- (djm) Warn user if grabs fail in GNOME askpass. Patch from Zack Weinberg

   <zack@wolery.cumb.org>

3 files changed, 44 insertions, 20 deletions

diff --git a/CREDITS b/CREDITS
index 3539addc3..c59babe74 100644
--- a/CREDITS
+++ b/CREDITS
@@ -51,6 +51,7 @@ Thomas Neumann <tom@smart.ruhr.de> - Shadow passwords
 Tom Bertelson's <tbert@abac.com> - AIX auth fixes
 Tor-Ake Fransson <torake@hotmail.com> - AIX support
 Tudor Bosman <tudorb@jm.nu> - MD5 password support
+Zack Weinberg <zack@wolery.cumb.org> - GNOME askpass enhancement
 
 Apologies to anyone I have missed.
 
diff --git a/ChangeLog b/ChangeLog
index 997aa31d0..46a444280 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,6 +1,8 @@
 20000606
  - (djm) Fix rsh path in RPMs. Report from Jason L Tibbitts III 
    <tibbs@math.uh.edu>
+ - (djm) Warn user if grabs fail in GNOME askpass. Patch from Zack Weinberg
+   <zack@wolery.cumb.org>
  - (djm) OpenBSD CVS updates:
   - todd@cvs.openbsd.org
     [sshconnect2.c]
diff --git a/contrib/gnome-ssh-askpass.c b/contrib/gnome-ssh-askpass.c
index fd537e676..5b6f65e88 100644
--- a/contrib/gnome-ssh-askpass.c
+++ b/contrib/gnome-ssh-askpass.c
@@ -49,7 +49,22 @@
 #include <X11/Xlib.h>
 #include <gdk/gdkx.h>
 
-int passphrase_dialog(char **passphrase_p, char *message)
+void
+report_failed_grab (void)
+{
+        GtkWidget *err;
+
+        err = gnome_message_box_new("Could not grab keyboard or mouse.\n"
+                "A malicious client may be eavesdropping on your session.",
+                                    GNOME_MESSAGE_BOX_ERROR, "EXIT", NULL);
+        gtk_window_set_position(GTK_WINDOW(err), GTK_WIN_POS_CENTER);
+        gtk_object_set(GTK_OBJECT(err), "type", GTK_WINDOW_POPUP, NULL);
+
+        gnome_dialog_run_and_close(GNOME_DIALOG(err));
+}
+
+void
+passphrase_dialog(char *message)
 {
         char *passphrase;
         int result;
@@ -80,41 +95,51 @@ int passphrase_dialog(char **passphrase_p, char *message)
 
         /* Grab focus */
         XGrabServer(GDK_DISPLAY());
-        gdk_pointer_grab(dialog->window, TRUE, 0, NULL, NULL, GDK_CURRENT_TIME);
-        gdk_keyboard_grab(dialog->window, FALSE, GDK_CURRENT_TIME);
+        if (gdk_pointer_grab(dialog->window, TRUE, 0,
+                             NULL, NULL, GDK_CURRENT_TIME))
+                goto nograb;
+        if (gdk_keyboard_grab(dialog->window, FALSE, GDK_CURRENT_TIME))
+                goto nograbkb;
 
         /* Make <enter> close dialog */
         gnome_dialog_editable_enters(GNOME_DIALOG(dialog), GTK_EDITABLE(entry));
 
         /* Run dialog */
         result = gnome_dialog_run(GNOME_DIALOG(dialog));
-                
+
         /* Ungrab */
         XUngrabServer(GDK_DISPLAY());
         gdk_pointer_ungrab(GDK_CURRENT_TIME);
         gdk_keyboard_ungrab(GDK_CURRENT_TIME);
         gdk_flush();
 
+        /* Report passphrase if user selected OK */
         passphrase = gtk_entry_get_text(GTK_ENTRY(entry));
-
-        /* Take copy of passphrase if user selected OK */
-        if (result == 0)        
-                *passphrase_p = strdup(passphrase);
-        else
-                *passphrase_p = NULL;
+        if (result == 0)
+                puts(passphrase);
                 
-        /* Zero existing passphrase */
+        /* Zero passphrase in memory */
         memset(passphrase, '\0', strlen(passphrase));
         gtk_entry_set_text(GTK_ENTRY(entry), passphrase);
                         
         gnome_dialog_close(GNOME_DIALOG(dialog));
+        return;
 
-        return (result == 0);
+        /* At least one grab failed - ungrab what we got, and report
+           the failure to the user.  Note that XGrabServer() cannot
+           fail.  */
+ nograbkb:
+        gdk_pointer_ungrab(GDK_CURRENT_TIME);
+ nograb:
+        XUngrabServer(GDK_DISPLAY());
+        gnome_dialog_close(GNOME_DIALOG(dialog));
+        
+        report_failed_grab();
 }
 
-int main(int argc, char **argv)
+int
+main(int argc, char **argv)
 {
-        char *passphrase;
         char *message;
         
         gnome_init("GNOME ssh-askpass", "0.1", argc, argv);
@@ -124,11 +149,7 @@ int main(int argc, char **argv)
         else
                 message = "Enter your OpenSSH passphrase:";
 
-        if (passphrase_dialog(&passphrase, message))
-        {
-                puts(passphrase);
-                memset(passphrase, '\0', strlen(passphrase));
-        }
-        
+        setvbuf(stdout, 0, _IONBF, 0);
+        passphrase_dialog(message);
         return 0;
 }