examples/client-safe.c

   1 /* client-safe.c --- Sample Shishi authenticated client with integrity
   2  *                   protected application data exchange.
   3  * Copyright (C) 2003, 2004, 2007  Simon Josefsson
   4  *
   5  * This file is part of Shishi.
   6  *
   7  * Shishi is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 3 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * Shishi is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * 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, see http://www.gnu.org/licenses or write
  19  * to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
  20  * Floor, Boston, MA 02110-1301, USA
  21  *
  22  */
  23
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27
  28 #include <shishi.h>
  29
  30 #define SERVICE "sample"
  31
  32 /* XXX remove this */
  33 const char *program_name = "client";
  34
  35 static int
  36 doit (Shishi * handle, Shishi_ap * ap, int verbose)
  37 {
  38   char line[BUFSIZ];
  39   int res;
  40
  41   printf ("Application exchange start.  Press ^D to finish.\n");
  42
  43   while (fgets (line, sizeof (line), stdin))
  44     {
  45       Shishi_safe *safe;
  46
  47       line[strlen(line)-1] = '\0';
  48       printf ("read: %s\n", line);
  49
  50       res = shishi_safe (handle, &safe);
  51       if (res != SHISHI_OK)
  52         {
  53           printf ("Could not build SAFE: %s\n", shishi_strerror (res));
  54           return res;
  55         }
  56
  57       res = shishi_safe_set_user_data (handle, shishi_safe_safe (safe),
  58                                        line, strlen (line));
  59       if (res != SHISHI_OK)
  60         {
  61           printf ("Could not set application data in SAFE: %s\n",
  62                   shishi_strerror (res));
  63           return res;
  64         }
  65
  66       res = shishi_safe_build (safe, shishi_ap_key (ap));
  67       if (res != SHISHI_OK)
  68         {
  69           printf ("Could not build SAFE: %s\n", shishi_strerror (res));
  70           return res;
  71         }
  72
  73       res = shishi_safe_print (handle, stdout, shishi_safe_safe (safe));
  74       if (res != SHISHI_OK)
  75         {
  76           printf ("Could not print SAFE: %s\n", shishi_strerror (res));
  77           return res;
  78         }
  79     }
  80
  81   if (ferror (stdin))
  82     {
  83       printf ("error reading stdin\n");
  84       return 1;
  85     }
  86
  87   return 0;
  88 }
  89
  90 static Shishi_ap *
  91 auth (Shishi * h, int verbose, const char *cname, const char *sname)
  92 {
  93   Shishi_ap *ap;
  94   Shishi_tkt *tkt;
  95   Shishi_tkts_hint hint;
  96   int rc;
  97
  98   printf ("Client: %s\n", cname);
  99   printf ("Server: %s\n", sname);
 100
 101   /* Get a ticket for the server. */
 102
 103   memset (&hint, 0, sizeof (hint));
 104   hint.client = (char *) cname;
 105   hint.server = (char *) sname;
 106   tkt = shishi_tkts_get (shishi_tkts_default (h), &hint);
 107   if (!tkt)
 108     {
 109       printf ("cannot find ticket for \"%s\"\n", sname);
 110       return NULL;
 111     }
 112
 113   if (verbose)
 114     shishi_tkt_pretty_print (tkt, stderr);
 115
 116   /* Create Authentication context */
 117
 118   rc = shishi_ap_tktoptions (h, &ap, tkt, SHISHI_APOPTIONS_MUTUAL_REQUIRED);
 119   if (rc != SHISHI_OK)
 120     {
 121       printf ("cannot create authentication context\n");
 122       return NULL;
 123     }
 124
 125   /* Build Authentication request */
 126
 127   rc = shishi_ap_req_build (ap);
 128   if (rc != SHISHI_OK)
 129     {
 130       printf ("cannot build authentication request: %s\n",
 131               shishi_strerror (rc));
 132       return NULL;
 133     }
 134
 135   if (verbose)
 136     shishi_authenticator_print (h, stderr, shishi_ap_authenticator (ap));
 137
 138   /* Authentication ourself to server */
 139
 140   shishi_apreq_print (h, stdout, shishi_ap_req (ap));
 141   /* Note: to get the binary blob to send, use:
 142    *
 143    * char *out; int outlen;
 144    * ...
 145    * rc = shishi_ap_req_der (ap, &out, &outlen);
 146    * ...
 147    * write(fd, out, outlen);
 148    */
 149
 150   /* For mutual authentication, wait for server reply. */
 151
 152   if (shishi_apreq_mutual_required_p (h, shishi_ap_req (ap)))
 153     {
 154       Shishi_asn1 aprep;
 155
 156       printf ("Waiting for server to authenticate itself...\n");
 157
 158       rc = shishi_aprep_parse (h, stdin, &aprep);
 159       if (rc != SHISHI_OK)
 160         {
 161           printf ("Cannot parse AP-REP from server: %s\n",
 162                   shishi_strerror (rc));
 163           return NULL;
 164         }
 165
 166       rc = shishi_ap_rep_verify_asn1 (ap, aprep);
 167       if (rc == SHISHI_OK)
 168         printf ("AP-REP verification OK...\n");
 169       else
 170         {
 171           if (rc == SHISHI_APREP_VERIFY_FAILED)
 172             printf ("AP-REP verification failed...\n");
 173           else
 174             printf ("AP-REP verification error: %s\n", shishi_strerror (rc));
 175           return NULL;
 176         }
 177
 178       /* The server is authenticated. */
 179       printf ("Server authenticated.\n");
 180     }
 181
 182   /* We are now authenticated. */
 183   printf ("User authenticated.\n");
 184
 185   return ap;
 186 }
 187
 188 int
 189 main (int argc, char *argv[])
 190 {
 191   Shishi *h;
 192   Shishi_ap *ap;
 193   char *sname;
 194   int rc;
 195
 196   printf ("sample-client (shishi " SHISHI_VERSION ")\n");
 197
 198   if (!shishi_check_version (SHISHI_VERSION))
 199     {
 200       printf ("shishi_check_version() failed:\n"
 201               "Header file incompatible with shared library.\n");
 202       return 1;
 203     }
 204
 205   rc = shishi_init (&h);
 206   if (rc != SHISHI_OK)
 207     {
 208       printf ("error initializing shishi: %s\n", shishi_strerror (rc));
 209       return 1;
 210     }
 211
 212   if (argc > 1)
 213     sname = argv[1];
 214   else
 215     sname = shishi_server_for_local_service (h, SERVICE);
 216
 217   ap = auth (h, 1, shishi_principal_default (h), sname);
 218
 219   if (ap)
 220     rc = doit (h, ap, 1);
 221   else
 222     rc = 1;
 223
 224   shishi_done (h);
 225
 226   return rc;
 227 }