Python os.setgid() Examples

def createDirs(self):
        uid_change = pwd.getpwnam(self.user).pw_uid
        gid_change = pwd.getpwnam(self.user).pw_gid
        pidx = os.fork()
        if pidx == 0:
            try:
                os.setgid(gid_change)
                os.setuid(uid_change)
                if not os.path.exists(self.directory):
                    os.makedirs(self.directory)
                os.chdir(self.directory)
                man_dir = os.path.abspath("manifests")
                userlists_dir = os.path.abspath("userlists")
                self.copy(self.manifests, man_dir)
                self.copy(self.userlists, userlists_dir)
            finally:
                os._exit(0)
        os.waitpid(pidx, 0) 

def demote(self, uid, gid):
        def fn_uid_gid():
            os.setgid(gid)
            os.setuid(uid)

        def fn_uid():
            os.setuid(uid)

        def fn_gid():
            os.setgid(gid)

        def fn_nop():
            pass

        if uid and gid:
            return fn_uid_gid
        elif uid:
            return fn_uid
        elif gid:
            return fn_gid
        return fn_nop 

def test_mockPTYSetUidInParent(self):
        """
        Try creating a PTY process with setting its uid, in the parent path: it
        should switch to root before fork, then restore initial uid/gids.
        """
        self.mockos.child = False
        cmd = '/mock/ouch'

        d = defer.Deferred()
        p = TrivialProcessProtocol(d)
        oldPTYProcess = process.PTYProcess
        try:
            process.PTYProcess = DumbPTYProcess
            reactor.spawnProcess(p, cmd, ['ouch'], env=None,
                                 usePTY=True, uid=8080)
        finally:
            process.PTYProcess = oldPTYProcess
        self.assertEquals(self.mockos.actions,
            [('setuid', 0), ('setgid', 0), ('fork', False),
             ('setregid', 1235, 1234), ('setreuid', 1237, 1236), 'waitpid']) 

def drop_privileges(uid, gid):
    try:
        if gid is not None:
            os.setgid(gid)
            os.setegid(gid)
            logger.debug('switched uid to {}'.format(uid))

        if uid is not None:
            os.setuid(uid)
            os.seteuid(uid)
            logger.debug('switched gid to {}'.format(gid))

        logger.info('running as {} ({}:{})'.format(args.user, uid, gid))
    except Exception as e:
        logger.error('dropping privileges failed: {}'.format(e))
        return False

    return True 

def make_preexec_fn(self, cluster):  # pragma: nocover
        # Borrowed and modified from jupyterhub/spawner.py
        pwnam = getpwnam(cluster.username)
        uid = pwnam.pw_uid
        gid = pwnam.pw_gid
        groups = [g.gr_gid for g in grp.getgrall() if cluster.username in g.gr_mem]
        workdir = cluster.state["workdir"]

        def preexec():
            os.setgid(gid)
            try:
                os.setgroups(groups)
            except Exception as e:
                print("Failed to set groups %s" % e, file=sys.stderr)
            os.setuid(uid)
            os.chdir(workdir)

        return preexec 

def _execChild(self, path, uid, gid, executable, args, environment):
        """
        The exec() which is done in the forked child.
        """
        if path:
            os.chdir(path)
        if uid is not None or gid is not None:
            if uid is None:
                uid = os.geteuid()
            if gid is None:
                gid = os.getegid()
            # set the UID before I actually exec the process
            os.setuid(0)
            os.setgid(0)
            switchUID(uid, gid)
        os.execvpe(executable, args, environment) 

def test_mockSetUid(self):
        """
        Try creating a process with setting its uid: it's almost the same path
        as the standard path, but with a C{switchUID} call before the exec.
        """
        cmd = '/mock/ouch'

        d = defer.Deferred()
        p = TrivialProcessProtocol(d)
        try:
            reactor.spawnProcess(p, cmd, ['ouch'], env=None,
                                 usePTY=False, uid=8080)
        except SystemError:
            self.assert_(self.mockos.exited)
            self.assertEquals(self.mockos.actions,
                [('setuid', 0), ('setgid', 0), ('fork', False),
                  ('switchuid', 8080, 1234), 'exec', 'exit'])
        else:
            self.fail("Should not be here") 

def test_mockSetUid(self):
        """
        Try creating a process with setting its uid: it's almost the same path
        as the standard path, but with a C{switchUID} call before the exec.
        """
        cmd = b'/mock/ouch'

        d = defer.Deferred()
        p = TrivialProcessProtocol(d)
        try:
            reactor.spawnProcess(p, cmd, [b'ouch'], env=None,
                                 usePTY=False, uid=8080)
        except SystemError:
            self.assertTrue(self.mockos.exited)
            self.assertEqual(
                self.mockos.actions,
                [('fork', False), ('setuid', 0), ('setgid', 0),
                 ('switchuid', 8080, 1234), 'exec', ('exit', 1)])
        else:
            self.fail("Should not be here") 

def test_mockPTYSetUid(self):
        """
        Try creating a PTY process with setting its uid: it's almost the same
        path as the standard path, but with a C{switchUID} call before the
        exec.
        """
        cmd = b'/mock/ouch'

        d = defer.Deferred()
        p = TrivialProcessProtocol(d)
        try:
            reactor.spawnProcess(p, cmd, [b'ouch'], env=None,
                                 usePTY=True, uid=8081)
        except SystemError:
            self.assertTrue(self.mockos.exited)
            self.assertEqual(
                self.mockos.actions,
                [('fork', False), 'setsid', ('setuid', 0), ('setgid', 0),
                 ('switchuid', 8081, 1234), 'exec', ('exit', 1)])
        else:
            self.fail("Should not be here") 

def shutil_setuid(user = None, group = None):
    """ set fork-child uid/gid (returns pw-info env-settings)"""
    if group:
        import grp
        gid = grp.getgrnam(group).gr_gid
        os.setgid(gid)
        logg.debug("setgid %s '%s'", gid, group)
    if user:
        import pwd
        pw = pwd.getpwnam(user)
        if not group:
            gid = pw.pw_gid
            os.setgid(gid)
            logg.debug("setgid %s", gid)
        uid = pw.pw_uid
        os.setuid(uid)
        logg.debug("setuid %s '%s'", uid, user)
        home = pw.pw_dir
        shell = pw.pw_shell
        logname = pw.pw_name
        return { "USER": user, "LOGNAME": logname, "HOME": home, "SHELL": shell }
    return {} 

def switch(self):
        """
        Switch the current process's user/group to ``self.user``, and
        ``self.group``.  Change directory to ``self.dir``, and write the
        current pid out to ``self.pid_file``.
        """
        # set the running uid/gid
        LOG.debug('setting process uid(%s) and gid(%s)' %
                  (self.user.pw_uid, self.group.gr_gid))
        os.setgid(self.group.gr_gid)
        os.setuid(self.user.pw_uid)
        os.environ['HOME'] = self.user.pw_dir
        os.chdir(self.dir)
        if self.pid_file and os.path.exists(self.pid_file):
            raise exc.FrameworkError("Process already running (%s)" %
                                     self.pid_file)
        else:
            self._write_pid_file() 

def run_as(pwent, umask=0o22):
    """Drop privileges to given user's password entry, and set up
    environment. Assumes the parent process has root privileges.
    """
    os.umask(umask)
    home = pwent.home
    try:
      os.chdir(home)
    except OSError:
      os.chdir("/")
    # drop privs to user
    os.setgroups(pwent.groups)
    os.setgid(pwent.gid)
    os.setegid(pwent.gid)
    os.setuid(pwent.uid)
    os.seteuid(pwent.uid)
    os.environ["HOME"] = home
    os.environ["USER"] = pwent.name
    os.environ["LOGNAME"] = pwent.name
    os.environ["SHELL"] = pwent.shell
    os.environ["PATH"] = "/bin:/usr/bin:/usr/local/bin"
    return None 

def drop_privileges(user):
    """
    Change the system user of the current python process.

    It will only work if called as root or as the target user.

    :param string user: target user
    :raise KeyError: if the target user doesn't exists
    :raise OSError: when the user change fails
    """
    pw = pwd.getpwnam(user)
    if pw.pw_uid == os.getuid():
        return
    groups = [e.gr_gid for e in grp.getgrall() if pw.pw_name in e.gr_mem]
    groups.append(pw.pw_gid)
    os.setgroups(groups)
    os.setgid(pw.pw_gid)
    os.setuid(pw.pw_uid)
    os.environ['HOME'] = pw.pw_dir 

def drop_privileges(uid_name='nobody', gid_name='nogroup'):
    try: import pwd, grp
    except ImportError: return False # Windows

    # Get the uid/gid from the name
    running_uid = pwd.getpwnam(uid_name).pw_uid
    running_uid_home = pwd.getpwnam(uid_name).pw_dir
    running_gid = grp.getgrnam(gid_name).gr_gid

    # Remove group privileges
    os.setgroups([])

    # Try setting the new uid/gid
    os.setgid(running_gid)
    os.setuid(running_uid)

    # Ensure a very conservative umask
    old_umask = os.umask(int('077', 8))
    value = (os.getuid() == running_uid and os.getgid() == running_gid)
    if value:  # could be useful
       os.environ['HOME'] = running_uid_home
       logger.info('Changed permissions to: %s: %i, %s, %i' % (uid_name, running_uid, gid_name, running_gid))
    return value 

def _execChild(self, path, uid, gid, executable, args, environment):
        """
        The exec() which is done in the forked child.
        """
        if path:
            os.chdir(path)
        if uid is not None or gid is not None:
            if uid is None:
                uid = os.geteuid()
            if gid is None:
                gid = os.getegid()
            # set the UID before I actually exec the process
            os.setuid(0)
            os.setgid(0)
            switchUID(uid, gid)
        os.execvpe(executable, args, environment) 

def set_groups(path, new_uid, new_gid, verbose=True):
    '''For sudo case, set GID to non-SuperUser value.'''
    if not app_state['sudo_based_usage']:
        debug('set_groups: called for non-sudo use')
        return False
    try:
        debug('Changing file owner: file=' + path + ', uid=' + str(new_uid))
        new_gid_list = []
        new_gid_list = os.getgroups()
        if verbose:
            debug('os.getgroups: new_gid_list: ' + str(new_gid_list))
        os.setgroups([])
        if verbose:
            debug('calling os.setgroups(' + str(new_gid_list) + ')..')
        # os.setgroups(new_gid_list)  # XXX macOS: ValueError: too many groups
        os.setgroups([new_gid_list[0]])  # XXX macOS: ValueError: too many groups
        if verbose:
            debug('calling os.setgid(' + str(new_gid) + ')..')
        os.setgid(new_gid)
    except OSError as e:
        critical(e, 'Unable to to update UID on file: ' + path)
        sys.exc_info()
        log('Exception ' + str(e.errno) + ': ' + str(e))
        return False
    return True 

def test_mockSetUid(self):
        """
        Try creating a process with setting its uid: it's almost the same path
        as the standard path, but with a C{switchUID} call before the exec.
        """
        cmd = b'/mock/ouch'

        d = defer.Deferred()
        p = TrivialProcessProtocol(d)
        try:
            reactor.spawnProcess(p, cmd, [b'ouch'], env=None,
                                 usePTY=False, uid=8080)
        except SystemError:
            self.assertTrue(self.mockos.exited)
            self.assertEqual(
                self.mockos.actions,
                [('fork', False), ('setuid', 0), ('setgid', 0),
                 ('switchuid', 8080, 1234), 'exec', ('exit', 1)])
        else:
            self.fail("Should not be here") 

def test_mockPTYSetUid(self):
        """
        Try creating a PTY process with setting its uid: it's almost the same
        path as the standard path, but with a C{switchUID} call before the
        exec.
        """
        cmd = b'/mock/ouch'

        d = defer.Deferred()
        p = TrivialProcessProtocol(d)
        try:
            reactor.spawnProcess(p, cmd, [b'ouch'], env=None,
                                 usePTY=True, uid=8081)
        except SystemError:
            self.assertTrue(self.mockos.exited)
            self.assertEqual(
                self.mockos.actions,
                [('fork', False), 'setsid', ('setuid', 0), ('setgid', 0),
                 ('switchuid', 8081, 1234), 'exec', ('exit', 1)])
        else:
            self.fail("Should not be here") 

def switch(self):
        """
        Switch the current process's user/group to ``self.user``, and
        ``self.group``.  Change directory to ``self.dir``, and write the
        current pid out to ``self.pid_file``.
        """
        # set the running uid/gid
        LOG.debug('setting process uid(%s) and gid(%s)' %
                  (self.user.pw_uid, self.group.gr_gid))
        os.setgid(self.group.gr_gid)
        os.setuid(self.user.pw_uid)
        os.environ['HOME'] = self.user.pw_dir
        os.chdir(self.dir)
        if self.pid_file and os.path.exists(self.pid_file):
            raise exc.FrameworkError("Process already running (%s)" %
                                     self.pid_file)
        else:
            self._write_pid_file() 

def change_process_owner(uid, gid):
    """ Change the owning UID and GID of this process.

        Sets the GID then the UID of the process (in that order, to
        avoid permission errors) to the specified `gid` and `uid`
        values. Requires appropriate OS privileges for this process.

        """
    try:
        os.setgid(gid)
        os.setuid(uid)
    except Exception, exc:
        error = DaemonOSEnvironmentError(
            "Unable to change file creation mask (%(exc)s)"
            % vars())
        raise error 

def _setgroup(group):
    ''' Normalizes group to a gid and sets the current gid, or does 
    nothing if group is None.
    '''
    if group is None:
        return
        
    # Normalize group to gid
    elif isinstance(group, str):
        gid = grp.getgrnam(group).gr_gid
    # The group is already a gid.
    else:
        gid = group
        
    try:
        os.setgid(gid)
    except OSError:
        self.logger.error('Unable to change group.')
        sys.exit(1) 

def su() -> None:
    """
    switch user. Useful when starting localslackirc
    as a service as root user.
    """
    if sys.platform.startswith('win'):
        return

    # Nothing to do, already not root
    if os.getuid() != 0:
        return

    username = environ.get('PROCESS_OWNER', 'nobody')
    userdata = pwd.getpwnam(username)
    os.setgid(userdata.pw_gid)
    os.setegid(userdata.pw_gid)
    os.setuid(userdata.pw_uid)
    os.seteuid(userdata.pw_uid) 

def test_mockErrorInForkRestoreUID(self):
        """
        If C{os.fork} raises an exception and a UID change has been made, the
        previous UID and GID are restored.
        """
        self.mockos.raiseFork = OSError(errno.EAGAIN, None)
        protocol = TrivialProcessProtocol(None)
        self.assertRaises(OSError, reactor.spawnProcess, protocol, None,
                          uid=8080)
        self.assertEqual(self.mockos.actions,
            [('setuid', 0), ('setgid', 0), ("fork", False),
             ('setregid', 1235, 1234), ('setreuid', 1237, 1236)]) 

def set_user(username):
    if username is None:
        return

    import pwd
    import grp

    try:
        pwrec = pwd.getpwnam(username)
    except KeyError:
        logging.error('user not found: %s' % username)
        raise
    user = pwrec[0]
    uid = pwrec[2]
    gid = pwrec[3]

    cur_uid = os.getuid()
    if uid == cur_uid:
        return
    if cur_uid != 0:
        logging.error('can not set user as nonroot user')
        # will raise later

    # inspired by supervisor
    if hasattr(os, 'setgroups'):
        groups = [grprec[2] for grprec in grp.getgrall() if user in grprec[3]]
        groups.insert(0, gid)
        os.setgroups(groups)
    os.setgid(gid)
    os.setuid(uid) 

def set_user(username):
    if username is None:
        return

    import pwd
    import grp

    try:
        pwrec = pwd.getpwnam(username)
    except KeyError:
        logging.error('user not found: %s' % username)
        raise
    user = pwrec[0]
    uid = pwrec[2]
    gid = pwrec[3]

    cur_uid = os.getuid()
    if uid == cur_uid:
        return
    if cur_uid != 0:
        logging.error('can not set user as nonroot user')
        # will raise later

    # inspired by supervisor
    if hasattr(os, 'setgroups'):
        groups = [grprec[2] for grprec in grp.getgrall() if user in grprec[3]]
        groups.insert(0, gid)
        os.setgroups(groups)
    os.setgid(gid)
    os.setuid(uid) 

def drop_privileges():
    from certidude import config
    import pwd
    _, _, uid, gid, gecos, root, shell = pwd.getpwnam("certidude")
    restricted_groups = []
    restricted_groups.append(gid)

    # PAM needs access to /etc/shadow
    if config.AUTHENTICATION_BACKENDS == {"pam"}:
        import grp
        name, passwd, num, mem = grp.getgrnam("shadow")
        click.echo("Adding current user to shadow group due to PAM authentication backend")
        restricted_groups.append(num)

    os.setgroups(restricted_groups)
    os.setgid(gid)
    os.setuid(uid)
    click.echo("Switched %s (pid=%d) to user %s (uid=%d, gid=%d); member of groups %s" %
        (getproctitle(), os.getpid(), "certidude", os.getuid(), os.getgid(), ", ".join([str(j) for j in os.getgroups()])))
    os.umask(0o007) 

def test_mockSetUidInParent(self):
        """
        Try creating a process with setting its uid, in the parent path: it
        should switch to root before fork, then restore initial uid/gids.
        """
        self.mockos.child = False
        cmd = '/mock/ouch'

        d = defer.Deferred()
        p = TrivialProcessProtocol(d)
        reactor.spawnProcess(p, cmd, ['ouch'], env=None,
                             usePTY=False, uid=8080)
        self.assertEquals(self.mockos.actions,
            [('setuid', 0), ('setgid', 0), ('fork', False),
             ('setregid', 1235, 1234), ('setreuid', 1237, 1236), 'waitpid']) 

def uproot():
    if os.name == 'posix' and not os.geteuid():
        login = getuser()

        if login != 'root':
            import pwd
            click.echo(
                'Why are you using root to run this command? You should be using %s! Bringing you down...' % login,
                err=True
            )
            user = pwd.getpwnam(login)
            os.setgid(user.pw_gid)
            os.setuid(user.pw_uid) 

def set_user(username):
    if username is None:
        return

    import pwd
    import grp

    try:
        pwrec = pwd.getpwnam(username)
    except KeyError:
        logging.error('user not found: %s' % username)
        raise
    user = pwrec[0]
    uid = pwrec[2]
    gid = pwrec[3]

    cur_uid = os.getuid()
    if uid == cur_uid:
        return
    if cur_uid != 0:
        logging.error('can not set user as nonroot user')
        # will raise later

    # inspired by supervisor
    if hasattr(os, 'setgroups'):
        groups = [grprec[2] for grprec in grp.getgrall() if user in grprec[3]]
        groups.insert(0, gid)
        os.setgroups(groups)
    os.setgid(gid)
    os.setuid(uid) 

def run_package_reporter(self):
        """
        Run the L{PackageReporter} if there were successfully completed tasks.
        """
        if self.handled_tasks_count == 0:
            # Nothing was done
            return

        if os.getuid() == 0:
            os.setgid(grp.getgrnam("landscape").gr_gid)
            os.setuid(pwd.getpwnam("landscape").pw_uid)
        command = find_reporter_command(self._config)
        if self._config.config is not None:
            command += " -c %s" % self._config.config
        os.system(command)