1 /* crypto/srp/srp_vfy.c */
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.
7 /* ====================================================================
8 * Copyright (c) 2004 The OpenSSL Project. All rights reserved.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
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
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/)"
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.
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.
36 * 6. Redistributions of any form whatsoever must retain the following
38 * "This product includes software developed by the OpenSSL Project
39 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
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 * ====================================================================
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).
60 #ifndef OPENSSL_NO_SRP
61 # include "cryptlib.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>
69 # define SRP_RANDOM_SALT_LEN 20
72 static char b64table[] =
73 "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz./";
76 * the following two conversion routines have been inspired by code from
81 * Convert a base64 string into raw byte array representation.
83 static int t_fromb64(unsigned char *a, size_t alen, const char *src)
89 while (*src && (*src == ' ' || *src == '\t' || *src == '\n'))
92 if (alen > INT_MAX || size > (int)alen)
97 loc = strchr(b64table, src[i]);
101 a[i] = loc - b64table;
104 /* if nothing valid to process we have a zero length response */
114 a[j] |= (a[i] & 3) << 6;
116 a[j] = (unsigned char)((a[i] & 0x3c) >> 2);
119 a[j] |= (a[i] & 0xf) << 4;
121 a[j] = (unsigned char)((a[i] & 0x30) >> 4);
130 while (a[j] == 0 && j <= size)
139 * Convert a raw byte string into a null-terminated base64 ASCII string.
141 static char *t_tob64(char *dst, const unsigned char *src, int size)
143 int c, pos = size % 3;
144 unsigned char b0 = 0, b1 = 0, b2 = 0, notleading = 0;
158 c = (b0 & 0xfc) >> 2;
159 if (notleading || c != 0) {
160 *dst++ = b64table[c];
163 c = ((b0 & 3) << 4) | ((b1 & 0xf0) >> 4);
164 if (notleading || c != 0) {
165 *dst++ = b64table[c];
168 c = ((b1 & 0xf) << 2) | ((b2 & 0xc0) >> 6);
169 if (notleading || c != 0) {
170 *dst++ = b64table[c];
174 if (notleading || c != 0) {
175 *dst++ = b64table[c];
191 void SRP_user_pwd_free(SRP_user_pwd *user_pwd)
193 if (user_pwd == NULL)
195 BN_free(user_pwd->s);
196 BN_clear_free(user_pwd->v);
197 OPENSSL_free(user_pwd->id);
198 OPENSSL_free(user_pwd->info);
199 OPENSSL_free(user_pwd);
202 static SRP_user_pwd *SRP_user_pwd_new()
204 SRP_user_pwd *ret = OPENSSL_malloc(sizeof(SRP_user_pwd));
216 static void SRP_user_pwd_set_gN(SRP_user_pwd *vinfo, const BIGNUM *g,
223 static int SRP_user_pwd_set_ids(SRP_user_pwd *vinfo, const char *id,
226 if (id != NULL && NULL == (vinfo->id = BUF_strdup(id)))
228 return (info == NULL || NULL != (vinfo->info = BUF_strdup(info)));
231 static int SRP_user_pwd_set_sv(SRP_user_pwd *vinfo, const char *s,
234 unsigned char tmp[MAX_LEN];
240 len = t_fromb64(tmp, sizeof(tmp), v);
243 if (NULL == (vinfo->v = BN_bin2bn(tmp, len, NULL)))
245 len = t_fromb64(tmp, sizeof(tmp), s);
248 vinfo->s = BN_bin2bn(tmp, len, NULL);
249 if (vinfo->s == NULL)
258 static int SRP_user_pwd_set_sv_BN(SRP_user_pwd *vinfo, BIGNUM *s, BIGNUM *v)
262 return (vinfo->s != NULL && vinfo->v != NULL);
265 static SRP_user_pwd *srp_user_pwd_dup(SRP_user_pwd *src)
271 if ((ret = SRP_user_pwd_new()) == NULL)
274 SRP_user_pwd_set_gN(ret, src->g, src->N);
275 if (!SRP_user_pwd_set_ids(ret, src->id, src->info)
276 || !SRP_user_pwd_set_sv_BN(ret, BN_dup(src->s), BN_dup(src->v))) {
277 SRP_user_pwd_free(ret);
283 SRP_VBASE *SRP_VBASE_new(char *seed_key)
285 SRP_VBASE *vb = (SRP_VBASE *)OPENSSL_malloc(sizeof(SRP_VBASE));
289 if (!(vb->users_pwd = sk_SRP_user_pwd_new_null()) ||
290 !(vb->gN_cache = sk_SRP_gN_cache_new_null())) {
294 vb->default_g = NULL;
295 vb->default_N = NULL;
297 if ((seed_key != NULL) && (vb->seed_key = BUF_strdup(seed_key)) == NULL) {
298 sk_SRP_user_pwd_free(vb->users_pwd);
299 sk_SRP_gN_cache_free(vb->gN_cache);
306 int SRP_VBASE_free(SRP_VBASE *vb)
308 sk_SRP_user_pwd_pop_free(vb->users_pwd, SRP_user_pwd_free);
309 sk_SRP_gN_cache_free(vb->gN_cache);
310 OPENSSL_free(vb->seed_key);
315 static SRP_gN_cache *SRP_gN_new_init(const char *ch)
317 unsigned char tmp[MAX_LEN];
320 SRP_gN_cache *newgN =
321 (SRP_gN_cache *)OPENSSL_malloc(sizeof(SRP_gN_cache));
325 len = t_fromb64(tmp, sizeof(tmp), ch);
329 if ((newgN->b64_bn = BUF_strdup(ch)) == NULL)
332 if ((newgN->bn = BN_bin2bn(tmp, len, NULL)))
335 OPENSSL_free(newgN->b64_bn);
341 static void SRP_gN_free(SRP_gN_cache *gN_cache)
343 if (gN_cache == NULL)
345 OPENSSL_free(gN_cache->b64_bn);
346 BN_free(gN_cache->bn);
347 OPENSSL_free(gN_cache);
350 static SRP_gN *SRP_get_gN_by_id(const char *id, STACK_OF(SRP_gN) *gN_tab)
356 for (i = 0; i < sk_SRP_gN_num(gN_tab); i++) {
357 gN = sk_SRP_gN_value(gN_tab, i);
358 if (gN && (id == NULL || strcmp(gN->id, id) == 0))
362 return SRP_get_default_gN(id);
365 static BIGNUM *SRP_gN_place_bn(STACK_OF(SRP_gN_cache) *gN_cache, char *ch)
368 if (gN_cache == NULL)
371 /* search if we have already one... */
372 for (i = 0; i < sk_SRP_gN_cache_num(gN_cache); i++) {
373 SRP_gN_cache *cache = sk_SRP_gN_cache_value(gN_cache, i);
374 if (strcmp(cache->b64_bn, ch) == 0)
377 { /* it is the first time that we find it */
378 SRP_gN_cache *newgN = SRP_gN_new_init(ch);
380 if (sk_SRP_gN_cache_insert(gN_cache, newgN, 0) > 0)
389 * this function parses verifier file. Format is:
390 * string(index):base64(N):base64(g):0
391 * string(username):base64(v):base64(salt):int(index)
394 int SRP_VBASE_init(SRP_VBASE *vb, char *verifier_file)
397 STACK_OF(SRP_gN) *SRP_gN_tab = sk_SRP_gN_new_null();
398 char *last_index = NULL;
403 SRP_user_pwd *user_pwd = NULL;
405 TXT_DB *tmpdb = NULL;
406 BIO *in = BIO_new(BIO_s_file());
408 error_code = SRP_ERR_OPEN_FILE;
410 if (in == NULL || BIO_read_filename(in, verifier_file) <= 0)
413 error_code = SRP_ERR_VBASE_INCOMPLETE_FILE;
415 if ((tmpdb = TXT_DB_read(in, DB_NUMBER)) == NULL)
418 error_code = SRP_ERR_MEMORY;
421 last_index = SRP_get_default_gN(NULL)->id;
423 for (i = 0; i < sk_OPENSSL_PSTRING_num(tmpdb->data); i++) {
424 pp = sk_OPENSSL_PSTRING_value(tmpdb->data, i);
425 if (pp[DB_srptype][0] == DB_SRP_INDEX) {
427 * we add this couple in the internal Stack
430 if ((gN = (SRP_gN *) OPENSSL_malloc(sizeof(SRP_gN))) == NULL)
433 if (!(gN->id = BUF_strdup(pp[DB_srpid]))
435 SRP_gN_place_bn(vb->gN_cache, pp[DB_srpverifier]))
436 || !(gN->g = SRP_gN_place_bn(vb->gN_cache, pp[DB_srpsalt]))
437 || sk_SRP_gN_insert(SRP_gN_tab, gN, 0) == 0)
442 if (vb->seed_key != NULL) {
443 last_index = pp[DB_srpid];
445 } else if (pp[DB_srptype][0] == DB_SRP_VALID) {
446 /* it is a user .... */
448 if ((lgN = SRP_get_gN_by_id(pp[DB_srpgN], SRP_gN_tab)) != NULL) {
449 error_code = SRP_ERR_MEMORY;
450 if ((user_pwd = SRP_user_pwd_new()) == NULL)
453 SRP_user_pwd_set_gN(user_pwd, lgN->g, lgN->N);
454 if (!SRP_user_pwd_set_ids
455 (user_pwd, pp[DB_srpid], pp[DB_srpinfo]))
458 error_code = SRP_ERR_VBASE_BN_LIB;
459 if (!SRP_user_pwd_set_sv
460 (user_pwd, pp[DB_srpsalt], pp[DB_srpverifier]))
463 if (sk_SRP_user_pwd_insert(vb->users_pwd, user_pwd, 0) == 0)
465 user_pwd = NULL; /* abandon responsability */
470 if (last_index != NULL) {
471 /* this means that we want to simulate a default user */
473 if (((gN = SRP_get_gN_by_id(last_index, SRP_gN_tab)) == NULL)) {
474 error_code = SRP_ERR_VBASE_BN_LIB;
477 vb->default_g = gN->g;
478 vb->default_N = gN->N;
481 error_code = SRP_NO_ERROR;
485 * there may be still some leaks to fix, if this fails, the application
486 * terminates most likely
490 OPENSSL_free(gN->id);
494 SRP_user_pwd_free(user_pwd);
501 sk_SRP_gN_free(SRP_gN_tab);
507 static SRP_user_pwd *find_user(SRP_VBASE *vb, char *username)
515 for (i = 0; i < sk_SRP_user_pwd_num(vb->users_pwd); i++) {
516 user = sk_SRP_user_pwd_value(vb->users_pwd, i);
517 if (strcmp(user->id, username) == 0)
525 * This method ignores the configured seed and fails for an unknown user.
526 * Ownership of the returned pointer is not released to the caller.
527 * In other words, caller must not free the result.
529 SRP_user_pwd *SRP_VBASE_get_by_user(SRP_VBASE *vb, char *username)
531 return find_user(vb, username);
535 * Ownership of the returned pointer is released to the caller.
536 * In other words, caller must free the result once done.
538 SRP_user_pwd *SRP_VBASE_get1_by_user(SRP_VBASE *vb, char *username)
541 unsigned char digv[SHA_DIGEST_LENGTH];
542 unsigned char digs[SHA_DIGEST_LENGTH];
548 if ((user = find_user(vb, username)) != NULL)
549 return srp_user_pwd_dup(user);
551 if ((vb->seed_key == NULL) ||
552 (vb->default_g == NULL) || (vb->default_N == NULL))
555 /* if the user is unknown we set parameters as well if we have a seed_key */
557 if ((user = SRP_user_pwd_new()) == NULL)
560 SRP_user_pwd_set_gN(user, vb->default_g, vb->default_N);
562 if (!SRP_user_pwd_set_ids(user, username, NULL))
565 if (RAND_bytes(digv, SHA_DIGEST_LENGTH) <= 0)
567 EVP_MD_CTX_init(&ctxt);
568 EVP_DigestInit_ex(&ctxt, EVP_sha1(), NULL);
569 EVP_DigestUpdate(&ctxt, vb->seed_key, strlen(vb->seed_key));
570 EVP_DigestUpdate(&ctxt, username, strlen(username));
571 EVP_DigestFinal_ex(&ctxt, digs, NULL);
572 EVP_MD_CTX_cleanup(&ctxt);
573 if (SRP_user_pwd_set_sv_BN
574 (user, BN_bin2bn(digs, SHA_DIGEST_LENGTH, NULL),
575 BN_bin2bn(digv, SHA_DIGEST_LENGTH, NULL)))
578 err:SRP_user_pwd_free(user);
583 * create a verifier (*salt,*verifier,g and N are in base64)
585 char *SRP_create_verifier(const char *user, const char *pass, char **salt,
586 char **verifier, const char *N, const char *g)
589 char *result = NULL, *vf = NULL;
590 BIGNUM *N_bn = NULL, *g_bn = NULL, *s = NULL, *v = NULL;
591 unsigned char tmp[MAX_LEN];
592 unsigned char tmp2[MAX_LEN];
593 char *defgNid = NULL;
596 if ((user == NULL) ||
597 (pass == NULL) || (salt == NULL) || (verifier == NULL))
601 if (!(len = t_fromb64(tmp, sizeof(tmp), N)))
603 N_bn = BN_bin2bn(tmp, len, NULL);
604 if (!(len = t_fromb64(tmp, sizeof(tmp), g)))
606 g_bn = BN_bin2bn(tmp, len, NULL);
609 SRP_gN *gN = SRP_get_gN_by_id(g, NULL);
618 if (RAND_bytes(tmp2, SRP_RANDOM_SALT_LEN) <= 0)
621 s = BN_bin2bn(tmp2, SRP_RANDOM_SALT_LEN, NULL);
623 if (!(len = t_fromb64(tmp2, sizeof(tmp2), *salt)))
625 s = BN_bin2bn(tmp2, len, NULL);
628 if (!SRP_create_verifier_BN(user, pass, &s, &v, N_bn, g_bn))
632 vfsize = BN_num_bytes(v) * 2;
633 if (((vf = OPENSSL_malloc(vfsize)) == NULL))
635 t_tob64(vf, tmp, BN_num_bytes(v));
640 if ((tmp_salt = OPENSSL_malloc(SRP_RANDOM_SALT_LEN * 2)) == NULL) {
643 t_tob64(tmp_salt, tmp2, SRP_RANDOM_SALT_LEN);
657 OPENSSL_cleanse(vf, vfsize);
665 * create a verifier (*salt,*verifier,g and N are BIGNUMs). If *salt != NULL
666 * then the provided salt will be used. On successful exit *verifier will point
667 * to a newly allocated BIGNUM containing the verifier and (if a salt was not
668 * provided) *salt will be populated with a newly allocated BIGNUM containing a
670 * The caller is responsible for freeing the allocated *salt and *verifier
673 int SRP_create_verifier_BN(const char *user, const char *pass, BIGNUM **salt,
674 BIGNUM **verifier, BIGNUM *N, BIGNUM *g)
678 BN_CTX *bn_ctx = BN_CTX_new();
679 unsigned char tmp2[MAX_LEN];
680 BIGNUM *salttmp = NULL;
682 if ((user == NULL) ||
685 (verifier == NULL) || (N == NULL) || (g == NULL) || (bn_ctx == NULL))
692 if (RAND_bytes(tmp2, SRP_RANDOM_SALT_LEN) <= 0)
695 salttmp = BN_bin2bn(tmp2, SRP_RANDOM_SALT_LEN, NULL);
700 x = SRP_Calc_x(salttmp, user, pass);
702 *verifier = BN_new();
703 if (*verifier == NULL)
706 if (!BN_mod_exp(*verifier, g, x, N, bn_ctx)) {
707 BN_clear_free(*verifier);
711 srp_bn_print(*verifier);
717 if (*salt != salttmp)
718 BN_clear_free(salttmp);