1/*
2 * Copyright (c) 2000-2002 Damien Miller.  All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
14 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
15 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
16 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
17 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
18 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
19 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
20 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
22 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23 */
24
25/*
26 * This is a simple GNOME SSH passphrase grabber. To use it, set the
27 * environment variable SSH_ASKPASS to point to the location of
28 * gnome-ssh-askpass before calling "ssh-add < /dev/null".
29 *
30 * There is only two run-time options: if you set the environment variable
31 * "GNOME_SSH_ASKPASS_GRAB_SERVER=true" then gnome-ssh-askpass will grab
32 * the X server. If you set "GNOME_SSH_ASKPASS_GRAB_POINTER=true", then the
33 * pointer will be grabbed too. These may have some benefit to security if
34 * you don't trust your X server. We grab the keyboard always.
35 */
36
37/*
38 * Compile with:
39 *
40 * cc `gnome-config --cflags gnome gnomeui` \
41 *    gnome-ssh-askpass1.c -o gnome-ssh-askpass \
42 *    `gnome-config --libs gnome gnomeui`
43 *
44 */
45
46#include <stdlib.h>
47#include <stdio.h>
48#include <string.h>
49#include <gnome.h>
50#include <X11/Xlib.h>
51#include <gdk/gdkx.h>
52
53void
54report_failed_grab (void)
55{
56	GtkWidget *err;
57
58	err = gnome_message_box_new("Could not grab keyboard or mouse.\n"
59		"A malicious client may be eavesdropping on your session.",
60				    GNOME_MESSAGE_BOX_ERROR, "EXIT", NULL);
61	gtk_window_set_position(GTK_WINDOW(err), GTK_WIN_POS_CENTER);
62	gtk_object_set(GTK_OBJECT(err), "type", GTK_WINDOW_POPUP, NULL);
63
64	gnome_dialog_run_and_close(GNOME_DIALOG(err));
65}
66
67int
68passphrase_dialog(char *message)
69{
70	char *passphrase;
71	char **messages;
72	int result, i, grab_server, grab_pointer;
73	GtkWidget *dialog, *entry, *label;
74
75	grab_server = (getenv("GNOME_SSH_ASKPASS_GRAB_SERVER") != NULL);
76	grab_pointer = (getenv("GNOME_SSH_ASKPASS_GRAB_POINTER") != NULL);
77
78	dialog = gnome_dialog_new("OpenSSH", GNOME_STOCK_BUTTON_OK,
79	    GNOME_STOCK_BUTTON_CANCEL, NULL);
80
81	messages = g_strsplit(message, "\\n", 0);
82	if (messages)
83		for(i = 0; messages[i]; i++) {
84			label = gtk_label_new(messages[i]);
85			gtk_box_pack_start(GTK_BOX(GNOME_DIALOG(dialog)->vbox),
86			    label, FALSE, FALSE, 0);
87		}
88
89	entry = gtk_entry_new();
90	gtk_box_pack_start(GTK_BOX(GNOME_DIALOG(dialog)->vbox), entry, FALSE,
91	    FALSE, 0);
92	gtk_entry_set_visibility(GTK_ENTRY(entry), FALSE);
93	gtk_widget_grab_focus(entry);
94
95	/* Center window and prepare for grab */
96	gtk_object_set(GTK_OBJECT(dialog), "type", GTK_WINDOW_POPUP, NULL);
97	gnome_dialog_set_default(GNOME_DIALOG(dialog), 0);
98	gtk_window_set_position (GTK_WINDOW(dialog), GTK_WIN_POS_CENTER);
99	gtk_window_set_policy(GTK_WINDOW(dialog), FALSE, FALSE, TRUE);
100	gnome_dialog_close_hides(GNOME_DIALOG(dialog), TRUE);
101	gtk_container_set_border_width(GTK_CONTAINER(GNOME_DIALOG(dialog)->vbox),
102	    GNOME_PAD);
103	gtk_widget_show_all(dialog);
104
105	/* Grab focus */
106	if (grab_server)
107		XGrabServer(GDK_DISPLAY());
108	if (grab_pointer && gdk_pointer_grab(dialog->window, TRUE, 0,
109	    NULL, NULL, GDK_CURRENT_TIME))
110		goto nograb;
111	if (gdk_keyboard_grab(dialog->window, FALSE, GDK_CURRENT_TIME))
112		goto nograbkb;
113
114	/* Make <enter> close dialog */
115	gnome_dialog_editable_enters(GNOME_DIALOG(dialog), GTK_EDITABLE(entry));
116
117	/* Run dialog */
118	result = gnome_dialog_run(GNOME_DIALOG(dialog));
119
120	/* Ungrab */
121	if (grab_server)
122		XUngrabServer(GDK_DISPLAY());
123	if (grab_pointer)
124		gdk_pointer_ungrab(GDK_CURRENT_TIME);
125	gdk_keyboard_ungrab(GDK_CURRENT_TIME);
126	gdk_flush();
127
128	/* Report passphrase if user selected OK */
129	passphrase = gtk_entry_get_text(GTK_ENTRY(entry));
130	if (result == 0)
131		puts(passphrase);
132
133	/* Zero passphrase in memory */
134	memset(passphrase, '\0', strlen(passphrase));
135	gtk_entry_set_text(GTK_ENTRY(entry), passphrase);
136
137	gnome_dialog_close(GNOME_DIALOG(dialog));
138	return (result == 0 ? 0 : -1);
139
140	/* At least one grab failed - ungrab what we got, and report
141	   the failure to the user.  Note that XGrabServer() cannot
142	   fail.  */
143 nograbkb:
144	gdk_pointer_ungrab(GDK_CURRENT_TIME);
145 nograb:
146	if (grab_server)
147		XUngrabServer(GDK_DISPLAY());
148	gnome_dialog_close(GNOME_DIALOG(dialog));
149
150	report_failed_grab();
151	return (-1);
152}
153
154int
155main(int argc, char **argv)
156{
157	char *message;
158	int result;
159
160	gnome_init("GNOME ssh-askpass", "0.1", argc, argv);
161
162	if (argc == 2)
163		message = argv[1];
164	else
165		message = "Enter your OpenSSH passphrase:";
166
167	setvbuf(stdout, 0, _IONBF, 0);
168	result = passphrase_dialog(message);
169
170	return (result);
171}
172