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 "internal/cryptlib.h"
62 # include <openssl/sha.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
, const char *src
)
89 while (*src
&& (*src
== ' ' || *src
== '\t' || *src
== '\n'))
94 loc
= strchr(b64table
, src
[i
]);
98 a
[i
] = loc
- b64table
;
101 /* if nothing valid to process we have a zero length response */
111 a
[j
] |= (a
[i
] & 3) << 6;
113 a
[j
] = (unsigned char)((a
[i
] & 0x3c) >> 2);
116 a
[j
] |= (a
[i
] & 0xf) << 4;
118 a
[j
] = (unsigned char)((a
[i
] & 0x30) >> 4);
127 while (a
[j
] == 0 && j
<= size
)
136 * Convert a raw byte string into a null-terminated base64 ASCII string.
138 static char *t_tob64(char *dst
, const unsigned char *src
, int size
)
140 int c
, pos
= size
% 3;
141 unsigned char b0
= 0, b1
= 0, b2
= 0, notleading
= 0;
155 c
= (b0
& 0xfc) >> 2;
156 if (notleading
|| c
!= 0) {
157 *dst
++ = b64table
[c
];
160 c
= ((b0
& 3) << 4) | ((b1
& 0xf0) >> 4);
161 if (notleading
|| c
!= 0) {
162 *dst
++ = b64table
[c
];
165 c
= ((b1
& 0xf) << 2) | ((b2
& 0xc0) >> 6);
166 if (notleading
|| c
!= 0) {
167 *dst
++ = b64table
[c
];
171 if (notleading
|| c
!= 0) {
172 *dst
++ = b64table
[c
];
188 static void SRP_user_pwd_free(SRP_user_pwd
*user_pwd
)
190 if (user_pwd
== NULL
)
192 BN_free(user_pwd
->s
);
193 BN_clear_free(user_pwd
->v
);
194 OPENSSL_free(user_pwd
->id
);
195 OPENSSL_free(user_pwd
->info
);
196 OPENSSL_free(user_pwd
);
199 static SRP_user_pwd
*SRP_user_pwd_new(void)
201 SRP_user_pwd
*ret
= OPENSSL_malloc(sizeof(*ret
));
213 static void SRP_user_pwd_set_gN(SRP_user_pwd
*vinfo
, const BIGNUM
*g
,
220 static int SRP_user_pwd_set_ids(SRP_user_pwd
*vinfo
, const char *id
,
223 if (id
!= NULL
&& NULL
== (vinfo
->id
= BUF_strdup(id
)))
225 return (info
== NULL
|| NULL
!= (vinfo
->info
= BUF_strdup(info
)));
228 static int SRP_user_pwd_set_sv(SRP_user_pwd
*vinfo
, const char *s
,
231 unsigned char tmp
[MAX_LEN
];
234 if (strlen(s
) > MAX_LEN
|| strlen(v
) > MAX_LEN
)
236 len
= t_fromb64(tmp
, v
);
237 if (NULL
== (vinfo
->v
= BN_bin2bn(tmp
, len
, NULL
)))
239 len
= t_fromb64(tmp
, s
);
240 return ((vinfo
->s
= BN_bin2bn(tmp
, len
, NULL
)) != NULL
);
243 static int SRP_user_pwd_set_sv_BN(SRP_user_pwd
*vinfo
, BIGNUM
*s
, BIGNUM
*v
)
247 return (vinfo
->s
!= NULL
&& vinfo
->v
!= NULL
);
250 SRP_VBASE
*SRP_VBASE_new(char *seed_key
)
252 SRP_VBASE
*vb
= OPENSSL_malloc(sizeof(*vb
));
256 if ((vb
->users_pwd
= sk_SRP_user_pwd_new_null()) == NULL
257 || (vb
->gN_cache
= sk_SRP_gN_cache_new_null()) == NULL
) {
261 vb
->default_g
= NULL
;
262 vb
->default_N
= NULL
;
264 if ((seed_key
!= NULL
) && (vb
->seed_key
= BUF_strdup(seed_key
)) == NULL
) {
265 sk_SRP_user_pwd_free(vb
->users_pwd
);
266 sk_SRP_gN_cache_free(vb
->gN_cache
);
273 void SRP_VBASE_free(SRP_VBASE
*vb
)
277 sk_SRP_user_pwd_pop_free(vb
->users_pwd
, SRP_user_pwd_free
);
278 sk_SRP_gN_cache_free(vb
->gN_cache
);
279 OPENSSL_free(vb
->seed_key
);
283 static SRP_gN_cache
*SRP_gN_new_init(const char *ch
)
285 unsigned char tmp
[MAX_LEN
];
287 SRP_gN_cache
*newgN
= OPENSSL_malloc(sizeof(*newgN
));
292 if ((newgN
->b64_bn
= BUF_strdup(ch
)) == NULL
)
295 len
= t_fromb64(tmp
, ch
);
296 if ((newgN
->bn
= BN_bin2bn(tmp
, len
, NULL
)))
299 OPENSSL_free(newgN
->b64_bn
);
305 static void SRP_gN_free(SRP_gN_cache
*gN_cache
)
307 if (gN_cache
== NULL
)
309 OPENSSL_free(gN_cache
->b64_bn
);
310 BN_free(gN_cache
->bn
);
311 OPENSSL_free(gN_cache
);
314 static SRP_gN
*SRP_get_gN_by_id(const char *id
, STACK_OF(SRP_gN
) *gN_tab
)
320 for (i
= 0; i
< sk_SRP_gN_num(gN_tab
); i
++) {
321 gN
= sk_SRP_gN_value(gN_tab
, i
);
322 if (gN
&& (id
== NULL
|| strcmp(gN
->id
, id
) == 0))
326 return SRP_get_default_gN(id
);
329 static BIGNUM
*SRP_gN_place_bn(STACK_OF(SRP_gN_cache
) *gN_cache
, char *ch
)
332 if (gN_cache
== NULL
)
335 /* search if we have already one... */
336 for (i
= 0; i
< sk_SRP_gN_cache_num(gN_cache
); i
++) {
337 SRP_gN_cache
*cache
= sk_SRP_gN_cache_value(gN_cache
, i
);
338 if (strcmp(cache
->b64_bn
, ch
) == 0)
341 { /* it is the first time that we find it */
342 SRP_gN_cache
*newgN
= SRP_gN_new_init(ch
);
344 if (sk_SRP_gN_cache_insert(gN_cache
, newgN
, 0) > 0)
353 * this function parses verifier file. Format is:
354 * string(index):base64(N):base64(g):0
355 * string(username):base64(v):base64(salt):int(index)
358 int SRP_VBASE_init(SRP_VBASE
*vb
, char *verifier_file
)
361 STACK_OF(SRP_gN
) *SRP_gN_tab
= sk_SRP_gN_new_null();
362 char *last_index
= NULL
;
367 SRP_user_pwd
*user_pwd
= NULL
;
369 TXT_DB
*tmpdb
= NULL
;
370 BIO
*in
= BIO_new(BIO_s_file());
372 error_code
= SRP_ERR_OPEN_FILE
;
374 if (in
== NULL
|| BIO_read_filename(in
, verifier_file
) <= 0)
377 error_code
= SRP_ERR_VBASE_INCOMPLETE_FILE
;
379 if ((tmpdb
= TXT_DB_read(in
, DB_NUMBER
)) == NULL
)
382 error_code
= SRP_ERR_MEMORY
;
385 last_index
= SRP_get_default_gN(NULL
)->id
;
387 for (i
= 0; i
< sk_OPENSSL_PSTRING_num(tmpdb
->data
); i
++) {
388 pp
= sk_OPENSSL_PSTRING_value(tmpdb
->data
, i
);
389 if (pp
[DB_srptype
][0] == DB_SRP_INDEX
) {
391 * we add this couple in the internal Stack
394 if ((gN
= OPENSSL_malloc(sizeof(*gN
))) == NULL
)
397 if ((gN
->id
= BUF_strdup(pp
[DB_srpid
])) == NULL
398 || (gN
->N
= SRP_gN_place_bn(vb
->gN_cache
, pp
[DB_srpverifier
]))
400 || (gN
->g
= SRP_gN_place_bn(vb
->gN_cache
, pp
[DB_srpsalt
]))
402 || sk_SRP_gN_insert(SRP_gN_tab
, gN
, 0) == 0)
407 if (vb
->seed_key
!= NULL
) {
408 last_index
= pp
[DB_srpid
];
410 } else if (pp
[DB_srptype
][0] == DB_SRP_VALID
) {
411 /* it is a user .... */
414 if ((lgN
= SRP_get_gN_by_id(pp
[DB_srpgN
], SRP_gN_tab
)) != NULL
) {
415 error_code
= SRP_ERR_MEMORY
;
416 if ((user_pwd
= SRP_user_pwd_new()) == NULL
)
419 SRP_user_pwd_set_gN(user_pwd
, lgN
->g
, lgN
->N
);
420 if (!SRP_user_pwd_set_ids
421 (user_pwd
, pp
[DB_srpid
], pp
[DB_srpinfo
]))
424 error_code
= SRP_ERR_VBASE_BN_LIB
;
425 if (!SRP_user_pwd_set_sv
426 (user_pwd
, pp
[DB_srpsalt
], pp
[DB_srpverifier
]))
429 if (sk_SRP_user_pwd_insert(vb
->users_pwd
, user_pwd
, 0) == 0)
431 user_pwd
= NULL
; /* abandon responsability */
436 if (last_index
!= NULL
) {
437 /* this means that we want to simulate a default user */
439 if (((gN
= SRP_get_gN_by_id(last_index
, SRP_gN_tab
)) == NULL
)) {
440 error_code
= SRP_ERR_VBASE_BN_LIB
;
443 vb
->default_g
= gN
->g
;
444 vb
->default_N
= gN
->N
;
447 error_code
= SRP_NO_ERROR
;
451 * there may be still some leaks to fix, if this fails, the application
452 * terminates most likely
456 OPENSSL_free(gN
->id
);
460 SRP_user_pwd_free(user_pwd
);
465 sk_SRP_gN_free(SRP_gN_tab
);
471 SRP_user_pwd
*SRP_VBASE_get_by_user(SRP_VBASE
*vb
, char *username
)
475 unsigned char digv
[SHA_DIGEST_LENGTH
];
476 unsigned char digs
[SHA_DIGEST_LENGTH
];
481 for (i
= 0; i
< sk_SRP_user_pwd_num(vb
->users_pwd
); i
++) {
482 user
= sk_SRP_user_pwd_value(vb
->users_pwd
, i
);
483 if (strcmp(user
->id
, username
) == 0)
486 if ((vb
->seed_key
== NULL
) ||
487 (vb
->default_g
== NULL
) || (vb
->default_N
== NULL
))
490 /* if the user is unknown we set parameters as well if we have a seed_key */
492 if ((user
= SRP_user_pwd_new()) == NULL
)
495 SRP_user_pwd_set_gN(user
, vb
->default_g
, vb
->default_N
);
497 if (!SRP_user_pwd_set_ids(user
, username
, NULL
))
500 if (RAND_bytes(digv
, SHA_DIGEST_LENGTH
) <= 0)
502 EVP_MD_CTX_init(&ctxt
);
503 EVP_DigestInit_ex(&ctxt
, EVP_sha1(), NULL
);
504 EVP_DigestUpdate(&ctxt
, vb
->seed_key
, strlen(vb
->seed_key
));
505 EVP_DigestUpdate(&ctxt
, username
, strlen(username
));
506 EVP_DigestFinal_ex(&ctxt
, digs
, NULL
);
507 EVP_MD_CTX_cleanup(&ctxt
);
508 if (SRP_user_pwd_set_sv_BN
509 (user
, BN_bin2bn(digs
, SHA_DIGEST_LENGTH
, NULL
),
510 BN_bin2bn(digv
, SHA_DIGEST_LENGTH
, NULL
)))
514 SRP_user_pwd_free(user
);
519 * create a verifier (*salt,*verifier,g and N are in base64)
521 char *SRP_create_verifier(const char *user
, const char *pass
, char **salt
,
522 char **verifier
, const char *N
, const char *g
)
525 char *result
= NULL
, *vf
= NULL
;
526 BIGNUM
*N_bn
= NULL
, *g_bn
= NULL
, *s
= NULL
, *v
= NULL
;
527 unsigned char tmp
[MAX_LEN
];
528 unsigned char tmp2
[MAX_LEN
];
529 char *defgNid
= NULL
;
532 if ((user
== NULL
) ||
533 (pass
== NULL
) || (salt
== NULL
) || (verifier
== NULL
))
537 if ((len
= t_fromb64(tmp
, N
)) == 0)
539 N_bn
= BN_bin2bn(tmp
, len
, NULL
);
540 if ((len
= t_fromb64(tmp
, g
)) == 0)
542 g_bn
= BN_bin2bn(tmp
, len
, NULL
);
545 SRP_gN
*gN
= SRP_get_gN_by_id(g
, NULL
);
554 if (RAND_bytes(tmp2
, SRP_RANDOM_SALT_LEN
) <= 0)
557 s
= BN_bin2bn(tmp2
, SRP_RANDOM_SALT_LEN
, NULL
);
559 if ((len
= t_fromb64(tmp2
, *salt
)) == 0)
561 s
= BN_bin2bn(tmp2
, len
, NULL
);
564 if (!SRP_create_verifier_BN(user
, pass
, &s
, &v
, N_bn
, g_bn
))
568 vfsize
= BN_num_bytes(v
) * 2;
569 if (((vf
= OPENSSL_malloc(vfsize
)) == NULL
))
571 t_tob64(vf
, tmp
, BN_num_bytes(v
));
576 if ((tmp_salt
= OPENSSL_malloc(SRP_RANDOM_SALT_LEN
* 2)) == NULL
) {
579 t_tob64(tmp_salt
, tmp2
, SRP_RANDOM_SALT_LEN
);
592 OPENSSL_clear_free(vf
, vfsize
);
599 * create a verifier (*salt,*verifier,g and N are BIGNUMs). If *salt != NULL
600 * then the provided salt will be used. On successful exit *verifier will point
601 * to a newly allocated BIGNUM containing the verifier and (if a salt was not
602 * provided) *salt will be populated with a newly allocated BIGNUM containing a
604 * The caller is responsible for freeing the allocated *salt and *verifier
607 int SRP_create_verifier_BN(const char *user
, const char *pass
, BIGNUM
**salt
,
608 BIGNUM
**verifier
, const BIGNUM
*N
,
613 BN_CTX
*bn_ctx
= BN_CTX_new();
614 unsigned char tmp2
[MAX_LEN
];
615 BIGNUM
*salttmp
= NULL
;
617 if ((user
== NULL
) ||
620 (verifier
== NULL
) || (N
== NULL
) || (g
== NULL
) || (bn_ctx
== NULL
))
624 if (RAND_bytes(tmp2
, SRP_RANDOM_SALT_LEN
) <= 0)
627 salttmp
= BN_bin2bn(tmp2
, SRP_RANDOM_SALT_LEN
, NULL
);
632 x
= SRP_Calc_x(salttmp
, user
, pass
);
634 *verifier
= BN_new();
635 if (*verifier
== NULL
)
638 if (!BN_mod_exp(*verifier
, g
, x
, N
, bn_ctx
)) {
639 BN_clear_free(*verifier
);
647 if (salt
!= NULL
&& *salt
!= salttmp
)
648 BN_clear_free(salttmp
);