Snippet of code containing the verification function for 2FA

otp_auth.py

@app.route("/login/auth", methods=['GET', 'POST'])
def OTP_auth():
  if session['username'] == None:
    return redirect(url_for('login'))
  if request.method == 'POST':
    #verify OTP
    totp_instance = pyotp.TOTP(app.config["OTP_CODE"])
    valid = totp_instance.verify(request.form.get("otp"))
    if valid:
      return render_template("success.html")
    else:
      flash("Invalid code. Please try again.")
  else:
    if app.config["OTP_ENABLED"] == "True":
      return render_template('auth.html')
    else:
      app.config["OTP_ENABLED"] = "True"
      return render_template('auth.html', secret_key=app.config["OTP_CODE"])
  return redirect(url_for("OTP_auth"))