Access_Control.py

from __future__ import print_function
import hashlib
import MFRC522
import mysql.connector as mariadb
import RPi.GPIO as gpio
import signal
import sys
import time

# Database variables
connection = None
cursor = None
DB_USER = "****" # Omitted
DB_PASS = "*****" # Omitted
DB_NAME = "****************" # Omitted

# RFID-Reader Variable
MIFAREReader = None

# Defining keypad constants
matrix = [["1", "2", "3", "A"],
          ["4", "5", "6", "B"],
          ["7", "8", "9", "C"],
          ["*", "0", "#", "D"]]
# No GPIO numbering because MFRC522 uses BCM
columns = [32, 36, 38, 40]
rows = [12, 16, 18, 11]

# Lockout variables
FailedCount = 0
PenaltyTime = 0
TerminalLocked = False


class bc:
  #  Console color constants
  PINK = '\033[95m'
  BLUE = '\033[94m'
  GREEN = '\033[92m'
  YELLOW = '\033[93m'
  RED = '\033[91m'
  WHITE = '\033[0m'
  BOLD = '\033[1m'
  UNDERLINE = '\033[4m'


def getKey():
  # Returns pressed key or nothing
  for j in range(len(columns)):
    gpio.output(columns[j], 0)
    for i in range(len(rows)):
      if gpio.input(rows[i]) == 0:
        while gpio.input(rows[i]) == 0:
          pass
        time.sleep(0.2)
        return matrix[i][j]
    gpio.output(columns[j], 1)
  return False


# Cleaning up and exiting
def over():
  cursor.close()
  connection.close()
  gpio.cleanup()
  sys.exit()


# CTRL-C handler
def signal_handler(sig, frame):
  print("\nCtrl-C has been pressed. Quitting...")
  over()


# Calls log procedure and exits
def log_access(args):
  # Call procedure and commit
  cursor.callproc("log_access", args)
  connection.commit()

  # Quit if last argument is true
  if args[3]:
    over()


# Access status output
def access_msg(msg, success):
  if success:
    print("{}\nAccess granted{}".format(bc.GREEN, bc.WHITE))
  else:
    print("{}\nAccess denied{}".format(bc.RED, bc.WHITE))

  print(msg)


def failhandler():
  global FailedCount
  global PenaltyTime
  global TerminalLocked

  # Increment failed count and penaltytime
  FailedCount = FailedCount + 1
  PenaltyTime = PenaltyTime + 5

  # Check how many attempts failed so far
  if FailedCount > 2:
    print("Too many failed attempts, terminal is locked")
    print("Please ask an administrator to unlock")
    TerminalLocked = True
  else:
    print("Please try again in {} seconds".format(PenaltyTime))
    time.sleep(PenaltyTime)
    print("Now you can try again")


def init():
  global cursor
  global connection
  global MIFAREReader

  # Initiate RFID-Reader Library
  MIFAREReader = MFRC522.MFRC522()

  # Activating GPIO outputs for keypad
  for i in range(4):
    gpio.setup(columns[i], gpio.OUT)
    gpio.output(columns[i], 1)
    gpio.setup(rows[i], gpio.IN, pull_up_down=gpio.PUD_UP)

  # Connecting to database and creating cursor object
  connection = mariadb.connect(
    user=DB_USER, password=DB_PASS, database=DB_NAME)
  cursor = connection.cursor()

  # Registering CTRL-C handler
  signal.signal(signal.SIGINT, signal_handler)


def md5encode(in_string):
  m = hashlib.md5()
  m.update(in_string)
  return m.hexdigest()


# Initialize script
init()

# Retrieves rooms into list and prints them to console
cursor.execute("SELECT idRaum, bezeichnung FROM raum ORDER BY idRaum")
rooms = cursor.fetchall()
while True:
  while True:
    # Ask user for a room
    print("Which room do you want to enter? ")
    for room in rooms:
      print("{} - {}".format(room[0], room[1]))

    in_raum = ""
    while True:
      # Retrieve keypress
      lastKey = getKey()

      # If a key has been pressed
      if lastKey:
        if lastKey == "*":
          # An asterisk exits the script
          over()
        if lastKey == "#":
          # A pound finishes the entry
          break
        else:
          # All other keys append to the entry
          in_raum = in_raum + lastKey
          sys.stdout.write(lastKey)
          sys.stdout.flush()

    # Evaluate if users chosen room exists
    cursor.execute("SELECT NULL FROM raum WHERE idRaum=%s", (in_raum,))
    cursor.fetchone()
    if cursor.rowcount == -1:
      print("There is no such room!")
    else:
      break

  # Retrieve room using list comprehension
  room = [r[1] for r in rooms if r[0] == int(in_raum)][0]
  print("Entering room: {}".format(room))
  sys.stdout.write("Enter keycode or scan your card: ")
  sys.stdout.flush()

  in_keycode = ""
  while True:
    # Retrieve latest keypad-key
    lastKey = getKey()

    # If any key has been pressed
    if lastKey:
      if lastKey == "*":
        # Delay probably no longer needed
        # Needs testing
        # time.sleep(0.2)
        break
      elif lastKey == "#":
        # If '#' has been pressed (input finished)
        if TerminalLocked:
          print("Terminal is locked")
        else:
          in_keycode = md5encode(in_keycode)

          # Check if keypad-entry is enabled for chosen room
          cursor.execute("""SELECT NULL FROM raum
            WHERE sicherheitslevel = 1
            AND idraum=%s;""", (in_raum,))
          cursor.fetchone()
          if cursor.rowcount == -1:
            access_msg("Only Administrators may enter this room", False)

            # Log failed attempt
            log_access([in_raum, in_keycode, None, False])
          else:
            # Check if code exists in database
            cursor.execute("SELECT NULL FROM keycode WHERE `code`=%s",
              (in_keycode,))
            cursor.fetchone()

            if cursor.rowcount == -1:
              access_msg("Wrong keycode!", False)

              # Log failed attempt
              log_access([in_raum, in_keycode, None, False])

              failhandler()
            else:
              # Retrieve employee info
              cursor.execute("""SELECT CONCAT(m.vorname, ' ', m.nachname)
                FROM mitarbeiter m INNER JOIN keycode k
                ON m.idkeycode = k.idkeycode
                AND k.`code`=%s;""", (in_keycode,))
              access_msg("Welcome, {}".format(cursor.fetchone()[0]),
                True)

              # Log successful attempt
              log_access([in_raum, in_keycode, None, True])
        in_keycode = ""
      else:
        # A number has been pressed

        # Output asterisk to console
        sys.stdout.write('*')
        sys.stdout.flush()

        # Append the new number to the keycode string
        in_keycode = in_keycode + lastKey

        # Delay probably no longer needed
        # Needs testing
        # time.sleep(0.2)

    # Prepare RFID-Scanner for reading
    status = MIFAREReader.MFRC522_Request(MIFAREReader.PICC_REQIDL)
    (status, uid) = MIFAREReader.MFRC522_Anticoll()
    if status == MIFAREReader.MI_OK:
      # This is the default key
      key = [0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF]
      # Select the tag
      MIFAREReader.MFRC522_SelectTag(uid)
      # Authenticate using block 8, the default key and the UID
      status = MIFAREReader.MFRC522_Auth(
        MIFAREReader.PICC_AUTHENT1A, 8, key, uid)

      if status == MIFAREReader.MI_OK:
        # Read Block 8 of RFID into variable
        card_content = MIFAREReader.MFRC522_Read(8)
        # Remove zero padded bytes from string
        # card_content = card_content.split(b'\0', 1)[0]
        card_content = card_content.partition(b'\0')[0]

        # Hash the RFID
        card_content = md5encode(card_content)

        MIFAREReader.MFRC522_StopCrypto1()

        # Search for card in database
        cursor.execute("SELECT NULL FROM transponder WHERE rfid=%s",
          (card_content,))
        cursor.fetchone()

        if cursor.rowcount == -1:
          if TerminalLocked:
            print("Terminal is locked")
          else:
            access_msg("This card is not registered in the system!",
                False)

            # Log failed attempt
            log_access([in_raum, None, card_content, False])

            failhandler()
        else:
          # Retrieve employee info
          cursor.execute("""SELECT CONCAT(m.vorname, ' ', m.nachname)
            FROM mitarbeiter m INNER JOIN transponder t
            ON m.idTransponder = t.idTransponder
            WHERE t.rfid=%s;""", (card_content,))

          access_msg("Welcome, {}".format(cursor.fetchone()[0]), True)
          if TerminalLocked:
            print("You have unlocked the terminal for the technicians")
            TerminalLocked = False

          # Log successful attempt
          log_access([in_raum, None, card_content, True])
          over()