#!/usr/bin/python
#
# Unix SMB/CIFS implementation.
# A script to compare differences of security descriotors between
# a remote host and the local Ldb
# Needs the local domain, the remote domain, IP of the remote host
# Username and password for the remote domain, must be at least
# Domain Administrator
#
# Copyright (C) Jelmer Vernooij <jelmer@samba.org> 2007-2008
# Copyright (C) Nadezhda Ivanova <nadezhda.ivanova@postpath.com> 2009
#
# Based on the original in EJS:
# Copyright (C) Andrew Tridgell <tridge@samba.org> 2005
#
# 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 getopt
import optparse
import sys
import os
import base64
import re

sys.path.insert(0, "bin/python")

import samba
from samba.auth import system_session
import samba.getopt as options
from samba import param
from samba.ndr import ndr_pack, ndr_unpack
from samba.dcerpc import security
from samba import Ldb
from samba.samdb import SamDB
from ldb import SCOPE_SUBTREE, SCOPE_ONELEVEL, SCOPE_BASE, LdbError

parser = optparse.OptionParser("get-descriptor [options]")
sambaopts = options.SambaOptions(parser)
credopts = options.CredentialsOptions(parser)
parser.add_option_group(credopts)

parser.add_option("--local-domain", type="string", metavar="LOCALDOMAIN",
                  help="set local domain")
parser.add_option("--remote-domain", type="string", metavar="REMOTEDOMAIN",
                  help="set remote domain")
parser.add_option("--host", type="string", metavar="HOST",
                  help="Ip of the remote host used for comparison")
parser.add_option("--as-ldif", help="Output in LDIF format", action="store_true")

lp = sambaopts.get_loadparm()
creds = credopts.get_credentials(lp)

opts = parser.parse_args()[0]

class DescrGetter:
    def __init__(self, localdomain, remotedomain):
        self.samdb = SamDB(session_info=system_session(), lp=lp, options=["modules:paged_searches"])
        self.remote_ldb= Ldb("ldap://" + opts.host + ":389", credentials=creds, lp=lp,
                             options=["modules:paged_searches"])
        self.local_domain = localdomain.replace(".", ",DC=")
        self.local_domain = "DC=" + self.local_domain
        self.remote_domain = remotedomain.replace(".", ",DC=")
        self.remote_domain = "DC=" + self.remote_domain
        self.local_map = {}
        self.remote_map = {}

    def get_domain_local_sid(self):
        res = self.samdb.search(base=self.local_domain,expression="(objectClass=*)", scope=SCOPE_BASE)
        self.local_sid = ndr_unpack( security.dom_sid,res[0]["objectSid"][0])

    def get_domain_remote_sid(self):
        res = self.remote_ldb.search(base=self.remote_domain, expression="(objectClass=*)", scope=SCOPE_BASE)
        self.remote_sid = ndr_unpack( security.dom_sid,res[0]["objectSid"][0])

    def add_to_ldif(self, dn, descr):
        ldif_entry = ["dn: " + dn,
                      "changetype: modify",
                      "replace: nTSecurityDescriptor",
                      "nTSecurityDescriptor::  " + base64.b64encode(ndr_pack(descr))]

        for line in ldif_entry:
            length = 79
            if len(line) <= length + 1:
                print line
            else:
                for i in range(len(line) / length + 1):
                    if i == 0:
                        l = line[i * length:((i + 1) * length)]
                    else:
                        l = " " + line[(i * length):((i + 1) * length)]
                    print l
        print "\n"

    def write_as_sddl(self, dn, descr):
        print dn
        print descr + "\n"

    def read_descr_by_base(self, search_base):
        res = self.samdb.search(base=search_base + self.local_domain, expression="(objectClass=*)", scope=SCOPE_SUBTREE, attrs=["nTSecurityDescriptor"])
        for entry in res:
            dn = entry["dn"].__str__().replace(self.local_domain, "")

            if "nTSecurityDescriptor" in entry:
                desc_obj = ndr_unpack(security.descriptor, entry["nTSecurityDescriptor"][0])
                self.local_map[dn] = desc_obj

        res = self.remote_ldb.search(base=search_base + self.remote_domain, expression="(objectClass=*)", scope=SCOPE_SUBTREE, attrs=["nTSecurityDescriptor"])
        for entry in res:
            dn = entry["dn"].__str__().replace(self.remote_domain, "")

            if "nTSecurityDescriptor" in entry:
                desc_obj = ndr_unpack(security.descriptor, entry["nTSecurityDescriptor"][0])
                self.remote_map[dn] = desc_obj

    def read_desc(self):
        self.read_descr_by_base("CN=Schema,CN=Configuration,")
        self.read_descr_by_base("CN=Configuration,")
        self.read_descr_by_base("")

    def write_desc_to_ldif(self):
        key_list_local = self.local_map.keys()
        key_list_remote = self.remote_map.keys()
        for key in key_list_remote:
            if key in key_list_local:
                sddl = self.remote_map[key].as_sddl(self.remote_sid)
                sddl_local = self.local_map[key].as_sddl(self.local_sid)
                if sddl != sddl_local:
                    descr = security.descriptor.from_sddl(sddl, self.local_sid)
                if opts.as_ldif:
                    self.add_to_ldif(key + self.local_domain, descr)
                else:
                    self.write_as_sddl(key, descr.as_sddl(self.local_sid))

    def run(self):
        self.get_domain_local_sid()
        self.get_domain_remote_sid()
        self.read_desc()
        self.write_desc_to_ldif()

desc = DescrGetter(opts.local_domain, opts.remote_domain)
desc.run()