#!/usr/bin/python3
#
# Authors:
#   Rob Crittenden <rcritten@redhat.com>
#   Jan Cholasta <jcholast@redhat.com>
#
# Copyright (C) 2013  Red Hat
# see file 'COPYING' for use and warranty information
#
# 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 sys
import os
import syslog
import tempfile
import shutil
import traceback

from ipalib.install import certstore
from ipapython import directivesetter
from ipapython import ipautil
from ipalib import api, errors
from ipalib import x509
from ipalib.install.kinit import kinit_keytab
from ipaserver.install import certs, cainstance
from ipaserver.plugins.ldap2 import ldap2
from ipaplatform import services
from ipaplatform.paths import paths
from ipapython.certdb import TrustFlags


def _main():
    nickname = sys.argv[1]

    api.bootstrap(
        in_server=True, context='restart', confdir=paths.ETC_IPA, log=None
    )
    api.finalize()

    dogtag_service = services.knownservices['pki_tomcatd']

    # dogtag opens its NSS database in read/write mode so we need it
    # shut down so certmonger can open it read/write mode. This avoids
    # database corruption. It should already be stopped by the pre-command
    # but lets be sure.
    if dogtag_service.is_running('pki-tomcat'):
        syslog.syslog(
            syslog.LOG_NOTICE, "Stopping %s" % dogtag_service.service_name)
        try:
            dogtag_service.stop('pki-tomcat')
        except Exception as e:
            syslog.syslog(
                syslog.LOG_ERR,
                "Cannot stop %s: %s" % (dogtag_service.service_name, e))
        else:
            syslog.syslog(
                syslog.LOG_NOTICE, "Stopped %s" % dogtag_service.service_name)

    # Fetch the new certificate
    db = certs.CertDB(api.env.realm, nssdir=paths.PKI_TOMCAT_ALIAS_DIR)
    cert = db.get_cert_from_db(nickname)
    if not cert:
        syslog.syslog(syslog.LOG_ERR, 'No certificate %s found.' % nickname)
        sys.exit(1)

    tmpdir = tempfile.mkdtemp(prefix="tmp-")
    try:
        principal = str('host/%s@%s' % (api.env.host, api.env.realm))
        ccache_filename = os.path.join(tmpdir, 'ccache')
        kinit_keytab(principal, paths.KRB5_KEYTAB, ccache_filename)
        os.environ['KRB5CCNAME'] = ccache_filename

        api.Backend.ldap2.connect()

        ca = cainstance.CAInstance(host_name=api.env.host)
        ca.update_cert_config(nickname, cert)
        if ca.is_renewal_master():
            cainstance.update_people_entry(cert)
            cainstance.update_authority_entry(cert)

        if nickname == 'auditSigningCert cert-pki-ca':
            # Fix trust on the audit cert
            try:
                db.run_certutil(['-M',
                                 '-n', nickname,
                                 '-t', 'u,u,Pu'])
                syslog.syslog(
                    syslog.LOG_NOTICE,
                    "Updated trust on certificate %s in %s" %
                    (nickname, db.secdir))
            except ipautil.CalledProcessError:
                syslog.syslog(
                    syslog.LOG_ERR,
                    "Updating trust on certificate %s failed in %s" %
                    (nickname, db.secdir))
        elif nickname == 'caSigningCert cert-pki-ca':
            # Update CS.cfg
            cfg_path = paths.CA_CS_CFG_PATH
            config = directivesetter.get_directive(
                cfg_path, 'subsystem.select', '=')
            if config == 'New':
                syslog.syslog(syslog.LOG_NOTICE, "Updating CS.cfg")
                if cert.is_self_signed():
                    directivesetter.set_directive(
                        cfg_path, 'hierarchy.select', 'Root',
                        quotes=False, separator='=')
                    directivesetter.set_directive(
                        cfg_path, 'subsystem.count', '1',
                        quotes=False, separator='=')
                else:
                    directivesetter.set_directive(
                        cfg_path, 'hierarchy.select', 'Subordinate',
                        quotes=False, separator='=')
                    directivesetter.set_directive(
                        cfg_path, 'subsystem.count', '0',
                        quotes=False, separator='=')
            else:
                syslog.syslog(syslog.LOG_NOTICE, "Not updating CS.cfg")

            # Remove old external CA certificates
            for ca_nick, ca_flags in db.list_certs():
                if ca_flags.has_key:
                    continue
                # Delete *all* certificates that use the nickname
                while True:
                    try:
                        db.delete_cert(ca_nick)
                    except ipautil.CalledProcessError:
                        syslog.syslog(
                            syslog.LOG_ERR,
                            "Failed to remove certificate %s" % ca_nick)
                        break
                    if not db.has_nickname(ca_nick):
                        break

            conn = None
            try:
                conn = ldap2(api)
                conn.connect(ccache=ccache_filename)
            except Exception as e:
                syslog.syslog(
                    syslog.LOG_ERR, "Failed to connect to LDAP: %s" % e)
            else:
                # Update CA certificate in LDAP
                if ca.is_renewal_master():
                    try:
                        certstore.update_ca_cert(conn, api.env.basedn, cert)
                    except errors.EmptyModlist:
                        pass
                    except Exception as e:
                        syslog.syslog(
                            syslog.LOG_ERR,
                            "Updating CA certificate failed: %s" % e)

                # Add external CA certificates
                try:
                    ca_certs = certstore.get_ca_certs_nss(
                        conn, api.env.basedn, api.env.realm, False)
                except Exception as e:
                    syslog.syslog(
                        syslog.LOG_ERR,
                        "Failed to get external CA certificates from LDAP: "
                        "%s" % e)
                    ca_certs = []

                for ca_cert, ca_nick, ca_flags in ca_certs:
                    try:
                        db.add_cert(ca_cert, ca_nick, ca_flags)
                    except ipautil.CalledProcessError as e:
                        syslog.syslog(
                            syslog.LOG_ERR,
                            "Failed to add certificate %s" % ca_nick)

                # Pass Dogtag's self-tests
                for ca_nick in db.find_root_cert(nickname)[-2:-1]:
                    ca_flags = dict(cc[1:] for cc in ca_certs)[ca_nick]
                    usages = ca_flags.usages or set()
                    ca_flags_modified = TrustFlags(ca_flags.has_key,
                        True, True,
                        usages | {x509.EKU_SERVER_AUTH})
                    db.trust_root_cert(ca_nick, ca_flags_modified)
            finally:
                if conn is not None and conn.isconnected():
                    conn.disconnect()
    finally:
        if api.Backend.ldap2.isconnected():
            api.Backend.ldap2.disconnect()
        shutil.rmtree(tmpdir)

    # Now we can start the CA. Using the services start should fire
    # off the servlet to verify that the CA is actually up and responding so
    # when this returns it should be good-to-go. The CA was stopped in the
    # pre-save state.
    syslog.syslog(
        syslog.LOG_NOTICE,
        'Starting %s' % dogtag_service.service_name)
    try:
        dogtag_service.start('pki-tomcat')
    except Exception as e:
        syslog.syslog(
            syslog.LOG_ERR,
            "Cannot start %s: %s" % (dogtag_service.service_name, e))
    else:
        syslog.syslog(
            syslog.LOG_NOTICE, "Started %s" % dogtag_service.service_name)


def main():
    try:
        _main()
    finally:
        certs.renewal_lock.release('renew_ca_cert')


try:
    main()
except Exception:
    syslog.syslog(syslog.LOG_ERR, traceback.format_exc())
