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#define PROMPT_ENTRY 0 43#define PROMPT_CONFIRM 1 44#define PROMPT_NONE 2 45 46/* 47 * Compile with: 48 * 49 * cc -Wall `pkg-config --cflags gtk+-2.0` \ 50 * gnome-ssh-askpass2.c -o gnome-ssh-askpass \ 51 * `pkg-config --libs gtk+-2.0` 52 * 53 */ 54 55#include <stdlib.h> 56#include <stdio.h> 57#include <string.h> 58#include <unistd.h> 59 60#include <X11/Xlib.h> 61#include <gtk/gtk.h> 62#include <gdk/gdkx.h> 63#include <gdk/gdkkeysyms.h> 64 65static void 66ok_dialog(GtkWidget *entry, gpointer dialog) 67{ 68 g_return_if_fail(GTK_IS_DIALOG(dialog)); 69 gtk_dialog_response(GTK_DIALOG(dialog), GTK_RESPONSE_OK); 70} 71 72static gboolean 73check_none(GtkWidget *widget, GdkEventKey *event, gpointer dialog) 74{ 75 switch (event->keyval) { 76 case GDK_KEY_Escape: 77 /* esc -> close dialog */ 78 gtk_dialog_response(GTK_DIALOG(dialog), GTK_RESPONSE_CLOSE); 79 return TRUE; 80 case GDK_KEY_Tab: 81 /* tab -> focus close button */ 82 gtk_widget_grab_focus(gtk_dialog_get_widget_for_response( 83 dialog, GTK_RESPONSE_CLOSE)); 84 return TRUE; 85 default: 86 /* eat all other key events */ 87 return TRUE; 88 } 89} 90 91static int 92parse_env_hex_color(const char *env, GdkColor *c) 93{ 94 const char *s; 95 unsigned long ul; 96 char *ep; 97 size_t n; 98 99 if ((s = getenv(env)) == NULL) 100 return 0; 101 102 memset(c, 0, sizeof(*c)); 103 104 /* Permit hex rgb or rrggbb optionally prefixed by '#' or '0x' */ 105 if (*s == '#') 106 s++; 107 else if (strncmp(s, "0x", 2) == 0) 108 s += 2; 109 n = strlen(s); 110 if (n != 3 && n != 6) 111 goto bad; 112 ul = strtoul(s, &ep, 16); 113 if (*ep != '\0' || ul > 0xffffff) { 114 bad: 115 fprintf(stderr, "Invalid $%s - invalid hex color code\n", env); 116 return 0; 117 } 118 /* Valid hex sequence; expand into a GdkColor */ 119 if (n == 3) { 120 /* 4-bit RGB */ 121 c->red = ((ul >> 8) & 0xf) << 12; 122 c->green = ((ul >> 4) & 0xf) << 12; 123 c->blue = (ul & 0xf) << 12; 124 } else { 125 /* 8-bit RGB */ 126 c->red = ((ul >> 16) & 0xff) << 8; 127 c->green = ((ul >> 8) & 0xff) << 8; 128 c->blue = (ul & 0xff) << 8; 129 } 130 return 1; 131} 132 133static int 134passphrase_dialog(char *message, int prompt_type) 135{ 136 const char *failed; 137 char *passphrase, *local; 138 int result, grab_tries, grab_server, grab_pointer; 139 int buttons, default_response; 140 GtkWidget *parent_window, *dialog, *entry, *err; 141 GdkGrabStatus status; 142 GdkColor fg, bg; 143 GdkSeat *seat; 144 GdkDisplay *display; 145 GdkSeatCapabilities caps; 146 int fg_set = 0, bg_set = 0; 147 148 grab_server = (getenv("GNOME_SSH_ASKPASS_GRAB_SERVER") != NULL); 149 grab_pointer = (getenv("GNOME_SSH_ASKPASS_GRAB_POINTER") != NULL); 150 grab_tries = 0; 151 152 fg_set = parse_env_hex_color("GNOME_SSH_ASKPASS_FG_COLOR", &fg); 153 bg_set = parse_env_hex_color("GNOME_SSH_ASKPASS_BG_COLOR", &bg); 154 155 /* Create an invisible parent window so that GtkDialog doesn't 156 * complain. */ 157 parent_window = gtk_window_new(GTK_WINDOW_TOPLEVEL); 158 159 switch (prompt_type) { 160 case PROMPT_CONFIRM: 161 buttons = GTK_BUTTONS_YES_NO; 162 default_response = GTK_RESPONSE_YES; 163 break; 164 case PROMPT_NONE: 165 buttons = GTK_BUTTONS_CLOSE; 166 default_response = GTK_RESPONSE_CLOSE; 167 break; 168 default: 169 buttons = GTK_BUTTONS_OK_CANCEL; 170 default_response = GTK_RESPONSE_OK; 171 break; 172 } 173 174 dialog = gtk_message_dialog_new(GTK_WINDOW(parent_window), 0, 175 GTK_MESSAGE_QUESTION, buttons, "%s", message); 176 177 gtk_window_set_title(GTK_WINDOW(dialog), "OpenSSH"); 178 gtk_window_set_position (GTK_WINDOW(dialog), GTK_WIN_POS_CENTER); 179 gtk_window_set_keep_above(GTK_WINDOW(dialog), TRUE); 180 gtk_dialog_set_default_response(GTK_DIALOG(dialog), default_response); 181 gtk_window_set_keep_above(GTK_WINDOW(dialog), TRUE); 182 183 if (fg_set) 184 gtk_widget_modify_fg(dialog, GTK_STATE_NORMAL, &fg); 185 if (bg_set) 186 gtk_widget_modify_bg(dialog, GTK_STATE_NORMAL, &bg); 187 188 if (prompt_type == PROMPT_ENTRY || prompt_type == PROMPT_NONE) { 189 entry = gtk_entry_new(); 190 if (fg_set) 191 gtk_widget_modify_fg(entry, GTK_STATE_NORMAL, &fg); 192 if (bg_set) 193 gtk_widget_modify_bg(entry, GTK_STATE_NORMAL, &bg); 194 gtk_box_pack_start( 195 GTK_BOX(gtk_dialog_get_content_area(GTK_DIALOG(dialog))), 196 entry, FALSE, FALSE, 0); 197 gtk_entry_set_visibility(GTK_ENTRY(entry), FALSE); 198 gtk_widget_grab_focus(entry); 199 if (prompt_type == PROMPT_ENTRY) { 200 gtk_widget_show(entry); 201 /* Make <enter> close dialog */ 202 g_signal_connect(G_OBJECT(entry), "activate", 203 G_CALLBACK(ok_dialog), dialog); 204 } else { 205 /* 206 * Ensure the 'close' button is not focused by default 207 * but is still reachable via tab. This is a bit of a 208 * hack - it uses a hidden entry that responds to a 209 * couple of keypress events (escape and tab only). 210 */ 211 gtk_widget_realize(entry); 212 g_signal_connect(G_OBJECT(entry), "key_press_event", 213 G_CALLBACK(check_none), dialog); 214 } 215 } 216 /* Grab focus */ 217 gtk_widget_show_now(dialog); 218 display = gtk_widget_get_display(GTK_WIDGET(dialog)); 219 seat = gdk_display_get_default_seat(display); 220 caps = GDK_SEAT_CAPABILITY_KEYBOARD; 221 if (grab_pointer) 222 caps |= GDK_SEAT_CAPABILITY_ALL_POINTING; 223 if (grab_server) 224 caps = GDK_SEAT_CAPABILITY_ALL; 225 for (;;) { 226 status = gdk_seat_grab(seat, gtk_widget_get_window(dialog), 227 caps, TRUE, NULL, NULL, NULL, NULL); 228 if (status == GDK_GRAB_SUCCESS) 229 break; 230 usleep(GRAB_WAIT * 1000); 231 if (++grab_tries > GRAB_TRIES) 232 goto nograb; 233 } 234 235 result = gtk_dialog_run(GTK_DIALOG(dialog)); 236 237 /* Ungrab */ 238 gdk_seat_ungrab(seat); 239 gdk_display_flush(display); 240 241 /* Report passphrase if user selected OK */ 242 if (prompt_type == PROMPT_ENTRY) { 243 passphrase = g_strdup(gtk_entry_get_text(GTK_ENTRY(entry))); 244 if (result == GTK_RESPONSE_OK) { 245 local = g_locale_from_utf8(passphrase, 246 strlen(passphrase), NULL, NULL, NULL); 247 if (local != NULL) { 248 puts(local); 249 memset(local, '\0', strlen(local)); 250 g_free(local); 251 } else { 252 puts(passphrase); 253 } 254 } 255 /* Zero passphrase in memory */ 256 memset(passphrase, '\b', strlen(passphrase)); 257 gtk_entry_set_text(GTK_ENTRY(entry), passphrase); 258 memset(passphrase, '\0', strlen(passphrase)); 259 g_free(passphrase); 260 } 261 262 gtk_widget_destroy(dialog); 263 if (result != GTK_RESPONSE_OK && result != GTK_RESPONSE_YES) 264 return -1; 265 return 0; 266 267 nograb: 268 gtk_widget_destroy(dialog); 269 err = gtk_message_dialog_new(GTK_WINDOW(parent_window), 0, 270 GTK_MESSAGE_ERROR, GTK_BUTTONS_CLOSE, 271 "Could not grab input. A malicious client may be eavesdropping " 272 "on your session."); 273 gtk_window_set_position(GTK_WINDOW(err), GTK_WIN_POS_CENTER); 274 gtk_dialog_run(GTK_DIALOG(err)); 275 gtk_widget_destroy(err); 276 return -1; 277} 278 279int 280main(int argc, char **argv) 281{ 282 char *message, *prompt_mode; 283 int result, prompt_type = PROMPT_ENTRY; 284 285 gtk_init(&argc, &argv); 286 287 if (argc > 1) { 288 message = g_strjoinv(" ", argv + 1); 289 } else { 290 message = g_strdup("Enter your OpenSSH passphrase:"); 291 } 292 293 if ((prompt_mode = getenv("SSH_ASKPASS_PROMPT")) != NULL) { 294 if (strcasecmp(prompt_mode, "confirm") == 0) 295 prompt_type = PROMPT_CONFIRM; 296 else if (strcasecmp(prompt_mode, "none") == 0) 297 prompt_type = PROMPT_NONE; 298 } 299 300 setvbuf(stdout, 0, _IONBF, 0); 301 result = passphrase_dialog(message, prompt_type); 302 g_free(message); 303 304 return (result); 305} 306