2 * Written by Christophe Renou (christophe.renou@edelweb.fr) with the
3 * precious help of Peter Sylvester (peter.sylvester@edelweb.fr) for the
4 * EdelKey project and contributed to the OpenSSL project 2004.
6 /* ====================================================================
7 * Copyright (c) 2004 The OpenSSL Project. All rights reserved.
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
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
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/)"
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.
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.
35 * 6. Redistributions of any form whatsoever must retain the following
37 * "This product includes software developed by the OpenSSL Project
38 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
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 * ====================================================================
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).
59 #ifndef OPENSSL_NO_SRP
60 # include "internal/cryptlib.h"
61 # include <openssl/sha.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>
68 # define SRP_RANDOM_SALT_LEN 20
71 static char b64table[] =
72 "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz./";
75 * the following two conversion routines have been inspired by code from
80 * Convert a base64 string into raw byte array representation.
82 static int t_fromb64(unsigned char *a, const char *src)
88 while (*src && (*src == ' ' || *src == '\t' || *src == '\n'))
93 loc = strchr(b64table, src[i]);
97 a[i] = loc - b64table;
100 /* if nothing valid to process we have a zero length response */
110 a[j] |= (a[i] & 3) << 6;
112 a[j] = (unsigned char)((a[i] & 0x3c) >> 2);
115 a[j] |= (a[i] & 0xf) << 4;
117 a[j] = (unsigned char)((a[i] & 0x30) >> 4);
126 while (a[j] == 0 && j <= size)
135 * Convert a raw byte string into a null-terminated base64 ASCII string.
137 static char *t_tob64(char *dst, const unsigned char *src, int size)
139 int c, pos = size % 3;
140 unsigned char b0 = 0, b1 = 0, b2 = 0, notleading = 0;
154 c = (b0 & 0xfc) >> 2;
155 if (notleading || c != 0) {
156 *dst++ = b64table[c];
159 c = ((b0 & 3) << 4) | ((b1 & 0xf0) >> 4);
160 if (notleading || c != 0) {
161 *dst++ = b64table[c];
164 c = ((b1 & 0xf) << 2) | ((b2 & 0xc0) >> 6);
165 if (notleading || c != 0) {
166 *dst++ = b64table[c];
170 if (notleading || c != 0) {
171 *dst++ = b64table[c];
187 static void SRP_user_pwd_free(SRP_user_pwd *user_pwd)
189 if (user_pwd == NULL)
191 BN_free(user_pwd->s);
192 BN_clear_free(user_pwd->v);
193 OPENSSL_free(user_pwd->id);
194 OPENSSL_free(user_pwd->info);
195 OPENSSL_free(user_pwd);
198 static SRP_user_pwd *SRP_user_pwd_new(void)
200 SRP_user_pwd *ret = OPENSSL_malloc(sizeof(*ret));
212 static void SRP_user_pwd_set_gN(SRP_user_pwd *vinfo, const BIGNUM *g,
219 static int SRP_user_pwd_set_ids(SRP_user_pwd *vinfo, const char *id,
222 if (id != NULL && NULL == (vinfo->id = OPENSSL_strdup(id)))
224 return (info == NULL || NULL != (vinfo->info = OPENSSL_strdup(info)));
227 static int SRP_user_pwd_set_sv(SRP_user_pwd *vinfo, const char *s,
230 unsigned char tmp[MAX_LEN];
233 if (strlen(s) > MAX_LEN || strlen(v) > MAX_LEN)
235 len = t_fromb64(tmp, v);
236 if (NULL == (vinfo->v = BN_bin2bn(tmp, len, NULL)))
238 len = t_fromb64(tmp, s);
239 return ((vinfo->s = BN_bin2bn(tmp, len, NULL)) != NULL);
242 static int SRP_user_pwd_set_sv_BN(SRP_user_pwd *vinfo, BIGNUM *s, BIGNUM *v)
246 return (vinfo->s != NULL && vinfo->v != NULL);
249 SRP_VBASE *SRP_VBASE_new(char *seed_key)
251 SRP_VBASE *vb = OPENSSL_malloc(sizeof(*vb));
255 if ((vb->users_pwd = sk_SRP_user_pwd_new_null()) == NULL
256 || (vb->gN_cache = sk_SRP_gN_cache_new_null()) == NULL) {
260 vb->default_g = NULL;
261 vb->default_N = NULL;
263 if ((seed_key != NULL) && (vb->seed_key = OPENSSL_strdup(seed_key)) == NULL) {
264 sk_SRP_user_pwd_free(vb->users_pwd);
265 sk_SRP_gN_cache_free(vb->gN_cache);
272 void SRP_VBASE_free(SRP_VBASE *vb)
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);
282 static SRP_gN_cache *SRP_gN_new_init(const char *ch)
284 unsigned char tmp[MAX_LEN];
286 SRP_gN_cache *newgN = OPENSSL_malloc(sizeof(*newgN));
291 if ((newgN->b64_bn = OPENSSL_strdup(ch)) == NULL)
294 len = t_fromb64(tmp, ch);
295 if ((newgN->bn = BN_bin2bn(tmp, len, NULL)))
298 OPENSSL_free(newgN->b64_bn);
304 static void SRP_gN_free(SRP_gN_cache *gN_cache)
306 if (gN_cache == NULL)
308 OPENSSL_free(gN_cache->b64_bn);
309 BN_free(gN_cache->bn);
310 OPENSSL_free(gN_cache);
313 static SRP_gN *SRP_get_gN_by_id(const char *id, STACK_OF(SRP_gN) *gN_tab)
319 for (i = 0; i < sk_SRP_gN_num(gN_tab); i++) {
320 gN = sk_SRP_gN_value(gN_tab, i);
321 if (gN && (id == NULL || strcmp(gN->id, id) == 0))
325 return SRP_get_default_gN(id);
328 static BIGNUM *SRP_gN_place_bn(STACK_OF(SRP_gN_cache) *gN_cache, char *ch)
331 if (gN_cache == NULL)
334 /* search if we have already one... */
335 for (i = 0; i < sk_SRP_gN_cache_num(gN_cache); i++) {
336 SRP_gN_cache *cache = sk_SRP_gN_cache_value(gN_cache, i);
337 if (strcmp(cache->b64_bn, ch) == 0)
340 { /* it is the first time that we find it */
341 SRP_gN_cache *newgN = SRP_gN_new_init(ch);
343 if (sk_SRP_gN_cache_insert(gN_cache, newgN, 0) > 0)
352 * this function parses verifier file. Format is:
353 * string(index):base64(N):base64(g):0
354 * string(username):base64(v):base64(salt):int(index)
357 int SRP_VBASE_init(SRP_VBASE *vb, char *verifier_file)
360 STACK_OF(SRP_gN) *SRP_gN_tab = sk_SRP_gN_new_null();
361 char *last_index = NULL;
366 SRP_user_pwd *user_pwd = NULL;
368 TXT_DB *tmpdb = NULL;
369 BIO *in = BIO_new(BIO_s_file());
371 error_code = SRP_ERR_OPEN_FILE;
373 if (in == NULL || BIO_read_filename(in, verifier_file) <= 0)
376 error_code = SRP_ERR_VBASE_INCOMPLETE_FILE;
378 if ((tmpdb = TXT_DB_read(in, DB_NUMBER)) == NULL)
381 error_code = SRP_ERR_MEMORY;
384 last_index = SRP_get_default_gN(NULL)->id;
386 for (i = 0; i < sk_OPENSSL_PSTRING_num(tmpdb->data); i++) {
387 pp = sk_OPENSSL_PSTRING_value(tmpdb->data, i);
388 if (pp[DB_srptype][0] == DB_SRP_INDEX) {
390 * we add this couple in the internal Stack
393 if ((gN = OPENSSL_malloc(sizeof(*gN))) == NULL)
396 if ((gN->id = OPENSSL_strdup(pp[DB_srpid])) == NULL
397 || (gN->N = SRP_gN_place_bn(vb->gN_cache, pp[DB_srpverifier]))
399 || (gN->g = SRP_gN_place_bn(vb->gN_cache, pp[DB_srpsalt]))
401 || sk_SRP_gN_insert(SRP_gN_tab, gN, 0) == 0)
406 if (vb->seed_key != NULL) {
407 last_index = pp[DB_srpid];
409 } else if (pp[DB_srptype][0] == DB_SRP_VALID) {
410 /* it is a user .... */
413 if ((lgN = SRP_get_gN_by_id(pp[DB_srpgN], SRP_gN_tab)) != NULL) {
414 error_code = SRP_ERR_MEMORY;
415 if ((user_pwd = SRP_user_pwd_new()) == NULL)
418 SRP_user_pwd_set_gN(user_pwd, lgN->g, lgN->N);
419 if (!SRP_user_pwd_set_ids
420 (user_pwd, pp[DB_srpid], pp[DB_srpinfo]))
423 error_code = SRP_ERR_VBASE_BN_LIB;
424 if (!SRP_user_pwd_set_sv
425 (user_pwd, pp[DB_srpsalt], pp[DB_srpverifier]))
428 if (sk_SRP_user_pwd_insert(vb->users_pwd, user_pwd, 0) == 0)
430 user_pwd = NULL; /* abandon responsability */
435 if (last_index != NULL) {
436 /* this means that we want to simulate a default user */
438 if (((gN = SRP_get_gN_by_id(last_index, SRP_gN_tab)) == NULL)) {
439 error_code = SRP_ERR_VBASE_BN_LIB;
442 vb->default_g = gN->g;
443 vb->default_N = gN->N;
446 error_code = SRP_NO_ERROR;
450 * there may be still some leaks to fix, if this fails, the application
451 * terminates most likely
455 OPENSSL_free(gN->id);
459 SRP_user_pwd_free(user_pwd);
464 sk_SRP_gN_free(SRP_gN_tab);
470 SRP_user_pwd *SRP_VBASE_get_by_user(SRP_VBASE *vb, char *username)
474 unsigned char digv[SHA_DIGEST_LENGTH];
475 unsigned char digs[SHA_DIGEST_LENGTH];
476 EVP_MD_CTX *ctxt = NULL;
480 for (i = 0; i < sk_SRP_user_pwd_num(vb->users_pwd); i++) {
481 user = sk_SRP_user_pwd_value(vb->users_pwd, i);
482 if (strcmp(user->id, username) == 0)
485 if ((vb->seed_key == NULL) ||
486 (vb->default_g == NULL) || (vb->default_N == NULL))
489 /* if the user is unknown we set parameters as well if we have a seed_key */
491 if ((user = SRP_user_pwd_new()) == NULL)
494 SRP_user_pwd_set_gN(user, vb->default_g, vb->default_N);
496 if (!SRP_user_pwd_set_ids(user, username, NULL))
499 if (RAND_bytes(digv, SHA_DIGEST_LENGTH) <= 0)
501 ctxt = EVP_MD_CTX_new();
502 EVP_DigestInit_ex(ctxt, EVP_sha1(), NULL);
503 EVP_DigestUpdate(ctxt, vb->seed_key, strlen(vb->seed_key));
504 EVP_DigestUpdate(ctxt, username, strlen(username));
505 EVP_DigestFinal_ex(ctxt, digs, NULL);
506 EVP_MD_CTX_free(ctxt);
508 if (SRP_user_pwd_set_sv_BN(user,
509 BN_bin2bn(digs, SHA_DIGEST_LENGTH, NULL),
510 BN_bin2bn(digv, SHA_DIGEST_LENGTH, NULL)))
514 EVP_MD_CTX_free(ctxt);
515 SRP_user_pwd_free(user);
520 * create a verifier (*salt,*verifier,g and N are in base64)
522 char *SRP_create_verifier(const char *user, const char *pass, char **salt,
523 char **verifier, const char *N, const char *g)
526 char *result = NULL, *vf = NULL;
527 BIGNUM *N_bn = NULL, *g_bn = NULL, *s = NULL, *v = NULL;
528 unsigned char tmp[MAX_LEN];
529 unsigned char tmp2[MAX_LEN];
530 char *defgNid = NULL;
533 if ((user == NULL) ||
534 (pass == NULL) || (salt == NULL) || (verifier == NULL))
538 if ((len = t_fromb64(tmp, N)) == 0)
540 N_bn = BN_bin2bn(tmp, len, NULL);
541 if ((len = t_fromb64(tmp, g)) == 0)
543 g_bn = BN_bin2bn(tmp, len, NULL);
546 SRP_gN *gN = SRP_get_gN_by_id(g, NULL);
555 if (RAND_bytes(tmp2, SRP_RANDOM_SALT_LEN) <= 0)
558 s = BN_bin2bn(tmp2, SRP_RANDOM_SALT_LEN, NULL);
560 if ((len = t_fromb64(tmp2, *salt)) == 0)
562 s = BN_bin2bn(tmp2, len, NULL);
565 if (!SRP_create_verifier_BN(user, pass, &s, &v, N_bn, g_bn))
569 vfsize = BN_num_bytes(v) * 2;
570 if (((vf = OPENSSL_malloc(vfsize)) == NULL))
572 t_tob64(vf, tmp, BN_num_bytes(v));
577 if ((tmp_salt = OPENSSL_malloc(SRP_RANDOM_SALT_LEN * 2)) == NULL) {
580 t_tob64(tmp_salt, tmp2, SRP_RANDOM_SALT_LEN);
593 OPENSSL_clear_free(vf, vfsize);
600 * create a verifier (*salt,*verifier,g and N are BIGNUMs). If *salt != NULL
601 * then the provided salt will be used. On successful exit *verifier will point
602 * to a newly allocated BIGNUM containing the verifier and (if a salt was not
603 * provided) *salt will be populated with a newly allocated BIGNUM containing a
605 * The caller is responsible for freeing the allocated *salt and *verifier
608 int SRP_create_verifier_BN(const char *user, const char *pass, BIGNUM **salt,
609 BIGNUM **verifier, const BIGNUM *N,
614 BN_CTX *bn_ctx = BN_CTX_new();
615 unsigned char tmp2[MAX_LEN];
616 BIGNUM *salttmp = NULL;
618 if ((user == NULL) ||
621 (verifier == NULL) || (N == NULL) || (g == NULL) || (bn_ctx == NULL))
625 if (RAND_bytes(tmp2, SRP_RANDOM_SALT_LEN) <= 0)
628 salttmp = BN_bin2bn(tmp2, SRP_RANDOM_SALT_LEN, NULL);
633 x = SRP_Calc_x(salttmp, user, pass);
635 *verifier = BN_new();
636 if (*verifier == NULL)
639 if (!BN_mod_exp(*verifier, g, x, N, bn_ctx)) {
640 BN_clear_free(*verifier);
648 if (salt != NULL && *salt != salttmp)
649 BN_clear_free(salttmp);