examples/client-safe.c

   1 /* client-safe.c --- Sample Shishi authenticated client with integrity
   2  *                   protected application data exchange.
   3  * Copyright (C) 2003, 2004  Simon Josefsson
   4  *
   5  * This file is part of Shishi.
   6  *
   7  * Shishi is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * Shishi is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with Shishi; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
  20  *
  21  */
  22
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26
  27 #include <shishi.h>
  28
  29 #define SERVICE "sample"
  30
  31 /* XXX remove this */
  32 const char *program_name = "client";
  33
  34 static int
  35 doit (Shishi * handle, Shishi_ap * ap, int verbose)
  36 {
  37   char line[BUFSIZ];
  38   int res;
  39
  40   printf ("Application exchange start.  Press ^D to finish.\n");
  41
  42   while (fgets (line, sizeof (line), stdin))
  43     {
  44       Shishi_safe *safe;
  45
  46       line[strlen(line)-1] = '\0';
  47       printf ("read: %s\n", line);
  48
  49       res = shishi_safe (handle, &safe);
  50       if (res != SHISHI_OK)
  51         {
  52           printf ("Could not build SAFE: %s\n", shishi_strerror (res));
  53           return res;
  54         }
  55
  56       res = shishi_safe_set_user_data (handle, shishi_safe_safe (safe),
  57                                        line, strlen (line));
  58       if (res != SHISHI_OK)
  59         {
  60           printf ("Could not set application data in SAFE: %s\n",
  61                   shishi_strerror (res));
  62           return res;
  63         }
  64
  65       res = shishi_safe_build (safe, shishi_ap_key (ap));
  66       if (res != SHISHI_OK)
  67         {
  68           printf ("Could not build SAFE: %s\n", shishi_strerror (res));
  69           return res;
  70         }
  71
  72       res = shishi_safe_print (handle, stdout, shishi_safe_safe (safe));
  73       if (res != SHISHI_OK)
  74         {
  75           printf ("Could not print SAFE: %s\n", shishi_strerror (res));
  76           return res;
  77         }
  78     }
  79
  80   if (ferror (stdin))
  81     {
  82       printf ("error reading stdin\n");
  83       return 1;
  84     }
  85
  86   return 0;
  87 }
  88
  89 static Shishi_ap *
  90 auth (Shishi * h, int verbose, const char *cname, const char *sname)
  91 {
  92   Shishi_ap *ap;
  93   Shishi_tkt *tkt;
  94   Shishi_tkts_hint hint;
  95   int rc;
  96
  97   printf ("Client: %s\n", cname);
  98   printf ("Server: %s\n", sname);
  99
 100   /* Get a ticket for the server. */
 101
 102   memset (&hint, 0, sizeof (hint));
 103   hint.client = (char *) cname;
 104   hint.server = (char *) sname;
 105   tkt = shishi_tkts_get (shishi_tkts_default (h), &hint);
 106   if (!tkt)
 107     {
 108       printf ("cannot find ticket for \"%s\"\n", sname);
 109       return NULL;
 110     }
 111
 112   if (verbose)
 113     shishi_tkt_pretty_print (tkt, stderr);
 114
 115   /* Create Authentication context */
 116
 117   rc = shishi_ap_tktoptions (h, &ap, tkt, SHISHI_APOPTIONS_MUTUAL_REQUIRED);
 118   if (rc != SHISHI_OK)
 119     {
 120       printf ("cannot create authentication context\n");
 121       return NULL;
 122     }
 123
 124   /* Build Authentication request */
 125
 126   rc = shishi_ap_req_build (ap);
 127   if (rc != SHISHI_OK)
 128     {
 129       printf ("cannot build authentication request: %s\n",
 130               shishi_strerror (rc));
 131       return NULL;
 132     }
 133
 134   if (verbose)
 135     shishi_authenticator_print (h, stderr, shishi_ap_authenticator (ap));
 136
 137   /* Authentication ourself to server */
 138
 139   shishi_apreq_print (h, stdout, shishi_ap_req (ap));
 140   /* Note: to get the binary blob to send, use:
 141    *
 142    * char *out; int outlen;
 143    * ...
 144    * rc = shishi_ap_req_der (ap, &out, &outlen);
 145    * ...
 146    * write(fd, out, outlen);
 147    */
 148
 149   /* For mutual authentication, wait for server reply. */
 150
 151   if (shishi_apreq_mutual_required_p (h, shishi_ap_req (ap)))
 152     {
 153       Shishi_asn1 aprep;
 154
 155       printf ("Waiting for server to authenticate itself...\n");
 156
 157       rc = shishi_aprep_parse (h, stdin, &aprep);
 158       if (rc != SHISHI_OK)
 159         {
 160           printf ("Cannot parse AP-REP from server: %s\n",
 161                   shishi_strerror (rc));
 162           return NULL;
 163         }
 164
 165       rc = shishi_ap_rep_verify_asn1 (ap, aprep);
 166       if (rc == SHISHI_OK)
 167         printf ("AP-REP verification OK...\n");
 168       else
 169         {
 170           if (rc == SHISHI_APREP_VERIFY_FAILED)
 171             printf ("AP-REP verification failed...\n");
 172           else
 173             printf ("AP-REP verification error: %s\n", shishi_strerror (rc));
 174           return NULL;
 175         }
 176
 177       /* The server is authenticated. */
 178       printf ("Server authenticated.\n");
 179     }
 180
 181   /* We are now authenticated. */
 182   printf ("User authenticated.\n");
 183
 184   return ap;
 185 }
 186
 187 int
 188 main (int argc, char *argv[])
 189 {
 190   Shishi *h;
 191   Shishi_ap *ap;
 192   char *sname;
 193   int rc;
 194
 195   printf ("sample-client (shishi " SHISHI_VERSION ")\n");
 196
 197   if (!shishi_check_version (SHISHI_VERSION))
 198     {
 199       printf ("shishi_check_version() failed:\n"
 200               "Header file incompatible with shared library.\n");
 201       return 1;
 202     }
 203
 204   rc = shishi_init (&h);
 205   if (rc != SHISHI_OK)
 206     {
 207       printf ("error initializing shishi: %s\n", shishi_strerror (rc));
 208       return 1;
 209     }
 210
 211   if (argc > 1)
 212     sname = argv[1];
 213   else
 214     sname = shishi_server_for_local_service (h, SERVICE);
 215
 216   ap = auth (h, 1, shishi_principal_default (h), sname);
 217
 218   if (ap)
 219     rc = doit (h, ap, 1);
 220   else
 221     rc = 1;
 222
 223   shishi_done (h);
 224
 225   return rc;
 226 }