examples/client-callback.c

   1 /* client-callback.c --- Example SASL client, with callback for user info.
   2  * Copyright (C) 2004, 2005  Simon Josefsson
   3  *
   4  * This file is part of GNU SASL.
   5  *
   6  * GNU SASL is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * GNU SASL is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with GNU SASL; if not, write to the Free Software
  18  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  19  *
  20  */
  21
  22 #include <stdarg.h>
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26
  27 #include <gsasl.h>
  28
  29 static void
  30 client_authenticate (Gsasl * ctx, Gsasl_session * session)
  31 {
  32   char buf[BUFSIZ] = "";
  33   char *p;
  34   int rc;
  35
  36   /* This loop mimic a protocol where the server get to send data first. */
  37
  38   do
  39     {
  40       printf ("Input base64 encoded data from server:\n");
  41       fgets (buf, sizeof (buf) - 1, stdin);
  42       if (buf[strlen (buf) - 1] == '\n')
  43         buf[strlen (buf) - 1] = '\0';
  44
  45       rc = gsasl_step64 (session, buf, &p);
  46
  47       if (rc == GSASL_NEEDS_MORE || rc == GSASL_OK)
  48         {
  49           printf ("Output:\n%s\n", p);
  50           free (p);
  51         }
  52     }
  53   while (rc == GSASL_NEEDS_MORE);
  54
  55   printf ("\n");
  56
  57   if (rc != GSASL_OK)
  58     {
  59       printf ("Authentication error (%d): %s\n", rc, gsasl_strerror (rc));
  60       return;
  61     }
  62
  63   /* The client is done.  Here you would typically check if the server
  64      let the client in.  If not, you could try again. */
  65
  66   printf ("If server accepted us, we're done.\n");
  67 }
  68
  69 static void
  70 client (Gsasl * ctx)
  71 {
  72   Gsasl_session *session;
  73   const char *mech = "SECURID";
  74   int rc;
  75
  76   /* Create new authentication session. */
  77   if ((rc = gsasl_client_start (ctx, mech, &session)) != GSASL_OK)
  78     {
  79       printf ("Cannot initialize client (%d): %s\n", rc, gsasl_strerror (rc));
  80       return;
  81     }
  82
  83   /* Do it. */
  84   client_authenticate (ctx, session);
  85
  86   /* Cleanup. */
  87   gsasl_finish (session);
  88 }
  89
  90 static int
  91 callback (Gsasl * ctx, Gsasl_session * sctx, Gsasl_property prop)
  92 {
  93   char buf[BUFSIZ] = "";
  94   int rc = GSASL_NO_CALLBACK;
  95
  96   /* Get user info from user. */
  97
  98   printf ("Callback invoked, for property %d.\n", prop);
  99
 100   switch (prop)
 101     {
 102     case GSASL_PASSCODE:
 103       printf ("Enter passcode:\n");
 104       fgets (buf, sizeof (buf) - 1, stdin);
 105       buf[strlen (buf) - 1] = '\0';
 106
 107       gsasl_property_set (sctx, GSASL_PASSCODE, buf);
 108       rc = GSASL_OK;
 109       break;
 110
 111     case GSASL_AUTHID:
 112       printf ("Enter username:\n");
 113       fgets (buf, sizeof (buf) - 1, stdin);
 114       buf[strlen (buf) - 1] = '\0';
 115
 116       gsasl_property_set (sctx, GSASL_AUTHID, buf);
 117       rc = GSASL_OK;
 118       break;
 119
 120     default:
 121       printf ("Unknown property!  Don't worry.\n");
 122       break;
 123     }
 124
 125   return rc;
 126 }
 127
 128 int
 129 main (int argc, char *argv[])
 130 {
 131   Gsasl *ctx = NULL;
 132   int rc;
 133
 134   /* Initialize library. */
 135   if ((rc = gsasl_init (&ctx)) != GSASL_OK)
 136     {
 137       printf ("Cannot initialize libgsasl (%d): %s", rc, gsasl_strerror (rc));
 138       return 1;
 139     }
 140
 141   /* Set the callback handler for the library. */
 142   gsasl_callback_set (ctx, callback);
 143
 144   /* Do it. */
 145   client (ctx);
 146
 147   /* Cleanup. */
 148   gsasl_done (ctx);
 149
 150   return 0;
 151 }