/*
* Copyright (c) 2000-2002 Damien Miller. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/* GTK2 support by Nalin Dahyabhai <nalin@redhat.com> */
/*
* This is a simple GNOME SSH passphrase grabber. To use it, set the
* environment variable SSH_ASKPASS to point to the location of
* gnome-ssh-askpass before calling "ssh-add < /dev/null".
*
* There is only two run-time options: if you set the environment variable
* "GNOME_SSH_ASKPASS_GRAB_SERVER=true" then gnome-ssh-askpass will grab
* the X server. If you set "GNOME_SSH_ASKPASS_GRAB_POINTER=true", then the
* pointer will be grabbed too. These may have some benefit to security if
* you don't trust your X server. We grab the keyboard always.
*/
#define GRAB_TRIES 16
#define GRAB_WAIT 250 /* milliseconds */
/*
* Compile with:
*
* cc -Wall `pkg-config --cflags gtk+-2.0` \
* gnome-ssh-askpass2.c -o gnome-ssh-askpass \
* `pkg-config --libs gtk+-2.0`
*
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <X11/Xlib.h>
#include <gtk/gtk.h>
#include <gdk/gdkx.h>
static void
report_failed_grab (GtkWidget *parent_window, const char *what)
{
GtkWidget *err;
err = gtk_message_dialog_new(GTK_WINDOW(parent_window), 0,
GTK_MESSAGE_ERROR,
GTK_BUTTONS_CLOSE,
"Could not grab %s. "
"A malicious client may be eavesdropping "
"on your session.", what);
gtk_window_set_position(GTK_WINDOW(err), GTK_WIN_POS_CENTER);
gtk_dialog_run(GTK_DIALOG(err));
gtk_widget_destroy(err);
}
static void
ok_dialog(GtkWidget *entry, gpointer dialog)
{
g_return_if_fail(GTK_IS_DIALOG(dialog));
gtk_dialog_response(GTK_DIALOG(dialog), GTK_RESPONSE_OK);
}
static int
passphrase_dialog(char *message)
{
const char *failed;
char *passphrase, *local;
int result, grab_tries, grab_server, grab_pointer;
GtkWidget *parent_window, *dialog, *entry;
GdkGrabStatus status;
grab_server = (getenv("GNOME_SSH_ASKPASS_GRAB_SERVER") != NULL);
grab_pointer = (getenv("GNOME_SSH_ASKPASS_GRAB_POINTER") != NULL);
grab_tries = 0;
/* Create an invisible parent window so that GtkDialog doesn't
* complain. */
parent_window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
dialog = gtk_message_dialog_new(GTK_WINDOW(parent_window), 0,
GTK_MESSAGE_QUESTION,
GTK_BUTTONS_OK_CANCEL,
"%s",
message);
entry = gtk_entry_new();
gtk_box_pack_start(
GTK_BOX(gtk_dialog_get_content_area(GTK_DIALOG(dialog))), entry,
FALSE, FALSE, 0);
gtk_entry_set_visibility(GTK_ENTRY(entry), FALSE);
gtk_widget_grab_focus(entry);
gtk_widget_show(entry);
gtk_window_set_title(GTK_WINDOW(dialog), "OpenSSH");
gtk_window_set_position (GTK_WINDOW(dialog), GTK_WIN_POS_CENTER);
gtk_window_set_keep_above(GTK_WINDOW(dialog), TRUE);
/* Make <enter> close dialog */
gtk_dialog_set_default_response(GTK_DIALOG(dialog), GTK_RESPONSE_OK);
g_signal_connect(G_OBJECT(entry), "activate",
G_CALLBACK(ok_dialog), dialog);
gtk_window_set_keep_above(GTK_WINDOW(dialog), TRUE);
/* Grab focus */
gtk_widget_show_now(dialog);
if (grab_pointer) {
for(;;) {
status = gdk_pointer_grab(
(gtk_widget_get_window(GTK_WIDGET(dialog))), TRUE,
0, NULL, NULL, GDK_CURRENT_TIME);
if (status == GDK_GRAB_SUCCESS)
break;
usleep(GRAB_WAIT * 1000);
if (++grab_tries > GRAB_TRIES) {
failed = "mouse";
goto nograb;
}
}
}
for(;;) {
status = gdk_keyboard_grab(
gtk_widget_get_window(GTK_WIDGET(dialog)), FALSE,
GDK_CURRENT_TIME);
if (status == GDK_GRAB_SUCCESS)
break;
usleep(GRAB_WAIT * 1000);
if (++grab_tries > GRAB_TRIES) {
failed = "keyboard";
goto nograbkb;
}
}
if (grab_server) {
gdk_x11_grab_server();
}
result = gtk_dialog_run(GTK_DIALOG(dialog));
/* Ungrab */
if (grab_server)
XUngrabServer(gdk_x11_get_default_xdisplay());
if (grab_pointer)
gdk_pointer_ungrab(GDK_CURRENT_TIME);
gdk_keyboard_ungrab(GDK_CURRENT_TIME);
gdk_flush();
/* Report passphrase if user selected OK */
passphrase = g_strdup(gtk_entry_get_text(GTK_ENTRY(entry)));
if (result == GTK_RESPONSE_OK) {
local = g_locale_from_utf8(passphrase, strlen(passphrase),
NULL, NULL, NULL);
if (local != NULL) {
puts(local);
memset(local, '\0', strlen(local));
g_free(local);
} else {
puts(passphrase);
}
}
/* Zero passphrase in memory */
memset(passphrase, '\b', strlen(passphrase));
gtk_entry_set_text(GTK_ENTRY(entry), passphrase);
memset(passphrase, '\0', strlen(passphrase));
g_free(passphrase);
gtk_widget_destroy(dialog);
return (result == GTK_RESPONSE_OK ? 0 : -1);
/* At least one grab failed - ungrab what we got, and report
the failure to the user. Note that XGrabServer() cannot
fail. */
nograbkb:
gdk_pointer_ungrab(GDK_CURRENT_TIME);
nograb:
if (grab_server)
XUngrabServer(gdk_x11_get_default_xdisplay());
gtk_widget_destroy(dialog);
report_failed_grab(parent_window, failed);
return (-1);
}
int
main(int argc, char **argv)
{
char *message;
int result;
gtk_init(&argc, &argv);
if (argc > 1) {
message = g_strjoinv(" ", argv + 1);
} else {
message = g_strdup("Enter your OpenSSH passphrase:");
}
setvbuf(stdout, 0, _IONBF, 0);
result = passphrase_dialog(message);
g_free(message);
return (result);
}