lib/src/callback.c

   1 /* callback.c --- Callback handling.
   2  * Copyright (C) 2002, 2003, 2004, 2005, 2006  Simon Josefsson
   3  *
   4  * This file is part of GNU SASL Library.
   5  *
   6  * GNU SASL Library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public License
   8  * as published by the Free Software Foundation; either version 2.1 of
   9  * the License, or (at your option) any later version.
  10  *
  11  * GNU SASL Library 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 GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License License along with GNU SASL Library; if not, write to the
  18  * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  19  * Boston, MA 02110-1301, USA.
  20  *
  21  */
  22
  23 #include "internal.h"
  24
  25 /**
  26  * gsasl_callback_set:
  27  * @ctx: handle received from gsasl_init().
  28  * @cb: pointer to function implemented by application.
  29  *
  30  * Store the pointer to the application provided callback in the
  31  * library handle.  The callback will be used, via gsasl_callback(),
  32  * by mechanisms to discover various parameters (such as username and
  33  * passwords).  The callback function will be called with a
  34  * Gsasl_property value indicating the requested behaviour.  For
  35  * example, for GSASL_ANONYMOUS_TOKEN, the function is expected to
  36  * invoke gsasl_property_set(CTX, GSASL_ANONYMOUS_TOKEN, "token")
  37  * where "token" is the anonymous token the application wishes the
  38  * SASL mechanism to use.  See the manual for the meaning of all
  39  * parameters.
  40  *
  41  * Since: 0.2.0
  42  **/
  43 void
  44 gsasl_callback_set (Gsasl * ctx, Gsasl_callback_function cb)
  45 {
  46   ctx->cb = cb;
  47 }
  48
  49 /**
  50  * gsasl_callback:
  51  * @ctx: handle received from gsasl_init(), may be NULL to derive it
  52  *   from @sctx.
  53  * @sctx: session handle.
  54  * @prop: enumerated value of Gsasl_property type.
  55  *
  56  * Invoke the application callback.  The @prop value indicate what the
  57  * callback is expected to do.  For example, for
  58  * GSASL_ANONYMOUS_TOKEN, the function is expected to invoke
  59  * gsasl_property_set(SCTX, GSASL_ANONYMOUS_TOKEN, "token") where
  60  * "token" is the anonymous token the application wishes the SASL
  61  * mechanism to use.  See the manual for the meaning of all
  62  * parameters.
  63  *
  64  * Note that if no callback has been set by the application, but the
  65  * obsolete callback interface has been used, this function will
  66  * translate the old callback interface into the new.  This interface
  67  * should be sufficient to invoke all callbacks, both new and old.
  68  *
  69  * Return value: Returns whatever the application callback return, or
  70  *   GSASL_NO_CALLBACK if no application was known.
  71  *
  72  * Since: 0.2.0
  73  **/
  74 int
  75 gsasl_callback (Gsasl * ctx, Gsasl_session * sctx, Gsasl_property prop)
  76 {
  77   if (ctx == NULL && sctx == NULL)
  78     return GSASL_NO_CALLBACK;
  79
  80   if (ctx == NULL)
  81     ctx = sctx->ctx;
  82
  83   if (ctx->cb)
  84     return ctx->cb (ctx, sctx, prop);
  85
  86 #ifndef GSASL_NO_OBSOLETE
  87   {
  88     /* Call obsolete callbacks.  Remove this when the obsolete
  89      * callbacks are no longer supported.  */
  90     Gsasl_server_callback_anonymous cb_anonymous;
  91     Gsasl_server_callback_external cb_external;
  92     Gsasl_server_callback_securid cb_securid;
  93     Gsasl_server_callback_gssapi cb_gssapi;
  94     Gsasl_server_callback_validate cb_validate;
  95     Gsasl_server_callback_retrieve cb_retrieve;
  96     char buf[BUFSIZ];
  97     size_t buflen = BUFSIZ - 1;
  98     int res;
  99
 100     switch (prop)
 101       {
 102       case GSASL_VALIDATE_ANONYMOUS:
 103         if (!sctx->anonymous_token)
 104           break;
 105         cb_anonymous = gsasl_server_callback_anonymous_get (sctx->ctx);
 106         if (!cb_anonymous)
 107           break;
 108         res = cb_anonymous (sctx, sctx->anonymous_token);
 109         return res;
 110         break;
 111
 112       case GSASL_VALIDATE_EXTERNAL:
 113         cb_external = gsasl_server_callback_external_get (sctx->ctx);
 114         if (!cb_external)
 115           break;
 116         res = cb_external (sctx);
 117         return res;
 118         break;
 119
 120       case GSASL_VALIDATE_SECURID:
 121         cb_securid = gsasl_server_callback_securid_get (sctx->ctx);
 122         if (!cb_securid)
 123           break;
 124         res = cb_securid (sctx, sctx->authid, sctx->authzid, sctx->passcode,
 125                           sctx->pin, buf, &buflen);
 126         if (buflen > 0 && buflen < BUFSIZ - 1)
 127           {
 128             buf[buflen] = '\0';
 129             gsasl_property_set (sctx, GSASL_SUGGESTED_PIN, buf);
 130           }
 131         return res;
 132         break;
 133
 134       case GSASL_VALIDATE_GSSAPI:
 135         cb_gssapi = gsasl_server_callback_gssapi_get (sctx->ctx);
 136         if (!cb_gssapi)
 137           break;
 138         res = cb_gssapi (sctx, sctx->gssapi_display_name, sctx->authzid);
 139         return res;
 140         break;
 141
 142       case GSASL_VALIDATE_SIMPLE:
 143         cb_validate = gsasl_server_callback_validate_get (sctx->ctx);
 144         if (!cb_validate)
 145           break;
 146         res = cb_validate (sctx, sctx->authzid, sctx->authid, sctx->password);
 147         return res;
 148         break;
 149
 150       case GSASL_PASSWORD:
 151         cb_retrieve = gsasl_server_callback_retrieve_get (sctx->ctx);
 152         if (!cb_retrieve)
 153           break;
 154         res = cb_retrieve (sctx, sctx->authid, sctx->authzid,
 155                            sctx->hostname, buf, &buflen);
 156         if (res == GSASL_OK)
 157           gsasl_property_set_raw (sctx, GSASL_PASSWORD, buf, buflen);
 158         /* FIXME else if (res == GSASL_TOO_SMALL_BUFFER)... */
 159         return res;
 160         break;
 161
 162       default:
 163         break;
 164       }
 165   }
 166 #endif
 167
 168   return GSASL_NO_CALLBACK;
 169 }
 170
 171 /**
 172  * gsasl_callback_hook_set:
 173  * @ctx: libgsasl handle.
 174  * @hook: opaque pointer to application specific data.
 175  *
 176  * Store application specific data in the libgsasl handle.
 177  *
 178  * The application data can be later (for instance, inside a callback)
 179  * be retrieved by calling gsasl_callback_hook_get().  This is
 180  * normally used by the application to maintain a global state between
 181  * the main program and callbacks.
 182  *
 183  * Since: 0.2.0
 184  **/
 185 void
 186 gsasl_callback_hook_set (Gsasl * ctx, void *hook)
 187 {
 188   ctx->application_hook = hook;
 189 }
 190
 191 /**
 192  * gsasl_callback_hook_get:
 193  * @ctx: libgsasl handle.
 194  *
 195  * Retrieve application specific data from libgsasl handle.
 196  *
 197  * The application data is set using gsasl_callback_hook_set().  This
 198  * is normally used by the application to maintain a global state
 199  * between the main program and callbacks.
 200  *
 201  * Return value: Returns the application specific data, or NULL.
 202  *
 203  * Since: 0.2.0
 204  **/
 205 void *
 206 gsasl_callback_hook_get (Gsasl * ctx)
 207 {
 208   return ctx->application_hook;
 209 }
 210
 211 /**
 212  * gsasl_session_hook_set:
 213  * @sctx: libgsasl session handle.
 214  * @hook: opaque pointer to application specific data.
 215  *
 216  * Store application specific data in the libgsasl session handle.
 217  *
 218  * The application data can be later (for instance, inside a callback)
 219  * be retrieved by calling gsasl_session_hook_get().  This is normally
 220  * used by the application to maintain a per-session state between the
 221  * main program and callbacks.
 222  *
 223  * Since: 0.2.14
 224  **/
 225 void
 226 gsasl_session_hook_set (Gsasl_session * sctx, void *hook)
 227 {
 228   sctx->application_hook = hook;
 229 }
 230
 231 /**
 232  * gsasl_session_hook_get:
 233  * @sctx: libgsasl session handle.
 234  *
 235  * Retrieve application specific data from libgsasl session handle.
 236  *
 237  * The application data is set using gsasl_callback_hook_set().  This
 238  * is normally used by the application to maintain a per-session state
 239  * between the main program and callbacks.
 240  *
 241  * Return value: Returns the application specific data, or NULL.
 242  *
 243  * Since: 0.2.14
 244  **/
 245 void *
 246 gsasl_session_hook_get (Gsasl_session * sctx)
 247 {
 248   return sctx->application_hook;
 249 }