#!/usr/bin/python

import sys
import os
import random
import shutil
import tempfile

try:
    import ldap
except ImportError, e:
    print "Please install python-ldap before running this program"
    sys.exit(1)

basedn="<%= dc_suffix %>"
peopledn="ou=people,%s" % basedn
<%-
  ldap_servers.map! { |l| "'ldaps://#{l}'" }
-%>
uris=[<%= ldap_servers.join(", ") %>]
random.shuffle(uris)
uri = " ".join(uris)
timeout=5
binddn="cn=<%= fqdn %>,ou=Hosts,%s" % basedn
pwfile="<%= ldap_pwfile %>"
# filter out disabled accounts also
# too bad uidNumber doesn't support >= filters
filter="(&(objectClass=inetOrgPerson)(objectClass=ldapPublicKey)(objectClass=posixAccount)(sshPublicKey=*))"
keypathprefix='/home'

def usage():
    print "%s" % sys.argv[0]
    print
    print "Will fetch all enabled user accounts under %s" % peopledn
    print "with ssh keys in them and write each one to"
    print "%s/<login>/authorized_keys" % keypathprefix
    print
    print "It will return failure when no keys are updated and success"
    print "when one or more keys have changed."
    print
    print "This script is intented to be run from cron as root"
    print

def get_pw(pwfile):
    try:
        f = open(pwfile, 'r')
    except IOError, e:
        print "Error while reading password file, aborting"
        print e
        sys.exit(1)
    pw = f.readline().strip()
    f.close()
    return pw

def write_keys(keys, user, uid, gid):
    if not os.path.isdir("%s/%s" % (keypathprefix,user)):
       shutil.copytree('/etc/skel', "%s/%s" % (keypathprefix,user))
       os.chown("%s/%s" % (keypathprefix,user), uid, gid)
       for root, dirs, files in os.walk("%s/%s" % (keypathprefix,user)):
           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("%s/%s/.ssh" % (keypathprefix,user), 0700)
    except:
        pass
    os.chmod("%s/%s/.ssh" % (keypathprefix,user), 0700)
    os.chown("%s/%s/.ssh" % (keypathprefix,user), uid, gid)

    keyfile = "%s/%s/.ssh/authorized_keys" % (keypathprefix,user)

    fromldap = ''
    for key in keys:
        fromldap += key.strip() + "\n"

    fromfile = ''
    try:
        f = open(keyfile, 'r')
        fromfile = f.read()
        f.close()
    except:
        pass

    if fromldap != fromfile:
        (fd, tmpname) = tempfile.mkstemp('', 'ldap-sshkey2file-')
        os.write(fd, fromldap);
        os.close(fd)
        os.chmod(tmpname, 0600)
        os.chown(tmpname, uid, gid)
        shutil.move(tmpname, keyfile)
        # Hmm, aparently shutil.move does not preserve user/group so lets reapply
        # them. I still like doing it before as this should be more "automic"
        # if it actually worked, so it's "good practice", even if shutil.move sucks
        os.chown(keyfile, uid, gid)
        os.chmod(keyfile, 0600)
        return True

    return False


if len(sys.argv) != 1:
    usage()
    sys.exit(1)

bindpw = get_pw(pwfile)

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, filter, ['uid','sshPublicKey','uidNumber','gidNumber'])
    try:
        os.makedirs(keypathprefix, 0701)
    except:
        pass

    for result in res:
        dn, entry = result
        # skip possible system users
        if 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, e:
    print "Error"
    raise

if changed:
    sys.exit(0)

sys.exit(1)


# vim:ts=4:sw=4:et:ai:si