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freebsd/crypto/openssh/auth-chall.c
Dag-Erling Smørgrav fc0824d97d If an ssh1 client initiated challenge-response authentication but did
not respond to challenge, and later successfully authenticated itself
using another method, the kbdint context would never be released,
leaving the PAM child process behind even after the connection ended.

Fix this by automatically releasing the kbdint context if a packet of
type SSH_CMSG_AUTH_TIS is follwed by anything but a packet of type
SSH_CMSG_AUTH_TIS_RESPONSE.

MFC after:	1 week
2003-03-31 13:45:36 +00:00

110 lines
3.3 KiB
C

/*
* 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"
RCSID("$OpenBSD: auth-chall.c,v 1.8 2001/05/18 14:13:28 markus Exp $");
RCSID("$FreeBSD$");
#include "auth.h"
#include "log.h"
#include "xmalloc.h"
/* limited protocol v1 interface to kbd-interactive authentication */
extern KbdintDevice *devices[];
static KbdintDevice *device;
char *
get_challenge(Authctxt *authctxt)
{
char *challenge, *name, *info, **prompts;
u_int i, numprompts;
u_int *echo_on;
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++)
xfree(prompts[i]);
xfree(prompts);
xfree(name);
xfree(echo_on);
xfree(info);
return (challenge);
}
int
verify_response(Authctxt *authctxt, const char *response)
{
char *resp[1];
int res;
if (device == NULL)
return 0;
if (authctxt->kbdintctxt == NULL)
return 0;
resp[0] = (char *)response;
res = device->respond(authctxt->kbdintctxt, 1, resp);
if (res == 1) {
/* postponed - send a null query just in case */
char *name, *info, **prompts;
u_int i, numprompts, *echo_on;
res = device->query(authctxt->kbdintctxt, &name, &info,
&numprompts, &prompts, &echo_on);
if (res == 0) {
for (i = 0; i < numprompts; i++)
xfree(prompts[i]);
xfree(prompts);
xfree(name);
xfree(echo_on);
xfree(info);
}
/* if we received more prompts, we're screwed */
res = (numprompts != 0);
}
device->free_ctx(authctxt->kbdintctxt);
authctxt->kbdintctxt = NULL;
return res ? 0 : 1;
}
void
abandon_challenge_response(Authctxt *authctxt)
{
if (authctxt->kbdintctxt != NULL) {
device->free_ctx(authctxt->kbdintctxt);
authctxt->kbdintctxt = NULL;
}
}