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
53 void
report_failed_grab(void)54 report_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
67 int
passphrase_dialog(char * message)68 passphrase_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
154 int
main(int argc,char ** argv)155 main(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