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freebsd/crypto/openssh/auth-chall.c
Dag-Erling Smørgrav 07fd326c9c Fix keyboard-interactive authentication for ssh1. The problem was twofold:
- The PAM kbdint device sometimes doesn't know authentication succeeded
   until you re-query it.  The ssh1 kbdint code would never re-query the
   device, so authentication would always fail.  This patch has been
   submitted to the OpenSSH developers.

 - The monitor code for PAM sometimes forgot to tell the monitor that
   authentication had succeeded.  This caused the monitor to veto the
   privsep child's decision to allow the connection.

These patches have been tested with OpenSSH clients on -STABLE, NetBSD and
Linux, and with ssh.com's ssh1 on Solaris.

Sponsored by:	DARPA, NAI Labs
2003-01-31 11:08:07 +00:00

102 lines
3.1 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;
}