1 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
2 /* dbus-nonce.c Nonce handling functions used by nonce-tcp (internal to D-Bus implementation)
4 * Copyright (C) 2009 Klaralvdalens Datakonsult AB, a KDAB Group company, info@kdab.net
6 * Licensed under the Academic Free License version 2.1
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
25 // major sections of this file are modified code from libassuan, (C) FSF
26 #include "dbus-nonce.h"
27 #include "dbus-internals.h"
28 #include "dbus-protocol.h"
29 #include "dbus-sysdeps.h"
38 do_check_nonce (int fd, const DBusString *nonce, DBusError *error)
46 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
50 if ( !_dbus_string_init (&buffer)
51 || !_dbus_string_init (&p) ) {
52 dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
53 _dbus_string_free (&p);
54 _dbus_string_free (&buffer);
60 n = _dbus_read_socket (fd, &p, nleft);
61 if (n == -1 && _dbus_get_is_errno_eintr())
63 else if (n == -1 && _dbus_get_is_errno_eagain_or_ewouldblock())
64 _dbus_sleep_milliseconds (100);
67 dbus_set_error (error, DBUS_ERROR_IO_ERROR, "Could not read nonce from socket (fd=%d)", fd );
68 _dbus_string_free (&p);
69 _dbus_string_free (&buffer);
74 _dbus_string_free (&p);
75 _dbus_string_free (&buffer);
76 dbus_set_error (error, DBUS_ERROR_IO_ERROR, "Could not read nonce from socket (fd=%d)", fd );
81 _dbus_string_append_len(&buffer, _dbus_string_get_const_data (&p), n);
86 result = _dbus_string_equal_len (&buffer, nonce, 16);
88 dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED, "Nonces do not match, access denied (fd=%d)", fd );
90 _dbus_string_free (&p);
91 _dbus_string_free (&buffer);
97 * reads the nonce from the nonce file and stores it in a string
99 * @param fname the file to read the nonce from
100 * @param nonce returns the nonce. Must be an initialized string, the nonce will be appended.
101 * @param error error object to report possible errors
102 * @return FALSE iff reading the nonce fails (error is set then)
105 _dbus_read_nonce (const DBusString *fname, DBusString *nonce, DBusError* error)
111 buffer[sizeof buffer - 1] = '\0';
113 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
115 _dbus_verbose ("reading nonce from file: %s\n", _dbus_string_get_const_data (fname));
118 fp = fopen (_dbus_string_get_const_data (fname), "rb");
121 nread = fread (buffer, 1, sizeof buffer - 1, fp);
125 dbus_set_error (error, DBUS_ERROR_FILE_NOT_FOUND, "Could not read nonce from file %s", _dbus_string_get_const_data (fname));
129 if (!_dbus_string_append_len (nonce, buffer, sizeof buffer - 1 ))
131 dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
138 _dbus_accept_with_noncefile (int listen_fd, const DBusNonceFile *noncefile)
143 _dbus_assert (noncefile != NULL);
144 _dbus_string_init (&nonce);
145 //PENDING(kdab): set better errors
146 if (_dbus_read_nonce (_dbus_noncefile_get_path(noncefile), &nonce, NULL) != TRUE)
148 fd = _dbus_accept (listen_fd);
149 if (_dbus_socket_is_invalid (fd))
151 if (do_check_nonce(fd, &nonce, NULL) != TRUE) {
152 _dbus_verbose ("nonce check failed. Closing socket.\n");
153 _dbus_close_socket(fd, NULL);
161 generate_and_write_nonce (const DBusString *filename, DBusError *error)
166 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
168 _dbus_string_init (&nonce);
170 if (!_dbus_generate_random_bytes (&nonce, 16))
172 dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
173 _dbus_string_free (&nonce);
177 ret = _dbus_string_save_to_file (&nonce, filename, error);
179 _dbus_string_free (&nonce);
185 * sends the nonce over a given socket. Blocks while doing so.
187 * @param fd the file descriptor to write the nonce data to (usually a socket)
188 * @param noncefile the noncefile location to read the nonce from
189 * @param error contains error details if FALSE is returned
190 * @return TRUE iff the nonce was successfully sent. Note that this does not
191 * indicate whether the server accepted the nonce.
194 _dbus_send_nonce(int fd, const DBusString *noncefile, DBusError *error)
196 dbus_bool_t read_result;
201 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
203 if (_dbus_string_get_length (noncefile) == 0)
206 if ( !_dbus_string_init (&nonce) )
208 dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
212 read_result = _dbus_read_nonce (noncefile, &nonce, NULL);
216 dbus_set_error (error,
217 _dbus_error_from_errno (errno),
218 "Could not read nonce from file %s (%s)",
219 _dbus_string_get_const_data (noncefile), _dbus_strerror(errno));
220 _dbus_string_free (&nonce);
224 send_result = _dbus_write_socket (fd, &nonce, 0, _dbus_string_get_length (&nonce));
226 _dbus_string_free (&nonce);
228 if (send_result == -1)
230 dbus_set_error (error,
231 _dbus_error_from_errno (errno),
232 "Failed to send nonce (fd=%d): %s",
233 fd, _dbus_strerror(errno));
241 do_noncefile_create (DBusNonceFile *noncefile,
243 dbus_bool_t use_subdir)
246 DBusString randomStr;
248 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
250 _dbus_assert (noncefile);
252 if (!_dbus_string_init (&randomStr))
254 dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
258 if (!_dbus_generate_random_ascii (&randomStr, 8))
260 dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
264 if (!_dbus_string_init (&noncefile->dir)
265 || !_dbus_string_append (&noncefile->dir, _dbus_get_tmpdir()))
267 dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
272 if (!_dbus_string_append (&noncefile->dir, "/dbus_nonce-")
273 || !_dbus_string_append (&noncefile->dir, _dbus_string_get_const_data (&randomStr)) )
275 dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
278 if (!_dbus_string_init (&noncefile->path)
279 || !_dbus_string_copy (&noncefile->dir, 0, &noncefile->path, 0)
280 || !_dbus_string_append (&noncefile->dir, "/nonce"))
282 dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
285 if (!_dbus_create_directory (&noncefile->dir, error))
293 if (!_dbus_string_init (&noncefile->path)
294 || !_dbus_string_copy (&noncefile->dir, 0, &noncefile->path, 0)
295 || !_dbus_string_append (&noncefile->path, "/dbus_nonce-")
296 || !_dbus_string_append (&noncefile->path, _dbus_string_get_const_data (&randomStr)))
298 dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
304 if (!generate_and_write_nonce (&noncefile->path, error))
307 _dbus_delete_directory (&noncefile->dir, NULL); //we ignore possible errors deleting the dir and return the write error instead
311 _dbus_string_free (&randomStr);
316 _dbus_delete_directory (&noncefile->dir, NULL);
317 _dbus_string_free (&noncefile->dir);
318 _dbus_string_free (&noncefile->path);
319 _dbus_string_free (&randomStr);
325 * creates a nonce file in a user-readable location and writes a generated nonce to it
327 * @param noncefile returns the nonce file location
328 * @param error error details if creating the nonce file fails
329 * @return TRUE iff the nonce file was successfully created
332 _dbus_noncefile_create (DBusNonceFile *noncefile,
335 return do_noncefile_create (noncefile, error, /*use_subdir=*/FALSE);
339 * deletes the noncefile and frees the DBusNonceFile object.
341 * @param noncefile the nonce file to delete. Contents will be freed.
342 * @param error error details if the nonce file could not be deleted
346 _dbus_noncefile_delete (DBusNonceFile *noncefile,
349 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
351 _dbus_delete_file (&noncefile->path, error);
352 _dbus_string_free (&noncefile->dir);
353 _dbus_string_free (&noncefile->path);
359 * creates a nonce file in a user-readable location and writes a generated nonce to it.
360 * Initializes the noncefile object.
362 * @param noncefile returns the nonce file location
363 * @param error error details if creating the nonce file fails
364 * @return TRUE iff the nonce file was successfully created
367 _dbus_noncefile_create (DBusNonceFile *noncefile,
370 return do_noncefile_create (noncefile, error, /*use_subdir=*/TRUE);
374 * deletes the noncefile and frees the DBusNonceFile object.
376 * @param noncefile the nonce file to delete. Contents will be freed.
377 * @param error error details if the nonce file could not be deleted
381 _dbus_noncefile_delete (DBusNonceFile *noncefile,
384 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
386 _dbus_delete_directory (&noncefile->dir, error);
387 _dbus_string_free (&noncefile->dir);
388 _dbus_string_free (&noncefile->path);
395 * returns the absolute file path of the nonce file
397 * @param noncefile an initialized noncefile object
398 * @return the absolute path of the nonce file
401 _dbus_noncefile_get_path (const DBusNonceFile *noncefile)
403 _dbus_assert (noncefile);
404 return &noncefile->path;
408 * reads data from a file descriptor and checks if the received data matches
409 * the data in the given noncefile.
411 * @param fd the file descriptor to read the nonce from
412 * @param noncefile the nonce file to check the received data against
413 * @param error error details on fail
414 * @return TRUE iff a nonce could be successfully read from the file descriptor
415 * and matches the nonce from the given nonce file
418 _dbus_noncefile_check_nonce (int fd,
419 const DBusNonceFile *noncefile,
422 return do_check_nonce (fd, _dbus_noncefile_get_path (noncefile), error);
426 /** @} end of nonce */