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authorPerberos <[email protected]>2011-11-04 22:16:15 -0300
committerPerberos <[email protected]>2011-11-04 22:16:15 -0300
commitfff4ecc82f2bcfa7427596e7ad9c3769fcab040b (patch)
treeac4f1812a7991609c9c32c776daede2d8492f7b5 /src/gs-auth-pam.c
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first commit
Diffstat (limited to 'src/gs-auth-pam.c')
-rw-r--r--src/gs-auth-pam.c843
1 files changed, 843 insertions, 0 deletions
diff --git a/src/gs-auth-pam.c b/src/gs-auth-pam.c
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+++ b/src/gs-auth-pam.c
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+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8 -*-
+ *
+ * Copyright (C) 2006 William Jon McCann <[email protected]>
+ * Copyright (C) 2006 Ray Strode <[email protected]>
+ * Copyright (C) 2003 Bill Nottingham <[email protected]>
+ * Copyright (c) 1993-2003 Jamie Zawinski <[email protected]>
+ *
+ * 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 "config.h"
+
+#include <stdlib.h>
+#ifdef HAVE_UNISTD_H
+# include <unistd.h>
+#endif
+
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+#include <pwd.h>
+#include <grp.h>
+#include <security/pam_appl.h>
+#include <signal.h>
+#include <errno.h>
+
+#include <glib.h>
+#include <glib/gstdio.h>
+#include <glib/gi18n.h>
+#include <gtk/gtk.h>
+
+#include "gs-auth.h"
+
+#include "subprocs.h"
+
+/* Some time between Red Hat 4.2 and 7.0, the words were transposed
+ in the various PAM_x_CRED macro names. Yay!
+*/
+#ifndef PAM_REFRESH_CRED
+# define PAM_REFRESH_CRED PAM_CRED_REFRESH
+#endif
+
+#ifdef HAVE_PAM_FAIL_DELAY
+/* We handle delays ourself.*/
+/* Don't set this to 0 (Linux bug workaround.) */
+# define PAM_NO_DELAY(pamh) pam_fail_delay ((pamh), 1)
+#else /* !HAVE_PAM_FAIL_DELAY */
+# define PAM_NO_DELAY(pamh) /* */
+#endif /* !HAVE_PAM_FAIL_DELAY */
+
+
+/* On SunOS 5.6, and on Linux with PAM 0.64, pam_strerror() takes two args.
+ On some other Linux systems with some other version of PAM (e.g.,
+ whichever Debian release comes with a 2.2.5 kernel) it takes one arg.
+ I can't tell which is more "recent" or "correct" behavior, so configure
+ figures out which is in use for us. Shoot me!
+*/
+#ifdef PAM_STRERROR_TWO_ARGS
+# define PAM_STRERROR(pamh, status) pam_strerror((pamh), (status))
+#else /* !PAM_STRERROR_TWO_ARGS */
+# define PAM_STRERROR(pamh, status) pam_strerror((status))
+#endif /* !PAM_STRERROR_TWO_ARGS */
+
+static gboolean verbose_enabled = FALSE;
+static pam_handle_t *pam_handle = NULL;
+static gboolean did_we_ask_for_password = FALSE;
+
+struct pam_closure
+{
+ const char *username;
+ GSAuthMessageFunc cb_func;
+ gpointer cb_data;
+ int signal_fd;
+ int result;
+};
+
+typedef struct
+{
+ struct pam_closure *closure;
+ GSAuthMessageStyle style;
+ const char *msg;
+ char **resp;
+ gboolean should_interrupt_stack;
+} GsAuthMessageHandlerData;
+
+static GCond *message_handled_condition;
+static GMutex *message_handler_mutex;
+
+GQuark
+gs_auth_error_quark (void)
+{
+ static GQuark quark = 0;
+ if (! quark)
+ {
+ quark = g_quark_from_static_string ("gs_auth_error");
+ }
+
+ return quark;
+}
+
+void
+gs_auth_set_verbose (gboolean enabled)
+{
+ verbose_enabled = enabled;
+}
+
+gboolean
+gs_auth_get_verbose (void)
+{
+ return verbose_enabled;
+}
+
+static GSAuthMessageStyle
+pam_style_to_gs_style (int pam_style)
+{
+ GSAuthMessageStyle style;
+
+ switch (pam_style)
+ {
+ case PAM_PROMPT_ECHO_ON:
+ style = GS_AUTH_MESSAGE_PROMPT_ECHO_ON;
+ break;
+ case PAM_PROMPT_ECHO_OFF:
+ style = GS_AUTH_MESSAGE_PROMPT_ECHO_OFF;
+ break;
+ case PAM_ERROR_MSG:
+ style = GS_AUTH_MESSAGE_ERROR_MSG;
+ break;
+ case PAM_TEXT_INFO:
+ style = GS_AUTH_MESSAGE_TEXT_INFO;
+ break;
+ default:
+ g_assert_not_reached ();
+ break;
+ }
+
+ return style;
+}
+
+static gboolean
+auth_message_handler (GSAuthMessageStyle style,
+ const char *msg,
+ char **response,
+ gpointer data)
+{
+ gboolean ret;
+
+ ret = TRUE;
+ *response = NULL;
+
+ switch (style)
+ {
+ case GS_AUTH_MESSAGE_PROMPT_ECHO_ON:
+ break;
+ case GS_AUTH_MESSAGE_PROMPT_ECHO_OFF:
+ if (msg != NULL && g_str_has_prefix (msg, _("Password:")))
+ {
+ did_we_ask_for_password = TRUE;
+ }
+ break;
+ case GS_AUTH_MESSAGE_ERROR_MSG:
+ break;
+ case GS_AUTH_MESSAGE_TEXT_INFO:
+ break;
+ default:
+ g_assert_not_reached ();
+ }
+
+ return ret;
+}
+
+static gboolean
+gs_auth_queued_message_handler (GsAuthMessageHandlerData *data)
+{
+ gboolean res;
+
+ if (gs_auth_get_verbose ())
+ {
+ g_message ("Waiting for lock");
+ }
+
+ g_mutex_lock (message_handler_mutex);
+
+ if (gs_auth_get_verbose ())
+ {
+ g_message ("Waiting for response");
+ }
+
+ res = data->closure->cb_func (data->style,
+ data->msg,
+ data->resp,
+ data->closure->cb_data);
+
+ data->should_interrupt_stack = res == FALSE;
+
+ g_cond_signal (message_handled_condition);
+ g_mutex_unlock (message_handler_mutex);
+
+ if (gs_auth_get_verbose ())
+ {
+ g_message ("Got response");
+ }
+
+ return FALSE;
+}
+
+static gboolean
+gs_auth_run_message_handler (struct pam_closure *c,
+ GSAuthMessageStyle style,
+ const char *msg,
+ char **resp)
+{
+ GsAuthMessageHandlerData data;
+
+ data.closure = c;
+ data.style = style;
+ data.msg = msg;
+ data.resp = resp;
+ data.should_interrupt_stack = TRUE;
+
+ g_mutex_lock (message_handler_mutex);
+
+ /* Queue the callback in the gui (the main) thread
+ */
+ g_idle_add ((GSourceFunc) gs_auth_queued_message_handler, &data);
+
+ if (gs_auth_get_verbose ())
+ {
+ g_message ("Waiting for respose to message style %d: '%s'", style, msg);
+ }
+
+ /* Wait for the response
+ */
+ g_cond_wait (message_handled_condition,
+ message_handler_mutex);
+ g_mutex_unlock (message_handler_mutex);
+
+ if (gs_auth_get_verbose ())
+ {
+ g_message ("Got respose to message style %d: interrupt:%d", style, data.should_interrupt_stack);
+ }
+
+ return data.should_interrupt_stack == FALSE;
+}
+
+static int
+pam_conversation (int nmsgs,
+ const struct pam_message **msg,
+ struct pam_response **resp,
+ void *closure)
+{
+ int replies = 0;
+ struct pam_response *reply = NULL;
+ struct pam_closure *c = (struct pam_closure *) closure;
+ gboolean res;
+ int ret;
+
+ reply = (struct pam_response *) calloc (nmsgs, sizeof (*reply));
+
+ if (reply == NULL)
+ {
+ return PAM_CONV_ERR;
+ }
+
+ res = TRUE;
+ ret = PAM_SUCCESS;
+
+ for (replies = 0; replies < nmsgs && ret == PAM_SUCCESS; replies++)
+ {
+ GSAuthMessageStyle style;
+ char *utf8_msg;
+
+ style = pam_style_to_gs_style (msg [replies]->msg_style);
+
+ utf8_msg = g_locale_to_utf8 (msg [replies]->msg,
+ -1,
+ NULL,
+ NULL,
+ NULL);
+
+ /* if we couldn't convert text from locale then
+ * assume utf-8 and hope for the best */
+ if (utf8_msg == NULL)
+ {
+ char *p;
+ char *q;
+
+ utf8_msg = g_strdup (msg [replies]->msg);
+
+ p = utf8_msg;
+ while (*p != '\0' && !g_utf8_validate ((const char *)p, -1, (const char **)&q))
+ {
+ *q = '?';
+ p = q + 1;
+ }
+ }
+
+ /* handle message locally first */
+ auth_message_handler (style,
+ utf8_msg,
+ &reply [replies].resp,
+ NULL);
+
+ if (c->cb_func != NULL)
+ {
+ if (gs_auth_get_verbose ())
+ {
+ g_message ("Handling message style %d: '%s'", style, utf8_msg);
+ }
+
+ /* blocks until the gui responds
+ */
+ res = gs_auth_run_message_handler (c,
+ style,
+ utf8_msg,
+ &reply [replies].resp);
+
+ if (gs_auth_get_verbose ())
+ {
+ g_message ("Msg handler returned %d", res);
+ }
+
+ /* If the handler returns FALSE - interrupt the PAM stack */
+ if (res)
+ {
+ reply [replies].resp_retcode = PAM_SUCCESS;
+ }
+ else
+ {
+ int i;
+ for (i = 0; i <= replies; i++)
+ {
+ free (reply [i].resp);
+ }
+ free (reply);
+ reply = NULL;
+ ret = PAM_CONV_ERR;
+ }
+ }
+
+ g_free (utf8_msg);
+ }
+
+ *resp = reply;
+
+ return ret;
+}
+
+static gboolean
+close_pam_handle (int status)
+{
+
+ if (pam_handle != NULL)
+ {
+ int status2;
+
+ status2 = pam_end (pam_handle, status);
+ pam_handle = NULL;
+
+ if (gs_auth_get_verbose ())
+ {
+ g_message (" pam_end (...) ==> %d (%s)",
+ status2,
+ (status2 == PAM_SUCCESS ? "Success" : "Failure"));
+ }
+ }
+
+ if (message_handled_condition != NULL)
+ {
+ g_cond_free (message_handled_condition);
+ message_handled_condition = NULL;
+ }
+
+ if (message_handler_mutex != NULL)
+ {
+ g_mutex_free (message_handler_mutex);
+ message_handler_mutex = NULL;
+ }
+
+ return TRUE;
+}
+
+static gboolean
+create_pam_handle (const char *username,
+ const char *display,
+ struct pam_conv *conv,
+ int *status_code)
+{
+ int status;
+ const char *service = PAM_SERVICE_NAME;
+ char *disp;
+ gboolean ret;
+
+ if (pam_handle != NULL)
+ {
+ g_warning ("create_pam_handle: Stale pam handle around, cleaning up");
+ close_pam_handle (PAM_SUCCESS);
+ }
+
+ /* init things */
+ pam_handle = NULL;
+ status = -1;
+ disp = NULL;
+ ret = TRUE;
+
+ /* Initialize a PAM session for the user */
+ if ((status = pam_start (service, username, conv, &pam_handle)) != PAM_SUCCESS)
+ {
+ pam_handle = NULL;
+ g_warning (_("Unable to establish service %s: %s\n"),
+ service,
+ PAM_STRERROR (NULL, status));
+
+ if (status_code != NULL)
+ {
+ *status_code = status;
+ }
+
+ ret = FALSE;
+ goto out;
+ }
+
+ if (gs_auth_get_verbose ())
+ {
+ g_message ("pam_start (\"%s\", \"%s\", ...) ==> %d (%s)",
+ service,
+ username,
+ status,
+ PAM_STRERROR (pam_handle, status));
+ }
+
+ disp = g_strdup (display);
+ if (disp == NULL)
+ {
+ disp = g_strdup (":0.0");
+ }
+
+ if ((status = pam_set_item (pam_handle, PAM_TTY, disp)) != PAM_SUCCESS)
+ {
+ g_warning (_("Can't set PAM_TTY=%s"), display);
+
+ if (status_code != NULL)
+ {
+ *status_code = status;
+ }
+
+ ret = FALSE;
+ goto out;
+ }
+
+ ret = TRUE;
+ message_handled_condition = g_cond_new ();
+ message_handler_mutex = g_mutex_new ();
+
+out:
+ if (status_code != NULL)
+ {
+ *status_code = status;
+ }
+
+ g_free (disp);
+
+ return ret;
+}
+
+static void
+set_pam_error (GError **error,
+ int status)
+{
+ if (status == PAM_AUTH_ERR || status == PAM_USER_UNKNOWN)
+ {
+ char *msg;
+
+ if (did_we_ask_for_password)
+ {
+ msg = g_strdup (_("Incorrect password."));
+ }
+ else
+ {
+ msg = g_strdup (_("Authentication failed."));
+ }
+
+ g_set_error (error,
+ GS_AUTH_ERROR,
+ GS_AUTH_ERROR_AUTH_ERROR,
+ "%s",
+ msg);
+ g_free (msg);
+ }
+ else if (status == PAM_PERM_DENIED)
+ {
+ g_set_error (error,
+ GS_AUTH_ERROR,
+ GS_AUTH_ERROR_AUTH_DENIED,
+ "%s",
+ _("Not permitted to gain access at this time."));
+ }
+ else if (status == PAM_ACCT_EXPIRED)
+ {
+ g_set_error (error,
+ GS_AUTH_ERROR,
+ GS_AUTH_ERROR_AUTH_DENIED,
+ "%s",
+ _("No longer permitted to access the system."));
+ }
+
+}
+
+static int
+gs_auth_thread_func (int auth_operation_fd)
+{
+ static const int flags = 0;
+ int status;
+ int status2;
+ struct timespec timeout;
+ sigset_t set;
+ const void *p;
+
+ timeout.tv_sec = 0;
+ timeout.tv_nsec = 1;
+
+ set = block_sigchld ();
+
+ status = pam_authenticate (pam_handle, flags);
+
+ sigtimedwait (&set, NULL, &timeout);
+ unblock_sigchld ();
+
+ if (gs_auth_get_verbose ())
+ {
+ g_message (" pam_authenticate (...) ==> %d (%s)",
+ status,
+ PAM_STRERROR (pam_handle, status));
+ }
+
+ if (status != PAM_SUCCESS)
+ {
+ goto done;
+ }
+
+ if ((status = pam_get_item (pam_handle, PAM_USER, &p)) != PAM_SUCCESS)
+ {
+ /* is not really an auth problem, but it will
+ pretty much look as such, it shouldn't really
+ happen */
+ goto done;
+ }
+
+ /* We don't actually care if the account modules fail or succeed,
+ * but we need to run them anyway because certain pam modules
+ * depend on side effects of the account modules getting run.
+ */
+ status2 = pam_acct_mgmt (pam_handle, 0);
+
+ if (gs_auth_get_verbose ())
+ {
+ g_message ("pam_acct_mgmt (...) ==> %d (%s)\n",
+ status2,
+ PAM_STRERROR (pam_handle, status2));
+ }
+
+ /* FIXME: should we handle these? */
+ switch (status2)
+ {
+ case PAM_SUCCESS:
+ break;
+ case PAM_NEW_AUTHTOK_REQD:
+ break;
+ case PAM_AUTHINFO_UNAVAIL:
+ break;
+ case PAM_ACCT_EXPIRED:
+ break;
+ case PAM_PERM_DENIED:
+ break;
+ default :
+ break;
+ }
+
+ /* Each time we successfully authenticate, refresh credentials,
+ for Kerberos/AFS/DCE/etc. If this fails, just ignore that
+ failure and blunder along; it shouldn't matter.
+
+ Note: this used to be PAM_REFRESH_CRED instead of
+ PAM_REINITIALIZE_CRED, but Jason Heiss <[email protected]>
+ says that the Linux PAM library ignores that one, and only refreshes
+ credentials when using PAM_REINITIALIZE_CRED.
+ */
+ status2 = pam_setcred (pam_handle, PAM_REINITIALIZE_CRED);
+ if (gs_auth_get_verbose ())
+ {
+ g_message (" pam_setcred (...) ==> %d (%s)",
+ status2,
+ PAM_STRERROR (pam_handle, status2));
+ }
+
+done:
+ /* we're done, close the fd and wake up the main
+ * loop
+ */
+ close (auth_operation_fd);
+
+ return status;
+}
+
+static gboolean
+gs_auth_loop_quit (GIOChannel *source,
+ GIOCondition condition,
+ gboolean *thread_done)
+{
+ *thread_done = TRUE;
+ gtk_main_quit ();
+ return FALSE;
+}
+
+static gboolean
+gs_auth_pam_verify_user (pam_handle_t *handle,
+ int *status)
+{
+ GThread *auth_thread;
+ GIOChannel *channel;
+ guint watch_id;
+ int auth_operation_fds[2];
+ int auth_status;
+ gboolean thread_done;
+
+ channel = NULL;
+ watch_id = 0;
+ auth_status = PAM_AUTH_ERR;
+
+ /* This pipe gives us a set of fds we can hook into
+ * the event loop to be notified when our helper thread
+ * is ready to be reaped.
+ */
+ if (pipe (auth_operation_fds) < 0)
+ {
+ goto out;
+ }
+
+ if (fcntl (auth_operation_fds[0], F_SETFD, FD_CLOEXEC) < 0)
+ {
+ close (auth_operation_fds[0]);
+ close (auth_operation_fds[1]);
+ goto out;
+ }
+
+ if (fcntl (auth_operation_fds[1], F_SETFD, FD_CLOEXEC) < 0)
+ {
+ close (auth_operation_fds[0]);
+ close (auth_operation_fds[1]);
+ goto out;
+ }
+
+ channel = g_io_channel_unix_new (auth_operation_fds[0]);
+
+ /* we use a recursive main loop to process ui events
+ * while we wait on a thread to handle the blocking parts
+ * of pam authentication.
+ */
+ thread_done = FALSE;
+ watch_id = g_io_add_watch (channel, G_IO_ERR | G_IO_HUP,
+ (GIOFunc) gs_auth_loop_quit, &thread_done);
+
+ auth_thread = g_thread_create ((GThreadFunc) gs_auth_thread_func,
+ GINT_TO_POINTER (auth_operation_fds[1]),
+ TRUE, NULL);
+
+ if (auth_thread == NULL)
+ {
+ goto out;
+ }
+
+ gtk_main ();
+
+ /* if the event loop was quit before the thread is done then we can't
+ * reap the thread without blocking on it finishing. The
+ * thread may not ever finish though if the pam module is blocking.
+ *
+ * The only time the event loop is going to stop when the thread isn't
+ * done, however, is if the dialog quits early (from, e.g., "cancel"),
+ * so we can just exit. An alternative option would be to switch to
+ * using pthreads directly and calling pthread_cancel.
+ */
+ if (!thread_done)
+ {
+ raise (SIGTERM);
+ }
+
+ auth_status = GPOINTER_TO_INT (g_thread_join (auth_thread));
+
+out:
+ if (watch_id != 0)
+ {
+ g_source_remove (watch_id);
+ }
+
+ if (channel != NULL)
+ {
+ g_io_channel_unref (channel);
+ }
+
+ if (status)
+ {
+ *status = auth_status;
+ }
+
+ return auth_status == PAM_SUCCESS;
+}
+
+gboolean
+gs_auth_verify_user (const char *username,
+ const char *display,
+ GSAuthMessageFunc func,
+ gpointer data,
+ GError **error)
+{
+ int status = -1;
+ struct pam_conv conv;
+ struct pam_closure c;
+ struct passwd *pwent;
+
+ pwent = getpwnam (username);
+ if (pwent == NULL)
+ {
+ return FALSE;
+ }
+
+ c.username = username;
+ c.cb_func = func;
+ c.cb_data = data;
+
+ conv.conv = &pam_conversation;
+ conv.appdata_ptr = (void *) &c;
+
+ /* Initialize PAM. */
+ create_pam_handle (username, display, &conv, &status);
+ if (status != PAM_SUCCESS)
+ {
+ goto done;
+ }
+
+ pam_set_item (pam_handle, PAM_USER_PROMPT, _("Username:"));
+
+ PAM_NO_DELAY(pam_handle);
+
+ did_we_ask_for_password = FALSE;
+ if (! gs_auth_pam_verify_user (pam_handle, &status))
+ {
+ goto done;
+ }
+
+done:
+ if (status != PAM_SUCCESS)
+ {
+ set_pam_error (error, status);
+ }
+
+ close_pam_handle (status);
+
+ return (status == PAM_SUCCESS ? TRUE : FALSE);
+}
+
+gboolean
+gs_auth_init (void)
+{
+ return TRUE;
+}
+
+gboolean
+gs_auth_priv_init (void)
+{
+ /* We have nothing to do at init-time.
+ However, we might as well do some error checking.
+ If "/etc/pam.d" exists and is a directory, but "/etc/pam.d/xlock"
+ does not exist, warn that PAM probably isn't going to work.
+
+ This is a priv-init instead of a non-priv init in case the directory
+ is unreadable or something (don't know if that actually happens.)
+ */
+ const char dir [] = "/etc/pam.d";
+ const char file [] = "/etc/pam.d/" PAM_SERVICE_NAME;
+ const char file2 [] = "/etc/pam.conf";
+ struct stat st;
+
+ if (g_stat (dir, &st) == 0 && st.st_mode & S_IFDIR)
+ {
+ if (g_stat (file, &st) != 0)
+ {
+ g_warning ("%s does not exist.\n"
+ "Authentication via PAM is unlikely to work.",
+ file);
+ }
+ }
+ else if (g_stat (file2, &st) == 0)
+ {
+ FILE *f = g_fopen (file2, "r");
+ if (f)
+ {
+ gboolean ok = FALSE;
+ char buf[255];
+ while (fgets (buf, sizeof(buf), f))
+ {
+ if (strstr (buf, PAM_SERVICE_NAME))
+ {
+ ok = TRUE;
+ break;
+ }
+ }
+
+ fclose (f);
+ if (!ok)
+ {
+ g_warning ("%s does not list the `%s' service.\n"
+ "Authentication via PAM is unlikely to work.",
+ file2, PAM_SERVICE_NAME);
+ }
+ }
+ /* else warn about file2 existing but being unreadable? */
+ }
+ else
+ {
+ g_warning ("Neither %s nor %s exist.\n"
+ "Authentication via PAM is unlikely to work.",
+ file2, file);
+ }
+
+ /* Return true anyway, just in case. */
+ return TRUE;
+}