestInit_ex(&ctxt, EVP_sha1(), NULL);
572 EVP_DigestUpdate(&ctxt, vb->seed_key, strlen(vb->seed_key));
573 EVP_DigestUpdate(&ctxt, username, strlen(username));
574 EVP_DigestFinal_ex(&ctxt, digs, NULL);
575 EVP_MD_CTX_cleanup(&ctxt);
576 if (SRP_user_pwd_set_sv_BN
577 (user, BN_bin2bn(digs, SHA_DIGEST_LENGTH, NULL),
578 BN_bin2bn(digv, SHA_DIGEST_LENGTH, NULL)))
579 return user;
580
581 err:SRP_user_pwd_free(user);
582 return NULL;
583 }
584
585 /*
586 * create a verifier (*salt,*verifier,g and N are in base64)
587 */
SRP_create_verifier(const char * user,const char * pass,char ** salt,char ** verifier,const char * N,const char * g)588 char *SRP_create_verifier(const char *user, const char *pass, char **salt,
589 char **verifier, const char *N, const char *g)
590 {
591 int len;
592 char *result = NULL, *vf = NULL;
593 BIGNUM *N_bn = NULL, *g_bn = NULL, *s = NULL, *v = NULL;
594 unsigned char tmp[MAX_LEN];
595 unsigned char tmp2[MAX_LEN];
596 char *defgNid = NULL;
597 int vfsize = 0;
598
599 if ((user == NULL) ||
600 (pass == NULL) || (salt == NULL) || (verifier == NULL))
601 goto err;
602
603 if (N) {
604 if (!(len = t_fromb64(tmp, sizeof(tmp), N)))
605 goto err;
606 N_bn = BN_bin2bn(tmp, len, NULL);
607 if (!(len = t_fromb64(tmp, sizeof(tmp), g)))
608 goto err;
609 g_bn = BN_bin2bn(tmp, len, NULL);
610 defgNid = "*";
611 } else {
612 SRP_gN *gN = SRP_get_gN_by_id(g, NULL);
613 if (gN == NULL)
614 goto err;
615 N_bn = gN->N;
616 g_bn = gN->g;
617 defgNid = gN->id;
618 }
619
620 if (*salt == NULL) {
621 if (RAND_bytes(tmp2, SRP_RANDOM_SALT_LEN) <= 0)
622 goto err;
623
624 s = BN_bin2bn(tmp2, SRP_RANDOM_SALT_LEN, NULL);
625 } else {
626 if (!(len = t_fromb64(tmp2, sizeof(tmp2), *salt)))
627 goto err;
628 s = BN_bin2bn(tmp2, len, NULL);
629 }
630
631 if (!SRP_create_verifier_BN(user, pass, &s, &v, N_bn, g_bn))
632 goto err;
633
634 BN_bn2bin(v, tmp);
635 vfsize = BN_num_bytes(v) * 2;
636 if (((vf = OPENSSL_malloc(vfsize)) == NULL))
637 goto err;
638 t_tob64(vf, tmp, BN_num_bytes(v));
639
640 if (*salt == NULL) {
641 char *tmp_salt;
642
643 if ((tmp_salt = OPENSSL_malloc(SRP_RANDOM_SALT_LEN * 2)) == NULL) {
644 goto err;
645 }
646 t_tob64(tmp_salt, tmp2, SRP_RANDOM_SALT_LEN);
647 *salt = tmp_salt;
648 }
649
650 *verifier = vf;
651 vf = NULL;
652 result = defgNid;
653
654 err:
655 if (N) {
656 BN_free(N_bn);
657 BN_free(g_bn);
658 }
659 if (vf != NULL)
660 OPENSSL_cleanse(vf, vfsize);
661 OPENSSL_free(vf);
662 BN_clear_free(s);
663 BN_clear_free(v);
664 return result;
665 }
666
667 /*
668 * create a verifier (*salt,*verifier,g and N are BIGNUMs). If *salt != NULL
669 * then the provided salt will be used. On successful exit *verifier will point
670 * to a newly allocated BIGNUM containing the verifier and (if a salt was not
671 * provided) *salt will be populated with a newly allocated BIGNUM containing a
672 * random salt.
673 * The caller is responsible for freeing the allocated *salt and *verifier
674 * BIGNUMS.
675 */
SRP_create_verifier_BN(const char * user,const char * pass,BIGNUM ** salt,BIGNUM ** verifier,BIGNUM * N,BIGNUM * g)676 int SRP_create_verifier_BN(const char *user, const char *pass, BIGNUM **salt,
677 BIGNUM **verifier, BIGNUM *N, BIGNUM *g)
678 {
679 int result = 0;
680 BIGNUM *x = NULL;
681 BN_CTX *bn_ctx = BN_CTX_new();
682 unsigned char tmp2[MAX_LEN];
683 BIGNUM *salttmp = NULL;
684
685 if ((user == NULL) ||
686 (pass == NULL) ||
687 (salt == NULL) ||
688 (verifier == NULL) || (N == NULL) || (g == NULL) || (bn_ctx == NULL))
689 goto err;
690
691 srp_bn_print(N);
692 srp_bn_print(g);
693
694 if (*salt == NULL) {
695 if (RAND_bytes(tmp2, SRP_RANDOM_SALT_LEN) <= 0)
696 goto err;
697
698 salttmp = BN_bin2bn(tmp2, SRP_RANDOM_SALT_LEN, NULL);
699 } else {
700 salttmp = *salt;
701 }
702
703 x = SRP_Calc_x(salttmp, user, pass);
704
705 *verifier = BN_new();
706 if (*verifier == NULL)
707 goto err;
708
709 if (!BN_mod_exp(*verifier, g, x, N, bn_ctx)) {
710 BN_clear_free(*verifier);
711 goto err;
712 }
713
714 srp_bn_print(*verifier);
715
716 result = 1;
717 *salt = salttmp;
718
719 err:
720 if (*salt != salttmp)
721 BN_clear_free(salttmp);
722 BN_clear_free(x);
723 BN_CTX_free(bn_ctx);
724 return result;
725 }
726
727 #endif
728