#!/usr/bin/python
#
# Copyright (c) 2017-2019  Joe Clarke <jclarke@cisco.com>
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.

from __future__ import print_function
from builtins import bytes
from pyad import *
import re
from functools import wraps
from flask import request, Response, session, redirect
from flask import Flask
import pythoncom
import CLEUCreds
import socket
from cleu.config import Config as C

LOG_EMERG = 0  #  system is unusable
LOG_ALERT = 1  #  action must be taken immediately
LOG_CRIT = 2  #  critical conditions
LOG_ERR = 3  #  error conditions
LOG_WARNING = 4  #  warning conditions
LOG_NOTICE = 5  #  normal but significant condition
LOG_INFO = 6  #  informational
LOG_DEBUG = 7  #  debug-level messages

#  facility codes
LOG_KERN = 0  #  kernel messages
LOG_USER = 1  #  random user-level messages
LOG_MAIL = 2  #  mail system
LOG_DAEMON = 3  #  system daemons
LOG_AUTH = 4  #  security/authorization messages
LOG_SYSLOG = 5  #  messages generated internally by syslogd
LOG_LPR = 6  #  line printer subsystem
LOG_NEWS = 7  #  network news subsystem
LOG_UUCP = 8  #  UUCP subsystem
LOG_CRON = 9  #  clock daemon
LOG_AUTHPRIV = 10  #  security/authorization messages (private)
LOG_FTP = 11  #  FTP daemon

#  other codes through 15 reserved for system use
LOG_LOCAL0 = 16  #  reserved for local use
LOG_LOCAL1 = 17  #  reserved for local use
LOG_LOCAL2 = 18  #  reserved for local use
LOG_LOCAL3 = 19  #  reserved for local use
LOG_LOCAL4 = 20  #  reserved for local use
LOG_LOCAL5 = 21  #  reserved for local use
LOG_LOCAL6 = 22  #  reserved for local use
LOG_LOCAL7 = 23  #  reserved for local use


AD_DC = "dc1-ad." + C.AD_DOMAIN

app = Flask("CLEU Password Reset")


def send_syslog(msg, facility=LOG_LOCAL7, severity=LOG_NOTICE, host="localhost", port=514):
    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    if severity is not None and facility is not None:
        data = "<%d>%s" % (severity + facility * 8, msg)
    else:
        data = msg
    sock.sendto(bytes(data, "utf-8"), (host, port))
    sock.close()


def query_user(username, password, target_user):
    global AD_DC

    try:
        adcontainer.ADContainer.from_dn(C.AD_DN_BASE, options={"ldap_server": AD_DC, "username": username, "password": password})
    except Exception as e:
        print(e)
        return None

    try:
        q = adquery.ADQuery(options={"ldap_server": AD_DC, "username": username, "password": password})
        q.execute_query(
            attributes=["distinguishedName"],
            where_clause="sAMAccountName='{}'".format(target_user),
            base_dn=C.AD_DN_BASE,
            options={"ldap_server": AD_DC, "username": username, "password": password},
        )
        for row in q.get_results():
            return row["distinguishedName"]
    except Exception as e:
        print(e)
        return None


def check_auth(username, password):
    pythoncom.CoInitialize()

    if username == C.VPN_USER or username == C.VPN_USER + "@" + C.AD_DOMAIN:
        return False

    if "dn" in session:
        return True

    if not re.search(r"@{}$".format(C.AD_DOMAIN), username):
        username += "@{}".format(C.AD_DOMAIN)

    target_username = username.replace("@{}".format(C.AD_DOMAIN), "")

    try:
        dn = query_user(username, password, target_username)
        if dn is not None:
            session["dn"] = dn
            session["target_username"] = target_username
            session["first_time"] = False
            return True
        else:
            try:
                dn = None
                dn = query_user(CLEUCreds.AD_ADMIN, CLEUCreds.AD_PASSWORD, target_username)
                if dn is None:
                    return False

                adu = aduser.ADUser.from_dn(
                    dn, options={"ldap_server": AD_DC, "username": CLEUCreds.AD_ADMIN, "password": CLEUCreds.AD_PASSWORD}
                )
                obj = adu.get_attribute("pwdLastSet", False)
                if password == CLEUCreds.DEFAULT_USER_PASSWORD and int(obj.highpart) == 0 and int(obj.lowpart) == 0:
                    session["dn"] = dn
                    session["target_username"] = target_username
                    session["first_time"] = True
                    return True

            except Exception as ie:
                print(ie)
                return False
    except Exception as e:
        print(e)
        return False

    return False


def authenticate():
    if "loggedout" in session:
        del session["loggedout"]
    return Response(
        "Failed to verify credentials for password reset.\n" "You have to login with proper credentials.",
        401,
        {"WWW-Authenticate": 'Basic realm="CLEU Password Reset; !!!ENTER YOUR AD USERNAME AND PASSWORD!!!"'},
    )


def requires_auth(f):
    @wraps(f)
    def decorated(*args, **kwargs):
        auth = request.authorization
        if session.get("loggedout", False) or not auth or not check_auth(auth.username, auth.password):
            return authenticate()
        return f(*args, **kwargs)

    return decorated


@app.route("/logout", methods=["GET"])
def logout():
    session.clear()
    session["loggedout"] = True
    return redirect("/", code=302)


@app.route("/reset-password", methods=["POST"])
@requires_auth
def reset_password():
    new_pw = request.form.get("new_pass")
    new_pw_confirm = request.form.get("new_pass_confirm")
    vpnuser = request.form.get("vpnuser")
    if new_pw.strip() == "" or new_pw_confirm.strip() == "":
        return Response(
            """
<html>
  <head>
    <title>Bad Password</title>
  </head>
  <body>
  <p>You must specify a new password.</p>
  </body>
</html>""",
            mimetype="text/html",
        )

    if new_pw != new_pw_confirm:
        return Response(
            """
<html>
  <head>
    <title>Bad Password</title>
  </head>
  <body>
    <p>Passwords did not match</p>
  </body>
</html>""",
            mimetype="text/html",
        )

    adu = aduser.ADUser.from_dn(
        session["dn"], options={"ldap_server": AD_DC, "username": CLEUCreds.AD_ADMIN, "password": CLEUCreds.AD_PASSWORD}
    )
    try:
        adu.set_password(new_pw)
    except Exception as e:
        return Response(
            """
<html>
  <head>
    <title>Failed to Reset Password</title>
  </head>
  <body>
  <h1>Password Reset Failed!</h1>
  <p>{}</p>
  </body>
</html>""".format(
                e
            ),
            mimetype="text/html",
        )

    adu.grant_password_lease()
    del session["dn"]

    resp = """
<html>
  <head>
    <title>Password Changed Successfully!</title>
  </head>
  <body>
    <h1>Password Changed Successfully!</h1>"""

    if session.get("first_time", False):
        send_syslog(
            "PRINT-LABEL: requesting to print label for userid {}".format(session["target_username"]),
            None,
            None,
            C.TOOL,
        )
        resp += "\n<h1>Please go see Dave Shen to get your barcode label.</h1>"

    if vpnuser and vpnuser == "true":
        resp += "\n<h1>Please disconnect your VPN and connect again with your AD credentials.</h1>"
    else:
        resp += "\n<h1>Please close this browser window.</h1>"
        resp += "\n<script>setTimeout(function() { window.location = '/logout'; }, 60000);</script>"

    resp += """
 </body>
</html>"""

    return Response(resp, mimetype="text/html")


@app.route("/")
@requires_auth
def get_main():
    page = """
<html>
  <head>
    <title>Password Reset Form</title>
    <link rel="stylesheet" href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
      <link rel="stylesheet" href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap-theme.min.css" integrity="sha384-rHyoN1iRsVXV4nD0JutlnGaslCJuC7uwjduW9SVrLvRYooPp2bWYgmgJQIXwl/Sp" crossorigin="anonymous">      <link rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/datatables/1.10.12/css/dataTables.bootstrap.min.css" integrity="sha256-7MXHrlaY+rYR1p4jeLI23tgiUamQVym2FWmiUjksFDc=" crossorigin="anonymous" />

      <meta name="viewport" content="width=device-width, initial-scale=1">
      <script type="text/javascript" src="//cdnjs.cloudflare.com/ajax/libs/jquery/1.12.4/jquery.min.js" integrity="sha256-ZosEbRLbNQzLpnKIkEdrPv7lOy9C27hHQ+Xp8a4MxAQ=" crossorigin="anonymous"></script>
  		<script src="//maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js" integrity="sha384-Tc5IQib027qvyjSMfHjOMaLkfuWVxZxUPnCJA7l2mCWNIpG9mGCD8wGNIcPD7Txa" crossorigin="anonymous"></script>      <script type="text/javascript" src="//cdnjs.cloudflare.com/ajax/libs/datatables/1.10.12/js/jquery.dataTables.min.js" integrity="sha256-TX6POJQ2u5/aJmHTJ/XUL5vWCbuOw0AQdgUEzk4vYMc=" crossorigin="anonymous"></script>
<script type="text/javascript" src="//cdnjs.cloudflare.com/ajax/libs/datatables/1.10.12/js/dataTables.bootstrap.min.js" integrity="sha256-90YqnHom4j8OhcEQgyUI2IhmGYTBO54Adcf3YDZU9xM=" crossorigin="anonymous"></script>
    <script>
    function verify() {
	if (!$('#new_pass').val().trim()) {
		alert('Please specify a new password.');
		return false;
	}
    if (!$('#new_pass_confirm').val().trim()) {
        alert('Please confirm the new password.');
        return false;
    }
    if ($('#new_pass_confirm').val().trim() != $('#new_pass').val().trim()) {
        alert('Passwords do not match.');
        return false;
    }
	return true;
	}
    </script>
    </head>
    <body>
    <div class="container" role="main" style="width: 100%;">
      <div class="page-header">
        <h3>Password Reset Form</h3>
      </div>

      <div class="row">
        <div class="col-sm-8">

          <form method="POST" onSubmit="return verify();" action="/reset-password">
            <div class="form-group">
              <label for="new_pass">New Password:</label>
              <input type="password" name="new_pass" id="new_pass" class="form-control" placeholder="New Password">
           </div>
           <div class="form-group">
             <label for="new_pass_confirm">Confirm New Password:</label>
             <input type="password" name="new_pass_confirm" id="new_pass_confirm" class="form-control" placeholder="Confirm New Password">
           </div>
           <div class="form-group">
             <input type="submit" name="submit" value="Reset My Password!" class="btn btn-primary">
             <input type="reset" name="reset" value="Start Over" class="btn btn-default">
           </div>"""
    page += '\n<input type="hidden" name="vpnuser" value="%s"/>' % (request.args.get("vpnuser"))
    page += """
         </form>
       </div>
     </div>
     </div>
  </body>
</html>"""

    return Response(page, mimetype="text/html")


if __name__ == "__main__":
    app.secret_key = CLEUCreds.AD_PASSWORD
    app.run(host="10.100.252.25", port=8443, threaded=True, ssl_context=("chain.pem", "privkey.pem"))