--- /dev/null
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
+/* dbus-keyring.c Store secret cookies in your homedir
+ *
+ * Copyright (C) 2003, 2004 Red Hat Inc.
+ *
+ * Licensed under the Academic Free License version 2.1
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#include "dbus-keyring.h"
+#include "dbus-protocol.h"
+#include <dbus/dbus-string.h>
+#include <dbus/dbus-list.h>
+#include <dbus/dbus-sysdeps.h>
+
+/**
+ * @defgroup DBusKeyring keyring class
+ * @ingroup DBusInternals
+ * @brief DBusKeyring data structure
+ *
+ * Types and functions related to DBusKeyring. DBusKeyring is intended
+ * to manage cookies used to authenticate clients to servers. This is
+ * essentially the "verify that client can read the user's homedir"
+ * authentication mechanism. Both client and server must have access
+ * to the homedir.
+ *
+ * The secret keys are not kept in locked memory, and are written to a
+ * file in the user's homedir. However they are transient (only used
+ * by a single server instance for a fixed period of time, then
+ * discarded). Also, the keys are not sent over the wire.
+ *
+ * @todo there's a memory leak on some codepath in here, I saw it once
+ * when running make check - probably some specific initial cookies
+ * present in the cookie file, then depending on what we do with them.
+ */
+
+/**
+ * @defgroup DBusKeyringInternals DBusKeyring implementation details
+ * @ingroup DBusInternals
+ * @brief DBusKeyring implementation details
+ *
+ * The guts of DBusKeyring.
+ *
+ * @{
+ */
+
+/** The maximum age of a key before we create a new key to use in
+ * challenges. This isn't super-reliably enforced, since system
+ * clocks can change or be wrong, but we make a best effort to only
+ * use keys for a short time.
+ */
+#define NEW_KEY_TIMEOUT_SECONDS (60*5)
+/**
+ * The time after which we drop a key from the secrets file.
+ * The EXPIRE_KEYS_TIMEOUT_SECONDS - NEW_KEY_TIMEOUT_SECONDS is the minimum
+ * time window a client has to complete authentication.
+ */
+#define EXPIRE_KEYS_TIMEOUT_SECONDS (NEW_KEY_TIMEOUT_SECONDS + (60*2))
+/**
+ * The maximum amount of time a key can be in the future.
+ */
+#define MAX_TIME_TRAVEL_SECONDS (60*5)
+
+/**
+ * Maximum number of keys in the keyring before
+ * we just ignore the rest
+ */
+#ifdef DBUS_BUILD_TESTS
+#define MAX_KEYS_IN_FILE 10
+#else
+#define MAX_KEYS_IN_FILE 256
+#endif
+
+/**
+ * A single key from the cookie file
+ */
+typedef struct
+{
+ dbus_int32_t id; /**< identifier used to refer to the key */
+
+ long creation_time; /**< when the key was generated,
+ * as unix timestamp. signed long
+ * matches struct timeval.
+ */
+
+ DBusString secret; /**< the actual key */
+
+} DBusKey;
+
+/**
+ * @brief Internals of DBusKeyring.
+ *
+ * DBusKeyring internals. DBusKeyring is an opaque object, it must be
+ * used via accessor functions.
+ */
+struct DBusKeyring
+{
+ int refcount; /**< Reference count */
+ DBusString directory; /**< Directory the below two items are inside */
+ DBusString filename; /**< Keyring filename */
+ DBusString filename_lock; /**< Name of lockfile */
+ DBusKey *keys; /**< Keys loaded from the file */
+ int n_keys; /**< Number of keys */
+ DBusCredentials *credentials; /**< Credentials containing user the keyring is for */
+};
+
+static DBusKeyring*
+_dbus_keyring_new (void)
+{
+ DBusKeyring *keyring;
+
+ keyring = dbus_new0 (DBusKeyring, 1);
+ if (keyring == NULL)
+ goto out_0;
+
+ if (!_dbus_string_init (&keyring->directory))
+ goto out_1;
+
+ if (!_dbus_string_init (&keyring->filename))
+ goto out_2;
+
+ if (!_dbus_string_init (&keyring->filename_lock))
+ goto out_3;
+
+ keyring->refcount = 1;
+ keyring->keys = NULL;
+ keyring->n_keys = 0;
+
+ return keyring;
+
+ /* out_4: */
+ _dbus_string_free (&keyring->filename_lock);
+ out_3:
+ _dbus_string_free (&keyring->filename);
+ out_2:
+ _dbus_string_free (&keyring->directory);
+ out_1:
+ dbus_free (keyring);
+ out_0:
+ return NULL;
+}
+
+static void
+free_keys (DBusKey *keys,
+ int n_keys)
+{
+ int i;
+
+ /* should be safe for args NULL, 0 */
+
+ i = 0;
+ while (i < n_keys)
+ {
+ _dbus_string_free (&keys[i].secret);
+ ++i;
+ }
+
+ dbus_free (keys);
+}
+
+/* Our locking scheme is highly unreliable. However, there is
+ * unfortunately no reliable locking scheme in user home directories;
+ * between bugs in Linux NFS, people using Tru64 or other total crap
+ * NFS, AFS, random-file-system-of-the-week, and so forth, fcntl() in
+ * homedirs simply generates tons of bug reports. This has been
+ * learned through hard experience with GConf, unfortunately.
+ *
+ * This bad hack might work better for the kind of lock we have here,
+ * which we don't expect to hold for any length of time. Crashing
+ * while we hold it should be unlikely, and timing out such that we
+ * delete a stale lock should also be unlikely except when the
+ * filesystem is running really slowly. Stuff might break in corner
+ * cases but as long as it's not a security-level breakage it should
+ * be OK.
+ */
+
+/** Maximum number of timeouts waiting for lock before we decide it's stale */
+#define MAX_LOCK_TIMEOUTS 32
+/** Length of each timeout while waiting for a lock */
+#define LOCK_TIMEOUT_MILLISECONDS 250
+
+static dbus_bool_t
+_dbus_keyring_lock (DBusKeyring *keyring)
+{
+ int n_timeouts;
+
+ n_timeouts = 0;
+ while (n_timeouts < MAX_LOCK_TIMEOUTS)
+ {
+ DBusError error = DBUS_ERROR_INIT;
+
+ if (_dbus_create_file_exclusively (&keyring->filename_lock,
+ &error))
+ break;
+
+ _dbus_verbose ("Did not get lock file, sleeping %d milliseconds (%s)\n",
+ LOCK_TIMEOUT_MILLISECONDS, error.message);
+ dbus_error_free (&error);
+
+ _dbus_sleep_milliseconds (LOCK_TIMEOUT_MILLISECONDS);
+
+ ++n_timeouts;
+ }
+
+ if (n_timeouts == MAX_LOCK_TIMEOUTS)
+ {
+ DBusError error = DBUS_ERROR_INIT;
+
+ _dbus_verbose ("Lock file timed out %d times, assuming stale\n",
+ n_timeouts);
+
+ if (!_dbus_delete_file (&keyring->filename_lock, &error))
+ {
+ _dbus_verbose ("Couldn't delete old lock file: %s\n",
+ error.message);
+ dbus_error_free (&error);
+ return FALSE;
+ }
+
+ if (!_dbus_create_file_exclusively (&keyring->filename_lock,
+ &error))
+ {
+ _dbus_verbose ("Couldn't create lock file after deleting stale one: %s\n",
+ error.message);
+ dbus_error_free (&error);
+ return FALSE;
+ }
+ }
+
+ return TRUE;
+}
+
+static void
+_dbus_keyring_unlock (DBusKeyring *keyring)
+{
+ DBusError error = DBUS_ERROR_INIT;
+
+ if (!_dbus_delete_file (&keyring->filename_lock, &error))
+ {
+ _dbus_warn ("Failed to delete lock file: %s\n",
+ error.message);
+ dbus_error_free (&error);
+ }
+}
+
+static DBusKey*
+find_key_by_id (DBusKey *keys,
+ int n_keys,
+ int id)
+{
+ int i;
+
+ i = 0;
+ while (i < n_keys)
+ {
+ if (keys[i].id == id)
+ return &keys[i];
+
+ ++i;
+ }
+
+ return NULL;
+}
+
+static dbus_bool_t
+add_new_key (DBusKey **keys_p,
+ int *n_keys_p,
+ DBusError *error)
+{
+ DBusKey *new;
+ DBusString bytes;
+ int id;
+ long timestamp;
+ const unsigned char *s;
+ dbus_bool_t retval;
+ DBusKey *keys;
+ int n_keys;
+
+ _DBUS_ASSERT_ERROR_IS_CLEAR (error);
+
+ if (!_dbus_string_init (&bytes))
+ {
+ dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
+ return FALSE;
+ }
+
+ keys = *keys_p;
+ n_keys = *n_keys_p;
+ retval = FALSE;
+
+ /* Generate an integer ID and then the actual key. */
+ retry:
+
+ if (!_dbus_generate_random_bytes (&bytes, 4))
+ {
+ dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
+ goto out;
+ }
+
+ s = (const unsigned char*) _dbus_string_get_const_data (&bytes);
+
+ id = s[0] | (s[1] << 8) | (s[2] << 16) | (s[3] << 24);
+ if (id < 0)
+ id = - id;
+ _dbus_assert (id >= 0);
+
+ if (find_key_by_id (keys, n_keys, id) != NULL)
+ {
+ _dbus_string_set_length (&bytes, 0);
+ _dbus_verbose ("Key ID %d already existed, trying another one\n",
+ id);
+ goto retry;
+ }
+
+ _dbus_verbose ("Creating key with ID %d\n", id);
+
+#define KEY_LENGTH_BYTES 24
+ _dbus_string_set_length (&bytes, 0);
+ if (!_dbus_generate_random_bytes (&bytes, KEY_LENGTH_BYTES))
+ {
+ dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
+ goto out;
+ }
+
+ new = dbus_realloc (keys, sizeof (DBusKey) * (n_keys + 1));
+ if (new == NULL)
+ {
+ dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
+ goto out;
+ }
+
+ keys = new;
+ *keys_p = keys; /* otherwise *keys_p ends up invalid */
+ n_keys += 1;
+
+ if (!_dbus_string_init (&keys[n_keys-1].secret))
+ {
+ n_keys -= 1; /* we don't want to free the one we didn't init */
+ dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
+ goto out;
+ }
+
+ _dbus_get_current_time (×tamp, NULL);
+
+ keys[n_keys-1].id = id;
+ keys[n_keys-1].creation_time = timestamp;
+ if (!_dbus_string_move (&bytes, 0,
+ &keys[n_keys-1].secret,
+ 0))
+ {
+ dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
+ _dbus_string_free (&keys[n_keys-1].secret);
+ n_keys -= 1;
+ goto out;
+ }
+
+ retval = TRUE;
+
+ out:
+ *n_keys_p = n_keys;
+
+ _dbus_string_free (&bytes);
+ return retval;
+}
+
+/**
+ * Reloads the keyring file, optionally adds one new key to the file,
+ * removes all expired keys from the file iff a key was added, then
+ * resaves the file. Stores the keys from the file in keyring->keys.
+ * Note that the file is only resaved (written to) if a key is added,
+ * this means that only servers ever write to the file and need to
+ * lock it, which avoids a lot of lock contention at login time and
+ * such.
+ *
+ * @param keyring the keyring
+ * @param add_new #TRUE to add a new key to the file, expire keys, and resave
+ * @param error return location for errors
+ * @returns #FALSE on failure
+ */
+static dbus_bool_t
+_dbus_keyring_reload (DBusKeyring *keyring,
+ dbus_bool_t add_new,
+ DBusError *error)
+{
+ DBusString contents;
+ DBusString line;
+ dbus_bool_t retval;
+ dbus_bool_t have_lock;
+ DBusKey *keys;
+ int n_keys;
+ int i;
+ long now;
+ DBusError tmp_error;
+
+ _DBUS_ASSERT_ERROR_IS_CLEAR (error);
+
+ if (!_dbus_check_dir_is_private_to_user (&keyring->directory, error))
+ return FALSE;
+
+ if (!_dbus_string_init (&contents))
+ {
+ dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
+ return FALSE;
+ }
+
+ if (!_dbus_string_init (&line))
+ {
+ dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
+ _dbus_string_free (&contents);
+ return FALSE;
+ }
+
+ keys = NULL;
+ n_keys = 0;
+ retval = FALSE;
+ have_lock = FALSE;
+
+ _dbus_get_current_time (&now, NULL);
+
+ if (add_new)
+ {
+ if (!_dbus_keyring_lock (keyring))
+ {
+ dbus_set_error (error, DBUS_ERROR_FAILED,
+ "Could not lock keyring file to add to it");
+ goto out;
+ }
+
+ have_lock = TRUE;
+ }
+
+ dbus_error_init (&tmp_error);
+ if (!_dbus_file_get_contents (&contents,
+ &keyring->filename,
+ &tmp_error))
+ {
+ _dbus_verbose ("Failed to load keyring file: %s\n",
+ tmp_error.message);
+ /* continue with empty keyring file, so we recreate it */
+ dbus_error_free (&tmp_error);
+ }
+
+ if (!_dbus_string_validate_ascii (&contents, 0,
+ _dbus_string_get_length (&contents)))
+ {
+ _dbus_warn ("Secret keyring file contains non-ASCII! Ignoring existing contents\n");
+ _dbus_string_set_length (&contents, 0);
+ }
+
+ /* FIXME this is badly inefficient for large keyring files
+ * (not that large keyring files exist outside of test suites)
+ */
+ while (_dbus_string_pop_line (&contents, &line))
+ {
+ int next;
+ long val;
+ int id;
+ long timestamp;
+ int len;
+ int end;
+ DBusKey *new;
+
+ /* Don't load more than the max. */
+ if (n_keys >= (add_new ? MAX_KEYS_IN_FILE - 1 : MAX_KEYS_IN_FILE))
+ break;
+
+ next = 0;
+ if (!_dbus_string_parse_int (&line, 0, &val, &next))
+ {
+ _dbus_verbose ("could not parse secret key ID at start of line\n");
+ continue;
+ }
+
+ if (val > _DBUS_INT32_MAX || val < 0)
+ {
+ _dbus_verbose ("invalid secret key ID at start of line\n");
+ continue;
+ }
+
+ id = val;
+
+ _dbus_string_skip_blank (&line, next, &next);
+
+ if (!_dbus_string_parse_int (&line, next, ×tamp, &next))
+ {
+ _dbus_verbose ("could not parse secret key timestamp\n");
+ continue;
+ }
+
+ if (timestamp < 0 ||
+ (now + MAX_TIME_TRAVEL_SECONDS) < timestamp ||
+ (now - EXPIRE_KEYS_TIMEOUT_SECONDS) > timestamp)
+ {
+ _dbus_verbose ("dropping/ignoring %ld-seconds old key with timestamp %ld as current time is %ld\n",
+ now - timestamp, timestamp, now);
+ continue;
+ }
+
+ _dbus_string_skip_blank (&line, next, &next);
+
+ len = _dbus_string_get_length (&line);
+
+ if ((len - next) == 0)
+ {
+ _dbus_verbose ("no secret key after ID and timestamp\n");
+ continue;
+ }
+
+ /* We have all three parts */
+ new = dbus_realloc (keys, sizeof (DBusKey) * (n_keys + 1));
+ if (new == NULL)
+ {
+ dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
+ goto out;
+ }
+
+ keys = new;
+ n_keys += 1;
+
+ if (!_dbus_string_init (&keys[n_keys-1].secret))
+ {
+ n_keys -= 1; /* we don't want to free the one we didn't init */
+ dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
+ goto out;
+ }
+
+ keys[n_keys-1].id = id;
+ keys[n_keys-1].creation_time = timestamp;
+ if (!_dbus_string_hex_decode (&line, next, &end,
+ &keys[n_keys-1].secret, 0))
+ {
+ dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
+ goto out;
+ }
+
+ if (_dbus_string_get_length (&line) != end)
+ {
+ _dbus_verbose ("invalid hex encoding in keyring file\n");
+ _dbus_string_free (&keys[n_keys - 1].secret);
+ n_keys -= 1;
+ continue;
+ }
+ }
+
+ _dbus_verbose ("Successfully loaded %d existing keys\n",
+ n_keys);
+
+ if (add_new)
+ {
+ if (!add_new_key (&keys, &n_keys, error))
+ {
+ _dbus_verbose ("Failed to generate new key: %s\n",
+ error ? error->message : "(unknown)");
+ goto out;
+ }
+
+ _dbus_string_set_length (&contents, 0);
+
+ i = 0;
+ while (i < n_keys)
+ {
+ if (!_dbus_string_append_int (&contents,
+ keys[i].id))
+ goto nomem;
+
+ if (!_dbus_string_append_byte (&contents, ' '))
+ goto nomem;
+
+ if (!_dbus_string_append_int (&contents,
+ keys[i].creation_time))
+ goto nomem;
+
+ if (!_dbus_string_append_byte (&contents, ' '))
+ goto nomem;
+
+ if (!_dbus_string_hex_encode (&keys[i].secret, 0,
+ &contents,
+ _dbus_string_get_length (&contents)))
+ goto nomem;
+
+ if (!_dbus_string_append_byte (&contents, '\n'))
+ goto nomem;
+
+ ++i;
+ continue;
+
+ nomem:
+ dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
+ goto out;
+ }
+
+ if (!_dbus_string_save_to_file (&contents, &keyring->filename,
+ error))
+ goto out;
+ }
+
+ if (keyring->keys)
+ free_keys (keyring->keys, keyring->n_keys);
+ keyring->keys = keys;
+ keyring->n_keys = n_keys;
+ keys = NULL;
+ n_keys = 0;
+
+ retval = TRUE;
+
+ out:
+ if (have_lock)
+ _dbus_keyring_unlock (keyring);
+
+ if (! ((retval == TRUE && (error == NULL || error->name == NULL)) ||
+ (retval == FALSE && (error == NULL || error->name != NULL))))
+ {
+ if (error && error->name)
+ _dbus_verbose ("error is %s: %s\n", error->name, error->message);
+ _dbus_warn ("returning %d but error pointer %p name %s\n",
+ retval, error, error->name ? error->name : "(none)");
+ _dbus_assert_not_reached ("didn't handle errors properly");
+ }
+
+ if (keys != NULL)
+ {
+ i = 0;
+ while (i < n_keys)
+ {
+ _dbus_string_zero (&keys[i].secret);
+ _dbus_string_free (&keys[i].secret);
+ ++i;
+ }
+
+ dbus_free (keys);
+ }
+
+ _dbus_string_free (&contents);
+ _dbus_string_free (&line);
+
+ return retval;
+}
+
+/** @} */ /* end of internals */
+
+/**
+ * @addtogroup DBusKeyring
+ *
+ * @{
+ */
+
+/**
+ * Increments reference count of the keyring
+ *
+ * @param keyring the keyring
+ * @returns the keyring
+ */
+DBusKeyring *
+_dbus_keyring_ref (DBusKeyring *keyring)
+{
+ keyring->refcount += 1;
+
+ return keyring;
+}
+
+/**
+ * Decrements refcount and finalizes if it reaches
+ * zero.
+ *
+ * @param keyring the keyring
+ */
+void
+_dbus_keyring_unref (DBusKeyring *keyring)
+{
+ keyring->refcount -= 1;
+
+ if (keyring->refcount == 0)
+ {
+ if (keyring->credentials)
+ _dbus_credentials_unref (keyring->credentials);
+
+ _dbus_string_free (&keyring->filename);
+ _dbus_string_free (&keyring->filename_lock);
+ _dbus_string_free (&keyring->directory);
+ free_keys (keyring->keys, keyring->n_keys);
+ dbus_free (keyring);
+ }
+}
+
+/**
+ * Creates a new keyring that lives in the ~/.dbus-keyrings directory
+ * of the given user credentials. If the credentials are #NULL or
+ * empty, uses those of the current process.
+ *
+ * @param username username to get keyring for, or #NULL
+ * @param context which keyring to get
+ * @param error return location for errors
+ * @returns the keyring or #NULL on error
+ */
+DBusKeyring*
+_dbus_keyring_new_for_credentials (DBusCredentials *credentials,
+ const DBusString *context,
+ DBusError *error)
+{
+ DBusString ringdir;
+ DBusKeyring *keyring;
+ dbus_bool_t error_set;
+ DBusError tmp_error;
+ DBusCredentials *our_credentials;
+
+ _DBUS_ASSERT_ERROR_IS_CLEAR (error);
+
+ keyring = NULL;
+ error_set = FALSE;
+ our_credentials = NULL;
+
+ if (!_dbus_string_init (&ringdir))
+ {
+ dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
+ return NULL;
+ }
+
+ if (credentials != NULL)
+ {
+ our_credentials = _dbus_credentials_copy (credentials);
+ }
+ else
+ {
+ our_credentials = _dbus_credentials_new_from_current_process ();
+ }
+
+ if (our_credentials == NULL)
+ goto failed;
+
+ if (_dbus_credentials_are_anonymous (our_credentials))
+ {
+ if (!_dbus_credentials_add_from_current_process (our_credentials))
+ goto failed;
+ }
+
+ if (!_dbus_append_keyring_directory_for_credentials (&ringdir,
+ our_credentials))
+ goto failed;
+
+ keyring = _dbus_keyring_new ();
+ if (keyring == NULL)
+ goto failed;
+
+ _dbus_assert (keyring->credentials == NULL);
+ keyring->credentials = our_credentials;
+ our_credentials = NULL; /* so we don't unref it again later */
+
+ /* should have been validated already, but paranoia check here */
+ if (!_dbus_keyring_validate_context (context))
+ {
+ error_set = TRUE;
+ dbus_set_error_const (error,
+ DBUS_ERROR_FAILED,
+ "Invalid context in keyring creation");
+ goto failed;
+ }
+
+ /* Save keyring dir in the keyring object */
+ if (!_dbus_string_copy (&ringdir, 0,
+ &keyring->directory, 0))
+ goto failed;
+
+ /* Create keyring->filename based on keyring dir and context */
+ if (!_dbus_string_copy (&keyring->directory, 0,
+ &keyring->filename, 0))
+ goto failed;
+
+ if (!_dbus_concat_dir_and_file (&keyring->filename,
+ context))
+ goto failed;
+
+ /* Create lockfile name */
+ if (!_dbus_string_copy (&keyring->filename, 0,
+ &keyring->filename_lock, 0))
+ goto failed;
+
+ if (!_dbus_string_append (&keyring->filename_lock, ".lock"))
+ goto failed;
+
+ /* Reload keyring */
+ dbus_error_init (&tmp_error);
+ if (!_dbus_keyring_reload (keyring, FALSE, &tmp_error))
+ {
+ _dbus_verbose ("didn't load an existing keyring: %s\n",
+ tmp_error.message);
+ dbus_error_free (&tmp_error);
+ }
+
+ /* We don't fail fatally if we can't create the directory,
+ * but the keyring will probably always be empty
+ * unless someone else manages to create it
+ */
+ dbus_error_init (&tmp_error);
+ if (!_dbus_create_directory (&keyring->directory,
+ &tmp_error))
+ {
+ _dbus_verbose ("Creating keyring directory: %s\n",
+ tmp_error.message);
+ dbus_error_free (&tmp_error);
+ }
+
+ _dbus_string_free (&ringdir);
+
+ return keyring;
+
+ failed:
+ if (!error_set)
+ dbus_set_error_const (error,
+ DBUS_ERROR_NO_MEMORY,
+ NULL);
+ if (our_credentials)
+ _dbus_credentials_unref (our_credentials);
+ if (keyring)
+ _dbus_keyring_unref (keyring);
+ _dbus_string_free (&ringdir);
+ return NULL;
+
+}
+
+/**
+ * Checks whether the context is a valid context.
+ * Contexts that might cause confusion when used
+ * in filenames are not allowed (contexts can't
+ * start with a dot or contain dir separators).
+ *
+ * @todo this is the most inefficient implementation
+ * imaginable.
+ *
+ * @param context the context
+ * @returns #TRUE if valid
+ */
+dbus_bool_t
+_dbus_keyring_validate_context (const DBusString *context)
+{
+ if (_dbus_string_get_length (context) == 0)
+ {
+ _dbus_verbose ("context is zero-length\n");
+ return FALSE;
+ }
+
+ if (!_dbus_string_validate_ascii (context, 0,
+ _dbus_string_get_length (context)))
+ {
+ _dbus_verbose ("context not valid ascii\n");
+ return FALSE;
+ }
+
+ /* no directory separators */
+ if (_dbus_string_find (context, 0, "/", NULL))
+ {
+ _dbus_verbose ("context contains a slash\n");
+ return FALSE;
+ }
+
+ if (_dbus_string_find (context, 0, "\\", NULL))
+ {
+ _dbus_verbose ("context contains a backslash\n");
+ return FALSE;
+ }
+
+ /* prevent attempts to use dotfiles or ".." or ".lock"
+ * all of which might allow some kind of attack
+ */
+ if (_dbus_string_find (context, 0, ".", NULL))
+ {
+ _dbus_verbose ("context contains a dot\n");
+ return FALSE;
+ }
+
+ /* no spaces/tabs, those are used for separators in the protocol */
+ if (_dbus_string_find_blank (context, 0, NULL))
+ {
+ _dbus_verbose ("context contains a blank\n");
+ return FALSE;
+ }
+
+ if (_dbus_string_find (context, 0, "\n", NULL))
+ {
+ _dbus_verbose ("context contains a newline\n");
+ return FALSE;
+ }
+
+ if (_dbus_string_find (context, 0, "\r", NULL))
+ {
+ _dbus_verbose ("context contains a carriage return\n");
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+static DBusKey*
+find_recent_key (DBusKeyring *keyring)
+{
+ int i;
+ long tv_sec, tv_usec;
+
+ _dbus_get_current_time (&tv_sec, &tv_usec);
+
+ i = 0;
+ while (i < keyring->n_keys)
+ {
+ DBusKey *key = &keyring->keys[i];
+
+ _dbus_verbose ("Key %d is %ld seconds old\n",
+ i, tv_sec - key->creation_time);
+
+ if ((tv_sec - NEW_KEY_TIMEOUT_SECONDS) < key->creation_time)
+ return key;
+
+ ++i;
+ }
+
+ return NULL;
+}
+
+/**
+ * Gets a recent key to use for authentication.
+ * If no recent key exists, creates one. Returns
+ * the key ID. If a key can't be written to the keyring
+ * file so no recent key can be created, returns -1.
+ * All valid keys are > 0.
+ *
+ * @param keyring the keyring
+ * @param error error on failure
+ * @returns key ID to use for auth, or -1 on failure
+ */
+int
+_dbus_keyring_get_best_key (DBusKeyring *keyring,
+ DBusError *error)
+{
+ DBusKey *key;
+
+ _DBUS_ASSERT_ERROR_IS_CLEAR (error);
+
+ key = find_recent_key (keyring);
+ if (key)
+ return key->id;
+
+ /* All our keys are too old, or we've never loaded the
+ * keyring. Create a new one.
+ */
+ if (!_dbus_keyring_reload (keyring, TRUE,
+ error))
+ return -1;
+
+ key = find_recent_key (keyring);
+ if (key)
+ return key->id;
+ else
+ {
+ dbus_set_error_const (error,
+ DBUS_ERROR_FAILED,
+ "No recent-enough key found in keyring, and unable to create a new key");
+ return -1;
+ }
+}
+
+/**
+ * Checks whether the keyring is for the same user as the given credentials.
+ *
+ * @param keyring the keyring
+ * @param credentials the credentials to check
+ *
+ * @returns #TRUE if the keyring belongs to the given user
+ */
+dbus_bool_t
+_dbus_keyring_is_for_credentials (DBusKeyring *keyring,
+ DBusCredentials *credentials)
+{
+ return _dbus_credentials_same_user (keyring->credentials,
+ credentials);
+}
+
+/**
+ * Gets the hex-encoded secret key for the given ID.
+ * Returns #FALSE if not enough memory. Returns #TRUE
+ * but empty key on any other error such as unknown
+ * key ID.
+ *
+ * @param keyring the keyring
+ * @param key_id the key ID
+ * @param hex_key string to append hex-encoded key to
+ * @returns #TRUE if we had enough memory
+ */
+dbus_bool_t
+_dbus_keyring_get_hex_key (DBusKeyring *keyring,
+ int key_id,
+ DBusString *hex_key)
+{
+ DBusKey *key;
+
+ key = find_key_by_id (keyring->keys,
+ keyring->n_keys,
+ key_id);
+ if (key == NULL)
+ return TRUE; /* had enough memory, so TRUE */
+
+ return _dbus_string_hex_encode (&key->secret, 0,
+ hex_key,
+ _dbus_string_get_length (hex_key));
+}
+
+/** @} */ /* end of exposed API */
+
+#ifdef DBUS_BUILD_TESTS
+#include "dbus-test.h"
+#include <stdio.h>
+
+dbus_bool_t
+_dbus_keyring_test (void)
+{
+ DBusString context;
+ DBusKeyring *ring1;
+ DBusKeyring *ring2;
+ int id;
+ DBusError error;
+ int i;
+
+ ring1 = NULL;
+ ring2 = NULL;
+
+ /* Context validation */
+
+ _dbus_string_init_const (&context, "foo");
+ _dbus_assert (_dbus_keyring_validate_context (&context));
+ _dbus_string_init_const (&context, "org_freedesktop_blah");
+ _dbus_assert (_dbus_keyring_validate_context (&context));
+
+ _dbus_string_init_const (&context, "");
+ _dbus_assert (!_dbus_keyring_validate_context (&context));
+ _dbus_string_init_const (&context, ".foo");
+ _dbus_assert (!_dbus_keyring_validate_context (&context));
+ _dbus_string_init_const (&context, "bar.foo");
+ _dbus_assert (!_dbus_keyring_validate_context (&context));
+ _dbus_string_init_const (&context, "bar/foo");
+ _dbus_assert (!_dbus_keyring_validate_context (&context));
+ _dbus_string_init_const (&context, "bar\\foo");
+ _dbus_assert (!_dbus_keyring_validate_context (&context));
+ _dbus_string_init_const (&context, "foo\xfa\xf0");
+ _dbus_assert (!_dbus_keyring_validate_context (&context));
+ _dbus_string_init_const (&context, "foo\x80");
+ _dbus_assert (!_dbus_keyring_validate_context (&context));
+ _dbus_string_init_const (&context, "foo\x7f");
+ _dbus_assert (_dbus_keyring_validate_context (&context));
+ _dbus_string_init_const (&context, "foo bar");
+ _dbus_assert (!_dbus_keyring_validate_context (&context));
+
+ if (!_dbus_string_init (&context))
+ _dbus_assert_not_reached ("no memory");
+ if (!_dbus_string_append_byte (&context, '\0'))
+ _dbus_assert_not_reached ("no memory");
+ _dbus_assert (!_dbus_keyring_validate_context (&context));
+ _dbus_string_free (&context);
+
+ /* Now verify that if we create a key in keyring 1,
+ * it is properly loaded in keyring 2
+ */
+
+ _dbus_string_init_const (&context, "org_freedesktop_dbus_testsuite");
+ dbus_error_init (&error);
+ ring1 = _dbus_keyring_new_for_credentials (NULL, &context,
+ &error);
+ _dbus_assert (ring1 != NULL);
+ _dbus_assert (error.name == NULL);
+
+ id = _dbus_keyring_get_best_key (ring1, &error);
+ if (id < 0)
+ {
+ fprintf (stderr, "Could not load keyring: %s\n", error.message);
+ dbus_error_free (&error);
+ goto failure;
+ }
+
+ ring2 = _dbus_keyring_new_for_credentials (NULL, &context, &error);
+ _dbus_assert (ring2 != NULL);
+ _dbus_assert (error.name == NULL);
+
+ if (ring1->n_keys != ring2->n_keys)
+ {
+ fprintf (stderr, "Different number of keys in keyrings\n");
+ goto failure;
+ }
+
+ /* We guarantee we load and save keeping keys in a fixed
+ * order
+ */
+ i = 0;
+ while (i < ring1->n_keys)
+ {
+ if (ring1->keys[i].id != ring2->keys[i].id)
+ {
+ fprintf (stderr, "Keyring 1 has first key ID %d and keyring 2 has %d\n",
+ ring1->keys[i].id, ring2->keys[i].id);
+ goto failure;
+ }
+
+ if (ring1->keys[i].creation_time != ring2->keys[i].creation_time)
+ {
+ fprintf (stderr, "Keyring 1 has first key time %ld and keyring 2 has %ld\n",
+ ring1->keys[i].creation_time, ring2->keys[i].creation_time);
+ goto failure;
+ }
+
+ if (!_dbus_string_equal (&ring1->keys[i].secret,
+ &ring2->keys[i].secret))
+ {
+ fprintf (stderr, "Keyrings 1 and 2 have different secrets for same ID/timestamp\n");
+ goto failure;
+ }
+
+ ++i;
+ }
+
+ printf (" %d keys in test\n", ring1->n_keys);
+
+ /* Test ref/unref */
+ _dbus_keyring_ref (ring1);
+ _dbus_keyring_ref (ring2);
+ _dbus_keyring_unref (ring1);
+ _dbus_keyring_unref (ring2);
+
+
+ /* really unref */
+ _dbus_keyring_unref (ring1);
+ _dbus_keyring_unref (ring2);
+
+ return TRUE;
+
+ failure:
+ if (ring1)
+ _dbus_keyring_unref (ring1);
+ if (ring2)
+ _dbus_keyring_unref (ring2);
+
+ return FALSE;
+}
+
+#endif /* DBUS_BUILD_TESTS */
+
projects / monky / blobdiff