mirror of
https://github.com/GSA/notifications-api.git
synced 2025-12-10 23:32:27 -05:00
First pass at implementing API authentication using new JWT tokens
- NOTE - this does not manage secrets. There is only one URL and there is no functionality implemented - prior to rolling out we need to store secrets properly Uses the JWT libraries in [https://github.com/alphagov/notifications-python-client](https://github.com/alphagov/notifications-python-client) - Tokens are checked on every request and will be rejected if token is invalid as per the rules in the python clients.
This commit is contained in:
Martyn Inglis
@@ -1,9 +1,12 @@
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import os
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from flask._compat import string_types
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from flask import Flask
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from flask import Flask, _request_ctx_stack
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from werkzeug.local import LocalProxy
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from config import configs
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api_user = LocalProxy(lambda: _request_ctx_stack.top.api_user)
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def create_app(config_name):
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application = Flask(__name__)
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@@ -1,10 +1,5 @@
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from flask import Blueprint, request, abort
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from jwt import decode, DecodeError
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import calendar
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import time
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import base64
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import hashlib
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import hmac
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from flask import Blueprint
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from app.main.authentication.auth import requires_auth
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AUTHORIZATION_HEADER = 'Authorization'
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AUTHORIZATION_SCHEME = 'Bearer'
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@@ -13,87 +8,7 @@ WINDOW = 1
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main = Blueprint('main', __name__)
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def get_secrets(service_identifier):
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"""
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Temp method until secrets are stored in database etc
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:param service_identifier:
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:return: (Boolean, String)
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"""
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secrets = {
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'service1': '1234'
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}
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if service_identifier not in secrets:
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return False, None
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return True, secrets[service_identifier]
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def get_token_from_headers(headers):
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auth_header = headers.get(AUTHORIZATION_HEADER, '')
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if auth_header[:7] != AUTHORIZATION_SCHEME + " ":
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return None
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return auth_header[7:]
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def token_is_valid(token):
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try:
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# decode token to get service identifier
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# signature not checked
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unverified = decode(token, verify=False, algorithms=['HS256'])
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# service identifier used to get secret
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found, secret = get_secrets(unverified['iss'])
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# use secret to validate the token
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verified = decode(token, key=secret.encode(), verify=True, algorithms=['HS256'])
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# check expiry
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if not calendar.timegm(time.gmtime()) < verified['iat'] + WINDOW:
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print("TIMESTAMP FAILED")
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return False
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# check request
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signed_url = base64.b64encode(
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hmac.new(
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secret.encode(),
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"{} {}".format(request.method, request.path).encode(),
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digestmod=hashlib.sha256
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).digest()
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).decode()
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if signed_url != verified['req']:
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print("URL FAILED")
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return False
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# check body
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signed_json_request = base64.b64encode(
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hmac.new(
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secret.encode(),
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request.data,
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digestmod=hashlib.sha256
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).digest()
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).decode()
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print(verified)
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if signed_json_request != verified['pay']:
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print("PAYLOAD FAILED")
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return False
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except DecodeError:
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print("TOKEN VERIFICATION FAILED")
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return False
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return True
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def perform_authentication():
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incoming_token = get_token_from_headers(request.headers)
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if not incoming_token:
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abort(401)
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if not token_is_valid(incoming_token):
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abort(403)
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main.before_request(perform_authentication)
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main.before_request(requires_auth)
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from .views import notifications, index
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51
app/main/authentication/auth.py
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51
app/main/authentication/auth.py
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@@ -0,0 +1,51 @@
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from flask import request, jsonify, _request_ctx_stack
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from client.jwt import decode_jwt_token, get_token_issuer
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from client.errors import TokenDecodeError, TokenRequestError, TokenExpiredError, TokenPayloadError
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def authentication_response(message, code):
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return jsonify(
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error=message
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), code
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def requires_auth():
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auth_header = request.headers.get('Authorization', None)
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if not auth_header:
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return authentication_response('Unauthorized, authentication token must be provided', 401)
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auth_scheme = auth_header[:7]
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if auth_scheme != 'Bearer ':
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return authentication_response('Unauthorized, authentication bearer scheme must be used', 401)
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try:
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auth_token = auth_header[7:]
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api_client = fetch_client(get_token_issuer(auth_token))
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if api_client is None:
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authentication_response("Invalid credentials", 403)
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decode_jwt_token(
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auth_token,
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api_client['secret'],
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request.method,
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request.path,
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request.data.decode() if request.data else None
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)
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_request_ctx_stack.top.api_user = api_client
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except TokenRequestError:
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return authentication_response("Invalid token: request", 403)
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except TokenExpiredError:
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return authentication_response("Invalid token: expired", 403)
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except TokenPayloadError:
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return authentication_response("Invalid token: payload", 403)
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except TokenDecodeError:
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return authentication_response("Invalid token: signature", 403)
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def fetch_client(client):
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return {
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"client": client,
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"secret": "secret"
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}
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@@ -2,4 +2,4 @@ Flask==0.10.1
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Flask-Script==2.0.5
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PyJWT==1.4.0
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git+https://github.com/alphagov/notifications-python-client.git@0.0.2#egg=notifications-python-client==0.0.2
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git+https://github.com/alphagov/notifications-python-client.git@0.1.2#egg=notifications-python-client==0.1.2
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@@ -1,82 +0,0 @@
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from flask import json
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import jwt
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import hashlib
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import hmac
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import calendar
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import time
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import base64
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def sign_a_thing(thing_to_sign, secret_key):
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return base64.b64encode(
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hmac.new(
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secret_key.encode(),
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thing_to_sign.encode(),
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digestmod=hashlib.sha256
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).digest()
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)
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def token(request_method, request_url, secret_key, service_id, json_body):
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# request method and resource path - hash of request url - POST /path-to-resource
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signed_url = sign_a_thing("{} {}".format(request_method, request_url), secret_key)
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signed_payload = sign_a_thing(json_body, secret_key)
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headers = {
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"typ": "JWT",
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"alg": "HS256"
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}
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claims = {
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'iss': service_id, # issued by - identified by id of the service
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'iat': calendar.timegm(time.gmtime()), # issued at in epoch seconds
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'req': signed_url.decode(),
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'pay': signed_payload.decode() # signed payload
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}
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return jwt.encode(payload=claims, key=secret_key, headers=headers).decode()
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def test_should_not_allow_request_with_no_token(notify_api):
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response = notify_api.test_client().get("/")
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assert response.status_code == 401
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data = json.loads(response.get_data())
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assert data['error'] == 'Unauthorized, authentication token must be provided'
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def test_should_not_allow_request_with_invalid_token(notify_api):
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response = notify_api.test_client().get(
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"/",
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headers={'Authorization': 'Bearer 1234'}
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)
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assert response.status_code == 403
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data = json.loads(response.get_data())
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assert data['error'] == 'Forbidden, invalid authentication token provided'
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def test_should_allow_request_with_valid_token(notify_api):
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body = {
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"1": "A",
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"3": "A",
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"7": "A",
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"15": "A",
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"2": "B"
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}
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request_body = json.dumps(body)
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request_token = token("POST", "/", "1234", "service1", request_body)
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# from time import sleep
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# sleep(4)
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response = notify_api.test_client().post(
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"/",
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data=request_body,
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headers={
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'Authorization': "Bearer {}".format(request_token)
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},
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content_type='application/json'
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)
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assert response.status_code == 200
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131
tests/app/main/views/test_authentication.py
Normal file
131
tests/app/main/views/test_authentication.py
Normal file
@@ -0,0 +1,131 @@
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from flask import json
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from client.jwt import create_jwt_token
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def test_should_not_allow_request_with_no_token(notify_api):
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response = notify_api.test_client().get("/")
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assert response.status_code == 401
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data = json.loads(response.get_data())
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assert data['error'] == 'Unauthorized, authentication token must be provided'
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def test_should_not_allow_request_with_incorrect_header(notify_api):
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response = notify_api.test_client().get(
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"/",
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headers={
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'Authorization': 'Basic 1234'
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}
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)
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assert response.status_code == 401
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data = json.loads(response.get_data())
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assert data['error'] == 'Unauthorized, authentication bearer scheme must be used'
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def test_should_not_allow_request_with_incorrect_token(notify_api):
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response = notify_api.test_client().get(
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"/",
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headers={
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'Authorization': 'Bearer 1234'
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}
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)
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assert response.status_code == 403
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data = json.loads(response.get_data())
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assert data['error'] == 'Invalid token: signature'
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def test_should_not_allow_incorrect_path(notify_api):
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token = create_jwt_token(request_method="GET", request_path="/bad", secret="secret", client_id="client_id")
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response = notify_api.test_client().get(
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"/",
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headers={
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'Authorization': "Bearer {}".format(token)
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}
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)
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assert response.status_code == 403
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data = json.loads(response.get_data())
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assert data['error'] == 'Invalid token: request'
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def test_should_not_allow_incorrect_method(notify_api):
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token = create_jwt_token(request_method="POST", request_path="/", secret="secret", client_id="client_id")
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response = notify_api.test_client().get(
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"/",
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headers={
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'Authorization': "Bearer {}".format(token)
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}
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)
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assert response.status_code == 403
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data = json.loads(response.get_data())
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assert data['error'] == 'Invalid token: request'
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def test_should_not_allow_invalid_secret(notify_api):
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token = create_jwt_token(request_method="POST", request_path="/", secret="not-so-secret", client_id="client_id")
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response = notify_api.test_client().get(
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"/",
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headers={
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'Authorization': "Bearer {}".format(token)
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}
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)
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assert response.status_code == 403
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data = json.loads(response.get_data())
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assert data['error'] == 'Invalid token: signature'
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def test_should_allow_valid_token(notify_api):
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token = create_jwt_token(request_method="GET", request_path="/", secret="secret", client_id="client_id")
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response = notify_api.test_client().get(
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"/",
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headers={
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'Authorization': 'Bearer {}'.format(token)
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}
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)
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assert response.status_code == 201
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def test_should_allow_valid_token_with_post_body(notify_api):
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json_body = json.dumps({
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"key1": "value1",
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"key2": "value2",
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"key3": "value3"
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})
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token = create_jwt_token(
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request_method="POST",
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request_path="/",
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secret="secret",
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client_id="client_id",
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request_body=json_body
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)
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response = notify_api.test_client().post(
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"/",
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data=json_body,
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headers={
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'Authorization': 'Bearer {}'.format(token)
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}
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)
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assert response.status_code == 200
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def test_should_not_allow_valid_token_with_invalid_post_body(notify_api):
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json_body = json.dumps({
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"key1": "value1",
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"key2": "value2",
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"key3": "value3"
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})
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token = create_jwt_token(
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request_method="POST",
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request_path="/",
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secret="secret",
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client_id="client_id",
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request_body=json_body
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)
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response = notify_api.test_client().post(
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"/",
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data="spurious",
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headers={
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'Authorization': 'Bearer {}'.format(token)
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}
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)
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assert response.status_code == 403
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data = json.loads(response.get_data())
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assert data['error'] == 'Invalid token: payload'
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