contrib/gnome-ssh-askpass1.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 /*
  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
  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
  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
 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 }