examples/client-mech.c

   1 /* client-mech.c --- Example SASL client, with a choice of mechanism to use.
   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 const char *
  70 client_mechanism (Gsasl * ctx)
  71 {
  72   static char mech[GSASL_MAX_MECHANISM_SIZE + 1] = "";
  73   char mechlist[BUFSIZ] = "";
  74   const char *suggestion;
  75
  76   printf ("Enter list of mechanism that server support, separate by SPC:\n");
  77   fgets (mechlist, sizeof (mechlist) - 1, stdin);
  78
  79   suggestion = gsasl_client_suggest_mechanism (ctx, mechlist);
  80   if (suggestion)
  81     printf ("Library suggest use of `%s'.\n", suggestion);
  82
  83   printf ("Enter mechanism to use:\n");
  84   fgets (mech, sizeof (mech) - 1, stdin);
  85   mech[strlen (mech) - 1] = '\0';
  86
  87   return mech;
  88 }
  89
  90 static void
  91 client (Gsasl * ctx)
  92 {
  93   Gsasl_session *session;
  94   const char *mech;
  95   int rc;
  96
  97   /* Find out which mechanism to use. */
  98   mech = client_mechanism (ctx);
  99
 100   /* Create new authentication session. */
 101   if ((rc = gsasl_client_start (ctx, mech, &session)) != GSASL_OK)
 102     {
 103       printf ("Cannot initialize client (%d): %s\n", rc, gsasl_strerror (rc));
 104       return;
 105     }
 106
 107   /* Set username and password in session handle.  This info will be
 108      lost when this session is deallocated below.  */
 109   gsasl_property_set (session, GSASL_AUTHID, "jas");
 110   gsasl_property_set (session, GSASL_PASSWORD, "secret");
 111
 112   /* Do it. */
 113   client_authenticate (ctx, session);
 114
 115   /* Cleanup. */
 116   gsasl_finish (session);
 117 }
 118
 119 int
 120 main (int argc, char *argv[])
 121 {
 122   Gsasl *ctx = NULL;
 123   int rc;
 124
 125   /* Initialize library. */
 126   if ((rc = gsasl_init (&ctx)) != GSASL_OK)
 127     {
 128       printf ("Cannot initialize libgsasl (%d): %s", rc, gsasl_strerror (rc));
 129       return 1;
 130     }
 131
 132   /* Do it. */
 133   client (ctx);
 134
 135   /* Cleanup. */
 136   gsasl_done (ctx);
 137
 138   return 0;
 139 }