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;
96 /* if nothing valid to process we have a zero length response */
106 a[j] |= (a[i] & 3) << 6;
108 a[j] = (unsigned char) ((a[i] & 0x3c) >> 2);
110 a[j] |= (a[i] & 0xf) << 4;
112 a[j] = (unsigned char) ((a[i] & 0x30) >> 4);
119 while(a[j] == 0 && j <= size) ++j;
121 while (j <= size) a[i++] = a[j++];
127 * Convert a raw byte string into a null-terminated base64 ASCII string.
129 static char *t_tob64(char *dst, const unsigned char *src, int size)
131 int c, pos = size % 3;
132 unsigned char b0 = 0, b1 = 0, b2 = 0, notleading = 0;
148 c = (b0 & 0xfc) >> 2;
149 if(notleading || c != 0)
151 *dst++ = b64table[c];
154 c = ((b0 & 3) << 4) | ((b1 & 0xf0) >> 4);
155 if(notleading || c != 0)
157 *dst++ = b64table[c];
160 c = ((b1 & 0xf) << 2) | ((b2 & 0xc0) >> 6);
161 if(notleading || c != 0)
163 *dst++ = b64table[c];
167 if(notleading || c != 0)
169 *dst++ = b64table[c];
172 if(pos >= size) break;
185 static void SRP_user_pwd_free(SRP_user_pwd *user_pwd)
187 if (user_pwd == NULL)
189 BN_free(user_pwd->s);
190 BN_clear_free(user_pwd->v);
191 OPENSSL_free(user_pwd->id);
192 OPENSSL_free(user_pwd->info);
193 OPENSSL_free(user_pwd);
196 static SRP_user_pwd *SRP_user_pwd_new()
198 SRP_user_pwd *ret = OPENSSL_malloc(sizeof(SRP_user_pwd));
210 static void SRP_user_pwd_set_gN(SRP_user_pwd *vinfo, const BIGNUM *g,
217 static int SRP_user_pwd_set_ids(SRP_user_pwd *vinfo, const char *id,
220 if (id != NULL && NULL == (vinfo->id = BUF_strdup(id)))
222 return (info == NULL || NULL != (vinfo->info = BUF_strdup(info))) ;
225 static int SRP_user_pwd_set_sv(SRP_user_pwd *vinfo, const char *s,
228 unsigned char tmp[MAX_LEN];
231 if (strlen(s) > MAX_LEN || strlen(v) > MAX_LEN)
233 len = t_fromb64(tmp, v);
234 if (NULL == (vinfo->v = BN_bin2bn(tmp, len, NULL)) )
236 len = t_fromb64(tmp, s);
237 return ((vinfo->s = BN_bin2bn(tmp, len, NULL)) != NULL) ;
240 static int SRP_user_pwd_set_sv_BN(SRP_user_pwd *vinfo, BIGNUM *s, BIGNUM *v)
244 return (vinfo->s != NULL && vinfo->v != NULL) ;
247 SRP_VBASE *SRP_VBASE_new(char *seed_key)
249 SRP_VBASE *vb = (SRP_VBASE *) OPENSSL_malloc(sizeof(SRP_VBASE));
253 if (!(vb->users_pwd = sk_SRP_user_pwd_new_null()) ||
254 !(vb->gN_cache = sk_SRP_gN_cache_new_null()))
259 vb->default_g = NULL;
260 vb->default_N = NULL;
262 if ((seed_key != NULL) &&
263 (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);
274 int 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);
284 static SRP_gN_cache *SRP_gN_new_init(const char *ch)
286 unsigned char tmp[MAX_LEN];
289 SRP_gN_cache *newgN = (SRP_gN_cache *)OPENSSL_malloc(sizeof(SRP_gN_cache));
293 if ((newgN->b64_bn = BUF_strdup(ch)) == NULL)
296 len = t_fromb64(tmp, ch);
297 if ((newgN->bn = BN_bin2bn(tmp, len, NULL)))
300 OPENSSL_free(newgN->b64_bn);
307 static void SRP_gN_free(SRP_gN_cache *gN_cache)
309 if (gN_cache == NULL)
311 OPENSSL_free(gN_cache->b64_bn);
312 BN_free(gN_cache->bn);
313 OPENSSL_free(gN_cache);
316 static SRP_gN *SRP_get_gN_by_id(const char *id, STACK_OF(SRP_gN) *gN_tab)
322 for(i = 0; i < sk_SRP_gN_num(gN_tab); i++)
324 gN = sk_SRP_gN_value(gN_tab, i);
325 if (gN && (id == NULL || strcmp(gN->id,id)==0))
329 return SRP_get_default_gN(id);
332 static BIGNUM *SRP_gN_place_bn(STACK_OF(SRP_gN_cache) *gN_cache, char *ch)
335 if (gN_cache == NULL)
338 /* search if we have already one... */
339 for(i = 0; i < sk_SRP_gN_cache_num(gN_cache); i++)
341 SRP_gN_cache *cache = sk_SRP_gN_cache_value(gN_cache, i);
342 if (strcmp(cache->b64_bn,ch)==0)
345 { /* it is the first time that we find it */
346 SRP_gN_cache *newgN = SRP_gN_new_init(ch);
349 if (sk_SRP_gN_cache_insert(gN_cache,newgN,0)>0)
357 /* this function parses verifier file. Format is:
358 * string(index):base64(N):base64(g):0
359 * string(username):base64(v):base64(salt):int(index)
363 int SRP_VBASE_init(SRP_VBASE *vb, char *verifier_file)
366 STACK_OF(SRP_gN) *SRP_gN_tab = sk_SRP_gN_new_null();
367 char *last_index = NULL;
372 SRP_user_pwd *user_pwd = NULL ;
374 TXT_DB *tmpdb = NULL;
375 BIO *in = BIO_new(BIO_s_file());
377 error_code = SRP_ERR_OPEN_FILE;
379 if (in == NULL || BIO_read_filename(in,verifier_file) <= 0)
382 error_code = SRP_ERR_VBASE_INCOMPLETE_FILE;
384 if ((tmpdb =TXT_DB_read(in,DB_NUMBER)) == NULL)
387 error_code = SRP_ERR_MEMORY;
392 last_index = SRP_get_default_gN(NULL)->id;
394 for (i = 0; i < sk_OPENSSL_PSTRING_num(tmpdb->data); i++)
396 pp = sk_OPENSSL_PSTRING_value(tmpdb->data,i);
397 if (pp[DB_srptype][0] == DB_SRP_INDEX)
399 /*we add this couple in the internal Stack */
401 if ((gN = (SRP_gN *)OPENSSL_malloc(sizeof(SRP_gN))) == NULL)
404 if (!(gN->id = BUF_strdup(pp[DB_srpid]))
405 || !(gN->N = SRP_gN_place_bn(vb->gN_cache,pp[DB_srpverifier]))
406 || !(gN->g = SRP_gN_place_bn(vb->gN_cache,pp[DB_srpsalt]))
407 || sk_SRP_gN_insert(SRP_gN_tab,gN,0) == 0)
412 if (vb->seed_key != NULL)
414 last_index = pp[DB_srpid];
417 else if (pp[DB_srptype][0] == DB_SRP_VALID)
419 /* it is a user .... */
421 if ((lgN = SRP_get_gN_by_id(pp[DB_srpgN],SRP_gN_tab))!=NULL)
423 error_code = SRP_ERR_MEMORY;
424 if ((user_pwd = SRP_user_pwd_new()) == NULL)
427 SRP_user_pwd_set_gN(user_pwd,lgN->g,lgN->N);
428 if (!SRP_user_pwd_set_ids(user_pwd, pp[DB_srpid],pp[DB_srpinfo]))
431 error_code = SRP_ERR_VBASE_BN_LIB;
432 if (!SRP_user_pwd_set_sv(user_pwd, pp[DB_srpsalt],pp[DB_srpverifier]))
435 if (sk_SRP_user_pwd_insert(vb->users_pwd, user_pwd, 0) == 0)
437 user_pwd = NULL; /* abandon responsability */
442 if (last_index != NULL)
444 /* this means that we want to simulate a default user */
446 if (((gN = SRP_get_gN_by_id(last_index,SRP_gN_tab))==NULL))
448 error_code = SRP_ERR_VBASE_BN_LIB;
451 vb->default_g = gN->g ;
452 vb->default_N = gN->N ;
455 error_code = SRP_NO_ERROR;
458 /* there may be still some leaks to fix, if this fails, the application terminates most likely */
462 OPENSSL_free(gN->id);
466 SRP_user_pwd_free(user_pwd);
468 if (tmpdb) TXT_DB_free(tmpdb);
469 if (in) BIO_free_all(in);
471 sk_SRP_gN_free(SRP_gN_tab);
478 SRP_user_pwd *SRP_VBASE_get_by_user(SRP_VBASE *vb, char *username)
482 unsigned char digv[SHA_DIGEST_LENGTH];
483 unsigned char digs[SHA_DIGEST_LENGTH];
488 for(i = 0; i < sk_SRP_user_pwd_num(vb->users_pwd); i++)
490 user = sk_SRP_user_pwd_value(vb->users_pwd, i);
491 if (strcmp(user->id,username)==0)
494 if ((vb->seed_key == NULL) ||
495 (vb->default_g == NULL) ||
496 (vb->default_N == NULL))
499 /* if the user is unknown we set parameters as well if we have a seed_key */
501 if ((user = SRP_user_pwd_new()) == NULL)
504 SRP_user_pwd_set_gN(user,vb->default_g,vb->default_N);
506 if (!SRP_user_pwd_set_ids(user,username,NULL))
509 RAND_pseudo_bytes(digv, SHA_DIGEST_LENGTH);
510 EVP_MD_CTX_init(&ctxt);
511 EVP_DigestInit_ex(&ctxt, EVP_sha1(), NULL);
512 EVP_DigestUpdate(&ctxt, vb->seed_key, strlen(vb->seed_key));
513 EVP_DigestUpdate(&ctxt, username, strlen(username));
514 EVP_DigestFinal_ex(&ctxt, digs, NULL);
515 EVP_MD_CTX_cleanup(&ctxt);
516 if (SRP_user_pwd_set_sv_BN(user, BN_bin2bn(digs,SHA_DIGEST_LENGTH,NULL), BN_bin2bn(digv,SHA_DIGEST_LENGTH, NULL)))
519 err: SRP_user_pwd_free(user);
525 create a verifier (*salt,*verifier,g and N are in base64)
527 char *SRP_create_verifier(const char *user, const char *pass, char **salt,
528 char **verifier, const char *N, const char *g)
533 BIGNUM *N_bn = NULL, *g_bn = NULL, *s = NULL, *v = NULL;
534 unsigned char tmp[MAX_LEN];
535 unsigned char tmp2[MAX_LEN];
536 char * defgNid = NULL;
546 if (!(len = t_fromb64(tmp, N))) goto err;
547 N_bn = BN_bin2bn(tmp, len, NULL);
548 if (!(len = t_fromb64(tmp, g))) goto err;
549 g_bn = BN_bin2bn(tmp, len, NULL);
554 SRP_gN * gN = SRP_get_gN_by_id(g, NULL) ;
564 RAND_pseudo_bytes(tmp2, SRP_RANDOM_SALT_LEN);
566 s = BN_bin2bn(tmp2, SRP_RANDOM_SALT_LEN, NULL);
570 if (!(len = t_fromb64(tmp2, *salt)))
572 s = BN_bin2bn(tmp2, len, NULL);
576 if(!SRP_create_verifier_BN(user, pass, &s, &v, N_bn, g_bn)) goto err;
579 if (((vf = OPENSSL_malloc(BN_num_bytes(v)*2)) == NULL))
581 t_tob64(vf, tmp, BN_num_bytes(v));
588 if ((tmp_salt = OPENSSL_malloc(SRP_RANDOM_SALT_LEN * 2)) == NULL)
593 t_tob64(tmp_salt, tmp2, SRP_RANDOM_SALT_LEN);
609 create a verifier (*salt,*verifier,g and N are BIGNUMs)
611 int SRP_create_verifier_BN(const char *user, const char *pass, BIGNUM **salt, BIGNUM **verifier, BIGNUM *N, BIGNUM *g)
615 BN_CTX *bn_ctx = BN_CTX_new();
616 unsigned char tmp2[MAX_LEN];
632 RAND_pseudo_bytes(tmp2, SRP_RANDOM_SALT_LEN);
634 *salt = BN_bin2bn(tmp2,SRP_RANDOM_SALT_LEN,NULL);
637 x = SRP_Calc_x(*salt,user,pass);
639 *verifier = BN_new();
640 if(*verifier == NULL) goto err;
642 if (!BN_mod_exp(*verifier,g,x,N,bn_ctx))
644 BN_clear_free(*verifier);
648 srp_bn_print(*verifier);