# Authors: Karl MacMillan <kmacmillan@mentalrootkit.com>
#          Jan Cholasta <jcholast@redhat.com>
#
# Copyright (C) 2007-2013  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 os
import os.path
import pwd
import optparse

from ipaplatform.constants import constants
from ipaplatform.paths import paths
from ipapython import admintool
from ipapython.dn import DN
from ipalib import api, errors
from ipalib.constants import CACERT
from ipaserver.install import certs, dsinstance, installutils


class ServerCertInstall(admintool.AdminTool):
    command_name = 'ipa-server-certinstall'

    usage = "%prog <-d|-w> [options] <file> ..."

    description = "Install new SSL server certificates."

    @classmethod
    def add_options(cls, parser):
        super(ServerCertInstall, cls).add_options(parser)

        parser.add_option(
            "-d", "--dirsrv",
            dest="dirsrv", action="store_true", default=False,
            help="install certificate for the directory server")
        parser.add_option(
            "-w", "--http",
            dest="http", action="store_true", default=False,
            help="install certificate for the http server")
        parser.add_option(
            "--pin",
            dest="pin", metavar="PIN", sensitive=True,
            help="The password of the PKCS#12 file")
        parser.add_option(
            "--dirsrv_pin", "--http_pin",
            dest="pin",
            help=optparse.SUPPRESS_HELP)
        parser.add_option(
            "--cert-name",
            dest="cert_name", metavar="NAME",
            help="Name of the certificate to install")
        parser.add_option(
            "-p", "--dirman-password",
            dest="dirman_password",
            help="Directory Manager password")

    def validate_options(self):
        super(ServerCertInstall, self).validate_options(needs_root=True)

        installutils.check_server_configuration()

        if not self.options.dirsrv and not self.options.http:
            self.option_parser.error("you must specify dirsrv and/or http")

        if not self.args:
            self.option_parser.error("you must provide certificate filename")

    def ask_for_options(self):
        super(ServerCertInstall, self).ask_for_options()

        if not self.options.dirman_password:
            self.options.dirman_password = installutils.read_password(
                "Directory Manager", confirm=False, validate=False, retry=False)
            if self.options.dirman_password is None:
                raise admintool.ScriptError(
                    "Directory Manager password required")

        if self.options.pin is None:
            self.options.pin = installutils.read_password(
                "Enter private key unlock", confirm=False, validate=False)
            if self.options.pin is None:
                raise admintool.ScriptError(
                    "Private key unlock password required")

    def run(self):
        api.bootstrap(in_server=True)
        api.finalize()

        conn = api.Backend.ldap2
        conn.connect(bind_dn=DN(('cn', 'directory manager')),
                     bind_pw=self.options.dirman_password)

        if self.options.dirsrv:
            self.install_dirsrv_cert()

        if self.options.http:
            self.install_http_cert()

        conn.disconnect()

    def install_dirsrv_cert(self):
        serverid = installutils.realm_to_serverid(api.env.realm)
        dirname = dsinstance.config_dirname(serverid)

        conn = api.Backend.ldap2
        entry = conn.get_entry(DN(('cn', 'RSA'), ('cn', 'encryption'),
                                  ('cn', 'config')),
                               ['nssslpersonalityssl'])
        old_cert = entry.single_value['nssslpersonalityssl']

        server_cert = self.import_cert(dirname, self.options.pin,
                                       old_cert, 'ldap/%s' % api.env.host,
                                       'restart_dirsrv %s' % serverid)

        entry['nssslpersonalityssl'] = [server_cert]
        try:
            conn.update_entry(entry)
        except errors.EmptyModlist:
            pass

    def install_http_cert(self):
        dirname = certs.NSS_DIR

        old_cert = installutils.get_directive(paths.HTTPD_NSS_CONF,
                                              'NSSNickname')

        server_cert = self.import_cert(dirname, self.options.pin,
                                       old_cert, 'HTTP/%s' % api.env.host,
                                       'restart_httpd')

        installutils.set_directive(paths.HTTPD_NSS_CONF,
                                   'NSSNickname', server_cert)

        # Fix the database permissions
        os.chmod(os.path.join(dirname, 'cert8.db'), 0o640)
        os.chmod(os.path.join(dirname, 'key3.db'), 0o640)
        os.chmod(os.path.join(dirname, 'secmod.db'), 0o640)

        pent = pwd.getpwnam(constants.HTTPD_USER)
        os.chown(os.path.join(dirname, 'cert8.db'), 0, pent.pw_gid)
        os.chown(os.path.join(dirname, 'key3.db'), 0, pent.pw_gid)
        os.chown(os.path.join(dirname, 'secmod.db'), 0, pent.pw_gid)

    def import_cert(self, dirname, pkcs12_passwd, old_cert, principal, command):
        pkcs12_file, pin, ca_cert = installutils.load_pkcs12(
            cert_files=self.args,
            key_password=pkcs12_passwd,
            key_nickname=self.options.cert_name,
            ca_cert_files=[CACERT],
            host_name=api.env.host)

        cdb = certs.CertDB(api.env.realm, nssdir=dirname)
        try:
            ca_enabled = api.Command.ca_is_enabled()['result']
            if ca_enabled:
                cdb.untrack_server_cert(old_cert)

            cdb.delete_cert(old_cert)
            cdb.import_pkcs12(pkcs12_file.name, pin)
            server_cert = cdb.find_server_certs()[0][0]

            if ca_enabled:
                cdb.track_server_cert(server_cert, principal, cdb.passwd_fname,
                                      command)
        except RuntimeError as e:
            raise admintool.ScriptError(str(e))

        return server_cert