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

342 lines
9.4 KiB
C

/*
* Copyright (c) 2000-2002 Damien Miller. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/* GTK2 support by Nalin Dahyabhai <nalin@redhat.com> */
/*
* This is a simple GNOME SSH passphrase grabber. To use it, set the
* environment variable SSH_ASKPASS to point to the location of
* gnome-ssh-askpass before calling "ssh-add < /dev/null".
*
* There is only two run-time options: if you set the environment variable
* "GNOME_SSH_ASKPASS_GRAB_SERVER=true" then gnome-ssh-askpass will grab
* the X server. If you set "GNOME_SSH_ASKPASS_GRAB_POINTER=true", then the
* pointer will be grabbed too. These may have some benefit to security if
* you don't trust your X server. We grab the keyboard always.
*/
#define GRAB_TRIES 16
#define GRAB_WAIT 250 /* milliseconds */
#define PROMPT_ENTRY 0
#define PROMPT_CONFIRM 1
#define PROMPT_NONE 2
/*
* Compile with:
*
* cc -Wall `pkg-config --cflags gtk+-2.0` \
* gnome-ssh-askpass2.c -o gnome-ssh-askpass \
* `pkg-config --libs gtk+-2.0`
*
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <X11/Xlib.h>
#include <gtk/gtk.h>
#include <gdk/gdkx.h>
#include <gdk/gdkkeysyms.h>
static void
report_failed_grab (GtkWidget *parent_window, const char *what)
{
GtkWidget *err;
err = gtk_message_dialog_new(GTK_WINDOW(parent_window), 0,
GTK_MESSAGE_ERROR, GTK_BUTTONS_CLOSE,
"Could not grab %s. A malicious client may be eavesdropping "
"on your session.", what);
gtk_window_set_position(GTK_WINDOW(err), GTK_WIN_POS_CENTER);
gtk_dialog_run(GTK_DIALOG(err));
gtk_widget_destroy(err);
}
static void
ok_dialog(GtkWidget *entry, gpointer dialog)
{
g_return_if_fail(GTK_IS_DIALOG(dialog));
gtk_dialog_response(GTK_DIALOG(dialog), GTK_RESPONSE_OK);
}
static gboolean
check_none(GtkWidget *widget, GdkEventKey *event, gpointer dialog)
{
switch (event->keyval) {
case GDK_KEY_Escape:
/* esc -> close dialog */
gtk_dialog_response(GTK_DIALOG(dialog), GTK_RESPONSE_CLOSE);
return TRUE;
case GDK_KEY_Tab:
/* tab -> focus close button */
gtk_widget_grab_focus(gtk_dialog_get_widget_for_response(
dialog, GTK_RESPONSE_CLOSE));
return TRUE;
default:
/* eat all other key events */
return TRUE;
}
}
static int
parse_env_hex_color(const char *env, GdkColor *c)
{
const char *s;
unsigned long ul;
char *ep;
size_t n;
if ((s = getenv(env)) == NULL)
return 0;
memset(c, 0, sizeof(*c));
/* Permit hex rgb or rrggbb optionally prefixed by '#' or '0x' */
if (*s == '#')
s++;
else if (strncmp(s, "0x", 2) == 0)
s += 2;
n = strlen(s);
if (n != 3 && n != 6)
goto bad;
ul = strtoul(s, &ep, 16);
if (*ep != '\0' || ul > 0xffffff) {
bad:
fprintf(stderr, "Invalid $%s - invalid hex color code\n", env);
return 0;
}
/* Valid hex sequence; expand into a GdkColor */
if (n == 3) {
/* 4-bit RGB */
c->red = ((ul >> 8) & 0xf) << 12;
c->green = ((ul >> 4) & 0xf) << 12;
c->blue = (ul & 0xf) << 12;
} else {
/* 8-bit RGB */
c->red = ((ul >> 16) & 0xff) << 8;
c->green = ((ul >> 8) & 0xff) << 8;
c->blue = (ul & 0xff) << 8;
}
return 1;
}
static int
passphrase_dialog(char *message, int prompt_type)
{
const char *failed;
char *passphrase, *local;
int result, grab_tries, grab_server, grab_pointer;
int buttons, default_response;
GtkWidget *parent_window, *dialog, *entry;
GdkGrabStatus status;
GdkColor fg, bg;
int fg_set = 0, bg_set = 0;
grab_server = (getenv("GNOME_SSH_ASKPASS_GRAB_SERVER") != NULL);
grab_pointer = (getenv("GNOME_SSH_ASKPASS_GRAB_POINTER") != NULL);
grab_tries = 0;
fg_set = parse_env_hex_color("GNOME_SSH_ASKPASS_FG_COLOR", &fg);
bg_set = parse_env_hex_color("GNOME_SSH_ASKPASS_BG_COLOR", &bg);
/* Create an invisible parent window so that GtkDialog doesn't
* complain. */
parent_window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
switch (prompt_type) {
case PROMPT_CONFIRM:
buttons = GTK_BUTTONS_YES_NO;
default_response = GTK_RESPONSE_YES;
break;
case PROMPT_NONE:
buttons = GTK_BUTTONS_CLOSE;
default_response = GTK_RESPONSE_CLOSE;
break;
default:
buttons = GTK_BUTTONS_OK_CANCEL;
default_response = GTK_RESPONSE_OK;
break;
}
dialog = gtk_message_dialog_new(GTK_WINDOW(parent_window), 0,
GTK_MESSAGE_QUESTION, buttons, "%s", message);
gtk_window_set_title(GTK_WINDOW(dialog), "OpenSSH");
gtk_window_set_position (GTK_WINDOW(dialog), GTK_WIN_POS_CENTER);
gtk_window_set_keep_above(GTK_WINDOW(dialog), TRUE);
gtk_dialog_set_default_response(GTK_DIALOG(dialog), default_response);
gtk_window_set_keep_above(GTK_WINDOW(dialog), TRUE);
if (fg_set)
gtk_widget_modify_fg(dialog, GTK_STATE_NORMAL, &fg);
if (bg_set)
gtk_widget_modify_bg(dialog, GTK_STATE_NORMAL, &bg);
if (prompt_type == PROMPT_ENTRY || prompt_type == PROMPT_NONE) {
entry = gtk_entry_new();
if (fg_set)
gtk_widget_modify_fg(entry, GTK_STATE_NORMAL, &fg);
if (bg_set)
gtk_widget_modify_bg(entry, GTK_STATE_NORMAL, &bg);
gtk_box_pack_start(
GTK_BOX(gtk_dialog_get_content_area(GTK_DIALOG(dialog))),
entry, FALSE, FALSE, 0);
gtk_entry_set_visibility(GTK_ENTRY(entry), FALSE);
gtk_widget_grab_focus(entry);
if (prompt_type == PROMPT_ENTRY) {
gtk_widget_show(entry);
/* Make <enter> close dialog */
g_signal_connect(G_OBJECT(entry), "activate",
G_CALLBACK(ok_dialog), dialog);
} else {
/*
* Ensure the 'close' button is not focused by default
* but is still reachable via tab. This is a bit of a
* hack - it uses a hidden entry that responds to a
* couple of keypress events (escape and tab only).
*/
gtk_widget_realize(entry);
g_signal_connect(G_OBJECT(entry), "key_press_event",
G_CALLBACK(check_none), dialog);
}
}
/* Grab focus */
gtk_widget_show_now(dialog);
if (grab_pointer) {
for(;;) {
status = gdk_pointer_grab(
(gtk_widget_get_window(GTK_WIDGET(dialog))), TRUE,
0, NULL, NULL, GDK_CURRENT_TIME);
if (status == GDK_GRAB_SUCCESS)
break;
usleep(GRAB_WAIT * 1000);
if (++grab_tries > GRAB_TRIES) {
failed = "mouse";
goto nograb;
}
}
}
for(;;) {
status = gdk_keyboard_grab(
gtk_widget_get_window(GTK_WIDGET(dialog)), FALSE,
GDK_CURRENT_TIME);
if (status == GDK_GRAB_SUCCESS)
break;
usleep(GRAB_WAIT * 1000);
if (++grab_tries > GRAB_TRIES) {
failed = "keyboard";
goto nograbkb;
}
}
if (grab_server) {
gdk_x11_grab_server();
}
result = gtk_dialog_run(GTK_DIALOG(dialog));
/* Ungrab */
if (grab_server)
XUngrabServer(gdk_x11_get_default_xdisplay());
if (grab_pointer)
gdk_pointer_ungrab(GDK_CURRENT_TIME);
gdk_keyboard_ungrab(GDK_CURRENT_TIME);
gdk_flush();
/* Report passphrase if user selected OK */
if (prompt_type == PROMPT_ENTRY) {
passphrase = g_strdup(gtk_entry_get_text(GTK_ENTRY(entry)));
if (result == GTK_RESPONSE_OK) {
local = g_locale_from_utf8(passphrase,
strlen(passphrase), NULL, NULL, NULL);
if (local != NULL) {
puts(local);
memset(local, '\0', strlen(local));
g_free(local);
} else {
puts(passphrase);
}
}
/* Zero passphrase in memory */
memset(passphrase, '\b', strlen(passphrase));
gtk_entry_set_text(GTK_ENTRY(entry), passphrase);
memset(passphrase, '\0', strlen(passphrase));
g_free(passphrase);
}
gtk_widget_destroy(dialog);
if (result != GTK_RESPONSE_OK && result != GTK_RESPONSE_YES)
return -1;
return 0;
nograbkb:
/*
* At least one grab failed - ungrab what we got, and report
* the failure to the user. Note that XGrabServer() cannot
* fail.
*/
gdk_pointer_ungrab(GDK_CURRENT_TIME);
nograb:
if (grab_server)
XUngrabServer(gdk_x11_get_default_xdisplay());
gtk_widget_destroy(dialog);
report_failed_grab(parent_window, failed);
return (-1);
}
int
main(int argc, char **argv)
{
char *message, *prompt_mode;
int result, prompt_type = PROMPT_ENTRY;
gtk_init(&argc, &argv);
if (argc > 1) {
message = g_strjoinv(" ", argv + 1);
} else {
message = g_strdup("Enter your OpenSSH passphrase:");
}
if ((prompt_mode = getenv("SSH_ASKPASS_PROMPT")) != NULL) {
if (strcasecmp(prompt_mode, "confirm") == 0)
prompt_type = PROMPT_CONFIRM;
else if (strcasecmp(prompt_mode, "none") == 0)
prompt_type = PROMPT_NONE;
}
setvbuf(stdout, 0, _IONBF, 0);
result = passphrase_dialog(message, prompt_type);
g_free(message);
return (result);
}