Simple 2fa Access System

The components are connected as follows:

• ServoMotor SIGNAL pin to Giant Board PWM1
• ServoMotor VCC pin to 5V rail
• ServoMotor GND pin to GND rail
• Giant Board Micro-USB port to 5V cable connected to the power bank
• Giant Board AD3 to Arduino D0
• Giant Board AD2 to Arduino D1
• Arduino VIN to 5V rail
• Arduino GND to GND rail

Configuring the Giant Board

Installing necessary software

Firstly, we need to install a terminal emulation app, I'm using windows, so I chose Putty, you can get it at https://putty.org/. Once you have installed it, you will be greeted with this window:

We need to select the Serial tab and enter the serial port associated with our Giant Board, if you don't know it, you can find it at Device manager, under COM ports. After we have selected it, we need to set the baud rate to 115200, then we press Open. If it doesn't work first, wait for a bit so the Giant Board has time to boot.

Configuring the controller

The default username name is debian and the default password is temppwd. Once you type that in you will be greeted by the Giant Board console!. It is recommended that you change the password with the passwd command.

First, we need to configure the network. We enter the command sudo connmanctl, it will ask for your password, enter it. You will be greeted with a prompt like this:

Enter the command services, it will give you a list of one device, with a name like         gadget_5e70b6158b61_usb,  copy it, then type connect and paste the string, you paste with right-click. you will be greeted with Connected gadget_5e70b6158b61_usb,  if this is the case, then you are ready to go, if you encounter difficulties, the Giant Board documentation can be very helpful at https://groboards.com/docs/

Then we need to configure it inside Windows, go to Network and Sharing centre in the control panel, you should see something like this:

Click on the connection that has internet, in my case (Wi-Fi 2), and then go to Properties. Once you get there go to the Sharing tab and enable Sharing, this will make you select a network, select the network created by the Giant Board, in my case (Ethernet 6), once you did this, you will have Internet on your Giant Board.

The giant board uses Overlays to define hardware connectivity. You need to go enter sudo nano /boot/uboot/uEnv.txt,  then you need to uncomment the line: 

enable_uboot_overlays=1

Then, you need to add to two of the overlay lines:

GB-UART2-FLX4-AD2-AD3.dtbo 
GB-PWM1.dtbo

The first enables UART which will be used to communicate with the Arduino and the second enables PWM to control the Servo

We need to install the libraries for controlling the motor and the UART serial line and random number generation:

pip install Adafruit-Blinka

pip install pyserial

pip install random2

Writing the main script

Now we are going to write the main control script for the giant board, we will discuss it in parts, but the whole code can be copied from the Attachments.First, we need to create a file named backend.py at the bin directory, we do this by using the following command:

sudo nano bin/backend.py

This will open the text editor nano, it should look like this:

The shortcuts are in the lower part of the screen.Now we can get to writing the main script, first we add all the necessary libraries:

import serial
import random
import time
import board
import pulseio
from adafruit_motor import servo

Then we create the necessary objects such as the servo motor and the Serial Connection (UART):

# create a PWMOut object on Pin PWM1.
pwm = pulseio.PWMOut(board.PWM1, duty_cycle=2 ** 15, frequency=50)
 
# Create a servo object, my_servo.
my_servo = servo.Servo(pwm)
 
serialPort = serial.Serial(port = "/dev/ttyS1", baudrate=115200,bytesize=8, timeout=2, stopbits=serial.STOPBITS_ONE)         # Here you add Arduino parameters, those are default
serialString = ""                           # Used to hold data coming over UART

Now we initialize the servo motor to the closed position:

for angle in range(180, 0, -5): # 180 - 0 degrees, 5 degrees at a time.
    my_servo.angle = angle
    time.sleep(0.05)

We create the function that unlocks the door so we can call it later if the correct credentials are supplied:

def unlock():
    for angle in range(0, 180, 5):  # 0 - 180 degrees, 5 degrees at a time.
        my_servo.angle = angle
        time.sleep(0.05)
    time.sleep(2)
        for angle in range(180, 0, -5):  # 0 - 180 degrees, 5 degrees at a time.
        my_servo.angle = angle
        time.sleep(0.05)

If your motor is backward change 0 to 180, 180 to 0, 5 to -5, and -5 to 5 in the parameters of range.

Now we add the function that defines ourselves (the user):

# this is the secure info of user "me"
def me(type, token):
    # Here you put the passcode
    if (type == 1):
        return "111111"
    # Here you put the RFID tag info
    if (type == 2):
        return "66949828"
    if (type == 3):
        d1 = token[0]
        d2 = token[1]
        d3 = token[2]
        d4 = token[3]
        d5 = token[4]
        d6 = token[5]
        d7 = token[6]
        d8 = token[7]
        # here you write your 2FA rule
        result = ''
        result += str((d1 + 1) % 10)
        result += str((d2 + 2) % 10)
        result += str((d3 + 3) % 10)
        result += str((d4 + 4) % 10)
        result += str((d5 + 5) % 10)
        result += str((d6 + 6) % 10)
        result += str((d7 + 7) % 10)
        result += str((d8 + 8) % 10)
        return result

In the first 'if', we add our passcode, in the second, our RFID tag and in the third our 2FA rule, in this case, I take every digit and add 1 to the first digit 2 to the second, etc, taking only the last digit so we get an array with an identical number of digits.

The rest of the script is just validation:

def genrand():
    # here we generate a random token
    s1 = random.randint(0, 10)
    s2 = random.randint(0, 10)
    s3 = random.randint(0, 10)
    s4 = random.randint(0, 10)
    s5 = random.randint(0, 10)
    s6 = random.randint(0, 10)
    s7 = random.randint(0, 10)
    s8 = random.randint(0, 10)
    return [s1,s2,s3,s4,s5,s6,s7,s8], str(s1)+str(s2)+str(s3)+str(s4)+str(s5)+str(s6)+str(s7)+str(s8)
 
 
while(1):
 
    # Wait until there is data waiting in the serial buffer
    if(serialPort.in_waiting > 0):
        # Read data out of the buffer until a carraige return / new line is found
        serialString = serialPort.readline()
        # Print the contents of the serial data
        comm = serialString.decode('Ascii')
        comm = comm.strip()
        # Separate string into 2 parts delimited by '|'
        str1, str2 = comm.split('|')
        # Verify if the connection started
        if (str1 == 'COMM' and str2 == 'START'):
            print("Connection succesfull!")
 
        if (str1 == 'PASS'):
            print('PASS ==> ' + str2)
            if (me(1, '') == str2):
                print ("PASS OK")
                serialPort.write(b"MODE|SQRFIDn")
                exit = False
                while exit == False:
                    if (serialPort.in_waiting > 0):
                        exit = True
                        # Read data out of the buffer until a carraige return / new line is found
                        serialString = serialPort.readline()
                        # Print the contents of the serial data
                        comm = serialString.decode('Ascii')
                        comm = comm.strip()
                        # Separate string into 2 parts delimited by '|'
                        str1, str2 = comm.split('|')
                        if (str1 == 'RFID'):
                            if (me(2, '') == str2):
                                print('RFID OK')
                                serialPort.write(b"MODE|SQ2FAn")
                                exit1 = False
                                while exit1 == False:
                                    if (serialPort.in_waiting > 0):
                                        exit1 = True
                                        # Read data out of the buffer until a carraige return / new line is found
                                        serialString = serialPort.readline()
                                        # Print the contents of the serial data
                                        comm = serialString.decode('Ascii')
                                        comm = comm.strip()
                                        # Separate string into 2 parts delimited by '|'
                                        str1, str2 = comm.split('|')
                                        if (str1 == 'MODE'):
                                            token, tokenstr = genrand()
                                            tokenstr = tokenstr[0:8]
                                            serialPort.write(bytes((tokenstr + 'n').encode()))
                                            exit2 = False
                                            while exit2 == False:
                                                if (serialPort.in_waiting > 0):
                                                    exit2 = True
                                                    # Read data out of the buffer until a carraige return / new line is found
                                                    serialString = serialPort.readline()
                                                    # Print the contents of the serial data
                                                    comm = serialString.decode('Ascii')
                                                    comm = comm.strip()
                                                    # Separate string into 2 parts delimited by '|'
                                                    str1, str2 = comm.split('|')
                                                    if (str2 == me(3,token)):
                                                        print("2FA OK")
                                                        serialPort.write(b"ACC|GRANTn")
                                                        unlock () # unlock
                                                    else:
                                                        print("2FA FALSE")
                                                        serialPort.write(b"ACC|INTRn")
                            else:
                                print("RFID FALSE")
                                serialPort.write(b"ACC|INTRn")
            else:
                print("PASS FALSE")
                serialPort.write(b"ACC|INTRn")
 
        if (str1 == 'RFID'):
            print('RFID ==> ' + str2)
            if (me(2, '') == str2):
                print("RFID OK")
                serialPort.write(b"MODE|SQPASSn")
                exit = False
                while exit == False:
                    if (serialPort.in_waiting > 0):
                        exit = True
                        # Read data out of the buffer until a carraige return / new line is found
                        serialString = serialPort.readline()
                        # Print the contents of the serial data
                        comm = serialString.decode('Ascii')
                        comm = comm.strip()
                        # Separate string into 2 parts delimited by '|'
                        str1, str2 = comm.split('|')
                        if (str1 == 'PASS'):
                            if (me(1, '') == str2):
                                print('PASS OK')
                                serialPort.write(b"MODE|SQ2FAn")
                                exit1 = False
                                while exit1 == False:
                                    if (serialPort.in_waiting > 0):
                                        exit1 = True
                                        # Read data out of the buffer until a carraige return / new line is found
                                        serialString = serialPort.readline()
                                        # Print the contents of the serial data
                                        comm = serialString.decode('Ascii')
                                        comm = comm.strip()
                                        # Separate string into 2 parts delimited by '|'
                                        str1, str2 = comm.split('|')
                                        if (str1 == 'MODE'):
                                            token, tokenstr = genrand()
                                            tokenstr = tokenstr[0:8]
                                            serialPort.write(bytes((tokenstr + 'n').encode()))
                                            exit2 = False
                                            while exit2 == False:
                                                if (serialPort.in_waiting > 0):
                                                    exit2 = True
                                                    # Read data out of the buffer until a carraige return / new line is found
                                                    serialString = serialPort.readline()
                                                    # Print the contents of the serial data
                                                    comm = serialString.decode('Ascii')
                                                    comm = comm.strip()
                                                    # Separate string into 2 parts delimited by '|'
                                                    str1, str2 = comm.split('|')
                                                    if (str2 == me(3, token)):
                                                        print("2FA OK")
                                                        serialPort.write(b"ACC|GRANTn")
                                                        unlock() # unlock
                                                    else:
                                                        print("2FA FALSE")
                                                        serialPort.write(b"ACC|INTRn")
                            else:
                                print("PASS FALSE")
                                serialPort.write(b"ACC|INTRn")
            else:
                print("RFID FALSE")
                serialPort.write(b"ACC|INTRn")