lenticular_cloud2/lenticular_cloud/views/frontend.py

from authlib.integrations.base_client.errors import MissingTokenError, InvalidTokenError
from base64 import b64encode, b64decode
from flask import Blueprint, redirect, request
from flask import current_app
from flask import jsonify, session
from flask import render_template, url_for
from flask_login import logout_user, current_user
from http import HTTPStatus
from werkzeug.utils import redirect
import logging
from datetime import timedelta
from flask.typing import ResponseReturnValue 
from ory_hydra_client.api.o_auth_2 import list_o_auth_2_consent_sessions, revoke_o_auth_2_consent_sessions
from ory_hydra_client.models import GenericError
from urllib.parse import urlparse
from typing import Optional, Any
import jwt
from datetime import datetime, timedelta
import webauthn
from webauthn.helpers.structs import (
    AuthenticatorSelectionCriteria,
    PublicKeyCredentialDescriptor,
    ResidentKeyRequirement,
    UserVerificationRequirement,
)

from ..model import db, User, AppToken, PasskeyCredential
from ..form.frontend import ClientCertForm, PasswordChangeForm, \
    AppTokenForm, AppTokenDeleteForm, PasskeyRegisterForm
from ..form.base import  ButtonForm
from ..auth_providers import PasswordAuthProvider
from .oauth2 import redirect_login, oauth2
from ..hydra import hydra_service
from ..pki import pki
from ..lenticular_services import lenticular_services

frontend_views = Blueprint('frontend', __name__, url_prefix='')
logger = logging.getLogger(__name__)

def get_current_user() -> User:
    user_any: Any = current_user
    user: User = user_any
    return user


def before_request() -> Optional[ResponseReturnValue]:
    try:
        resp = oauth2.custom.get('/userinfo')
        if not get_current_user().is_authenticated or resp.status_code != 200:
            logger.info('user not logged in redirect')
            return redirect_login()
    except MissingTokenError:
        logger.info('MissingTokenError redirect user to login')
        return redirect_login()
    except InvalidTokenError:
        logger.info('InvalidTokenError redirect user to login')
        return redirect_login()

    return None


frontend_views.before_request(before_request)


@frontend_views.route('/logout')
def logout() -> ResponseReturnValue:
    logout_user()
    return redirect(
        f'{current_app.config["HYDRA_PUBLIC_URL"]}/oauth2/sessions/logout')


@frontend_views.route('/', methods=['GET'])
def index() -> ResponseReturnValue:
    if 'next_url' in session:
        next_url = session['next_url']
        del session['next_url']
        return redirect(next_url)
    return render_template(
        'frontend/index.html.j2',
        lenticular_services=lenticular_services,
    )


@frontend_views.route('/client_cert')
def client_cert() -> ResponseReturnValue:
    client_certs = {}
    for service in lenticular_services.values():
        client_certs[str(service.name)] = \
                pki.get_client_certs(get_current_user(), service)

    return render_template(
            'frontend/client_cert.html.j2',
            services=lenticular_services,
            client_certs=client_certs)


@frontend_views.route('/client_cert/<service_name>/<serial_number>')
def get_client_cert(service_name, serial_number) -> ResponseReturnValue:
    service = lenticular_services[service_name]
    cert = pki.get_client_cert(
            get_current_user(), service, serial_number)
    return jsonify({
        'data': {
            'pem': cert.pem()}
        })


@frontend_views.route(
        '/client_cert/<service_name>/<serial_number>', methods=['DELETE'])
def revoke_client_cert(service_name, serial_number) -> ResponseReturnValue:
    service = lenticular_services[service_name]
    cert = pki.get_client_cert(
            get_current_user(), service, serial_number)
    pki.revoke_certificate(cert)
    return jsonify({})


@frontend_views.route(
        '/client_cert/<service_name>/new',
        methods=['GET', 'POST'])
def client_cert_new(service_name) -> ResponseReturnValue:
    if service_name not in lenticular_services:
        return '', 404
    service = lenticular_services[service_name]
    form = ClientCertForm()
    if form.validate_on_submit():
        valid_time = int(form.data['valid_time']) * timedelta(1, 0, 0)
        cert = pki.signing_publickey(
                get_current_user(),
                service,
                form.data['publickey'],
                valid_time=valid_time)
        return jsonify({
                'status': 'ok',
                'data': {
                    'cert': cert.pem(),
                    'ca_cert': pki.get_ca_cert_pem(service)
                }})
    elif form.is_submitted():
        return jsonify({
                'status': 'error',
                'errors': form.errors
            })

    return render_template(
            'frontend/client_cert_new.html.j2',
            service=service,
            form=form)

@frontend_views.route('/app_token')
def app_token() -> ResponseReturnValue:
    delete_form = AppTokenDeleteForm()
    form = ClientCertForm()
    return render_template('frontend/app_token.html.j2',
                           delete_form=delete_form,
                           services=lenticular_services)

@frontend_views.route('/app_token/new', methods=['GET','POST'])
def app_token_new() -> ResponseReturnValue:
    form = AppTokenForm()

    if form.validate_on_submit():
        user_any = get_current_user() # type: Any
        user = user_any # type: User
        app_token = AppToken.new(user, name="",scopes="")
        form.populate_obj(app_token)
        # check for duplicate names
        for user_app_token in user.app_tokens:
            if user_app_token.name == app_token.name:
                return 'name already exist', 400
        user.app_tokens.append(app_token)
        db.session.commit()
        return render_template('frontend/app_token_new_show.html.j2', app_token=app_token)


    return render_template('frontend/app_token_new.html.j2',
                           form=form)

@frontend_views.route('/app_token/<app_token_name>', methods=["POST"])
def app_token_delete(app_token_name: str) -> ResponseReturnValue:
    form = AppTokenDeleteForm()

    if form.validate_on_submit():
        app_token = get_current_user().get_token_by_name(app_token_name)
        if app_token is None:
            return 'not found', 404
        db.session.delete(app_token)
        db.session.commit()

    return redirect(url_for('frontend.app_token'))

## Passkey

@frontend_views.route('/passkey/list', methods=['GET'])
def passkey() -> ResponseReturnValue:
    """list registered credentials for current user"""

    user = get_current_user()
    return render_template(
        'frontend/passkey_list.html.j2',
        credentials=user.passkey_credentials,
        button_form=ButtonForm()
    )



@frontend_views.route('/passkey/new', methods=['GET'])
def passkey_new() -> ResponseReturnValue:
    """register credential for current user"""
    public_url = urlparse(current_app.config['PUBLIC_URL'])

    user = get_current_user()
    form = PasskeyRegisterForm()

    options = webauthn.generate_registration_options(
        rp_name="Lenticluar Cloud",
        rp_id=public_url.hostname,
        user_id=str(user.id),
        user_name=user.username,
        authenticator_selection=AuthenticatorSelectionCriteria(
            user_verification=UserVerificationRequirement.REQUIRED,
            resident_key=ResidentKeyRequirement.REQUIRED,
        ),
        exclude_credentials = list(map(lambda x: PublicKeyCredentialDescriptor(id=x.credential_id), user.passkey_credentials))
    )
    secret_key = current_app.config['SECRET_KEY']
    token = jwt.encode({
            'challenge': b64encode(options.challenge).decode(),
            'iat': datetime.utcnow() - timedelta(minutes=1),
            'nbf': datetime.utcnow(),
            'exp': datetime.utcnow() + timedelta(minutes=15),
        }, secret_key, algorithm="HS256"
    )

    return render_template(
        'frontend/passkey_new.html.j2',
        form=form,
        options=webauthn.options_to_json(options),
        token=token,
    )

@frontend_views.route('/passkey/new', methods=['POST'])
def passkey_new_process() -> ResponseReturnValue:
    secret_key = current_app.config['SECRET_KEY']
    public_url = urlparse(current_app.config['PUBLIC_URL'])
    user = get_current_user()

    data = request.get_json()
    try:
        token = jwt.decode(
            data['token'], secret_key, algorithms=['HS256'], 
            options = {
                'require': ["challenge", "exp", "iat", "nbf"],
                
            })
    except jwt.exceptions.MissingRequiredClaimError:
        return jsonify({'message': "invalid token"}), 400
    challenge = b64decode(token['challenge'])
    credential = data['credential']
    name = data['name']
    
    result = webauthn.verify_registration_response(
        credential = credential,
        expected_rp_id = public_url.hostname,
        expected_challenge = challenge,
        expected_origin = [ public_url.geturl() ],
    )
    if not result.user_verified:
        return jsonify({ "message": "invalid auth" }), 403

    db.session.add(PasskeyCredential(
        id=None,
        user_id=user.id,
        credential_id=result.credential_id,
        credential_public_key=result.credential_public_key,
        name=name,
    ))
    db.session.commit()
    logger.info(f"add new passkey for user {user.username}")

    return jsonify({})

@frontend_views.route('/passkey/delete/<id>', methods=['POST'])
def passkey_delete(id: str) -> ResponseReturnValue:
    """delete registered credential"""

    user = get_current_user()
    form = ButtonForm()

    if form.validate_on_submit():
        cred = PasskeyCredential.query.filter(PasskeyCredential.id == id).first_or_404()
        if cred.user_id != user.id:
            return '', 404
        db.session.delete(cred)
        db.session.commit()
        return redirect(url_for('.passkey'))

    return '', HTTPStatus.BAD_REQUEST



@frontend_views.route('/password_change')
def password_change() -> ResponseReturnValue:
    form = PasswordChangeForm()
    return render_template('frontend/password_change.html.j2', form=form)


@frontend_views.route('/password_change', methods=['POST'])
def password_change_post() -> ResponseReturnValue:
    form = PasswordChangeForm()
    if form.validate():
        password_old = str(form.data['password_old'])
        password_new = str(form.data['password_new'])
        if not PasswordAuthProvider.check_auth_internal(
                get_current_user(), password_old):
            return jsonify(
                    {'errors': {'password_old': 'Old Password is invalid'}})

        get_current_user().change_password(password_new)
        logger.info(f"user {get_current_user().username} changed password")
        db.session.commit()
        return jsonify({})
    return jsonify({'errors': form.errors})


@frontend_views.route('/oauth2_token')
async def oauth2_tokens() -> ResponseReturnValue:

    subject = oauth2.custom.get('/userinfo').json()['sub']
    consent_sessions = await list_o_auth_2_consent_sessions.asyncio(subject=subject, _client=hydra_service.hydra_client)
    if consent_sessions is None or isinstance( consent_sessions, GenericError):
       return 'internal error, could not fetch sessions', 500
    return render_template(
            'frontend/oauth2_tokens.html.j2',
            consent_sessions=consent_sessions)


@frontend_views.route('/oauth2_token/<client_id>', methods=['DELETE'])
async def oauth2_token_revoke(client_id: str) -> ResponseReturnValue:
    subject = oauth2.session.get('/userinfo').json()['sub']
    await revoke_o_auth_2_consent_sessions.asyncio_detailed( _client=hydra_service.hydra_client,
                                subject=subject,
                                client=client_id)

    return jsonify({})