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|
#!/usr/bin/python3
import argparse
import os
import random
import shutil
import sys
import tempfile
import textwrap
from typing import Iterable
try:
import ldap
except ImportError:
print("Please install python-ldap before running this program")
sys.exit(1)
basedn = "<%= @dc_suffix %>"
peopledn = f"ou=people,{basedn}"
<%-
ldap_servers.map! { |l| "'ldaps://#{l}'" }
-%>
uris = [<%= ldap_servers.join(", ") %>]
random.shuffle(uris)
uri = " ".join(uris)
timeout = 5
binddn = f"cn=<%= @fqdn %>,ou=Hosts,{basedn}"
ldap_secret_file = "<%= @ldap_pwfile %>"
nslcd_conf_file = "<%= @nslcd_conf_file %>"
# filter out disabled accounts also
# too bad uidNumber doesn't support >= filters
objfilter = "(&(objectClass=inetOrgPerson)(objectClass=ldapPublicKey)(objectClass=posixAccount)(sshPublicKey=*))"
keypathprefix = "/home"
parser = argparse.ArgumentParser(
formatter_class=argparse.RawDescriptionHelpFormatter,
description=textwrap.dedent(f'''\
Will fetch all enabled user accounts under {peopledn}
with ssh keys in them and write each one to
{keypathprefix}/<login>/.ssh/authorized_keys
It will return failure when no keys are updated and success
when one or more keys have changed.
This script is intended to be run from cron as root;
'''))
parser.add_argument('-n', '--dry-run', action='store_true')
parser.add_argument('-v', '--verbose', action='store_true')
args = parser.parse_args()
def get_bindpw() -> str:
try:
return get_nslcd_bindpw(nslcd_conf_file)
except:
pass
try:
return get_ldap_secret(ldap_secret_file)
except:
pass
print("Error while reading password file, aborting")
sys.exit(1)
def get_nslcd_bindpw(pwfile: str) -> str:
try:
with open(pwfile, 'r') as f:
pwfield = "bindpw"
for line in f:
ls = line.strip().split()
if len(ls) == 2 and ls[0] == pwfield:
return ls[1]
except IOError as e:
print("Error while reading nslcd file " + pwfile)
print(e)
raise
print("No " + pwfield + " field found in nslcd file " + pwfile)
raise Exception()
def get_ldap_secret(pwfile: str) -> str:
try:
with open(pwfile, 'r') as f:
pw = f.readline().strip()
except IOError as e:
print("Error while reading password file " + pwfile)
print(e)
raise
return pw
def write_keys(keys: Iterable[bytes], user: bytes, uid: int, gid: int) -> bool:
userdir = f"{keypathprefix}/{user.decode('utf-8')}"
keyfile = f"{userdir}/.ssh/authorized_keys"
fromldap = ""
for key in keys:
fromldap += key.decode("utf-8").strip() + "\n"
fromfile = ""
try:
with open(keyfile, 'r') as f:
fromfile = f.read()
except FileNotFoundError:
pass
if fromldap == fromfile:
return False
if args.dry_run:
print(f"Would write {keyfile}")
return True
if args.verbose:
print(f"Writing {keyfile}")
if not os.path.isdir(userdir):
shutil.copytree('/etc/skel', userdir)
os.chown(userdir, uid, gid)
for root, dirs, files in os.walk(userdir):
for d in dirs:
os.chown(os.path.join(root, d), uid, gid)
for f in files:
os.chown(os.path.join(root, f), uid, gid)
try:
os.makedirs(f"{userdir}/.ssh", 0o700)
except FileExistsError:
pass
os.chmod(f"{userdir}/.ssh", 0o700)
os.chown(f"{userdir}/.ssh", uid, gid)
with tempfile.NamedTemporaryFile(
prefix='ldap-sshkey2file-', mode='w', delete=False) as tmpfile:
tmpfile.write(fromldap)
os.chmod(tmpfile.name, 0o600)
os.chown(tmpfile.name, uid, gid)
shutil.move(tmpfile.name, keyfile)
# Hmm, apparently shutil.move does not preserve user/group so let's reapply
# them. I still like doing it before as this should be more "atomic"
# if it actually worked, so it's "good practice", even if shutil.move sucks
os.chown(keyfile, uid, gid)
os.chmod(keyfile, 0o600)
return True
bindpw = get_bindpw()
changed = False
try:
ld = ldap.initialize(uri)
ld.set_option(ldap.OPT_NETWORK_TIMEOUT, timeout)
if uri.startswith("ldap:/"):
ld.start_tls_s()
ld.bind_s(binddn, bindpw)
res = ld.search_s(peopledn, ldap.SCOPE_ONELEVEL, objfilter,
['uid', 'sshPublicKey', 'uidNumber', 'gidNumber'])
try:
os.makedirs(keypathprefix, 0o701)
except FileExistsError:
pass
if args.verbose:
print("Found users:",
", ".join(sorted([x[1]['uid'][0].decode('utf-8') for x in res])))
for result in res:
dn, entry = result
# skip possible system users
if 'uidNumber' not in entry or int(entry['uidNumber'][0]) < 500:
continue
if write_keys(entry['sshPublicKey'], entry['uid'][0],
int(entry['uidNumber'][0]), int(entry['gidNumber'][0])):
changed = True
ld.unbind_s()
except Exception:
print("Error")
raise
if changed:
if args.verbose:
print("SSH keys changed")
sys.exit(0)
if args.verbose:
print("No changes in SSH keys")
sys.exit(1)
# vim:ts=4:sw=4:et:ai:si
|
