#! /usr/bin/python2 -E
# Authors: Rob Crittenden <rcritten@redhat.com>
#
# Copyright (C) 2011  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 shutil
from ConfigParser import RawConfigParser
from ipapython import ipautil

from ipaserver.install import installutils
from ipaserver.install import certs
from ipaserver.install.installutils import (
    ReplicaConfig, private_ccache, create_replica_config,
    validate_external_cert)
from ipaserver.install import dsinstance, cainstance, bindinstance
from ipaserver.install.replication import replica_conn_check
from ipapython import version
from ipalib import api, certstore, x509
from ipapython.dn import DN
from ipapython.config import IPAOptionParser
from ipapython import sysrestore
from ipapython import dogtag
from ipapython import certdb
from ipapython.ipa_log_manager import *
from ipaplatform import services
from ipaplatform.paths import paths

log_file_name = paths.IPAREPLICA_CA_INSTALL_LOG
REPLICA_INFO_TOP_DIR = None

def parse_options():
    usage = "%prog [options] REPLICA_FILE"
    parser = IPAOptionParser(usage=usage, version=version.VERSION)
    parser.add_option("-d", "--debug", dest="debug", action="store_true",
                      default=False, help="gather extra debugging information")
    parser.add_option("-p", "--password", dest="password", sensitive=True,
                      help="Directory Manager (existing master) password")
    parser.add_option("-w", "--admin-password", dest="admin_password", sensitive=True,
                      help="Admin user Kerberos password used for connection check")
    parser.add_option("--no-host-dns", dest="no_host_dns", action="store_true",
                      default=False,
                      help="Do not use DNS for hostname lookup during installation")
    parser.add_option("--skip-conncheck", dest="skip_conncheck", action="store_true",
                      default=False, help="skip connection check to remote master")
    parser.add_option("--skip-schema-check", dest="skip_schema_check", action="store_true",
                      default=False, help="skip check for updated CA DS schema on the remote master")
    parser.add_option("-U", "--unattended", dest="unattended", action="store_true",
                      default=False, help="unattended installation never prompts the user")
    parser.add_option("--external-ca", dest="external_ca", action="store_true",
                      default=False, help="Generate a CSR to be signed by an external CA")
    parser.add_option("--external_cert_file", dest="external_cert_file",
                      help="PEM file containing a certificate signed by the external CA")
    parser.add_option("--external_ca_file", dest="external_ca_file",
                      help="PEM file containing the external CA chain")

    options, args = parser.parse_args()
    safe_options = parser.get_safe_opts(options)

    if args:
        filename = args[0]

        if len(args) != 1:
            parser.error("you must provide a file generated by "
                         "ipa-replica-prepare")
    else:
        filename = None

        if options.external_ca:
            if options.external_cert_file:
                parser.error("You cannot specify --external_cert_file "
                             "together with --external-ca")
            if options.external_ca_file:
                parser.error("You cannot specify --external_ca_file together "
                             "with --external-ca")

    return safe_options, options, filename


def get_dirman_password():
    return installutils.read_password(
        "Directory Manager (existing master)", confirm=False, validate=False)


def install_dns_records(config, options):

    if not bindinstance.dns_container_exists(config.master_host_name,
                                             ipautil.realm_to_suffix(config.realm_name),
                                             dm_password=config.dirman_password):
        return

    bind = bindinstance.BindInstance(dm_password=config.dirman_password)
    disconnect = False
    try:
        if not api.Backend.ldap2.isconnected():
            api.Backend.ldap2.connect(bind_dn=DN(('cn', 'Directory Manager')),
                                      bind_pw=config.dirman_password)
            disconnect = True
        bind.add_ipa_ca_dns_records(config.host_name, config.domain_name)
    finally:
        if api.Backend.ldap2.isconnected() and disconnect:
            api.Backend.ldap2.disconnect()


def install_replica(safe_options, options, filename):
    standard_logging_setup(log_file_name, debug=options.debug)

    root_logger.debug('%s was invoked with argument "%s" and options: %s',
        sys.argv[0], filename, safe_options)
    root_logger.debug('IPA version %s', version.VENDOR_VERSION)

    if not ipautil.file_exists(filename):
        sys.exit("Replica file %s does not exist" % filename)

    global sstore
    sstore = sysrestore.StateFile(paths.SYSRESTORE)

    if not dsinstance.DsInstance().is_configured():
        sys.exit("IPA server is not configured on this system.\n")

    api.bootstrap(in_server=True)
    api.finalize()

    if api.env.ra_plugin == 'selfsign':
        sys.exit('A selfsign CA can not be added')

    # get the directory manager password
    dirman_password = options.password
    if not dirman_password:
        if options.unattended:
            sys.exit('Directory Manager password required')
        try:
            dirman_password = get_dirman_password()
        except KeyboardInterrupt:
            sys.exit(0)
        if dirman_password is None:
            sys.exit("Directory Manager password required")

    if not options.admin_password and not options.skip_conncheck and \
            options.unattended:
        sys.exit('admin password required')

    config = create_replica_config(dirman_password, filename, options)
    global REPLICA_INFO_TOP_DIR
    REPLICA_INFO_TOP_DIR = config.top_dir
    config.setup_ca = True

    if not ipautil.file_exists(config.dir + "/cacert.p12"):
        print 'CA cannot be installed in CA-less setup.'
        sys.exit(1)

    if not options.skip_conncheck:
        replica_conn_check(
            config.master_host_name, config.host_name, config.realm_name, True,
            config.ca_ds_port, options.admin_password)

    if options.skip_schema_check:
        root_logger.info("Skipping CA DS schema check")
    else:
        cainstance.replica_ca_install_check(config)

    # Configure the CA if necessary
    CA = cainstance.install_replica_ca(config, postinstall=True)

    # We need to ldap_enable the CA now that DS is up and running
    CA.ldap_enable('CA', config.host_name, config.dirman_password,
                   ipautil.realm_to_suffix(config.realm_name))

    # This is done within stopped_service context, which restarts CA
    CA.enable_client_auth_to_db(CA.dogtag_constants.CS_CFG_PATH)

    # Install CA DNS records
    install_dns_records(config, options)

    # We need to restart apache as we drop a new config file in there
    services.knownservices.httpd.restart(capture_output=True)

    #update dogtag version in config file
    try:
        fd = open(paths.IPA_DEFAULT_CONF, "a")
        fd.write(
            "dogtag_version=%s\n" % dogtag.install_constants.DOGTAG_VERSION)
        fd.close()
    except IOError, e:
        print "Failed to update /etc/ipa/default.conf"
        root_logger.error(str(e))
        sys.exit(1)


def install_master(safe_options, options):
    standard_logging_setup(paths.IPASERVER_CA_INSTALL_LOG, debug=options.debug)

    root_logger.debug(
        "%s was invoked with options: %s", sys.argv[0], safe_options)
    root_logger.debug("IPA version %s", version.VENDOR_VERSION)

    global sstore
    sstore = sysrestore.StateFile(paths.SYSRESTORE)

    if not dsinstance.DsInstance().is_configured():
        sys.exit("IPA server is not configured on this system.\n")

    api.bootstrap(in_server=True)
    api.finalize()

    if api.env.enable_ra:
        sys.exit("CA is already installed.\n")

    dm_password = options.password
    if not dm_password:
        if options.unattended:
            sys.exit('Directory Manager password required')
        try:
            dm_password = get_dirman_password()
        except KeyboardInterrupt:
            sys.exit(0)
        if dm_password is None:
            sys.exit("Directory Manager password required")

    api.Backend.ldap2.connect(bind_dn=DN(('cn', 'Directory Manager')),
                              bind_pw=dm_password)

    config = api.Command['config_show']()['result']
    subject_base = config['ipacertificatesubjectbase'][0]

    if options.external_ca:
        if cainstance.is_step_one_done():
            print ("CA is already installed.\nRun the installer with "
                   "--external-cert-file and --external-ca-file.")
            sys.exit(1)
    elif options.external_cert_file:
        if not cainstance.is_step_one_done():
            print ("CA is not installed yet. To install with an external CA "
                   "is a two-stage process.\nFirst run the installer with "
                   "--external-ca.")
            sys.exit(1)

        try:
            validate_external_cert(options.external_cert_file,
                                   options.external_ca_file, subject_base)
        except ValueError, e:
            print e
            sys.exit(1)

    if options.external_cert_file:
        external = 2
    elif options.external_ca:
        external = 1
    else:
        external = 0

    realm_name = api.env.realm
    domain_name = api.env.domain
    host_name = api.env.host

    dirname = dsinstance.config_dirname(
        dsinstance.realm_to_serverid(realm_name))
    cadb = certs.CertDB(realm_name, subject_base=subject_base)
    dsdb = certs.CertDB(realm_name, nssdir=dirname, subject_base=subject_base)

    for db in (cadb, dsdb):
        for nickname, trust_flags in db.list_certs():
            if nickname in (certdb.get_ca_nickname(realm_name),
                            'ipaCert',
                            'Signing-Cert'):
                print ("Certificate with nickname %s is present in %s, "
                       "cannot continue." % (nickname, db.secdir))
                sys.exit(1)

            cert = db.get_cert_from_db(nickname)
            if not cert:
                continue
            subject = DN(str(x509.get_subject(cert)))
            if subject in (DN('CN=Certificate Authority', subject_base),
                           DN('CN=IPA RA', subject_base),
                           DN('CN=Object Signing Cert', subject_base)):
                print ("Certificate with subject %s is present in %s, "
                       "cannot continue." % (subject, db.secdir))
                sys.exit(1)

    ca = cainstance.CAInstance(
        realm_name, certs.NSS_DIR,
        dogtag_constants=dogtag.install_constants)
    ca.create_ra_agent_db = False
    if external == 0:
        ca.configure_instance(host_name, domain_name, dm_password,
                              dm_password, subject_base=subject_base)
    elif external == 1:
        ca.configure_instance(host_name, domain_name, dm_password,
                              dm_password, csr_file=paths.ROOT_IPA_CSR,
                              subject_base=subject_base)
    else:
        ca.configure_instance(host_name, domain_name, dm_password,
                              dm_password,
                              cert_file=options.external_cert_file,
                              cert_chain_file=options.external_ca_file,
                              subject_base=subject_base)

    ca.stop(ca.dogtag_constants.PKI_INSTANCE_NAME)

    ca.ldap_enable('CA', host_name, dm_password,
                   ipautil.realm_to_suffix(realm_name), ['caRenewalMaster'])

    ca.enable_client_auth_to_db(ca.dogtag_constants.CS_CFG_PATH)

    # Install CA DNS records
    config = ReplicaConfig()
    config.realm_name = realm_name
    config.domain_name = domain_name
    config.host_name = config.master_host_name = host_name
    config.dirman_password = dm_password
    install_dns_records(config, options)

    # We need to restart apache as we drop a new config file in there
    services.knownservices.httpd.restart(capture_output=True)

    # Update config file
    parser = RawConfigParser()
    parser.read(paths.IPA_DEFAULT_CONF)
    parser.set('global', 'enable_ra', 'True')
    parser.set('global', 'ra_plugin', 'dogtag')
    parser.set('global', 'dogtag_version',
               str(ca.dogtag_constants.DOGTAG_VERSION))
    with open(paths.IPA_DEFAULT_CONF, 'w') as f:
        parser.write(f)

    # Store the new IPA CA cert chain in DS NSS database and LDAP
    cadb = certs.CertDB(realm_name, subject_base=subject_base)
    dsdb = certs.CertDB(realm_name, nssdir=dirname, subject_base=subject_base)
    trust_flags = dict(reversed(cadb.list_certs()))
    trust_chain = cadb.find_root_cert('ipaCert')[:-1]
    for nickname in trust_chain[:-1]:
        cert = cadb.get_cert_from_db(nickname, pem=False)
        dsdb.add_cert(cert, nickname, trust_flags[nickname])
        certstore.put_ca_cert_nss(api.Backend.ldap2, api.env.basedn,
                                  cert, nickname, trust_flags[nickname])

    nickname = trust_chain[-1]
    cert = cadb.get_cert_from_db(nickname, pem=False)
    dsdb.add_cert(cert, nickname, trust_flags[nickname])
    certstore.put_ca_cert_nss(api.Backend.ldap2, api.env.basedn,
                              cert, nickname, trust_flags[nickname],
                              config_ipa=True, config_compat=True)

    # Restart DS
    ds = dsinstance.DsInstance()
    ds.init_info(realm_name, host_name, domain_name, dm_password, subject_base,
                 1101, 1100, None)
    ds.restart(ds.serverid)

    # Store DS CA cert in Dogtag NSS database
    dogtagdb = certs.CertDB(realm_name, nssdir=ca.dogtag_constants.ALIAS_DIR)
    trust_flags = dict(reversed(dsdb.list_certs()))
    server_certs = dsdb.find_server_certs()
    trust_chain = dsdb.find_root_cert(server_certs[0][0])[:-1]
    nickname = trust_chain[-1]
    cert = dsdb.get_cert_from_db(nickname)
    dogtagdb.add_cert(cert, nickname, trust_flags[nickname])

    ca.start(ca.dogtag_constants.PKI_INSTANCE_NAME)


def main():
    safe_options, options, filename = parse_options()

    if os.geteuid() != 0:
        sys.exit("\nYou must be root to run this script.\n")

    if filename is not None:
        install_replica(safe_options, options, filename)
    else:
        install_master(safe_options, options)

fail_message = '''
Your system may be partly configured.
Run /usr/sbin/ipa-server-install --uninstall to clean up.
'''

if __name__ == '__main__':
    try:
        with private_ccache():
            installutils.run_script(main, log_file_name=log_file_name,
                                    operation_name='ipa-ca-install',
                                    fail_message=fail_message)
    finally:
        # always try to remove decrypted replica file
        try:
            if REPLICA_INFO_TOP_DIR:
                shutil.rmtree(REPLICA_INFO_TOP_DIR)
        except OSError:
            pass