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 /*
  40  * Compile with:
  41  *
  42  * cc `pkg-config --cflags gtk+-2.0` \
  43  *    gnome-ssh-askpass2.c -o gnome-ssh-askpass \
  44  *    `pkg-config --libs gtk+-2.0`
  45  *
  46  */
  47
  48 #include <stdlib.h>
  49 #include <stdio.h>
  50 #include <string.h>
  51 #include <X11/Xlib.h>
  52 #include <gtk/gtk.h>
  53 #include <gdk/gdkx.h>
  54
  55 static void
  56 report_failed_grab (const char *what)
  57 {
  58         GtkWidget *err;
  59
  60         err = gtk_message_dialog_new(NULL, 0,
  61                                      GTK_MESSAGE_ERROR,
  62                                      GTK_BUTTONS_CLOSE,
  63                                      "Could not grab %s. "
  64                                      "A malicious client may be eavesdropping "
  65                                      "on your session.", what);
  66         gtk_window_set_position(GTK_WINDOW(err), GTK_WIN_POS_CENTER);
  67         gtk_label_set_line_wrap(GTK_LABEL((GTK_MESSAGE_DIALOG(err))->label),
  68                                 TRUE);
  69
  70         gtk_dialog_run(GTK_DIALOG(err));
  71
  72         gtk_widget_destroy(err);
  73 }
  74
  75 static void
  76 ok_dialog(GtkWidget *entry, gpointer dialog)
  77 {
  78         g_return_if_fail(GTK_IS_DIALOG(dialog));
  79         gtk_dialog_response(GTK_DIALOG(dialog), GTK_RESPONSE_OK);
  80 }
  81
  82 static int
  83 passphrase_dialog(char *message)
  84 {
  85         const char *failed;
  86         char *passphrase, *local;
  87         char **messages;
  88         int result, i, grab_server, grab_pointer;
  89         GtkWidget *dialog, *entry, *label;
  90         GdkGrabStatus status;
  91
  92         grab_server = (getenv("GNOME_SSH_ASKPASS_GRAB_SERVER") != NULL);
  93         grab_pointer = (getenv("GNOME_SSH_ASKPASS_GRAB_POINTER") != NULL);
  94
  95         dialog = gtk_message_dialog_new(NULL, 0,
  96                                         GTK_MESSAGE_QUESTION,
  97                                         GTK_BUTTONS_OK_CANCEL,
  98                                         "%s",
  99                                         message);
 100
 101         entry = gtk_entry_new();
 102         gtk_box_pack_start(GTK_BOX(GTK_DIALOG(dialog)->vbox), entry, FALSE,
 103             FALSE, 0);
 104         gtk_entry_set_visibility(GTK_ENTRY(entry), FALSE);
 105         gtk_widget_grab_focus(entry);
 106         gtk_widget_show(entry);
 107
 108         gtk_window_set_title(GTK_WINDOW(dialog), "OpenSSH");
 109         gtk_window_set_position (GTK_WINDOW(dialog), GTK_WIN_POS_CENTER);
 110         gtk_label_set_line_wrap(GTK_LABEL((GTK_MESSAGE_DIALOG(dialog))->label),
 111                                 TRUE);
 112
 113         /* Make <enter> close dialog */
 114         gtk_dialog_set_default_response(GTK_DIALOG(dialog), GTK_RESPONSE_OK);
 115         g_signal_connect(G_OBJECT(entry), "activate",
 116                          G_CALLBACK(ok_dialog), dialog);
 117
 118         /* Grab focus */
 119         gtk_widget_show_now(dialog);
 120         if (grab_server) {
 121                 gdk_x11_grab_server();
 122         }
 123         if (grab_pointer) {
 124                 status =  gdk_pointer_grab((GTK_WIDGET(dialog))->window, TRUE,
 125                                            0, NULL, NULL, GDK_CURRENT_TIME);
 126                 if (status != GDK_GRAB_SUCCESS) {
 127                         failed = "mouse";
 128                         goto nograb;
 129                 }
 130         }
 131         status = gdk_keyboard_grab((GTK_WIDGET(dialog))->window, FALSE,
 132                                    GDK_CURRENT_TIME);
 133         if (status != GDK_GRAB_SUCCESS) {
 134                 failed = "keyboard";
 135                 goto nograbkb;
 136         }
 137         result = gtk_dialog_run(GTK_DIALOG(dialog));
 138
 139         /* Ungrab */
 140         if (grab_server)
 141                 XUngrabServer(GDK_DISPLAY());
 142         if (grab_pointer)
 143                 gdk_pointer_ungrab(GDK_CURRENT_TIME);
 144         gdk_keyboard_ungrab(GDK_CURRENT_TIME);
 145         gdk_flush();
 146
 147         /* Report passphrase if user selected OK */
 148         passphrase = g_strdup(gtk_entry_get_text(GTK_ENTRY(entry)));
 149         if (result == GTK_RESPONSE_OK) {
 150                 local = g_locale_from_utf8(passphrase, strlen(passphrase),
 151                                            NULL, NULL, NULL);
 152                 if (local != NULL) {
 153                         puts(local);
 154                         memset(local, '\0', strlen(local));
 155                         g_free(local);
 156                 } else {
 157                         puts(passphrase);
 158                 }
 159         }
 160
 161         /* Zero passphrase in memory */
 162         memset(passphrase, '\b', strlen(passphrase));
 163         gtk_entry_set_text(GTK_ENTRY(entry), passphrase);
 164         memset(passphrase, '\0', strlen(passphrase));
 165         g_free(passphrase);
 166
 167         gtk_widget_destroy(dialog);
 168         return (result == GTK_RESPONSE_OK ? 0 : -1);
 169
 170         /* At least one grab failed - ungrab what we got, and report
 171            the failure to the user.  Note that XGrabServer() cannot
 172            fail.  */
 173  nograbkb:
 174         gdk_pointer_ungrab(GDK_CURRENT_TIME);
 175  nograb:
 176         if (grab_server)
 177                 XUngrabServer(GDK_DISPLAY());
 178         gtk_widget_destroy(dialog);
 179
 180         report_failed_grab(failed);
 181
 182         return (-1);
 183 }
 184
 185 int
 186 main(int argc, char **argv)
 187 {
 188         char *message;
 189         int result;
 190
 191         gtk_init(&argc, &argv);
 192
 193         if (argc > 1) {
 194                 message = g_strjoinv(" ", argv + 1);
 195         } else {
 196                 message = g_strdup("Enter your OpenSSH passphrase:");
 197         }
 198
 199         setvbuf(stdout, 0, _IONBF, 0);
 200         result = passphrase_dialog(message);
 201         g_free(message);
 202
 203         return (result);
 204 }