--- /dev/null
+# gp_cert_auto_enroll_ext samba group policy
+# Copyright (C) David Mulder <dmulder@suse.com> 2021
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+import os
+from samba.gpclass import gp_pol_ext
+from samba import Ldb
+from ldb import SCOPE_SUBTREE
+from samba.auth import system_session
+from samba.gpclass import get_dc_hostname
+import base64
+from tempfile import NamedTemporaryFile
+from shutil import move, which
+from subprocess import Popen, PIPE
+import re
+from glob import glob
+import json
+
+cert_wrap = b"""
+-----BEGIN CERTIFICATE-----
+%s
+-----END CERTIFICATE-----"""
+global_trust_dir = '/etc/pki/trust/anchors'
+
+def fetch_certification_authorities(ldb):
+ result = []
+ basedn = ldb.get_default_basedn()
+ dn = 'CN=Certification Authorities,CN=Public Key Services,CN=Services,CN=Configuration,%s' % basedn
+ expr = '(objectClass=certificationAuthority)'
+ res = ldb.search(dn, SCOPE_SUBTREE, expr, ['cn'])
+ if len(res) == 0:
+ return result
+ dn = 'CN=Enrollment Services,CN=Public Key Services,CN=Services,CN=Configuration,%s' % basedn
+ attrs = ['cACertificate', 'cn', 'certificateTemplates', 'dNSHostName']
+ for ca in res:
+ expr = '(cn=%s)' % ca['cn']
+ res2 = ldb.search(dn, SCOPE_SUBTREE, expr, attrs)
+ if len(res) != 1:
+ continue
+ templates = {}
+ for template in res2[0]['certificateTemplates']:
+ templates[template] = fetch_template_attrs(ldb, template)
+ res = dict(res2[0])
+ res['certificateTemplates'] = templates
+ result.append(res)
+ return result
+
+def fetch_template_attrs(ldb, name, attrs=['msPKI-Minimal-Key-Size']):
+ basedn = ldb.get_default_basedn()
+ dn = 'CN=Certificate Templates,CN=Public Key Services,CN=Services,CN=Configuration,%s' % basedn
+ expr = '(cn=%s)' % name
+ res = ldb.search(dn, SCOPE_SUBTREE, expr, attrs)
+ if len(res) == 1 and 'msPKI-Minimal-Key-Size' in res[0]:
+ return dict(res[0])
+ else:
+ return {'msPKI-Minimal-Key-Size': ['2048']}
+
+def format_root_cert(cert):
+ cert = base64.b64encode(cert)
+ return cert_wrap % re.sub(b"(.{64})", b"\\1\n", cert, 0, re.DOTALL)
+
+def find_cepces_submit():
+ certmonger_dirs = [os.environ.get("PATH"), '/usr/lib/certmonger',
+ '/usr/libexec/certmonger']
+ return which('cepces-submit', path=':'.join(certmonger_dirs))
+
+def get_supported_templates(server):
+ cepces_submit = find_cepces_submit()
+ if os.path.exists(cepces_submit):
+ env = os.environ
+ env['CERTMONGER_OPERATION'] = 'GET-SUPPORTED-TEMPLATES'
+ out, _ = Popen([cepces_submit, '--server=%s' % server], env=env,
+ stdout=PIPE, stderr=PIPE).communicate()
+ return out.strip().split()
+ return []
+
+def cert_enroll(ca, trust_dir, private_dir, logger):
+ # Install the root certificate chain
+ data = {'files': [], 'templates': []}
+ sscep = which('sscep')
+ if sscep is not None:
+ url = 'http://%s/CertSrv/mscep/mscep.dll/pkiclient.exe?' % \
+ ca['dNSHostName'][0]
+ root_cert = os.path.join(trust_dir, '%s.crt' % ca['cn'])
+ ret = Popen([sscep, 'getca', '-F', 'sha1', '-c',
+ root_cert, '-u', url]).wait()
+ if ret != 0:
+ logger.warn('sscep failed to fetch the root certificate chain.')
+ root_certs = glob('%s*' % root_cert)
+ data['files'].extend(root_certs)
+ for src in root_certs:
+ # Symlink the certs to global trust dir
+ dst = os.path.join(global_trust_dir, os.path.basename(src))
+ try:
+ os.symlink(src, dst)
+ data['files'].append(dst)
+ except PermissionError:
+ logger.warn('Failed to symlink root certificate to the' +
+ ' admin trust anchors')
+ except FileNotFoundError:
+ logger.warn('Failed to symlink root certificate to the' +
+ ' admin trust anchors.' +
+ ' The directory %s was not found' % \
+ global_trust_dir)
+ else:
+ logger.warn('sscep is not installed, which prevents the installation' +
+ ' of the root certificate chain.')
+ update = which('update-ca-certificates')
+ if update is not None:
+ Popen([update]).wait()
+ # Setup Certificate Auto Enrollment
+ getcert = which('getcert')
+ cepces_submit = find_cepces_submit()
+ if getcert is not None and os.path.exists(cepces_submit):
+ Popen([getcert, 'add-ca', '-c', ca['cn'][0], '-e',
+ '%s --server=%s' % (cepces_submit, ca['dNSHostName'][0])]).wait()
+ supported_templates = get_supported_templates(ca['dNSHostName'][0])
+ for template, attrs in ca['certificateTemplates'].items():
+ if template not in supported_templates:
+ continue
+ nickname = '%s.%s' % (ca['cn'][0], template.decode())
+ keyfile = os.path.join(private_dir, '%s.key' % nickname)
+ certfile = os.path.join(trust_dir, '%s.crt' % nickname)
+ Popen([getcert, 'request', '-c', ca['cn'][0],
+ '-T', template.decode(),
+ '-I', nickname, '-k', keyfile, '-f', certfile,
+ '-g', attrs['msPKI-Minimal-Key-Size'][0]]).wait()
+ data['files'].extend([keyfile, certfile])
+ data['templates'].append(nickname)
+ if update is not None:
+ Popen([update]).wait()
+ else:
+ logger.warn('certmonger and cepces must be installed for ' +
+ 'certificate auto enrollment to work')
+ return json.dumps(data)
+
+class gp_cert_auto_enroll_ext(gp_pol_ext):
+ def __str__(self):
+ return 'Cryptography\AutoEnrollment'
+
+ def process_group_policy(self, deleted_gpo_list, changed_gpo_list,
+ trust_dir=None, private_dir=None):
+ if trust_dir is None:
+ trust_dir = self.lp.cache_path('certs')
+ if private_dir is None:
+ private_dir = self.lp.private_path('certs')
+ if not os.path.exists(trust_dir):
+ os.mkdir(trust_dir, mode=0o755)
+ if not os.path.exists(private_dir):
+ os.mkdir(private_dir, mode=0o700)
+
+ for guid, settings in deleted_gpo_list:
+ self.gp_db.set_guid(guid)
+ if str(self) in settings:
+ for ca_cn_enc, data in settings[str(self)].items():
+ ca_cn = base64.b64decode(ca_cn_enc)
+ data = json.loads(data)
+ getcert = which('getcert')
+ if getcert is not None:
+ Popen([getcert, 'remove-ca', '-c', ca_cn]).wait()
+ for nickname in data['templates']:
+ Popen([getcert, 'stop-tracking',
+ '-i', nickname]).wait()
+ for f in data['files']:
+ if os.path.exists(f):
+ os.unlink(f)
+ self.gp_db.delete(str(self), ca_cn_enc)
+ self.gp_db.commit()
+
+ for gpo in changed_gpo_list:
+ if gpo.file_sys_path:
+ section = 'Software\Policies\Microsoft\Cryptography\AutoEnrollment'
+ 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.valuename == 'AEPolicy':
+ # This policy applies as specified in [MS-CAESO] 4.4.5.1
+ if e.data == 0x8000:
+ continue # The policy is disabled
+ enroll = e.data & 0x1 == 1
+ manage = e.data & 0x2 == 1
+ retrive_pending = e.data & 0x4 == 1
+ if enroll:
+ url = 'ldap://%s' % get_dc_hostname(self.creds,
+ self.lp)
+ ldb = Ldb(url=url, session_info=system_session(),
+ lp=self.lp, credentials=self.creds)
+ cas = fetch_certification_authorities(ldb)
+ for ca in cas:
+ data = cert_enroll(ca, trust_dir,
+ private_dir, self.logger)
+ self.gp_db.store(str(self),
+ base64.b64encode(ca['cn'][0]).decode(),
+ data)
+ self.gp_db.commit()
+
+ def rsop(self, gpo):
+ output = {}
+ pol_file = 'MACHINE/Registry.pol'
+ section = 'Software\Policies\Microsoft\Cryptography\AutoEnrollment'
+ 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.valuename == 'AEPolicy':
+ enroll = e.data & 0x1 == 1
+ if e.data == 0x8000 or not enroll:
+ continue
+ output['Auto Enrollment Policy'] = {}
+ url = 'ldap://%s' % get_dc_hostname(self.creds, self.lp)
+ ldb = Ldb(url=url, session_info=system_session(),
+ lp=self.lp, credentials=self.creds)
+ cas = fetch_certification_authorities(ldb)
+ for ca in cas:
+ policy = 'Auto Enrollment Policy'
+ cn = ca['cn'][0]
+ output[policy][cn] = {}
+ output[policy][cn]['CA Certificate'] = \
+ format_root_cert(ca['cACertificate'][0]).decode()
+ output[policy][cn]['Auto Enrollment Server'] = \
+ ca['dNSHostName'][0]
+ supported_templates = \
+ get_supported_templates(ca['dNSHostName'][0])
+ output[policy][cn]['Templates'] = \
+ [t.decode() for t in supported_templates]
+ return output
projects / thirdparty / samba.git / commitdiff
