Bug 20914 - Support for sudo/super
Summary: Support for sudo/super
Alias: None
Product: kdesu
Classification: Unclassified
Component: general (show other bugs)
Version: unspecified
Platform: Debian testing Linux
: NOR wishlist with 579 votes (vote)
Target Milestone: ---
Assignee: kdesu bugs tracker
Depends on:
Reported: 2001-02-26 00:33 UTC by Michael Schuerig
Modified: 2015-09-27 18:57 UTC (History)
8 users (show)

See Also:
Latest Commit:
Version Fixed In:

kdesu patch to kdelibs for sudo support (9.09 KB, patch)
2005-04-02 22:36 UTC, Jonathan Riddell
kdesu patch to kdelibs for sudo support (2.03 KB, patch)
2005-04-02 22:37 UTC, Jonathan Riddell

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Description Michael Schuerig 2001-02-26 00:18:07 UTC
(*** This bug was imported into bugs.kde.org ***)

Package:           kdesud
Version:           KDE 2.1.0 Beta 2
Severity:          wishlist
Installed from:    Debian Packages
Compiler:          Not Specified
OS:                Linux
OS/Compiler notes: Not Specified

Currently kdesu/kdesud always use su. It would be nice if they could be configured to use sudo/super alternatively.

(Submitted via bugs.kde.org)
Comment 1 Alan Eldridge 2002-10-16 11:25:10 UTC
Reassigned to new maintainer.
Comment 2 Dmitry Kolesnikov 2003-09-27 18:04:08 UTC
IMHO it's really will be good. 
As I imagine this, kdesu may be more useful if implement this work modes (switched 
somewhere in Control Center): 
1. 'sudo' mode -- to get root rights, user must type own password. This will be great, as 
example, in case when only one user use this PC -- usable and still secure. 
2. no-password mode -- only warning (and, maybe, checkbox 'I Agree'). May be used when 
physical access to PC is secured enought. :) (IMHO it's not worsest than option in kdm 'enable 
loggin in without password') 
3. 'su' mode, keeping current behavior. (By default). 
Comment 3 Luke-Jr 2004-07-09 01:20:01 UTC
82 votes... Not enough for anyone to consider implementing?
Comment 4 Waldo Bastian 2004-07-09 10:55:28 UTC
I looked into sudo-support two weeks ago but its a bit more work than I expected so I won't be doing it for KDE 3.3
Comment 5 Luke-Jr 2004-07-09 16:55:46 UTC
3.4, though? Any chance on patches for 3.3?
Comment 6 Mike Glukhovsky 2004-12-25 22:37:29 UTC
Just to clarify why I feel this ought to be resolved as soon as possible- Ubuntu Linux has removed the ability to "su" and only allowed "sudo", which works well enough in their default environment (GNOME). But for those who love KDE, it causes major problems with a lot of apps and in the general environment (particularly for al the control panel apps). If this was resolved, it'd make quite a few people happy.
Comment 7 Jimmy Kaplowitz 2005-01-27 11:34:20 UTC
KDE on Ubuntu definitely has the problem mentioned in comment #6, and many people on other distributions of Linux (including me) disable the root password for the same reasons Ubuntu does. I have not seen it as a default other than in Ubuntu, but it is common enough elsewhere as a sysadmin choice.

When implementing sudo mode, please don't just simulate it by having the option to type your own password. Please actually use sudo, so that settings in /etc/sudoers apply. I have seen a program called kdesudo that appears to do a lot of what is needed, but its last and only release was in 2003. http://ksudo.sourceforge.net/kdesudo/ is its website. I haven't tried it, since it appears not to be maintained any more.
Comment 8 Stefan Briesenick 2005-02-01 22:43:07 UTC
the "ability" to use "su" is putting yourself in the "wheel" group. Perhaps, optionally, check if /etc/pam.d/su is somehow disabled.

But nonetheless, you have at least 3 options to become securely "root" on your machine:

1. su <command>
2. sudo <command>
3. ssh root@localhost <command>

at least these three should be available in 'kdesu' via select box ('su', 'sudo', 'ssh'). Optionally configurable somehow in KControl. Last selected way is the default from now then. 

'ssh' in combination with pam_ssh_agent would do the "no-password" thingy.

Furthermore, a KControl module for 'visudo' and the /etc/ssh(2) stuff would be great!
Comment 9 Rene Horn 2005-03-11 10:48:41 UTC
I, too, would like to mention that this feature would be a great security feature as long as it respects my sudoers file.  What's great about sudo is that it allows for fine-grained privilege escalation.
Comment 10 Jonathan Riddell 2005-03-11 19:07:27 UTC
I have a patch to add this which I'll release once tested and tidied.
Comment 11 Jonathan Riddell 2005-04-02 22:36:43 UTC
Created attachment 10487 [details]
kdesu patch to kdelibs for sudo support
Comment 12 Jonathan Riddell 2005-04-02 22:37:51 UTC
Created attachment 10488 [details]
kdesu patch to kdelibs for sudo support
Comment 13 Jonathan Riddell 2005-04-02 22:53:17 UTC
Second patch it to kdebase not kdelibs, it just changes the string.

Unlike su you can not use a kill signal on sudo (why is this different?) so the patch stops the kill signals.  kdesu starts an instance of su/sudo to check if it needs a password, then is starts another one for real.  Because the sudo instance can not be killed the first one remains running until the parent process has finished.  It also means it asks for a password when one isn't required (sudo is started on pts1 to check for password, then on pts2 for real, because sudo on pts1 is never given the password sudo on pts1 will continue to need the password next time it runs while sudo on pts2 does not).
Comment 14 Sebastian Reitenbach 2005-06-28 11:44:03 UTC

for me in a corporate environment, using linux not only on servers but also KDE for our desktops and laptops, i would greatly appreciate this feature so i do not need to hand out the root passwords to the users or i can disable it at all.
Comment 15 Luk van den Borne 2005-10-10 21:37:29 UTC
Is there any chance that the patch will be included into 3.5 or so?
Comment 16 jos poortvliet 2005-10-10 22:22:36 UTC
wat'd ya say? if it'll be in 3.5?? :D 

for the record: i got 8 mails telling me about the question from Luk...
Comment 17 Philip Rodrigues 2006-08-05 11:53:58 UTC
Has Riddell's patch been merged into kubuntu? If so, would it make a suitable feature for the 3.5 feature unfreeze?
Comment 18 Lloeki 2006-08-05 12:37:03 UTC
This one has been going on for years and continuously popping up in various forums, both for gksu and kdesu (gksudo and kdesudo are NOT proper replacements, they are not called in many places and they're vaguely hackey). I bet kubuntu is not using Riddell's patch but their own. Whatever, it does not give you choice (via e.g Kcontrol). Isn't there any kind soul to put this in kde 3.5.5 ? Really, it's a major feature for sys admins.
Comment 19 Jonathan Riddell 2006-08-07 15:48:35 UTC
SVN commit 570635 by jriddell:

Add sudo support
See that bug for some remaining issues

 M  +8 -0      configure.in.in  
 M  +9 -0      process.cpp  
 M  +57 -9     su.cpp  
 M  +1 -0      su.h  

--- branches/KDE/3.5/kdelibs/kdesu/configure.in.in #570634:570635
@@ -6,6 +6,14 @@
     AC_DEFINE_UNQUOTED(__PATH_SU, "$path_su", [path to su])
+dnl Check for sudo
+AC_PATH_PROG(path_sudo, "sudo", "no")
+if test "$path_sudo" = "no"; then
+    AC_MSG_WARN(sudo was not found)
+    AC_DEFINE_UNQUOTED(__PATH_SUDO, "$path_sudo", [path to sudo])
 dnl Check for POSIX.1b scheduling
 AC_MSG_CHECKING([POSIX.1b scheduling])
--- branches/KDE/3.5/kdelibs/kdesu/process.cpp #570634:570635
@@ -48,6 +48,7 @@
 #include <qcstring.h>
 #include <qfile.h>
+#include <kconfig.h>
 #include <kdebug.h>
 #include <kstandarddirs.h>
@@ -73,7 +74,15 @@
 bool PtyProcess::checkPid(pid_t pid)
+	KConfig* config = KGlobal::config();
+	config->setGroup("super-user-command");
+	QString superUserCommand = config->readEntry("super-user-command", "sudo");
+	//sudo does not accept signals from user so we except it
+	if (superUserCommand == "sudo") {
+		return true;
+	} else {
 	return kill(pid,0) == 0;
+	}
--- branches/KDE/3.5/kdelibs/kdesu/su.cpp #570634:570635
@@ -5,6 +5,9 @@
 * This file is part of the KDE project, module kdesu.
 * Copyright (C) 1999,2000 Geert Jansen <jansen@kde.org>
+* Sudo support added by Jonathan Riddell <jriddell@ ubuntu.com>
+* Copyright (C) 2005 Canonical Ltd
 * This is free software; you can use this library under the GNU Library 
 * General Public License, version 2. See the file "COPYING.LIB" for the 
 * exact licensing terms.
@@ -30,6 +33,7 @@
 #include <qcstring.h>
 #include <qfile.h>
+#include <kconfig.h>
 #include <kdebug.h>
 #include <klocale.h>
 #include <kstandarddirs.h>
@@ -42,11 +46,25 @@
 #define __PATH_SU "false"
+#ifndef __PATH_SUDO
+#define __PATH_SUDO "false"
+//change to sudo or su according to your preferences
 SuProcess::SuProcess(const QCString &user, const QCString &command)
     m_User = user;
     m_Command = command;
+    KConfig* config = KGlobal::config();
+    config->setGroup("super-user-command");
+    superUserCommand = config->readEntry("super-user-command", DEFAULT_SUPER_USER_COMMAND);
+    if ( superUserCommand != "sudo" && superUserCommand != "su" ) {
+	kdWarning() << "unknown super user command" << endl;
+	superUserCommand = "su";
+    }
@@ -74,6 +92,9 @@
     QCStringList args;
+    if (superUserCommand == "sudo") {
+        args += "-u";
+    }
 #ifdef Q_OS_DARWIN
     args += "-c";
@@ -85,16 +106,27 @@
         args += m_User;
-    args += "-c";
+    if (superUserCommand == "su") {
+        args += "-c";
+    }
     args += QCString(__KDE_BINDIR) + "/kdesu_stub";
 #ifndef Q_OS_DARWIN
     args += "-";
-    QCString command = __PATH_SU;
-    if (::access(__PATH_SU, X_OK) != 0)
+    ///    QCString command = __PATH_SU;
+    ///    if (::access(__PATH_SU, X_OK) != 0)
+    QCString command;
+    if (superUserCommand == "sudo") {
+        command = __PATH_SUDO;
+    } else {
+        command = __PATH_SU;
+    }
+    if (::access(command, X_OK) != 0)
-        command = QFile::encodeName(KGlobal::dirs()->findExe("su"));
+      ///        command = QFile::encodeName(KGlobal::dirs()->findExe("su"));
+        command = QFile::encodeName( KGlobal::dirs()->findExe(superUserCommand.ascii()) );
         if (command.isEmpty())
             return check ? SuNotFound : -1;
@@ -119,10 +151,20 @@
         if (ret == killme)
-            if (kill(m_Pid, SIGKILL) < 0)
-            {
-                ret=error;
-            }
+	  ///            if (kill(m_Pid, SIGKILL) < 0)
+	  ///            {
+	  ///                ret=error;
+	  ///            }
+            if ( superUserCommand == "sudo" ) {
+ 	        // sudo can not be killed, just return
+ 	        return ret;
+ 	    }
+ 	    if (kill(m_Pid, SIGKILL) < 0) {
+ 	        kdDebug() << k_funcinfo << "kill < 0" << endl;
+ 		//FIXME SIGKILL doesn't work for sudo,
+ 		//why is this different from su?
+ 		ret=error;
+ 	    }
                 int iret = waitForChild();
@@ -144,7 +186,9 @@
     if (ret == notauthorized)
         kill(m_Pid, SIGKILL);
-        waitForChild();
+        if (superUserCommand != "sudo") {
+            waitForChild();
+        }
         return SuIncorrectPassword;
@@ -277,6 +321,10 @@
                     return ok;
+ 	        } else if (superUserCommand == "sudo") {
+ 	            // sudo gives a "sorry" line so reaches here
+ 	            // with the wrong password
+ 	            return notauthorized;
--- branches/KDE/3.5/kdelibs/kdesu/su.h #570634:570635
@@ -57,6 +57,7 @@
     class SuProcessPrivate;
     SuProcessPrivate *d;
+    QString superUserCommand;
Comment 20 Andrew Ash 2006-10-02 07:05:16 UTC
This bug has been marked resolved/fixed.  Does that mean jriddell's patch is in 3.5.4 ?
Comment 21 Mathias Homann 2006-10-02 09:37:54 UTC
by all experiences that i've made so far, being marked as fixed in here has NOTHING to do with being in any released version. by all means, this fix could be in kde 4.1. Anyways, from what I see with 3.5.4 on my box, it's not in it.
Comment 22 Philip Rodrigues 2006-10-02 10:09:53 UTC
"FIXED" on bugs.kde.org means 'fixed in SVN' and therefore the fix will be in the next released version. At the moment, this mean 3.5.5. For a few bugs (especially wishlists), the fix only goes into "trunk", which is the code that will become KDE 4. This only happens if there's some reason the fix can't be made in 3.5 (like binary compatibility, fix needs architectural changes, etc)

Hope this explanation helps.
Comment 23 Mathias Homann 2006-10-11 22:11:21 UTC
from the changelog for kde 3.5.5 it looks like kdesu uses sudo now (or CAN use sudo).

Now, on my laptop i'm in the wheel group, and sudo is configured not to ask passwords of wheel members.

If i start anything that needs to run as root, kdesu still wants the root password...

where/how do i actually tell kdesu to use sudo?
Comment 24 Lloeki 2006-10-12 08:12:43 UTC
activate it at compile time with a kdesu configure switch --with-sudo-kdesu-backend
or create a kdesurc file, see mine below:
cd /usr/kde/3.5/share/config/
# cat kdesurc
Comment 25 Mathias Homann 2006-10-12 09:35:34 UTC
thanks. will try with the kdesurc. does that work for a user config file as well?

btw, it would have been better if one wouldn't have to file a bug to get crucial information like that.
Even much better would be a kconfig module...
Comment 26 Mathias Homann 2006-10-12 10:26:19 UTC
I created a ~/.kde/share/config/kdesurc as described in #24, and it works just fine... BUT:

I started four different apps that are all configured to run kdesu'ed, and here's /var/log/messages:

Oct 12 10:22:07 mhomann-linux sudo:  mhomann : TTY=pts/3 ; PWD=/net/maximus/data/Fileserver/homes/mhomann ; USER=root ; COMMAND=/opt/kde3/bin/kdesu_stub -
Oct 12 10:22:07 mhomann-linux sudo:  mhomann : TTY=pts/4 ; PWD=/net/maximus/data/Fileserver/homes/mhomann ; USER=root ; COMMAND=/opt/kde3/bin/kdesu_stub -
Oct 12 10:22:26 mhomann-linux sudo:  mhomann : TTY=pts/3 ; PWD=/net/maximus/data/Fileserver/homes/mhomann ; USER=root ; COMMAND=/opt/kde3/bin/kdesu_stub -
Oct 12 10:22:26 mhomann-linux sudo:  mhomann : TTY=pts/4 ; PWD=/net/maximus/data/Fileserver/homes/mhomann ; USER=root ; COMMAND=/opt/kde3/bin/kdesu_stub -

It breaks security this way, since you can't limit sudo access to certain apps anymore when all that gets started by sudo is kdesu_stub with no additional parameters.

Also, it doesnt show up in the logs what the user did.
Comment 27 Lloeki 2006-10-12 11:38:24 UTC
I immediately noticed that running someting with kdesu in sudo mode yields same graphical results as running it in su mode. So I thought there must be something wrong with some env var. a quick test shows:

$ kdesu 'echo $HOME > blah.txt'
$ cat blah.txt

when it should be /home/lloeki
there may be other variables that behave like su when they should behave like sudo.
Comment 28 Thomas Ohms 2007-01-23 12:21:56 UTC
I agree with Mathias Homann:
There should be a more secure way to use kdesu, sudo and kdesu_stub.
Is there a fix planned??
Comment 29 Luke-Jr 2007-01-23 19:49:34 UTC
Sounds like the bug should be reopened. Using kdesu_stub is not using sudo.
Comment 30 Maciej Pilichowski 2007-04-07 19:12:26 UTC
KDE 3.5.6, this "trick" from #24 (thanks Lloeki)
or create a kdesurc file, see mine below: 
 cd /usr/kde/3.5/share/config/ 
 # cat kdesurc 
still does not work.

And what about this "fixed" status? Could someone please reopen this report, thanks in advance.
Comment 31 Bram Schoenmakers 2007-05-04 14:21:38 UTC
Reopening by Maciej's request. Could someone verify please?
Comment 32 Alfredo 2007-08-06 19:37:13 UTC
opensuse 10.2 / kde 3.5.5

kdesu only works when ALL ALL=(ALL) ALL is set in /etc/sudoers

The kdesurc trick does not work !
Comment 33 Kyle 2007-12-23 14:31:04 UTC
in the meantime i suggest using kdesudo (available at http://www.kde-apps.org/content/show.php/KdeSudo?content=72106) as Kubuntu does (with correct envvars and such)
Comment 34 Oswald Buddenhagen 2010-11-06 14:41:46 UTC
kde's current approach to privilege elevation is using policykit, so it's unlikely that effort is going to be put into improving kdesu's sudo support.
as noted in comment 33, kdesudo is available for those who need it.
Comment 35 Luke-Jr 2010-11-06 20:58:14 UTC
Since when is KDE a single-platform desktop? Comment #34 is like removing support for Phonon and just using ALSA everywhere. Or hard-coding KDE core components to use GNU extensions.
Comment 36 Mathias Homann 2010-11-06 22:53:25 UTC
#35, repeatedly.
Comment 37 B Rhodes 2011-07-07 11:32:57 UTC
Forget single-platform desktop, what happens if you want to use a GTK program in KDE which needs elevated permissions (like Synaptic)?  Is KDE taking the Apple route where all software installed on your system has to be pre-approved and certified compatible before you're allowed to install it?
Comment 38 jos poortvliet 2011-07-07 15:17:05 UTC
@Borden: this is not a KDE question as 'KDE' is not an OS, it is 'just people who write a bunch of software'. The OS (linux, windows, mac) under KDE apps has to make decisions on those things. KDE provides a tool to start apps like Synaptic as root, however - kdesu. And synaptic can use policykit itself too, without even needing any KDE facilities.
Comment 39 B Rhodes 2015-08-09 06:42:55 UTC
@jos, indeed, I have to keep reminding myself that KDE is volunteers who write code for the fun of it. Those wishing to share in the experience have to abide by the programmers' decisions and have no real say in the KDE process. This is demonstrated by this bug being summarily closed 'wontfix' despite the legitimate need for it to be addressed.
Comment 40 Christoph Feck 2015-09-27 18:57:29 UTC
If with today's "su" infrastructure of KDE software there is still something missing, please report it as a new ticket. It does not make sense to add a comment to a bug that was closed five years ago.