1 /* crypto/srp/srp_vfy.c */
2 /* Written by Christophe Renou (christophe.renou@edelweb.fr) with
3 * the precious help of Peter Sylvester (peter.sylvester@edelweb.fr)
4 * for the 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
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./";
74 /* the following two conversion routines have been inspired by code from Stanford */
77 * Convert a base64 string into raw byte array representation.
79 static int t_fromb64(unsigned char *a
, const char *src
)
85 while(*src
&& (*src
== ' ' || *src
== '\t' || *src
== '\n'))
91 loc
= strchr(b64table
, src
[i
]);
92 if(loc
== (char *) 0) break;
93 else a
[i
] = loc
- b64table
;
103 a
[j
] |= (a
[i
] & 3) << 6;
105 a
[j
] = (unsigned char) ((a
[i
] & 0x3c) >> 2);
107 a
[j
] |= (a
[i
] & 0xf) << 4;
109 a
[j
] = (unsigned char) ((a
[i
] & 0x30) >> 4);
116 while(a
[j
] == 0 && j
<= size
) ++j
;
118 while (j
<= size
) a
[i
++] = a
[j
++];
124 * Convert a raw byte string into a null-terminated base64 ASCII string.
126 static char *t_tob64(char *dst
, const unsigned char *src
, int size
)
128 int c
, pos
= size
% 3;
129 unsigned char b0
= 0, b1
= 0, b2
= 0, notleading
= 0;
145 c
= (b0
& 0xfc) >> 2;
146 if(notleading
|| c
!= 0)
148 *dst
++ = b64table
[c
];
151 c
= ((b0
& 3) << 4) | ((b1
& 0xf0) >> 4);
152 if(notleading
|| c
!= 0)
154 *dst
++ = b64table
[c
];
157 c
= ((b1
& 0xf) << 2) | ((b2
& 0xc0) >> 6);
158 if(notleading
|| c
!= 0)
160 *dst
++ = b64table
[c
];
164 if(notleading
|| c
!= 0)
166 *dst
++ = b64table
[c
];
169 if(pos
>= size
) break;
182 static void SRP_user_pwd_free(SRP_user_pwd
*user_pwd
)
184 if (user_pwd
== NULL
)
186 BN_free(user_pwd
->s
);
187 BN_clear_free(user_pwd
->v
);
188 OPENSSL_free(user_pwd
->id
);
189 OPENSSL_free(user_pwd
->info
);
190 OPENSSL_free(user_pwd
);
193 static SRP_user_pwd
*SRP_user_pwd_new()
195 SRP_user_pwd
*ret
= OPENSSL_malloc(sizeof(SRP_user_pwd
));
207 static void SRP_user_pwd_set_gN(SRP_user_pwd
*vinfo
, const BIGNUM
*g
,
214 static int SRP_user_pwd_set_ids(SRP_user_pwd
*vinfo
, const char *id
,
217 if (id
!= NULL
&& NULL
== (vinfo
->id
= BUF_strdup(id
)))
219 return (info
== NULL
|| NULL
!= (vinfo
->info
= BUF_strdup(info
))) ;
222 static int SRP_user_pwd_set_sv(SRP_user_pwd
*vinfo
, const char *s
,
225 unsigned char tmp
[MAX_LEN
];
228 if (strlen(s
) > MAX_LEN
|| strlen(v
) > MAX_LEN
)
230 len
= t_fromb64(tmp
, v
);
231 if (NULL
== (vinfo
->v
= BN_bin2bn(tmp
, len
, NULL
)) )
233 len
= t_fromb64(tmp
, s
);
234 return ((vinfo
->s
= BN_bin2bn(tmp
, len
, NULL
)) != NULL
) ;
237 static int SRP_user_pwd_set_sv_BN(SRP_user_pwd
*vinfo
, BIGNUM
*s
, BIGNUM
*v
)
241 return (vinfo
->s
!= NULL
&& vinfo
->v
!= NULL
) ;
244 SRP_VBASE
*SRP_VBASE_new(char *seed_key
)
246 SRP_VBASE
*vb
= (SRP_VBASE
*) OPENSSL_malloc(sizeof(SRP_VBASE
));
250 if (!(vb
->users_pwd
= sk_SRP_user_pwd_new_null()) ||
251 !(vb
->gN_cache
= sk_SRP_gN_cache_new_null()))
256 vb
->default_g
= NULL
;
257 vb
->default_N
= NULL
;
259 if ((seed_key
!= NULL
) &&
260 (vb
->seed_key
= BUF_strdup(seed_key
)) == NULL
)
262 sk_SRP_user_pwd_free(vb
->users_pwd
);
263 sk_SRP_gN_cache_free(vb
->gN_cache
);
271 int SRP_VBASE_free(SRP_VBASE
*vb
)
273 sk_SRP_user_pwd_pop_free(vb
->users_pwd
,SRP_user_pwd_free
);
274 sk_SRP_gN_cache_free(vb
->gN_cache
);
275 OPENSSL_free(vb
->seed_key
);
281 static SRP_gN_cache
*SRP_gN_new_init(const char *ch
)
283 unsigned char tmp
[MAX_LEN
];
286 SRP_gN_cache
*newgN
= (SRP_gN_cache
*)OPENSSL_malloc(sizeof(SRP_gN_cache
));
290 if ((newgN
->b64_bn
= BUF_strdup(ch
)) == NULL
)
293 len
= t_fromb64(tmp
, ch
);
294 if ((newgN
->bn
= BN_bin2bn(tmp
, len
, NULL
)))
297 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
++)
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
++)
338 SRP_gN_cache
*cache
= sk_SRP_gN_cache_value(gN_cache
, i
);
339 if (strcmp(cache
->b64_bn
,ch
)==0)
342 { /* it is the first time that we find it */
343 SRP_gN_cache
*newgN
= SRP_gN_new_init(ch
);
346 if (sk_SRP_gN_cache_insert(gN_cache
,newgN
,0)>0)
354 /* this function parses verifier file. Format is:
355 * string(index):base64(N):base64(g):0
356 * string(username):base64(v):base64(salt):int(index)
360 int SRP_VBASE_init(SRP_VBASE
*vb
, char *verifier_file
)
363 STACK_OF(SRP_gN
) *SRP_gN_tab
= sk_SRP_gN_new_null();
364 char *last_index
= NULL
;
369 SRP_user_pwd
*user_pwd
= NULL
;
371 TXT_DB
*tmpdb
= NULL
;
372 BIO
*in
= BIO_new(BIO_s_file());
374 error_code
= SRP_ERR_OPEN_FILE
;
376 if (in
== NULL
|| BIO_read_filename(in
,verifier_file
) <= 0)
379 error_code
= SRP_ERR_VBASE_INCOMPLETE_FILE
;
381 if ((tmpdb
=TXT_DB_read(in
,DB_NUMBER
)) == NULL
)
384 error_code
= SRP_ERR_MEMORY
;
389 last_index
= SRP_get_default_gN(NULL
)->id
;
391 for (i
= 0; i
< sk_OPENSSL_PSTRING_num(tmpdb
->data
); i
++)
393 pp
= (char **)sk_OPENSSL_PSTRING_value(tmpdb
->data
,i
);
394 if (pp
[DB_srptype
][0] == DB_SRP_INDEX
)
396 /*we add this couple in the internal Stack */
398 if ((gN
= (SRP_gN
*)OPENSSL_malloc(sizeof(SRP_gN
))) == NULL
)
401 if (!(gN
->id
= BUF_strdup(pp
[DB_srpid
]))
402 || !(gN
->N
= SRP_gN_place_bn(vb
->gN_cache
,pp
[DB_srpverifier
]))
403 || !(gN
->g
= SRP_gN_place_bn(vb
->gN_cache
,pp
[DB_srpsalt
]))
404 || sk_SRP_gN_insert(SRP_gN_tab
,gN
,0) == 0)
409 if (vb
->seed_key
!= NULL
)
411 last_index
= pp
[DB_srpid
];
414 else if (pp
[DB_srptype
][0] == DB_SRP_VALID
)
416 /* it is a user .... */
418 if ((lgN
= SRP_get_gN_by_id(pp
[DB_srpgN
],SRP_gN_tab
))!=NULL
)
420 error_code
= SRP_ERR_MEMORY
;
421 if ((user_pwd
= SRP_user_pwd_new()) == NULL
)
424 SRP_user_pwd_set_gN(user_pwd
,lgN
->g
,lgN
->N
);
425 if (!SRP_user_pwd_set_ids(user_pwd
, pp
[DB_srpid
],pp
[DB_srpinfo
]))
428 error_code
= SRP_ERR_VBASE_BN_LIB
;
429 if (!SRP_user_pwd_set_sv(user_pwd
, pp
[DB_srpsalt
],pp
[DB_srpverifier
]))
432 if (sk_SRP_user_pwd_insert(vb
->users_pwd
, user_pwd
, 0) == 0)
434 user_pwd
= NULL
; /* abandon responsability */
439 if (last_index
!= NULL
)
441 /* this means that we want to simulate a default user */
443 if (((gN
= SRP_get_gN_by_id(last_index
,SRP_gN_tab
))==NULL
))
445 error_code
= SRP_ERR_VBASE_BN_LIB
;
448 vb
->default_g
= gN
->g
;
449 vb
->default_N
= gN
->N
;
452 error_code
= SRP_NO_ERROR
;
455 /* there may be still some leaks to fix, if this fails, the application terminates most likely */
459 OPENSSL_free(gN
->id
);
463 SRP_user_pwd_free(user_pwd
);
465 if (tmpdb
) TXT_DB_free(tmpdb
);
466 if (in
) BIO_free_all(in
);
468 sk_SRP_gN_free(SRP_gN_tab
);
475 SRP_user_pwd
*SRP_VBASE_get_by_user(SRP_VBASE
*vb
, char *username
)
479 unsigned char digv
[SHA_DIGEST_LENGTH
];
480 unsigned char digs
[SHA_DIGEST_LENGTH
];
485 for(i
= 0; i
< sk_SRP_user_pwd_num(vb
->users_pwd
); i
++)
487 user
= sk_SRP_user_pwd_value(vb
->users_pwd
, i
);
488 if (strcmp(user
->id
,username
)==0)
491 if ((vb
->seed_key
== NULL
) ||
492 (vb
->default_g
== NULL
) ||
493 (vb
->default_N
== NULL
))
496 /* if the user is unknown we set parameters as well if we have a seed_key */
498 if ((user
= SRP_user_pwd_new()) == NULL
)
501 SRP_user_pwd_set_gN(user
,vb
->default_g
,vb
->default_N
);
503 if (!SRP_user_pwd_set_ids(user
,username
,NULL
))
506 RAND_pseudo_bytes(digv
, SHA_DIGEST_LENGTH
);
507 EVP_MD_CTX_init(&ctxt
);
508 EVP_DigestInit_ex(&ctxt
, EVP_sha1(), NULL
);
509 EVP_DigestUpdate(&ctxt
, vb
->seed_key
, strlen(vb
->seed_key
));
510 EVP_DigestUpdate(&ctxt
, username
, strlen(username
));
511 EVP_DigestFinal_ex(&ctxt
, digs
, NULL
);
512 EVP_MD_CTX_cleanup(&ctxt
);
513 if (SRP_user_pwd_set_sv_BN(user
, BN_bin2bn(digs
,SHA_DIGEST_LENGTH
,NULL
), BN_bin2bn(digv
,SHA_DIGEST_LENGTH
, NULL
)))
516 err
: SRP_user_pwd_free(user
);
522 create a verifier (*salt,*verifier,g and N are in base64)
524 char *SRP_create_verifier(const char *user
, const char *pass
, char **salt
,
525 char **verifier
, const char *N
, const char *g
)
530 BIGNUM
*N_bn
= NULL
, *g_bn
= NULL
, *s
= NULL
, *v
= NULL
;
531 unsigned char tmp
[MAX_LEN
];
532 unsigned char tmp2
[MAX_LEN
];
533 char * defgNid
= NULL
;
543 if (!(len
= t_fromb64(tmp
, N
))) goto err
;
544 N_bn
= BN_bin2bn(tmp
, len
, NULL
);
545 if (!(len
= t_fromb64(tmp
, g
))) goto err
;
546 g_bn
= BN_bin2bn(tmp
, len
, NULL
);
551 SRP_gN
* gN
= SRP_get_gN_by_id(g
, NULL
) ;
561 RAND_pseudo_bytes(tmp2
, SRP_RANDOM_SALT_LEN
);
563 s
= BN_bin2bn(tmp2
, SRP_RANDOM_SALT_LEN
, NULL
);
567 if (!(len
= t_fromb64(tmp2
, *salt
)))
569 s
= BN_bin2bn(tmp2
, len
, NULL
);
573 if(!SRP_create_verifier_BN(user
, pass
, &s
, &v
, N_bn
, g_bn
)) goto err
;
576 if (((vf
= OPENSSL_malloc(BN_num_bytes(v
)*2)) == NULL
))
578 t_tob64(vf
, tmp
, BN_num_bytes(v
));
584 if ((tmp_salt
= (char *)OPENSSL_malloc(SRP_RANDOM_SALT_LEN
* 2)) == NULL
)
589 t_tob64(tmp_salt
, tmp2
, SRP_RANDOM_SALT_LEN
);
605 create a verifier (*salt,*verifier,g and N are BIGNUMs)
607 int SRP_create_verifier_BN(const char *user
, const char *pass
, BIGNUM
**salt
, BIGNUM
**verifier
, BIGNUM
*N
, BIGNUM
*g
)
611 BN_CTX
*bn_ctx
= BN_CTX_new();
612 unsigned char tmp2
[MAX_LEN
];
628 RAND_pseudo_bytes(tmp2
, SRP_RANDOM_SALT_LEN
);
630 *salt
= BN_bin2bn(tmp2
,SRP_RANDOM_SALT_LEN
,NULL
);
633 x
= SRP_Calc_x(*salt
,user
,pass
);
635 *verifier
= BN_new();
636 if(*verifier
== NULL
) goto err
;
638 if (!BN_mod_exp(*verifier
,g
,x
,N
,bn_ctx
))
640 BN_clear_free(*verifier
);
644 srp_bn_print(*verifier
);