# Authors: Rob Crittenden <rcritten@redhat.com>
#
# Copyright (C) 2007  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; version 2 only
#
# 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, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#

import os
import os.path
import tempfile
import logging
import pwd
import shutil

import service
import certs
import dsinstance
import installutils
from ipapython import sysrestore
from ipapython import ipautil

HTTPD_DIR = "/etc/httpd"
SSL_CONF = HTTPD_DIR + "/conf.d/ssl.conf"
NSS_CONF = HTTPD_DIR + "/conf.d/nss.conf"
NSS_DIR  = HTTPD_DIR + "/alias"

selinux_warning = """WARNING: could not set selinux boolean httpd_can_network_connect to true.
The web interface may not function correctly until this boolean is
successfully change with the command:
   /usr/sbin/setsebool -P httpd_can_network_connect true
Try updating the policycoreutils and selinux-policy packages.
"""

class WebGuiInstance(service.SimpleServiceInstance):
    def __init__(self):
        service.SimpleServiceInstance.__init__(self, "ipa_webgui")

class HTTPInstance(service.Service):
    def __init__(self, fstore = None):
        service.Service.__init__(self, "httpd")
        if fstore:
            self.fstore = fstore
        else:
            self.fstore = sysrestore.FileStore('/var/lib/ipa/sysrestore')

    def create_instance(self, realm, fqdn, domain_name, autoconfig=True, pkcs12_info=None, self_signed_ca=False):
        self.fqdn = fqdn
        self.realm = realm
        self.domain = domain_name
        self.pkcs12_info = pkcs12_info
        self.self_signed_ca = self_signed_ca
        self.sub_dict = { "REALM" : realm, "FQDN": fqdn, "DOMAIN" : self.domain }

        self.step("disabling mod_ssl in httpd", self.__disable_mod_ssl)
        self.step("Setting mod_nss port to 443", self.__set_mod_nss_port)
        self.step("Setting mod_nss password file", self.__set_mod_nss_passwordfile)
        self.step("Adding URL rewriting rules", self.__add_include)
        self.step("configuring httpd", self.__configure_http)
        self.step("creating a keytab for httpd", self.__create_http_keytab)
        self.step("Setting up ssl", self.__setup_ssl)
        if autoconfig:
            self.step("Setting up browser autoconfig", self.__setup_autoconfig)
        self.step("publish CA cert", self.__publish_ca_cert)
        self.step("configuring SELinux for httpd", self.__selinux_config)
        self.step("restarting httpd", self.__start)
        self.step("configuring httpd to start on boot", self.__enable)

        self.start_creation("Configuring the web interface")

    def __start(self):
        self.backup_state("running", self.is_running())
        self.restart()

    def __enable(self):
        self.backup_state("enabled", self.is_running())
        self.chkconfig_on()

    def __selinux_config(self):
        selinux=0
        try:
            if (os.path.exists('/usr/sbin/selinuxenabled')):
                ipautil.run(["/usr/sbin/selinuxenabled"])
                selinux=1
        except ipautil.CalledProcessError:
            # selinuxenabled returns 1 if not enabled
            pass

        if selinux:
            try:
                # returns e.g. "httpd_can_network_connect --> off"
                (stdout, stderr) = ipautil.run(["/usr/sbin/getsebool",
                                                "httpd_can_network_connect"])
                self.backup_state("httpd_can_network_connect", stdout.split()[2])
            except:
                pass

            # Allow apache to connect to the turbogears web gui
            # This can still fail even if selinux is enabled
            try:
                ipautil.run(["/usr/sbin/setsebool", "-P", "httpd_can_network_connect", "true"])
            except:
                self.print_msg(selinux_warning)

    def __create_http_keytab(self):
        http_principal = "HTTP/" + self.fqdn + "@" + self.realm
        installutils.kadmin_addprinc(http_principal)
        installutils.create_keytab("/etc/httpd/conf/ipa.keytab", http_principal)

        pent = pwd.getpwnam("apache")
        os.chown("/etc/httpd/conf/ipa.keytab", pent.pw_uid, pent.pw_gid)

    def __configure_http(self):
        http_txt = ipautil.template_file(ipautil.SHARE_DIR + "ipa.conf", self.sub_dict)
        self.fstore.backup_file("/etc/httpd/conf.d/ipa.conf")
        http_fd = open("/etc/httpd/conf.d/ipa.conf", "w")
        http_fd.write(http_txt)
        http_fd.close()

        http_txt = ipautil.template_file(ipautil.SHARE_DIR + "ipa-rewrite.conf", self.sub_dict)
        self.fstore.backup_file("/etc/httpd/conf.d/ipa-rewrite.conf")
        http_fd = open("/etc/httpd/conf.d/ipa-rewrite.conf", "w")
        http_fd.write(http_txt)
        http_fd.close()

    def __disable_mod_ssl(self):
        if os.path.exists(SSL_CONF):
            self.fstore.backup_file(SSL_CONF)
            os.unlink(SSL_CONF)

    def __set_mod_nss_port(self):
        self.fstore.backup_file(NSS_CONF)
        if installutils.update_file(NSS_CONF, '8443', '443') != 0:
            print "Updating port in %s failed." % NSS_CONF

    def __set_mod_nss_nickname(self, nickname):
        installutils.set_directive(NSS_CONF, 'NSSNickname', nickname)

    def __set_mod_nss_passwordfile(self):
        installutils.set_directive(NSS_CONF, 'NSSPassPhraseDialog', 'file:/etc/httpd/conf/password.conf')

    def __add_include(self):
        """This should run after __set_mod_nss_port so is already backed up"""
        if installutils.update_file(NSS_CONF, '</VirtualHost>', 'Include conf.d/ipa-rewrite.conf\n</VirtualHost>') != 0:
            print "Adding Include conf.d/ipa-rewrite to %s failed." % NSS_CONF

    def __setup_ssl(self):
        if self.self_signed_ca:
            ca_db = certs.CertDB(NSS_DIR)
        else:
            ca_db = certs.CertDB(NSS_DIR, host_name=self.fqdn)
        db = certs.CertDB(NSS_DIR)
        if self.pkcs12_info:
            db.create_from_pkcs12(self.pkcs12_info[0], self.pkcs12_info[1], passwd="")
            server_certs = db.find_server_certs()
            if len(server_certs) == 0:
                raise RuntimeError("Could not find a suitable server cert in import in %s" % self.pkcs12_info[0])

            db.create_password_conf()
            # We only handle one server cert
            nickname = server_certs[0][0]

            self.__set_mod_nss_nickname(nickname)
        else:
            if self.self_signed_ca:
                db.create_from_cacert(ca_db.cacert_fname)
                db.create_password_conf()
                db.create_server_cert("Server-Cert", self.fqdn, ca_db)
                db.create_signing_cert("Signing-Cert", "Object Signing Cert", ca_db)
            else:
                db.create_server_cert("Server-Cert", self.fqdn, ca_db)
                db.create_signing_cert("Signing-Cert", "Object Signing Cert", ca_db)
                db.create_password_conf()

        # Fix the database permissions
        os.chmod(NSS_DIR + "/cert8.db", 0660)
        os.chmod(NSS_DIR + "/key3.db", 0660)
        os.chmod(NSS_DIR + "/secmod.db", 0660)
        os.chmod(NSS_DIR + "/pwdfile.txt", 0660)

        pent = pwd.getpwnam("apache")
        os.chown(NSS_DIR + "/cert8.db", 0, pent.pw_gid )
        os.chown(NSS_DIR + "/key3.db", 0, pent.pw_gid )
        os.chown(NSS_DIR + "/secmod.db", 0, pent.pw_gid )
        os.chown(NSS_DIR + "/pwdfile.txt", 0, pent.pw_gid )

        # Fix SELinux permissions on the database
        ipautil.run(["/sbin/restorecon", NSS_DIR + "/cert8.db"])
        ipautil.run(["/sbin/restorecon", NSS_DIR + "/key3.db"])

        # In case this got generated as part of the install, reset the
        # context
        if ipautil.file_exists(certs.CA_SERIALNO):
            ipautil.run(["/sbin/restorecon", certs.CA_SERIALNO])
            os.chown(certs.CA_SERIALNO, 0, pent.pw_gid)
            os.chmod(certs.CA_SERIALNO, 0664)

    def __setup_autoconfig(self):
        prefs_txt = ipautil.template_file(ipautil.SHARE_DIR + "preferences.html.template", self.sub_dict)
        prefs_fd = open("/usr/share/ipa/html/preferences.html", "w")
        prefs_fd.write(prefs_txt)
        prefs_fd.close()

        # The signing cert is generated in __setup_ssl
        db = certs.CertDB(NSS_DIR)

        pwdfile = open(db.passwd_fname)
        pwd = pwdfile.read()
        pwdfile.close()

        tmpdir = tempfile.mkdtemp(prefix = "tmp-")
        shutil.copy("/usr/share/ipa/html/preferences.html", tmpdir)
        db.run_signtool(["-k", "Signing-Cert",
                         "-Z", "/usr/share/ipa/html/configure.jar",
                         "-e", ".html", "-p", pwd,
                         tmpdir])
        shutil.rmtree(tmpdir)

    def __publish_ca_cert(self):
        ca_db = certs.CertDB(NSS_DIR)
        shutil.copy(ca_db.cacert_fname, "/usr/share/ipa/html/ca.crt")
        os.chmod("/usr/share/ipa/html/ca.crt", 0444)

    def uninstall(self):
        running = self.restore_state("running")
        enabled = self.restore_state("enabled")

        if not running is None:
            self.stop()

        if not enabled is None and not enabled:
            self.chkconfig_off()

        for f in ["/etc/httpd/conf.d/ipa.conf", SSL_CONF, NSS_CONF]:
            try:
                self.fstore.restore_file(f)
            except ValueError, error:
                logging.debug(error)
                pass

        sebool_state = self.restore_state("httpd_can_network_connect")
        if not sebool_state is None:
            try:
                ipautil.run(["/usr/sbin/setsebool", "-P", "httpd_can_network_connect", sebool_state])
            except:
                self.print_msg(selinux_warning)

        if not running is None and running:
            self.start()