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/*
* Copyright (C) 2001 Nikos Mavroyanopoulos
*
* This file is part of GNUTLS.
*
* GNUTLS is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* GNUTLS is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#include "gnutls_int.h"
#include "gnutls_random.h"
#include "gnutls_hash_int.h"
#include "auth_srp_passwd.h"
#include "gnutls_srp.h"
#include <gnutls_errors.h>
/* x = SHA(<salt> | SHA(<username> | ":" | <raw password>)) */
static const char magic[] = "";
char *crypt_srpsha1(const char *username, const char *passwd,
const char *salt, MPI g, MPI n)
{
unsigned char *sp, r1[MAX_HASH_SIZE];
int salt_size = strlen(salt);
unsigned char *local_salt, *v;
int passwd_len;
GNUTLS_MAC_HANDLE h1;
int vsize, hash_len = gnutls_hash_get_algo_len(GNUTLS_MAC_SHA);
opaque *tmp;
uint8 *rtext, *csalt;
int rsalt_size, len;
passwd_len = strlen(passwd); /* we do not want the null */
h1 = gnutls_hash_init(GNUTLS_MAC_SHA);
gnutls_hash(h1, (char *) username, strlen(username));
gnutls_hash(h1, ":", 1);
gnutls_hash(h1, (char *) passwd, passwd_len);
gnutls_hash_deinit(h1, r1);
local_salt = gnutls_malloc(salt_size + 1);
strcpy((char *) local_salt, salt);
sp = index( local_salt, ':'); /* move to salt - after verifier */
if (sp==NULL) {
gnutls_assert();
return NULL;
}
sp++;
len = (int)rindex(sp, ':');
if (len==0) { /* parse error */
len = strlen(sp);
} else
len -= (int)sp;
rsalt_size = _gnutls_sbase64_decode(sp, len, &csalt);
if (rsalt_size < 0) {
gnutls_assert();
return NULL;
}
h1 = gnutls_hash_init(GNUTLS_MAC_SHA);
gnutls_hash(h1, csalt, rsalt_size);
gnutls_free(csalt);
gnutls_hash(h1, r1, hash_len);
gnutls_hash_deinit(h1, r1);
/* v = g^x mod n */
vsize = _gnutls_srp_gx(r1, hash_len, &v, g, n);
if (vsize == -1 || v == NULL) {
gnutls_assert();
return NULL;
}
if (_gnutls_sbase64_encode(v, vsize, &rtext) < 0) {
gnutls_free(v);
gnutls_assert();
return NULL;
}
gnutls_free(v);
tmp =
gnutls_malloc(strlen(sp) + strlen(rtext) + strlen(magic) + 1 +
1);
sprintf(tmp, "%s%s:%s", magic, rtext, sp);
gnutls_free(rtext);
gnutls_free(local_salt);
return tmp;
}
/* salt here is the salt size */
char *crypt_srpsha1_wrapper(const char *username, const char *pass_new,
int salt, MPI g, MPI n)
{
unsigned char *result;
char *tcp;
opaque *rand;
char *e = NULL;
int result_size;
if (salt > 50 || salt <= 0)
return NULL; /* wow that's pretty long salt */
rand = gnutls_malloc(salt);
if (rand==NULL || _gnutls_get_random(rand, salt, GNUTLS_WEAK_RANDOM) < 0) {
gnutls_assert();
return NULL;
}
result_size = _gnutls_sbase64_encode(rand, salt, &result);
if (result_size < 0) {
gnutls_free(rand);
gnutls_assert();
return NULL;
}
tcp = gnutls_calloc(1, 1+ result_size + 1);
sprintf(tcp, ":%s", result);
gnutls_free(result);
gnutls_free(rand);
/* no longer need cleartext */
e = crypt_srpsha1(username, pass_new, (const char *) tcp, g, n);
gnutls_free(tcp);
return e;
}
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