app-MAIL-temp/app/auth/views/fido.py
2020-10-15 16:45:28 +02:00

163 lines
5.1 KiB
Python

import json
import secrets
import webauthn
from flask import (
request,
render_template,
redirect,
url_for,
flash,
session,
make_response,
g,
)
from flask_login import login_user
from flask_wtf import FlaskForm
from wtforms import HiddenField, validators, BooleanField
from app.auth.base import auth_bp
from app.config import MFA_USER_ID
from app.config import RP_ID, URL
from app.extensions import db, limiter
from app.log import LOG
from app.models import User, Fido, MfaBrowser
class FidoTokenForm(FlaskForm):
sk_assertion = HiddenField("sk_assertion", validators=[validators.DataRequired()])
remember = BooleanField(
"attr", default=False, description="Remember this browser for 30 days"
)
@auth_bp.route("/fido", methods=["GET", "POST"])
@limiter.limit(
"10/minute", deduct_when=lambda r: hasattr(g, "deduct_limit") and g.deduct_limit
)
def fido():
# passed from login page
user_id = session.get(MFA_USER_ID)
# user access this page directly without passing by login page
if not user_id:
flash("Unknown error, redirect back to main page", "warning")
return redirect(url_for("auth.login"))
user = User.get(user_id)
if not (user and user.fido_enabled()):
flash("Only user with security key linked should go to this page", "warning")
return redirect(url_for("auth.login"))
auto_activate = True
fido_token_form = FidoTokenForm()
next_url = request.args.get("next")
if request.cookies.get("mfa"):
browser = MfaBrowser.get_by(token=request.cookies.get("mfa"))
if browser and not browser.is_expired() and browser.user_id == user.id:
login_user(user)
flash(f"Welcome back {user.name}!", "success")
# Redirect user to correct page
return redirect(next_url or url_for("dashboard.index"))
else:
# Trigger rate limiter
g.deduct_limit = True
# Handling POST requests
if fido_token_form.validate_on_submit():
try:
sk_assertion = json.loads(fido_token_form.sk_assertion.data)
except Exception as e:
flash("Key verification failed. Error: Invalid Payload", "warning")
return redirect(url_for("auth.login"))
challenge = session["fido_challenge"]
try:
fido_key = Fido.get_by(
uuid=user.fido_uuid, credential_id=sk_assertion["id"]
)
webauthn_user = webauthn.WebAuthnUser(
user.fido_uuid,
user.email,
user.name if user.name else user.email,
False,
fido_key.credential_id,
fido_key.public_key,
fido_key.sign_count,
RP_ID,
)
webauthn_assertion_response = webauthn.WebAuthnAssertionResponse(
webauthn_user, sk_assertion, challenge, URL, uv_required=False
)
new_sign_count = webauthn_assertion_response.verify()
except Exception as e:
LOG.warning(f"An error occurred in WebAuthn verification process: {e}")
flash("Key verification failed.", "warning")
# Trigger rate limiter
g.deduct_limit = True
auto_activate = False
else:
user.fido_sign_count = new_sign_count
db.session.commit()
del session[MFA_USER_ID]
login_user(user)
flash(f"Welcome back {user.name}!", "success")
# Redirect user to correct page
response = make_response(redirect(next_url or url_for("dashboard.index")))
if fido_token_form.remember.data:
browser = MfaBrowser.create_new(user=user)
db.session.commit()
response.set_cookie(
"mfa",
value=browser.token,
expires=browser.expires.datetime,
secure=True if URL.startswith("https") else False,
httponly=True,
samesite="Lax",
)
return response
# Prepare information for key registration process
session.pop("challenge", None)
challenge = secrets.token_urlsafe(32)
session["fido_challenge"] = challenge.rstrip("=")
fidos = Fido.filter_by(uuid=user.fido_uuid).all()
webauthn_users = []
for fido in fidos:
webauthn_users.append(
webauthn.WebAuthnUser(
user.fido_uuid,
user.email,
user.name if user.name else user.email,
False,
fido.credential_id,
fido.public_key,
fido.sign_count,
RP_ID,
)
)
webauthn_assertion_options = webauthn.WebAuthnAssertionOptions(
webauthn_users, challenge
)
webauthn_assertion_options = webauthn_assertion_options.assertion_dict
return render_template(
"auth/fido.html",
fido_token_form=fido_token_form,
webauthn_assertion_options=webauthn_assertion_options,
enable_otp=user.enable_otp,
auto_activate=auto_activate,
next_url=next_url,
)