crypto/dist/ssh/auth-chall.c

   1 /*      $NetBSD$        */
   2 /* $OpenBSD: auth-chall.c,v 1.12 2006/08/03 03:34:41 deraadt Exp $ */
   3 /*
   4  * Copyright (c) 2001 Markus Friedl.  All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  */
  26
  27 #include "includes.h"
  28 __RCSID("$NetBSD: auth-chall.c,v 1.6 2003/07/10 01:09:41 lukem Exp $");
  29 #include <sys/types.h>
  30
  31 #include "xmalloc.h"
  32 #include "key.h"
  33 #include "hostfile.h"
  34 #include "auth.h"
  35 #include "log.h"
  36 #ifdef USE_PAM
  37 #include "buffer.h"
  38 #include "servconf.h"
  39 extern ServerOptions options;
  40 void remove_kbdint_device(const char *);
  41 #endif
  42
  43 /* limited protocol v1 interface to kbd-interactive authentication */
  44
  45 extern KbdintDevice *devices[];
  46 static KbdintDevice *device;
  47
  48 char *
  49 get_challenge(Authctxt *authctxt)
  50 {
  51         char *challenge, *name, *info, **prompts;
  52         u_int i, numprompts;
  53         u_int *echo_on;
  54
  55 #ifdef USE_PAM
  56         if (!options.use_pam)
  57                 remove_kbdint_device("pam");
  58 #endif
  59
  60         device = devices[0]; /* we always use the 1st device for protocol 1 */
  61         if (device == NULL)
  62                 return NULL;
  63         if ((authctxt->kbdintctxt = device->init_ctx(authctxt)) == NULL)
  64                 return NULL;
  65         if (device->query(authctxt->kbdintctxt, &name, &info,
  66             &numprompts, &prompts, &echo_on)) {
  67                 device->free_ctx(authctxt->kbdintctxt);
  68                 authctxt->kbdintctxt = NULL;
  69                 return NULL;
  70         }
  71         if (numprompts < 1)
  72                 fatal("get_challenge: numprompts < 1");
  73         challenge = xstrdup(prompts[0]);
  74         for (i = 0; i < numprompts; i++)
  75                 xfree(prompts[i]);
  76         xfree(prompts);
  77         xfree(name);
  78         xfree(echo_on);
  79         xfree(info);
  80
  81         return (challenge);
  82 }
  83 int
  84 verify_response(Authctxt *authctxt, const char *response)
  85 {
  86         char *resp[1];
  87         int authenticated = 0;
  88
  89         if (device == NULL)
  90                 return 0;
  91         if (authctxt->kbdintctxt == NULL)
  92                 return 0;
  93         resp[0] = (char *)response;
  94         if (device->respond(authctxt->kbdintctxt, 1, resp) == 0)
  95                 authenticated = 1;
  96         device->free_ctx(authctxt->kbdintctxt);
  97         authctxt->kbdintctxt = NULL;
  98         return authenticated;
  99 }