'''
    Onionr - Private P2P Communication

    Process incoming requests to the public api server for certain attacks
'''
'''
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.
'''
from flask import Blueprint, request, abort
from onionrservices import httpheaders
from onionrutils import epoch

class PublicAPISecurity:
    def __init__(self, public_api):
        public_api_security_bp = Blueprint('publicapisecurity', __name__)
        self.public_api_security_bp = public_api_security_bp

        @public_api_security_bp.before_app_request
        def validate_request():
            '''Validate request has the correct hostname'''
            # If high security level, deny requests to public (HS should be disabled anyway for Tor, but might not be for I2P)
            if public_api.config.get('general.security_level', default=1) > 0:
                abort(403)
            if type(public_api.torAdder) is None and type(public_api.i2pAdder) is None:
                # abort if our hs addresses are not known
                abort(403)
            if request.host not in (public_api.i2pAdder, public_api.torAdder):
                # Disallow connection if wrong HTTP hostname, in order to prevent DNS rebinding attacks
                abort(403)
            public_api.hitCount += 1 # raise hit count for valid requests

        @public_api_security_bp.after_app_request
        def send_headers(resp):
            '''Send api, access control headers'''
            resp = httpheaders.set_default_onionr_http_headers(resp)
            # Network API version
            resp.headers['X-API'] = public_api.API_VERSION
            public_api.lastRequest = epoch.get_rounded_epoch(roundS=5)
            return resp