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#!/usr/bin/python2
from ipaserver import dcerpc
from ipaserver.install.installutils import is_ipa_configured, ScriptError
from ipapython import config, ipautil
from ipalib import api
from ipapython.dn import DN
from ipalib.config import Env
from ipalib.constants import DEFAULT_CONFIG
from ipapython.ipautil import kinit_keytab
from ipaplatform.constants import constants
import sys
import os
import pwd
import six
import gssapi
if six.PY3:
unicode = str
def retrieve_keytab(api, ccache_name, oneway_keytab_name, oneway_principal):
getkeytab_args = ["/usr/sbin/ipa-getkeytab",
"-s", api.env.host,
"-p", oneway_principal,
"-k", oneway_keytab_name,
"-r"]
if os.path.isfile(oneway_keytab_name):
os.unlink(oneway_keytab_name)
ipautil.run(getkeytab_args, env={'KRB5CCNAME': ccache_name, 'LANG': 'C'},
raiseonerr=False)
# Make sure SSSD is able to read the keytab
try:
sssd = pwd.getpwnam(constants.SSSD_USER)
os.chown(oneway_keytab_name, sssd[2], sssd[3])
except KeyError as e:
# If user 'sssd' does not exist, we don't need to chown from root to sssd
# because it means SSSD does not run as sssd user
pass
def parse_options():
usage = "%prog <trusted domain name>\n"
parser = config.IPAOptionParser(usage=usage,
formatter=config.IPAFormatter())
parser.add_option("-d", "--debug", action="store_true", dest="debug",
help="Display debugging information")
options, args = parser.parse_args()
safe_options = parser.get_safe_opts(options)
return safe_options, options, args
if not is_ipa_configured():
# LSB status code 6: program is not configured
raise ScriptError("IPA is not configured " +
"(see man pages of ipa-server-install for help)", 6)
if not os.getegid() == 0:
# LSB status code 4: user had insufficient privilege
raise ScriptError("You must be root to run ipactl.", 4)
safe_options, options, args = parse_options()
if len(args) != 1:
# LSB status code 2: invalid or excess argument(s)
raise ScriptError("You must specify trusted domain name", 2)
trusted_domain = ipautil.fsdecode(args[0]).lower()
env = Env()
env._bootstrap(debug=options.debug, log=None)
env._finalize_core(**dict(DEFAULT_CONFIG))
# Initialize the API with the proper debug level
api.bootstrap(debug=env.debug, log=None)
api.finalize()
# Only import trust plugin after api is initialized or internal imports
# within the plugin will not work
from ipaserver.plugins import trust
# We have to dance with two different credentials caches:
# ccache_name -- for cifs/ipa.master@IPA.REALM to communicate with LDAP
# oneway_ccache_name -- for IPA$@AD.REALM to communicate with AD DCs
#
# ccache_name may not exist, we'll have to initialize it from Samba's keytab
#
# oneway_ccache_name may not exist either but to initialize it, we need
# to check if oneway_keytab_name keytab exists and fetch it first otherwise.
#
# to fetch oneway_keytab_name keytab, we need to initialize ccache_name ccache first
# and retrieve our own NetBIOS domain name and use cifs/ipa.master@IPA.REALM to
# retrieve the keys to oneway_keytab_name.
keytab_name = '/etc/samba/samba.keytab'
principal = str('cifs/' + api.env.host)
oneway_ccache_name = '/var/run/ipa/krb5cc_oddjob_trusts_fetch'
ccache_name = '/var/run/ipa/krb5cc_oddjob_trusts'
# Standard sequence:
# - check if ccache exists
# - if not, initialize it from Samba's keytab
# - check if ccache contains valid TGT
# - if not, initialize it from Samba's keytab
# - refer the correct ccache object for further use
#
have_ccache = False
try:
cred = kinit_keytab(principal, keytab_name, ccache_name)
if cred.lifetime > 0:
have_ccache = True
except gssapi.exceptions.ExpiredCredentialsError:
pass
if not have_ccache:
# delete stale ccache and try again
if os.path.exists(oneway_ccache_name):
os.unlink(ccache_name)
cred = kinit_keytab(principal, keytab_name, ccache_name)
old_ccache = os.environ.get('KRB5CCNAME')
api.Backend.ldap2.connect(ccache_name)
# Retrieve own NetBIOS name and trusted forest's name.
# We use script's input to retrieve the trusted forest's name to sanitize input
# for file-level access as we might need to wipe out keytab in /var/lib/sss/keytabs
own_trust_dn = DN(('cn', api.env.domain),('cn','ad'), ('cn', 'etc'), api.env.basedn)
own_trust_entry = api.Backend.ldap2.get_entry(own_trust_dn, ['ipantflatname'])
own_trust_flatname = own_trust_entry.single_value.get('ipantflatname').upper()
trusted_domain_dn = DN(('cn', trusted_domain.lower()), api.env.container_adtrusts, api.env.basedn)
trusted_domain_entry = api.Backend.ldap2.get_entry(trusted_domain_dn, ['cn'])
trusted_domain = trusted_domain_entry.single_value.get('cn').lower()
# At this point if we didn't find trusted forest name, an exception will be raised
# and script will quit. This is actually intended.
oneway_keytab_name = '/var/lib/sss/keytabs/' + trusted_domain + '.keytab'
oneway_principal = str('%s$@%s' % (own_trust_flatname, trusted_domain.upper()))
# If keytab does not exist, retrieve it
if not os.path.isfile(oneway_keytab_name):
retrieve_keytab(api, ccache_name, oneway_keytab_name, oneway_principal)
try:
have_ccache = False
try:
# The keytab may have stale key material (from older trust-add run)
cred = kinit_keytab(oneway_principal, oneway_keytab_name, oneway_ccache_name)
if cred.lifetime > 0:
have_ccache = True
except gssapi.exceptions.ExpiredCredentialsError:
pass
if not have_ccache:
if os.path.exists(oneway_ccache_name):
os.unlink(oneway_ccache_name)
kinit_keytab(oneway_principal, oneway_keytab_name, oneway_ccache_name)
except gssapi.exceptions.GSSError:
# If there was failure on using keytab, assume it is stale and retrieve again
retrieve_keytab(api, ccache_name, oneway_keytab_name, oneway_principal)
if os.path.exists(oneway_ccache_name):
os.unlink(oneway_ccache_name)
kinit_keytab(oneway_principal, oneway_keytab_name, oneway_ccache_name)
# We are done: we have ccache with TDO credentials and can fetch domains
ipa_domain = api.env.domain
os.environ['KRB5CCNAME'] = oneway_ccache_name
domains = dcerpc.fetch_domains(api, ipa_domain, trusted_domain, creds=True)
trust_domain_object = api.Command.trust_show(trusted_domain, raw=True)['result']
trust.add_new_domains_from_trust(api, None, trust_domain_object, domains)
if old_ccache:
os.environ['KRB5CCNAME'] = old_ccache
sys.exit(0)
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