crypto/openssh/contrib/gnome-ssh-askpass2.c

   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 /* GTK2 support by Nalin Dahyabhai <nalin@redhat.com> */
  26
  27 /*
  28  * This is a simple GNOME SSH passphrase grabber. To use it, set the
  29  * environment variable SSH_ASKPASS to point to the location of
  30  * gnome-ssh-askpass before calling "ssh-add < /dev/null".
  31  *
  32  * There is only two run-time options: if you set the environment variable
  33  * "GNOME_SSH_ASKPASS_GRAB_SERVER=true" then gnome-ssh-askpass will grab
  34  * the X server. If you set "GNOME_SSH_ASKPASS_GRAB_POINTER=true", then the
  35  * pointer will be grabbed too. These may have some benefit to security if
  36  * you don't trust your X server. We grab the keyboard always.
  37  */
  38
  39 #define GRAB_TRIES      16
  40 #define GRAB_WAIT       250 /* milliseconds */
  41
  42 /*
  43  * Compile with:
  44  *
  45  * cc -Wall `pkg-config --cflags gtk+-2.0` \
  46  *    gnome-ssh-askpass2.c -o gnome-ssh-askpass \
  47  *    `pkg-config --libs gtk+-2.0`
  48  *
  49  */
  50
  51 #include <stdlib.h>
  52 #include <stdio.h>
  53 #include <string.h>
  54 #include <unistd.h>
  55 #include <X11/Xlib.h>
  56 #include <gtk/gtk.h>
  57 #include <gdk/gdkx.h>
  58
  59 static void
  60 report_failed_grab (GtkWidget *parent_window, const char *what)
  61 {
  62         GtkWidget *err;
  63
  64         err = gtk_message_dialog_new(GTK_WINDOW(parent_window), 0,
  65                                      GTK_MESSAGE_ERROR,
  66                                      GTK_BUTTONS_CLOSE,
  67                                      "Could not grab %s. "
  68                                      "A malicious client may be eavesdropping "
  69                                      "on your session.", what);
  70         gtk_window_set_position(GTK_WINDOW(err), GTK_WIN_POS_CENTER);
  71
  72         gtk_dialog_run(GTK_DIALOG(err));
  73
  74         gtk_widget_destroy(err);
  75 }
  76
  77 static void
  78 ok_dialog(GtkWidget *entry, gpointer dialog)
  79 {
  80         g_return_if_fail(GTK_IS_DIALOG(dialog));
  81         gtk_dialog_response(GTK_DIALOG(dialog), GTK_RESPONSE_OK);
  82 }
  83
  84 static int
  85 passphrase_dialog(char *message)
  86 {
  87         const char *failed;
  88         char *passphrase, *local;
  89         int result, grab_tries, grab_server, grab_pointer;
  90         GtkWidget *parent_window, *dialog, *entry;
  91         GdkGrabStatus status;
  92
  93         grab_server = (getenv("GNOME_SSH_ASKPASS_GRAB_SERVER") != NULL);
  94         grab_pointer = (getenv("GNOME_SSH_ASKPASS_GRAB_POINTER") != NULL);
  95         grab_tries = 0;
  96
  97         /* Create an invisible parent window so that GtkDialog doesn't
  98          * complain.  */
  99         parent_window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
 100
 101         dialog = gtk_message_dialog_new(GTK_WINDOW(parent_window), 0,
 102                                         GTK_MESSAGE_QUESTION,
 103                                         GTK_BUTTONS_OK_CANCEL,
 104                                         "%s",
 105                                         message);
 106
 107         entry = gtk_entry_new();
 108         gtk_box_pack_start(
 109             GTK_BOX(gtk_dialog_get_content_area(GTK_DIALOG(dialog))), entry,
 110             FALSE, FALSE, 0);
 111         gtk_entry_set_visibility(GTK_ENTRY(entry), FALSE);
 112         gtk_widget_grab_focus(entry);
 113         gtk_widget_show(entry);
 114
 115         gtk_window_set_title(GTK_WINDOW(dialog), "OpenSSH");
 116         gtk_window_set_position (GTK_WINDOW(dialog), GTK_WIN_POS_CENTER);
 117         gtk_window_set_keep_above(GTK_WINDOW(dialog), TRUE);
 118
 119         /* Make <enter> close dialog */
 120         gtk_dialog_set_default_response(GTK_DIALOG(dialog), GTK_RESPONSE_OK);
 121         g_signal_connect(G_OBJECT(entry), "activate",
 122                          G_CALLBACK(ok_dialog), dialog);
 123
 124         gtk_window_set_keep_above(GTK_WINDOW(dialog), TRUE);
 125
 126         /* Grab focus */
 127         gtk_widget_show_now(dialog);
 128         if (grab_pointer) {
 129                 for(;;) {
 130                         status = gdk_pointer_grab(
 131                             (gtk_widget_get_window(GTK_WIDGET(dialog))), TRUE,
 132                             0, NULL, NULL, GDK_CURRENT_TIME);
 133                         if (status == GDK_GRAB_SUCCESS)
 134                                 break;
 135                         usleep(GRAB_WAIT * 1000);
 136                         if (++grab_tries > GRAB_TRIES) {
 137                                 failed = "mouse";
 138                                 goto nograb;
 139                         }
 140                 }
 141         }
 142         for(;;) {
 143                 status = gdk_keyboard_grab(
 144                     gtk_widget_get_window(GTK_WIDGET(dialog)), FALSE,
 145                     GDK_CURRENT_TIME);
 146                 if (status == GDK_GRAB_SUCCESS)
 147                         break;
 148                 usleep(GRAB_WAIT * 1000);
 149                 if (++grab_tries > GRAB_TRIES) {
 150                         failed = "keyboard";
 151                         goto nograbkb;
 152                 }
 153         }
 154         if (grab_server) {
 155                 gdk_x11_grab_server();
 156         }
 157
 158         result = gtk_dialog_run(GTK_DIALOG(dialog));
 159
 160         /* Ungrab */
 161         if (grab_server)
 162                 XUngrabServer(gdk_x11_get_default_xdisplay());
 163         if (grab_pointer)
 164                 gdk_pointer_ungrab(GDK_CURRENT_TIME);
 165         gdk_keyboard_ungrab(GDK_CURRENT_TIME);
 166         gdk_flush();
 167
 168         /* Report passphrase if user selected OK */
 169         passphrase = g_strdup(gtk_entry_get_text(GTK_ENTRY(entry)));
 170         if (result == GTK_RESPONSE_OK) {
 171                 local = g_locale_from_utf8(passphrase, strlen(passphrase),
 172                                            NULL, NULL, NULL);
 173                 if (local != NULL) {
 174                         puts(local);
 175                         memset(local, '\0', strlen(local));
 176                         g_free(local);
 177                 } else {
 178                         puts(passphrase);
 179                 }
 180         }
 181
 182         /* Zero passphrase in memory */
 183         memset(passphrase, '\b', strlen(passphrase));
 184         gtk_entry_set_text(GTK_ENTRY(entry), passphrase);
 185         memset(passphrase, '\0', strlen(passphrase));
 186         g_free(passphrase);
 187
 188         gtk_widget_destroy(dialog);
 189         return (result == GTK_RESPONSE_OK ? 0 : -1);
 190
 191         /* At least one grab failed - ungrab what we got, and report
 192            the failure to the user.  Note that XGrabServer() cannot
 193            fail.  */
 194  nograbkb:
 195         gdk_pointer_ungrab(GDK_CURRENT_TIME);
 196  nograb:
 197         if (grab_server)
 198                 XUngrabServer(gdk_x11_get_default_xdisplay());
 199         gtk_widget_destroy(dialog);
 200
 201         report_failed_grab(parent_window, failed);
 202
 203         return (-1);
 204 }
 205
 206 int
 207 main(int argc, char **argv)
 208 {
 209         char *message;
 210         int result;
 211
 212         gtk_init(&argc, &argv);
 213
 214         if (argc > 1) {
 215                 message = g_strjoinv(" ", argv + 1);
 216         } else {
 217                 message = g_strdup("Enter your OpenSSH passphrase:");
 218         }
 219
 220         setvbuf(stdout, 0, _IONBF, 0);
 221         result = passphrase_dialog(message);
 222         g_free(message);
 223
 224         return (result);
 225 }