Overview
What is TOTP?
Having 2 Factor Authentication on all your accounts is a good way to keep your data more secure. With 2FA logins, not only is a username and password needed, but also a one-time-use code. There are a few different ways to get that code, such as by email, phone or SMS. But my favorite way is to do it is via a 'Google Authenticator' time-based OTP (one time password), also known as a TOTP.
Using an app on your phone like Authy or Authenticator, you set up a secret code given to you by the service, then every 30 seconds, a new code is generated for you. What's extra nice is that the Google Authenticator protocol is supported by just about every service and phone/tablet.
So What's The Problem?
I could use my phone, but it's not always at my desk. It also may be charging or dead. Or maybe someone doesnt own a phone?
A Solution!
Luckily for us, the Google Authenticator protocol is really simple - You just need to be able to know the current time, and run a SHA1 hash.
Ladyada previously built a device which uses a Feather ESP8266 to display her TOTP codes.
This guide is a version of this device which uses the PyPortal. The PyPortal has WiFi so it can connect to NTP to get the current time at startup and a full-color touchscreen display.
The code supports displaying up to 5 keys which you can select by tapping the buttons on the PyPortal's display.
The PyPortal case used in this guide is the PyPortal Retro Case designed by the Ruiz Brothers. Click here to learn more and visit the guide...
THIS IS NOT A QUESTION MORE OF A COMMENT. YOU ARE PROGRAMMING THE TOTP SECRET INTO THE FLASH OF THE MICROCONTROLLER AND ITS NOT ENCRYPTED OR PROTECTED AT ALL ANYONE COULD BREAK INTO YOUR APARTMENT, GO TO YOUR BEDROOM, LOOK ON YOUR DESK, FIND THIS AND THEN CONNECT IT UP TO THEIR HACKER LAPTOP TO GRAB YOUR SECRET KEY THEN IF THEY HAD YOUR USERNAME AND PASSWORD THEY WOULD BE ABLE TO LOG IN AS YOU AND THIS IS REALLY INSECURE ITS SO IRRESPONSIBLE TO CONSIDER PUBLISHING A PROJECT LIKE THIS BY THE WAY DID YOU SEE THAT SNOWDEN APP? MAYBE YOU CAN RUN THAT ON A PHONE SO YOU CAN WATCH YOUR DESK REMOTELY AND MAKE SURE NOBODY BROKE IN TO STEAL YOUR PYPORTAL? OH WAIT YOU JUST SAID YOU DON'T HAVE A PHONE. OK I DONT KNOW WHAT MY QUESTION IS
This project is probably not for you
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PyPortal CircuitPython Setup
To use all the amazing features of your PyPortal with CircuitPython, you must first install a number of libraries. This page covers that process.
Adafruit CircuitPython Bundle
Download the Adafruit CircuitPython Library Bundle. You can find the latest release here:
Download the adafruit-circuitpython-bundle-*.x-mpy-*.zip bundle zip file where *.x MATCHES THE VERSION OF CIRCUITPYTHON YOU INSTALLED, and unzip a folder of the same name. Inside you'll find a lib folder. You have two options:
- You can add the lib folder to your CIRCUITPY drive. This will ensure you have all the drivers. But it will take a bunch of space on the 8 MB disk
- Add each library as you need it, this will reduce the space usage but you'll need to put in a little more effort.
At a minimum we recommend the following libraries, in fact we more than recommend. They're basically required. So grab them and install them into CIRCUITPY/lib now!
- adafruit_esp32spi - This is the library that gives you internet access via the ESP32 using (you guessed it!) SPI transport. You need this for anything Internet
- adafruit_requests - This library allows us to perform HTTP requests and get responses back from servers. GET/POST/PUT/PATCH - they're all in here!
- adafruit_connection_manager - used by adafruit_requests.
- adafruit_pyportal - This is our friendly wrapper library that does a lot of our projects, displays graphics and text, fetches data from the internet. Nearly all of our projects depend on it!
- adafruit_portalbase - This library is the base library that adafruit_pyportal library is built on top of.
- adafruit_touchscreen - a library for reading touches from the resistive touchscreen. Handles all the analog noodling, rotation and calibration for you.
- adafruit_io - this library helps connect the PyPortal to our free datalogging and viewing service
- adafruit_imageload - an image display helper, required for any graphics!
- adafruit_display_text - not surprisingly, it displays text on the screen
- adafruit_bitmap_font - we have fancy font support, and its easy to make new fonts. This library reads and parses font files.
- adafruit_slideshow - for making image slideshows - handy for quick display of graphics and sound
- neopixel - for controlling the onboard neopixel
- adafruit_adt7410 - library to read the temperature from the on-board Analog Devices ADT7410 precision temperature sensor (not necessary for Titano or Pynt)
- adafruit_bus_device - low level support for I2C/SPI
- adafruit_fakerequests - This library allows you to create fake HTTP requests by using local files.
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Create Your settings.toml File
CircuitPython works with WiFi-capable boards to enable you to make projects that have network connectivity. This means working with various passwords and API keys. As of CircuitPython 8, there is support for a settings.toml file. This is a file that is stored on your CIRCUITPY drive, that contains all of your secret network information, such as your SSID, SSID password and any API keys for IoT services. It is designed to separate your sensitive information from your code.py file so you are able to share your code without sharing your credentials.
CircuitPython previously used a secrets.py file for this purpose. The settings.toml file is quite similar.
CircuitPython settings.toml File
This section will provide a couple of examples of what your settings.toml file should look like, specifically for CircuitPython WiFi projects in general.
The most minimal settings.toml file must contain your WiFi SSID and password, as that is the minimum required to connect to WiFi. Copy this example, paste it into your settings.toml, and update:
your_wifi_ssidyour_wifi_password
CIRCUITPY_WIFI_SSID = "your_wifi_ssid" CIRCUITPY_WIFI_PASSWORD = "your_wifi_password"
Many CircuitPython network-connected projects on the Adafruit Learn System involve using Adafruit IO. For these projects, you must also include your Adafruit IO username and key. Copy the following example, paste it into your settings.toml file, and update:
your_wifi_ssidyour_wifi_passwordyour_aio_usernameyour_aio_key
CIRCUITPY_WIFI_SSID = "your_wifi_ssid" CIRCUITPY_WIFI_PASSWORD = "your_wifi_password" ADAFRUIT_AIO_USERNAME = "your_aio_username" ADAFRUIT_AIO_KEY = "your_aio_key"
Some projects use different variable names for the entries in the settings.toml file. For example, a project might use ADAFRUIT_AIO_ID in the place of ADAFRUIT_AIO_USERNAME. If you run into connectivity issues, one of the first things to check is that the names in the settings.toml file match the names in the code.
Here is an example settings.toml file.
# Comments are supported CIRCUITPY_WIFI_SSID = "guest wifi" CIRCUITPY_WIFI_PASSWORD = "guessable" CIRCUITPY_WEB_API_PORT = 80 CIRCUITPY_WEB_API_PASSWORD = "passw0rd" test_variable = "this is a test" thumbs_up = "\U0001f44d"
In a settings.toml file, it's important to keep these factors in mind:
- Strings are wrapped in double quotes; ex:
"your-string-here" - Integers are not quoted and may be written in decimal with optional sign (
+1,-1,1000) or hexadecimal (0xabcd).- Floats (decimal numbers), octal (
0o567) and binary (0b11011) are not supported.
- Floats (decimal numbers), octal (
- Use
\uescapes for weird characters,\xand\oooescapes are not available in .toml files- Example:
\U0001f44dfor 👍 (thumbs up emoji) and\u20acfor € (EUR sign)
- Example:
- Unicode emoji, and non-ASCII characters, stand for themselves as long as you're careful to save in "UTF-8 without BOM" format
When your settings.toml file is ready, you can save it in your text editor with the .toml extension.
In your code.py file, you'll need to import the os library to access the settings.toml file. Your settings are accessed with the os.getenv() function. You'll pass your settings entry to the function to import it into the code.py file.
import os
print(os.getenv("test_variable"))
In the upcoming CircuitPython WiFi examples, you'll see how the settings.toml file is used for connecting to your SSID and accessing your API keys.
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Internet Connect!
Connect to WiFi
OK, now that you have your settings.toml file set up - you can connect to the Internet.
To do this, you need to first install a few libraries, into the lib folder on your CIRCUITPY drive. Then you need to update code.py with the example script.
Thankfully, we can do this in one go. In the example below, click the Download Project Bundle button below to download the necessary libraries and the code.py file in a zip file. Extract the contents of the zip file, open the directory examples/ and then click on the directory that matches the version of CircuitPython you're using and copy the contents of that directory to your CIRCUITPY drive.
Your CIRCUITPY drive should now look similar to the following image:
# SPDX-FileCopyrightText: 2019 ladyada for Adafruit Industries
# SPDX-License-Identifier: MIT
from os import getenv
import adafruit_connection_manager
import adafruit_requests
import board
import busio
from digitalio import DigitalInOut
# Use this import for adafruit_esp32spi version 11.0.0 and up.
# Note that frozen libraries may not be up to date.
# import adafruit_esp32spi
from adafruit_esp32spi import adafruit_esp32spi
# Get wifi details and more from a settings.toml file
# tokens used by this Demo: CIRCUITPY_WIFI_SSID, CIRCUITPY_WIFI_PASSWORD
ssid = getenv("CIRCUITPY_WIFI_SSID")
password = getenv("CIRCUITPY_WIFI_PASSWORD")
print("ESP32 SPI webclient test")
TEXT_URL = "http://wifitest.adafruit.com/testwifi/index.html"
JSON_URL = "http://wifitest.adafruit.com/testwifi/sample.json"
# If you are using a board with pre-defined ESP32 Pins:
esp32_cs = DigitalInOut(board.ESP_CS)
esp32_ready = DigitalInOut(board.ESP_BUSY)
esp32_reset = DigitalInOut(board.ESP_RESET)
# If you have an AirLift Shield:
# esp32_cs = DigitalInOut(board.D10)
# esp32_ready = DigitalInOut(board.D7)
# esp32_reset = DigitalInOut(board.D5)
# If you have an AirLift Featherwing or ItsyBitsy Airlift:
# esp32_cs = DigitalInOut(board.D13)
# esp32_ready = DigitalInOut(board.D11)
# esp32_reset = DigitalInOut(board.D12)
# If you have an externally connected ESP32:
# NOTE: You may need to change the pins to reflect your wiring
# esp32_cs = DigitalInOut(board.D9)
# esp32_ready = DigitalInOut(board.D10)
# esp32_reset = DigitalInOut(board.D5)
# Secondary (SCK1) SPI used to connect to WiFi board on Arduino Nano Connect RP2040
if "SCK1" in dir(board):
spi = busio.SPI(board.SCK1, board.MOSI1, board.MISO1)
else:
spi = busio.SPI(board.SCK, board.MOSI, board.MISO)
esp = adafruit_esp32spi.ESP_SPIcontrol(spi, esp32_cs, esp32_ready, esp32_reset)
pool = adafruit_connection_manager.get_radio_socketpool(esp)
ssl_context = adafruit_connection_manager.get_radio_ssl_context(esp)
requests = adafruit_requests.Session(pool, ssl_context)
if esp.status == adafruit_esp32spi.WL_IDLE_STATUS:
print("ESP32 found and in idle mode")
print("Firmware vers.", esp.firmware_version)
print("MAC addr:", ":".join(f"{byte:02X}" for byte in esp.MAC_address))
for ap in esp.scan_networks():
print(f"\t{ap.ssid:<23} RSSI: {ap.rssi}")
print("Connecting to AP...")
while not esp.is_connected:
try:
esp.connect_AP(ssid, password)
except OSError as e:
print("could not connect to AP, retrying: ", e)
continue
print("Connected to", esp.ap_info.ssid, "\tRSSI:", esp.ap_info.rssi)
print("My IP address is", esp.ipv4_address)
print(f"IP lookup adafruit.com: {esp.pretty_ip(esp.get_host_by_name('adafruit.com'))}")
print(f"Ping google.com: {esp.ping('google.com')} ms")
# esp._debug = True
print("Fetching text from", TEXT_URL)
r = requests.get(TEXT_URL)
print("-" * 40)
print(r.text)
print("-" * 40)
r.close()
print()
print("Fetching json from", JSON_URL)
r = requests.get(JSON_URL)
print("-" * 40)
print(r.json())
print("-" * 40)
r.close()
print("Done!")
And save it to your board, with the name code.py.
Don't forget you'll also need to create the settings.toml file as seen above, with your WiFi ssid and password.
In a serial console, you should see something like the following. For more information about connecting with a serial console, view the guide Connecting to the Serial Console.
>>> import wifitest
ESP32 SPI webclient test
ESP32 found and in idle mode
Firmware vers. 1.7.5
MAC addr: 24:C9:DC:BD:0F:3F
HomeNetwork RSSI: -46
HomeNetwork RSSI: -76
Fios-12345 RSSI: -92
FiOS-AB123 RSSI: -92
NETGEAR53 RSSI: -93
Connecting to AP...
Connected to HomeNetwork RSSI: -45
My IP address is 192.168.1.245
IP lookup adafruit.com: 104.20.39.240
Ping google.com: 30 ms
Fetching text from http://wifitest.adafruit.com/testwifi/index.html
----------------------------------------
This is a test of Adafruit WiFi!
If you can read this, its working :)
----------------------------------------
Fetching json from http://wifitest.adafruit.com/testwifi/sample.json
----------------------------------------
{'fun': True, 'company': 'Adafruit', 'founded': 2005, 'primes': [2, 3, 5], 'pi': 3.14, 'mixed': [False, None, 3, True, 2.7, 'cheese']}
----------------------------------------
Done!
Going over the example above, here's a breakdown of what the program is doing:
- Initialize the ESP32 over SPI using the SPI port and 3 control pins:
esp32_cs = DigitalInOut(board.ESP_CS)
esp32_ready = DigitalInOut(board.ESP_BUSY)
esp32_reset = DigitalInOut(board.ESP_RESET)
#...
else:
spi = busio.SPI(board.SCK, board.MOSI, board.MISO)
esp = adafruit_esp32spi.ESP_SPIcontrol(spi, esp32_cs, esp32_ready, esp32_reset)
- Get the socket pool and the SSL context, and then tell the
adafruit_requestslibrary about them.
pool = adafruit_connection_manager.get_radio_socketpool(esp) ssl_context = adafruit_connection_manager.get_radio_ssl_context(esp) requests = adafruit_requests.Session(pool, ssl_context)
- Verify an ESP32 is found, checks the firmware and MAC address
if esp.status == adafruit_esp32spi.WL_IDLE_STATUS:
print("ESP32 found and in idle mode")
print("Firmware vers.", esp.firmware_version)
print("MAC addr:", ":".join("%02X" % byte for byte in esp.MAC_address))
- Perform a scan of all access points it can see and print out the name and signal strength.
for ap in esp.scan_networks():
print("\t%-23s RSSI: %d" % (ap.ssid, ap.rssi))
- Connect to the AP we've defined here, then print out the local IP address. Then attempt to do a domain name lookup and ping google.com to check network connectivity. (Note sometimes the ping fails or takes a while; this isn't a big deal.)
print("Connecting to AP...")
while not esp.is_connected:
try:
esp.connect_AP(ssid, password)
except OSError as e:
print("could not connect to AP, retrying: ", e)
continue
print("Connected to", esp.ap_info.ssid, "\tRSSI:", esp.ap_info.rssi)
print("My IP address is", esp.ipv4_address)
print(
"IP lookup adafruit.com: %s" % esp.pretty_ip(esp.get_host_by_name("adafruit.com"))
)
Now we're getting to the really interesting part of the example program. We've written a library for web fetching web data, named adafruit_requests. It is a lot like the regular Python library named requests. This library allows you to send HTTP and HTTPS requests easily and provides helpful methods for parsing the response from the server.
- Here is the part of the example program is fetching text data from a URL.
TEXT_URL = "http://wifitest.adafruit.com/testwifi/index.html" # Further up in the program
# ...
print("Fetching text from", TEXT_URL)
r = requests.get(TEXT_URL)
print('-' * 40)
print(r.text)
print('-' * 40)
r.close()
- Finally, here the program is fetching some JSON data. The
adafruit_requestslibrary will parse the JSON into a Python dictionary whose structure is the same as the structure of the JSON.
JSON_URL = "http://wifitest.adafruit.com/testwifi/sample.json" # Further up in the program
# ...
print("Fetching json from", JSON_URL)
r = requests.get(JSON_URL)
print('-' * 40)
print(r.json())
print('-' * 40)
r.close()
Advanced Requests Usage
Want to send custom HTTP headers, parse the response as raw bytes, or handle a response's http status code in your CircuitPython code?
We've written an example to show advanced usage of the requests module below.
To use with CircuitPython, you need to first install a few libraries, into the lib folder on your CIRCUITPY drive. Then you need to update code.py with the example script.
Thankfully, we can do this in one go. In the example below, click the Download Project Bundle button below to download the necessary libraries and the code.py file in a zip file. Extract the contents of the zip file, open the directory examples/ and then click on the directory that matches the version of CircuitPython you're using and copy the contents of that directory to your CIRCUITPY drive.
# SPDX-FileCopyrightText: 2021 ladyada for Adafruit Industries
# SPDX-License-Identifier: MIT
import os
import adafruit_connection_manager
import board
import busio
from adafruit_esp32spi import adafruit_esp32spi
from digitalio import DigitalInOut
import adafruit_requests
# Get WiFi details, ensure these are setup in settings.toml
ssid = os.getenv("CIRCUITPY_WIFI_SSID")
password = os.getenv("CIRCUITPY_WIFI_PASSWORD")
# If you are using a board with pre-defined ESP32 Pins:
esp32_cs = DigitalInOut(board.ESP_CS)
esp32_ready = DigitalInOut(board.ESP_BUSY)
esp32_reset = DigitalInOut(board.ESP_RESET)
# If you have an externally connected ESP32:
# esp32_cs = DigitalInOut(board.D9)
# esp32_ready = DigitalInOut(board.D10)
# esp32_reset = DigitalInOut(board.D5)
# If you have an AirLift Featherwing or ItsyBitsy Airlift:
# esp32_cs = DigitalInOut(board.D13)
# esp32_ready = DigitalInOut(board.D11)
# esp32_reset = DigitalInOut(board.D12)
spi = busio.SPI(board.SCK, board.MOSI, board.MISO)
radio = adafruit_esp32spi.ESP_SPIcontrol(spi, esp32_cs, esp32_ready, esp32_reset)
print("Connecting to AP...")
while not radio.is_connected:
try:
radio.connect_AP(ssid, password)
except RuntimeError as e:
print("could not connect to AP, retrying: ", e)
continue
print("Connected to", str(radio.ap_info.ssid, "utf-8"), "\tRSSI:", radio.ap_info.rssi)
# Initialize a requests session
pool = adafruit_connection_manager.get_radio_socketpool(radio)
ssl_context = adafruit_connection_manager.get_radio_ssl_context(radio)
requests = adafruit_requests.Session(pool, ssl_context)
JSON_GET_URL = "https://httpbin.org/get"
# Define a custom header as a dict.
headers = {"user-agent": "blinka/1.0.0"}
print(f"Fetching JSON data from {JSON_GET_URL}...")
with requests.get(JSON_GET_URL, headers=headers) as response:
print("-" * 60)
json_data = response.json()
headers = json_data["headers"]
print("Response's Custom User-Agent Header: {0}".format(headers["User-Agent"]))
print("-" * 60)
# Read Response's HTTP status code
print("Response HTTP Status Code: ", response.status_code)
print("-" * 60)
Your CIRCUITPY drive should now look similar to the following image:
WiFi Manager
The way the examples above connect to WiFi works but it's a little finicky. Since WiFi is not necessarily so reliable, you may have disconnects and need to reconnect. For more advanced uses, we recommend using the WiFiManager class. It will wrap the connection/status/requests loop for you - reconnecting if WiFi drops, resetting the ESP32 if it gets into a bad state, etc.
Here's a more advanced example that shows using the WiFiManager and also how to fetch the current time from a web source.
# SPDX-FileCopyrightText: 2019 ladyada for Adafruit Industries
# SPDX-License-Identifier: MIT
import time
from os import getenv
import board
import busio
import neopixel
import rtc
from digitalio import DigitalInOut
# Use these imports for adafruit_esp32spi version 11.0.0 and up.
# Note that frozen libraries may not be up to date.
# import adafruit_esp32spi
# from adafruit_esp32spi.wifimanager import WiFiManager
from adafruit_esp32spi import adafruit_esp32spi
from adafruit_esp32spi.adafruit_esp32spi_wifimanager import WiFiManager
# Get wifi details and more from a settings.toml file
# tokens used by this Demo: CIRCUITPY_WIFI_SSID, CIRCUITPY_WIFI_PASSWORD
ssid = getenv("CIRCUITPY_WIFI_SSID")
password = getenv("CIRCUITPY_WIFI_PASSWORD")
print("ESP32 local time")
TIME_API = "https://time.now/developer/api/ip"
# If you are using a board with pre-defined ESP32 Pins:
esp32_cs = DigitalInOut(board.ESP_CS)
esp32_ready = DigitalInOut(board.ESP_BUSY)
esp32_reset = DigitalInOut(board.ESP_RESET)
# If you have an externally connected ESP32:
# esp32_cs = DigitalInOut(board.D9)
# esp32_ready = DigitalInOut(board.D10)
# esp32_reset = DigitalInOut(board.D5)
# Secondary (SCK1) SPI used to connect to WiFi board on Arduino Nano Connect RP2040
if "SCK1" in dir(board):
spi = busio.SPI(board.SCK1, board.MOSI1, board.MISO1)
else:
spi = busio.SPI(board.SCK, board.MOSI, board.MISO)
esp = adafruit_esp32spi.ESP_SPIcontrol(spi, esp32_cs, esp32_ready, esp32_reset)
"""Use below for Most Boards"""
status_pixel = neopixel.NeoPixel(board.NEOPIXEL, 1, brightness=0.2)
"""Uncomment below for ItsyBitsy M4"""
# status_pixel = dotstar.DotStar(board.APA102_SCK, board.APA102_MOSI, 1, brightness=0.2)
"""Uncomment below for an externally defined RGB LED (including Arduino Nano Connect)"""
# import adafruit_rgbled
# from adafruit_esp32spi import PWMOut
# RED_LED = PWMOut.PWMOut(esp, 26)
# GREEN_LED = PWMOut.PWMOut(esp, 27)
# BLUE_LED = PWMOut.PWMOut(esp, 25)
# status_pixel = adafruit_rgbled.RGBLED(RED_LED, BLUE_LED, GREEN_LED)
wifi = WiFiManager(esp, ssid, password, status_pixel=status_pixel)
the_rtc = rtc.RTC()
response = None
while True:
try:
print("Fetching json from", TIME_API)
response = wifi.get(TIME_API)
break
except OSError as e:
print("Failed to get data, retrying\n", e)
continue
json = response.json()
current_time = json["datetime"]
the_date, the_time = current_time.split("T")
year, month, mday = (int(x) for x in the_date.split("-"))
the_time = the_time.split(".")[0]
hours, minutes, seconds = (int(x) for x in the_time.split(":"))
# We can also fill in these extra nice things
year_day = json["day_of_year"]
week_day = json["day_of_week"]
is_dst = json["dst"]
now = time.struct_time((year, month, mday, hours, minutes, seconds, week_day, year_day, is_dst))
print(now)
the_rtc.datetime = now
while True:
print(time.localtime())
time.sleep(1)
Further Information
For more information on the basics of doing networking in CircuitPython, see this guide:
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Code Setup
Install the Mu Editor
This guide requires you to edit and interact with CircuitPython code. While you can use any text editor of your choosing, Mu is a simple code editor that works with the Adafruit CircuitPython boards. It's written in Python and works on Windows, MacOS, Linux and Raspberry Pi. The serial console is built right in, so you get immediate feedback from your board's serial output!
Before proceeding, click the button below to install the Mu Editor. There are versions for PC, mac, and Linux.
In the embedded code element below, click on the Download Project Bundle button, and save the .zip archive file to your computer.
Then, uncompress the .zip file, it will unpack to a folder named PyPortal_TOTP_Friend.
Copy the contents of PyPortal_TOTP_Friend directory to your PyPortal CIRCUITPY drive.
# SPDX-FileCopyrightText: 2017 Limor Fried for Adafruit Industries
#
# SPDX-License-Identifier: MIT
import os
import time
import board
import busio
from digitalio import DigitalInOut
import displayio
import terminalio
from simpleio import map_range
import adafruit_hashlib as hashlib
import adafruit_touchscreen
from adafruit_button import Button
from adafruit_progressbar.progressbar import ProgressBar
from adafruit_display_text.label import Label
from adafruit_esp32spi import adafruit_esp32spi
from adafruit_pyportal import PyPortal
import rtc
# Background Color
BACKGROUND = 0x0
# Button color
BTN_COLOR = 0xFFFFFF
# Button text color
BTN_TEXT_COLOR = 0x0
# Set to true if you never want to go to sleep!
ALWAYS_ON = True
# How long to stay on if not in always_on mode
ON_SECONDS = 60
# Get totp_keys from a totp_keys.py file
try:
from totp_keys import totp_keys
except ImportError:
print("TOTP info not found in totp_keys.py, please add them there!")
# Initialize PyPortal Display
display = board.DISPLAY
WIDTH = board.DISPLAY.width
HEIGHT = board.DISPLAY.height
ts = adafruit_touchscreen.Touchscreen(board.TOUCH_XL, board.TOUCH_XR,
board.TOUCH_YD, board.TOUCH_YU,
calibration=(
(5200, 59000),
(5800, 57000)
),
size=(WIDTH, HEIGHT))
# Create a SHA1 Object
SHA1 = hashlib.sha1
# PyPortal ESP32 AirLift Pins
esp32_cs = DigitalInOut(board.ESP_CS)
esp32_ready = DigitalInOut(board.ESP_BUSY)
esp32_reset = DigitalInOut(board.ESP_RESET)
# Initialize PyPortal ESP32 AirLift
spi = busio.SPI(board.SCK, board.MOSI, board.MISO)
esp = adafruit_esp32spi.ESP_SPIcontrol(spi, esp32_cs, esp32_ready, esp32_reset)
def HMAC(k, m):
"""# HMAC implementation, as hashlib/hmac wouldn't fit
From https://en.wikipedia.org/wiki/Hash-based_message_authentication_code
"""
SHA1_BLOCK_SIZE = 64
KEY_BLOCK = k + (b'\0' * (SHA1_BLOCK_SIZE - len(k)))
KEY_INNER = bytes((x ^ 0x36) for x in KEY_BLOCK)
KEY_OUTER = bytes((x ^ 0x5C) for x in KEY_BLOCK)
inner_message = KEY_INNER + m
outer_message = KEY_OUTER + SHA1(inner_message).digest()
return SHA1(outer_message)
def base32_decode(encoded):
missing_padding = len(encoded) % 8
if missing_padding != 0:
encoded += '=' * (8 - missing_padding)
encoded = encoded.upper()
chunks = [encoded[i:i + 8] for i in range(0, len(encoded), 8)]
out = []
for chunk in chunks:
bits = 0
bitbuff = 0
for c in chunk:
if 'A' <= c <= 'Z':
n = ord(c) - ord('A')
elif '2' <= c <= '7':
n = ord(c) - ord('2') + 26
elif c == '=':
continue
else:
raise ValueError("Not base32")
# 5 bits per 8 chars of base32
bits += 5
# shift down and add the current value
bitbuff <<= 5
bitbuff |= n
# great! we have enough to extract a byte
if bits >= 8:
bits -= 8
byte = bitbuff >> bits # grab top 8 bits
bitbuff &= ~(0xFF << bits) # and clear them
out.append(byte) # store what we got
return out
def int_to_bytestring(int_val, padding=8):
result = []
while int_val != 0:
result.insert(0, int_val & 0xFF)
int_val >>= 8
result = [0] * (padding - len(result)) + result
return bytes(result)
def generate_otp(int_input, secret_key, digits=6):
""" HMAC -> OTP generator, pretty much same as
https://github.com/pyotp/pyotp/blob/master/src/pyotp/otp.py
"""
if int_input < 0:
raise ValueError('input must be positive integer')
hmac_hash = bytearray(
HMAC(bytes(base32_decode(secret_key)),
int_to_bytestring(int_input)).digest()
)
offset = hmac_hash[-1] & 0xf
code = ((hmac_hash[offset] & 0x7f) << 24 |
(hmac_hash[offset + 1] & 0xff) << 16 |
(hmac_hash[offset + 2] & 0xff) << 8 |
(hmac_hash[offset + 3] & 0xff))
str_code = str(code % 10 ** digits)
while len(str_code) < digits:
str_code = '0' + str_code
return str_code
def display_otp_key(secret_name, secret_otp):
"""Updates the displayio labels to display formatted OTP key and name.
"""
# display the key's name
label_title.text = secret_name
# format and display the OTP
label_secret.text = "{} {}".format(str(secret_otp)[0:3], str(secret_otp)[3:6])
print("OTP Name: {}\nOTP Key: {}".format(secret_name, secret_otp))
print("===========================================")
# GFX Font
font = terminalio.FONT
# Initialize new PyPortal object
pyportal = PyPortal(esp=esp,
external_spi=spi)
# Root DisplayIO
root_group = displayio.Group()
display.root_group = root_group
BACKGROUND = BACKGROUND if isinstance(BACKGROUND, int) else 0x0
bg_bitmap = displayio.Bitmap(display.width, display.height, 1)
bg_palette = displayio.Palette(1)
bg_palette[0] = BACKGROUND
background = displayio.TileGrid(bg_bitmap, pixel_shader=bg_palette)
# Create a new DisplayIO group
splash = displayio.Group()
splash.append(background)
key_group = displayio.Group(scale=5)
# We'll use a default text placeholder for this label
label_secret = Label(font, text="000 000")
label_secret.x = (display.width // 2) // 13
label_secret.y = 17
key_group.append(label_secret)
label_title = Label(font)
label_title.text = " Loading.."
label_title.x = 0
label_title.y = 5
key_group.append(label_title)
# append key_group to splash
splash.append(key_group)
# Show the group
display.root_group = splash
print("Connecting to AP...")
while not esp.is_connected:
try:
esp.connect_AP(os.getenv("CIRCUITPY_WIFI_SSID"), os.getenv("CIRCUITPY_WIFI_PASSWORD"))
except RuntimeError as e:
print("Could not connect to AP, retrying: ", e)
continue
print("Connected")
# get_time will raise ValueError if the time isn't available yet so loop until
# it works.
now_utc = None
while now_utc is None:
try:
now_utc = time.localtime(esp.get_time()[0])
except ValueError:
pass
rtc.RTC().datetime = now_utc
# Get the current time in seconds since Jan 1, 1970
t = time.time()
print("Seconds since Jan 1, 1970: {} seconds".format(t))
# Instead of using RTC which means converting back and forth
# we'll just keep track of seconds-elapsed-since-NTP-call
mono_time = int(time.monotonic())
print("Monotonic time", mono_time)
# Add buttons to the interface
assert len(totp_keys) < 6, "This code can only display 5 keys at a time"
# generate buttons
buttons = []
btn_x = 5
for i in totp_keys:
button = Button(name=i[0], x=btn_x,
y=175, width=60,
height=60, label=i[0].strip(" "),
label_font=font, label_color=BTN_TEXT_COLOR,
fill_color=BTN_COLOR, style=Button.ROUNDRECT)
buttons.append(button)
# add padding btween buttons
btn_x += 63
# append buttons to splash group
for b in buttons:
splash.append(b)
# refrsh timer label
label_timer = Label(font)
label_timer.x = (display.width // 2) // 13
label_timer.y = 15
splash.append(label_timer)
# create a new progress bar
progress_bar = ProgressBar(display.width//5, 125,
200, 30, bar_color = 0xAAAAAA)
splash.append(progress_bar)
# how long to stay on if not in always_on mode
countdown = ON_SECONDS
# current button state, defaults to first item in totp_keys
current_button = totp_keys[0][0]
buttons[0].selected = True
while ALWAYS_ON or (countdown > 0):
# Calculate current time based on NTP + monotonic
unix_time = t - mono_time + int(time.monotonic())
# Update the key refresh timer
timer = time.localtime(time.time()).tm_sec
# timer resets on :00/:30
if timer > 30:
countdown = 60 - timer
else:
countdown = 30 - timer
print('NTP Countdown: {}%'.format(countdown))
# change the timer bar's color if text is about to refresh
progress_bar.fill = 0xFFFFFF
if countdown < 5:
progress_bar.fill = 0xFF0000
# update the progress_bar with countdown
countdown = map_range(countdown, 0, 30, 0.0, 1.0)
progress_bar.progress = countdown
# poll the touchscreen
p = ts.touch_point
# if the touchscreen was pressed
if p:
for i, b in enumerate(buttons):
if b.contains(p):
b.selected = True
for name, secret in totp_keys:
# check if button name is the same as a key name
if b.name == name:
current_button = name
# Generate OTP
otp = generate_otp(unix_time // 30, secret)
display_otp_key(name, otp)
else:
b.selected = False
else:
for name, secret in totp_keys:
if current_button == name:
# Generate OTP
otp = generate_otp(unix_time // 30, secret)
display_otp_key(name, otp)
# We'll update every 1/4 second, we can hash very fast so its no biggie!
countdown -= 0.25
time.sleep(0.25)
Once all the files are copied from your computer to the PyPortal, you should have the following files on your CIRCUITPY drive:
CircuitPython Libraries
Before continuing make sure your board's lib folder has the following files and folders copied over:
- adafruit_binascii.mpy
- adafruit_esp32spi
- adafruit_pyportal.mpy
- adafruit_bitmap_font
- adafruit_hashlib
- adafruit_requests.mpy
- adafruit_bus_device
- adafruit_imageload
- adafruit_button.mpy
- adafruit_io
- adafruit_touchscreen.mpy
- adafruit_display_shapes
- adafruit_ntp.mpy
- neopixel.mpy
- adafruit_display_text
- adafruit_progressbar
- simpleio.mpy
Set Up Tokens
You'll also need to get 2 factor "authenticator tokens/secrets". Each site is a little different about how it does this.
For example, when you set up Gmail for 2FA it will show you a QR code like this:
Which is great for phones. For us, we need the base32-encoded token. Click the Can't Scan It? link or otherwise request the text token. You'll get a page like this.
(Don't freak out - this isnt a real key)
That string of letters and numbers may be uppercase or lower case, it may also be 16 digits or 24 or 32 or some other qty. It doesn't matter! Grab that string, and remove the spaces so its one long string like "ra4ndd2utltotseol564z3jijj5jo677" Note that the number 0 and number 1 never appear so anything that looks like an O, l or an I is a letter.
settings.toml File Setup
This file should already be set up with your WiFi SSID and password. In the past, secrets.py used to also include your WiFi credentials, but now they are in settings.toml.
totp_keys.py File Setup
Open the totp_keys.py file on your CircuitPython device using Mu. You will add the totp_keys you generated above to this file.
totp_keys = [
("Discord ", "JBSWY3DPEHPK3PXP"),
("Gmail", "JBSWY3DPEHPK3PZP"),
("GitHub", "JBSWY5DZEHPK3PXP"),
("Adafruit", "JBSWY6DZEHPK3PXP"),
("Outlook", "JBSWY7DZEHPK3PXP"),
]
This code displays up to five keys. If you have less than 5 keys to display, you may remove items from totp_keys. The buttons on the PyPortal display are dynamically generated based on how many items are in totp_keys:
totp_keys = [
("Discord ", "JBSWY3DPEHPK3PXP"),
("Gmail", "JBSWY3DPEHPK3PZP"),
("GitHub", "JBSWY5DZEHPK3PXP")
]
Once you've added your keys, save the modified totp_keys.py file.
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Code Usage
The PyPortal fetches and sets the microcontroller's current UTC time. This may take up to 15 seconds.
Formatting the Name Label
Add spaces to the left of the TOTP key name in the totp_keys list to pad the left side:
When the timer is five seconds away from refreshing, the progress bar will change from white to red.
Once the time hits zero, the progress bar resets and the key regenerates.
Customizing the Authentication Friend
Everyone's desk is different and we can do a bit of customization to our PyPortal authentication friend.
Background
In the code.py file, change BACKGROUND = 0x0to a new hexadecimal color value and save the file.
Customizing the Buttons
We can change the button's fill color and text color.
To change the button's fill color: in the code.py file, change BTN_COLOR = 0xFFFFFF to a hexadecimal color value.
To change the button's text color: in the code.py file, change BTN_TEXT_COLOR to a hexadecimal color value.
Formatting the Name Label
The x-location for the name label is zero by default. You may need to modify the totp_keys list to center shorter TOTP key names.
In totp_keys.py, add spaces to the left of the the key in totp_keys to center the names, if desired:
totp_keys = [
("Discord ", "JBSWY3DPEHPK3PXP"),
("Gmail", "JBSWY3DPEHPK3PZP"),
("GitHub", "JBSWY5DZEHPK3PXP"),
("Adafruit", "JBSWY6DZEHPK3PXP"),
("Outlook", "JBSWY7DZEHPK3PXP"),
]
Page last edited March 08, 2024
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