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/* $OpenBSD: auth-chall.c,v 1.13 2013/05/17 00:13:13 djm Exp $ */
/*
* Copyright (c) 2001 Markus Friedl. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "includes.h"
#include <sys/types.h>
#include <stdarg.h>
#include "xmalloc.h"
#include "key.h"
#include "hostfile.h"
#include "auth.h"
#include "log.h"
#include "servconf.h"
/* limited protocol v1 interface to kbd-interactive authentication */
extern KbdintDevice *devices[];
static KbdintDevice *device;
extern ServerOptions options;
char *
get_challenge(Authctxt *authctxt)
{
char *challenge, *name, *info, **prompts;
u_int i, numprompts;
u_int *echo_on;
#ifdef USE_PAM
if (!options.use_pam)
remove_kbdint_device("pam");
#endif
device = devices[0]; /* we always use the 1st device for protocol 1 */
if (device == NULL)
return NULL;
if ((authctxt->kbdintctxt = device->init_ctx(authctxt)) == NULL)
return NULL;
if (device->query(authctxt->kbdintctxt, &name, &info,
&numprompts, &prompts, &echo_on)) {
device->free_ctx(authctxt->kbdintctxt);
authctxt->kbdintctxt = NULL;
return NULL;
}
if (numprompts < 1)
fatal("get_challenge: numprompts < 1");
challenge = xstrdup(prompts[0]);
for (i = 0; i < numprompts; i++)
free(prompts[i]);
free(prompts);
free(name);
free(echo_on);
free(info);
return (challenge);
}
int
verify_response(Authctxt *authctxt, const char *response)
{
char *resp[1], *name, *info, **prompts;
u_int i, numprompts, *echo_on;
int authenticated = 0;
if (device == NULL)
return 0;
if (authctxt->kbdintctxt == NULL)
return 0;
resp[0] = (char *)response;
switch (device->respond(authctxt->kbdintctxt, 1, resp)) {
case 0: /* Success */
authenticated = 1;
break;
case 1: /* Postponed - retry with empty query for PAM */
if ((device->query(authctxt->kbdintctxt, &name, &info,
&numprompts, &prompts, &echo_on)) != 0)
break;
if (numprompts == 0 &&
device->respond(authctxt->kbdintctxt, 0, resp) == 0)
authenticated = 1;
for (i = 0; i < numprompts; i++)
free(prompts[i]);
free(prompts);
free(name);
free(echo_on);
free(info);
break;
}
device->free_ctx(authctxt->kbdintctxt);
authctxt->kbdintctxt = NULL;
return authenticated;
}
void
abandon_challenge_response(Authctxt *authctxt)
{
if (authctxt->kbdintctxt != NULL) {
device->free_ctx(authctxt->kbdintctxt);
authctxt->kbdintctxt = NULL;
}
}
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