examples/client-priv.c

   1 /* client-priv.c --- Sample Shishi authenticated client, with privacy
   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_priv *priv;
  46
  47       line[strlen(line)-1] = '\0';
  48       printf ("read: %s\n", line);
  49
  50       res = shishi_priv (handle, &priv);
  51       if (res != SHISHI_OK)
  52         {
  53           printf ("Could not build PRIV: %s\n", shishi_strerror (res));
  54           return res;
  55         }
  56
  57       res = shishi_encprivpart_set_user_data (handle,
  58                                               shishi_priv_encprivpart (priv),
  59                                               line, strlen (line));
  60       if (res != SHISHI_OK)
  61         {
  62           printf ("Could not set application data in PRIV: %s\n",
  63                   shishi_strerror (res));
  64           return res;
  65         }
  66
  67       res = shishi_priv_build (priv, shishi_ap_key (ap));
  68       if (res != SHISHI_OK)
  69         {
  70           printf ("Could not build PRIV: %s\n", shishi_strerror (res));
  71           return res;
  72         }
  73
  74       res = shishi_priv_print (handle, stdout, shishi_priv_priv (priv));
  75       if (res != SHISHI_OK)
  76         {
  77           printf ("Could not print PRIV: %s\n", shishi_strerror (res));
  78           return res;
  79         }
  80     }
  81
  82   if (ferror (stdin))
  83     {
  84       printf ("error reading stdin\n");
  85       return 1;
  86     }
  87
  88   return 0;
  89 }
  90
  91 static Shishi_ap *
  92 auth (Shishi * h, int verbose, const char *cname, const char *sname)
  93 {
  94   Shishi_ap *ap;
  95   Shishi_tkt *tkt;
  96   Shishi_tkts_hint hint;
  97   int rc;
  98
  99   printf ("Client: %s\n", cname);
 100   printf ("Server: %s\n", sname);
 101
 102   /* Get a ticket for the server. */
 103
 104   memset (&hint, 0, sizeof (hint));
 105   hint.client = (char *) cname;
 106   hint.server = (char *) sname;
 107   tkt = shishi_tkts_get (shishi_tkts_default (h), &hint);
 108   if (!tkt)
 109     {
 110       printf ("cannot find ticket for \"%s\"\n", sname);
 111       return NULL;
 112     }
 113
 114   if (verbose)
 115     shishi_tkt_pretty_print (tkt, stderr);
 116
 117   /* Create Authentication context */
 118
 119   rc = shishi_ap_tktoptions (h, &ap, tkt, SHISHI_APOPTIONS_MUTUAL_REQUIRED);
 120   if (rc != SHISHI_OK)
 121     {
 122       printf ("cannot create authentication context\n");
 123       return NULL;
 124     }
 125
 126   /* Build Authentication request */
 127
 128   rc = shishi_ap_req_build (ap);
 129   if (rc != SHISHI_OK)
 130     {
 131       printf ("cannot build authentication request: %s\n",
 132               shishi_strerror (rc));
 133       return NULL;
 134     }
 135
 136   if (verbose)
 137     shishi_authenticator_print (h, stderr, shishi_ap_authenticator (ap));
 138
 139   /* Authentication ourself to server */
 140
 141   shishi_apreq_print (h, stdout, shishi_ap_req (ap));
 142   /* Note: to get the binary blob to send, use:
 143    *
 144    * char *out; int outlen;
 145    * ...
 146    * rc = shishi_ap_req_der (ap, &out, &outlen);
 147    * ...
 148    * write(fd, out, outlen);
 149    */
 150
 151   /* For mutual authentication, wait for server reply. */
 152
 153   if (shishi_apreq_mutual_required_p (h, shishi_ap_req (ap)))
 154     {
 155       Shishi_asn1 aprep;
 156
 157       printf ("Waiting for server to authenticate itself...\n");
 158
 159       rc = shishi_aprep_parse (h, stdin, &aprep);
 160       if (rc != SHISHI_OK)
 161         {
 162           printf ("Cannot parse AP-REP from server: %s\n",
 163                   shishi_strerror (rc));
 164           return NULL;
 165         }
 166
 167       rc = shishi_ap_rep_verify_asn1 (ap, aprep);
 168       if (rc == SHISHI_OK)
 169         printf ("AP-REP verification OK...\n");
 170       else
 171         {
 172           if (rc == SHISHI_APREP_VERIFY_FAILED)
 173             printf ("AP-REP verification failed...\n");
 174           else
 175             printf ("AP-REP verification error: %s\n", shishi_strerror (rc));
 176           return NULL;
 177         }
 178
 179       /* The server is authenticated. */
 180       printf ("Server authenticated.\n");
 181     }
 182
 183   /* We are now authenticated. */
 184   printf ("User authenticated.\n");
 185
 186   return ap;
 187 }
 188
 189 int
 190 main (int argc, char *argv[])
 191 {
 192   Shishi *h;
 193   Shishi_ap *ap;
 194   char *sname;
 195   int rc;
 196
 197   printf ("sample-client (shishi " SHISHI_VERSION ")\n");
 198
 199   if (!shishi_check_version (SHISHI_VERSION))
 200     {
 201       printf ("shishi_check_version() failed:\n"
 202               "Header file incompatible with shared library.\n");
 203       return 1;
 204     }
 205
 206   rc = shishi_init (&h);
 207   if (rc != SHISHI_OK)
 208     {
 209       printf ("error initializing shishi: %s\n", shishi_strerror (rc));
 210       return 1;
 211     }
 212
 213   if (argc > 1)
 214     sname = argv[1];
 215   else
 216     sname = shishi_server_for_local_service (h, SERVICE);
 217
 218   ap = auth (h, 1, shishi_principal_default (h), sname);
 219
 220   if (ap)
 221     rc = doit (h, ap, 1);
 222   else
 223     rc = 1;
 224
 225   shishi_done (h);
 226
 227   return rc;
 228 }