gpo: Add Centrify Compatible Crontab Extensions

Signed-off-by: David Mulder <dmulder@suse.com>
Reviewed-by: Jeremy Allison <jra@samba.org>

Autobuild-User(master): Jeremy Allison <jra@samba.org>
Autobuild-Date(master): Tue May 10 20:05:48 UTC 2022 on sn-devel-184

1 files changed, 132 insertions, 4 deletions

diff --git a/python/samba/gp_centrify_crontab_ext.py b/python/samba/gp_centrify_crontab_ext.py
index 835d4680d6e..eace6a973cd 100644
--- a/python/samba/gp_centrify_crontab_ext.py
+++ b/python/samba/gp_centrify_crontab_ext.py
@@ -14,19 +14,147 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-from samba.gpclass import gp_pol_ext
+import os, re
+from subprocess import Popen, PIPE
+from samba.gpclass import gp_pol_ext, drop_privileges
+from hashlib import blake2b
+from tempfile import NamedTemporaryFile
+
+intro = '''
+### autogenerated by samba
+#
+# This file is generated by the gp_centrify_crontab_ext Group Policy
+# Client Side Extension. To modify the contents of this file,
+# modify the appropriate Group Policy objects which apply
+# to this machine. DO NOT MODIFY THIS FILE DIRECTLY.
+#
+
+'''
+end = '''
+### autogenerated by samba ###
+'''
 
 class gp_centrify_crontab_ext(gp_pol_ext):
-    def process_group_policy(self, deleted_gpo_list, changed_gpo_list, cdir=None):
-        pass
+    def __str__(self):
+        return 'Centrify/CrontabEntries'
+
+    def process_group_policy(self, deleted_gpo_list, changed_gpo_list,
+                             cdir=None):
+        for guid, settings in deleted_gpo_list:
+            self.gp_db.set_guid(guid)
+            if str(self) in settings:
+                for attribute, script in settings[str(self)].items():
+                    if os.path.exists(script):
+                        os.unlink(script)
+                    self.gp_db.delete(str(self), attribute)
+            self.gp_db.commit()
+
+        for gpo in changed_gpo_list:
+            if gpo.file_sys_path:
+                section = \
+                    'Software\\Policies\\Centrify\\UnixSettings\\CrontabEntries'
+                self.gp_db.set_guid(gpo.name)
+                pol_file = 'MACHINE/Registry.pol'
+                path = os.path.join(gpo.file_sys_path, pol_file)
+                pol_conf = self.parse(path)
+                if not pol_conf:
+                    continue
+                for e in pol_conf.entries:
+                    if e.keyname == section and e.data.strip():
+                        cron_dir = '/etc/cron.d' if not cdir else cdir
+                        attribute = blake2b(e.data.encode()).hexdigest()
+                        old_val = self.gp_db.retrieve(str(self), attribute)
+                        if not old_val:
+                            with NamedTemporaryFile(prefix='gp_', mode="w+",
+                                    delete=False, dir=cron_dir) as f:
+                                contents = '%s\n%s\n%s' % (intro, e.data, end)
+                                f.write(contents)
+                                self.gp_db.store(str(self), attribute, f.name)
+                        self.gp_db.commit()
 
     def rsop(self, gpo, target='MACHINE'):
         output = {}
+        section = 'Software\\Policies\\Centrify\\UnixSettings\\CrontabEntries'
+        pol_file = '%s/Registry.pol' % target
+        if gpo.file_sys_path:
+            path = os.path.join(gpo.file_sys_path, pol_file)
+            pol_conf = self.parse(path)
+            if not pol_conf:
+                return output
+            for e in pol_conf.entries:
+                if e.keyname == section and e.data.strip():
+                    if str(self) not in output.keys():
+                        output[str(self)] = []
+                    output[str(self)].append(e.data)
         return output
 
+def fetch_crontab(username):
+    p = Popen(['crontab', '-l', '-u', username], stdout=PIPE, stderr=PIPE)
+    out, err = p.communicate()
+    if p.returncode != 0:
+        raise RuntimeError('Failed to read the crontab: %s' % err)
+    m = re.findall('%s(.*)%s' % (intro, end), out.decode(), re.DOTALL)
+    if len(m) == 1:
+        entries = m[0].strip().split('\n')
+    else:
+        entries = []
+    m = re.findall('(.*)%s.*%s(.*)' % (intro, end), out.decode(), re.DOTALL)
+    if len(m) == 1:
+        others = '\n'.join([l.strip() for l in m[0]])
+    else:
+        others = out.decode()
+    return others, entries
+
+def install_crontab(fname, username):
+    p = Popen(['crontab', fname, '-u', username], stdout=PIPE, stderr=PIPE)
+    _, err = p.communicate()
+    if p.returncode != 0:
+        raise RuntimeError('Failed to install crontab: %s' % err)
+
 class gp_user_centrify_crontab_ext(gp_centrify_crontab_ext):
     def process_group_policy(self, deleted_gpo_list, changed_gpo_list):
-        pass
+        for guid, settings in deleted_gpo_list:
+            self.gp_db.set_guid(guid)
+            if str(self) in settings:
+                others, entries = fetch_crontab(self.username)
+                for attribute, entry in settings[str(self)].items():
+                    if entry in entries:
+                        entries.remove(entry)
+                    self.gp_db.delete(str(self), attribute)
+                with NamedTemporaryFile() as f:
+                    if len(entries) > 0:
+                        f.write('\n'.join([others, intro,
+                                '\n'.join(entries), end]).encode())
+                    else:
+                        f.write(others.encode())
+                    f.flush()
+                    install_crontab(f.name, self.username)
+            self.gp_db.commit()
+
+        for gpo in changed_gpo_list:
+            if gpo.file_sys_path:
+                section = \
+                    'Software\\Policies\\Centrify\\UnixSettings\\CrontabEntries'
+                self.gp_db.set_guid(gpo.name)
+                pol_file = 'USER/Registry.pol'
+                path = os.path.join(gpo.file_sys_path, pol_file)
+                pol_conf = drop_privileges('root', self.parse, path)
+                if not pol_conf:
+                    continue
+                for e in pol_conf.entries:
+                    if e.keyname == section and e.data.strip():
+                        attribute = blake2b(e.data.encode()).hexdigest()
+                        old_val = self.gp_db.retrieve(str(self), attribute)
+                        others, entries = fetch_crontab(self.username)
+                        if not old_val or e.data not in entries:
+                            entries.append(e.data)
+                            with NamedTemporaryFile() as f:
+                                f.write('\n'.join([others, intro,
+                                        '\n'.join(entries), end]).encode())
+                                f.flush()
+                                install_crontab(f.name, self.username)
+                            self.gp_db.store(str(self), attribute, e.data)
+                        self.gp_db.commit()
 
     def rsop(self, gpo):
         return super().rsop(gpo, target='USER')