examples/client-callback.c

   1 /* client-callback.c --- Example SASL client, with callback for user info.
   2  * Copyright (C) 2004, 2005, 2007  Simon Josefsson
   3  *
   4  * This file is part of GNU SASL.
   5  *
   6  * This program 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 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
  18  *
  19  */
  20
  21 #include <stdarg.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25
  26 #include <gsasl.h>
  27
  28 static void
  29 client_authenticate (Gsasl * ctx, Gsasl_session * session)
  30 {
  31   char buf[BUFSIZ] = "";
  32   char *p;
  33   int rc;
  34
  35   /* This loop mimic a protocol where the server get to send data first. */
  36
  37   do
  38     {
  39       printf ("Input base64 encoded data from server:\n");
  40       fgets (buf, sizeof (buf) - 1, stdin);
  41       if (buf[strlen (buf) - 1] == '\n')
  42         buf[strlen (buf) - 1] = '\0';
  43
  44       rc = gsasl_step64 (session, buf, &p);
  45
  46       if (rc == GSASL_NEEDS_MORE || rc == GSASL_OK)
  47         {
  48           printf ("Output:\n%s\n", p);
  49           free (p);
  50         }
  51     }
  52   while (rc == GSASL_NEEDS_MORE);
  53
  54   printf ("\n");
  55
  56   if (rc != GSASL_OK)
  57     {
  58       printf ("Authentication error (%d): %s\n", rc, gsasl_strerror (rc));
  59       return;
  60     }
  61
  62   /* The client is done.  Here you would typically check if the server
  63      let the client in.  If not, you could try again. */
  64
  65   printf ("If server accepted us, we're done.\n");
  66 }
  67
  68 static void
  69 client (Gsasl * ctx)
  70 {
  71   Gsasl_session *session;
  72   const char *mech = "SECURID";
  73   int rc;
  74
  75   /* Create new authentication session. */
  76   if ((rc = gsasl_client_start (ctx, mech, &session)) != GSASL_OK)
  77     {
  78       printf ("Cannot initialize client (%d): %s\n", rc, gsasl_strerror (rc));
  79       return;
  80     }
  81
  82   /* Do it. */
  83   client_authenticate (ctx, session);
  84
  85   /* Cleanup. */
  86   gsasl_finish (session);
  87 }
  88
  89 static int
  90 callback (Gsasl * ctx, Gsasl_session * sctx, Gsasl_property prop)
  91 {
  92   char buf[BUFSIZ] = "";
  93   int rc = GSASL_NO_CALLBACK;
  94
  95   /* Get user info from user. */
  96
  97   printf ("Callback invoked, for property %d.\n", prop);
  98
  99   switch (prop)
 100     {
 101     case GSASL_PASSCODE:
 102       printf ("Enter passcode:\n");
 103       fgets (buf, sizeof (buf) - 1, stdin);
 104       buf[strlen (buf) - 1] = '\0';
 105
 106       gsasl_property_set (sctx, GSASL_PASSCODE, buf);
 107       rc = GSASL_OK;
 108       break;
 109
 110     case GSASL_AUTHID:
 111       printf ("Enter username:\n");
 112       fgets (buf, sizeof (buf) - 1, stdin);
 113       buf[strlen (buf) - 1] = '\0';
 114
 115       gsasl_property_set (sctx, GSASL_AUTHID, buf);
 116       rc = GSASL_OK;
 117       break;
 118
 119     default:
 120       printf ("Unknown property!  Don't worry.\n");
 121       break;
 122     }
 123
 124   return rc;
 125 }
 126
 127 int
 128 main (int argc, char *argv[])
 129 {
 130   Gsasl *ctx = NULL;
 131   int rc;
 132
 133   /* Initialize library. */
 134   if ((rc = gsasl_init (&ctx)) != GSASL_OK)
 135     {
 136       printf ("Cannot initialize libgsasl (%d): %s", rc, gsasl_strerror (rc));
 137       return 1;
 138     }
 139
 140   /* Set the callback handler for the library. */
 141   gsasl_callback_set (ctx, callback);
 142
 143   /* Do it. */
 144   client (ctx);
 145
 146   /* Cleanup. */
 147   gsasl_done (ctx);
 148
 149   return 0;
 150 }