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
);