I have a CherryPy web application that requires authentication. I have working HTTP Basic Authentication with a configuration that looks like this:
app_config = {
'/' : {
'tools.sessions.on': True,
'tools.sessions.name': 'zknsrv',
'tools.auth_basic.on': True,
'tools.auth_basic.realm': 'zknsrv',
'tools.auth_basic.checkpassword': checkpassword,
}
}
HTTP auth works great at this point. For example, this will give me the successful login message that I defined inside AuthTest:
curl http://realuser:realpass#localhost/AuthTest/
Since sessions are on, I can save cookies and examine the one that CherryPy sets:
curl --cookie-jar cookie.jar http://realuser:realpass#localhost/AuthTest/
The cookie.jar file will end up looking like this:
# Netscape HTTP Cookie File
# http://curl.haxx.se/rfc/cookie_spec.html
# This file was generated by libcurl! Edit at your own risk.
localhost FALSE / FALSE 1348640978 zknsrv 821aaad0ba34fd51f77b2452c7ae3c182237deb3
However, I'll get an HTTP 401 Not Authorized failure if I provide this session ID without the username and password, like this:
curl --cookie 'zknsrv=821aaad0ba34fd51f77b2452c7ae3c182237deb3' http://localhost/AuthTest
What am I missing?
Thanks very much for any help.
So, the short answer is you can do this, but you have to write your own CherryPy tool (a before_handler), and you must not enable Basic Authentication in the CherryPy config (that is, you shouldn't do anything like tools.auth.on or tools.auth.basic... etc) - you have to handle HTTP Basic Authentication yourself. The reason for this is that the built-in Basic Authentication stuff is apparently pretty primitive. If you protect something by enabling Basic Authentication like I did above, it will do that authentication check before it checks the session, and your cookies will do nothing.
My solution, in prose
Fortunately, even though CherryPy doesn't have a way to do both built-in, you can still use its built-in session code. You still have to write your own code for handling the Basic Authentication part, but in total this is not so bad, and using the session code is a big win because writing a custom session manager is a good way to introduce security bugs into your webapp.
I ended up being able to take a lot of things from a page on the CherryPy wiki called Simple authentication and access restrictions helpers. That code uses CP sessions, but rather than Basic Auth it uses a special page with a login form that submits ?username=USERNAME&password=PASSWORD. What I did is basically nothing more than changing the provided check_auth function from using the special login page to using the HTTP auth headers.
In general, you need a function you can add as a CherryPy tool - specifically a before_handler. (In the original code, this function was called check_auth(), but I renamed it to protect().) This function first tries to see if the cookies contain a (valid) session ID, and if that fails, it tries to see if there is HTTP auth information in the headers.
You then need a way to require authentication for a given page; I do this with require(), plus some conditions, which are just callables that return True. In my case, those conditions are zkn_admin(), and user_is() functions; if you have more complex needs, you might want to also look at member_of(), any_of(), and all_of() from the original code.
If you do it like that, you already have a way to log in - you just submit a valid session cookie or HTTPBA credentials to any URL you protect with the #require() decorator. All you need now is a way to log out.
(The original code instead has an AuthController class which contains login() and logout(), and you can use the whole AuthController object in your HTTP document tree by just putting auth = AuthController() inside your CherryPy root class, and get to it with a URL of e.g. http://example.com/auth/login and http://example.com/auth/logout. My code doesn't use an authcontroller object, just a few functions.)
Some notes about my code
Caveat: Because I wrote my own parser for HTTP auth headers, it only parses what I told it about, which means just HTTP Basic Auth - not, for example, Digest Auth or anything else. For my application that's fine; for yours, it may not be.
It assumes a few functions defined elsewhere in my code: user_verify() and user_is_admin()
I also use a debugprint() function which only prints output when a DEBUG variable is set, and I've left these calls in for clarity.
You can call it cherrypy.tools.WHATEVER (see the last line); I called it zkauth based on the name of my app. Take care NOT to call it auth, or the name of any other built-in tool, though .
You then have to enable cherrypy.tools.WHATEVER in your CherryPy configuration.
As you can see by all the TODO: messages, this code is still in a state of flux and not 100% tested against edge cases - sorry about that! It will still give you enough of an idea to go on, though, I hope.
My solution, in code
import base64
import re
import cherrypy
SESSION_KEY = '_zkn_username'
def protect(*args, **kwargs):
debugprint("Inside protect()...")
authenticated = False
conditions = cherrypy.request.config.get('auth.require', None)
debugprint("conditions: {}".format(conditions))
if conditions is not None:
# A condition is just a callable that returns true or false
try:
# TODO: I'm not sure if this is actually checking for a valid session?
# or if just any data here would work?
this_session = cherrypy.session[SESSION_KEY]
# check if there is an active session
# sessions are turned on so we just have to know if there is
# something inside of cherrypy.session[SESSION_KEY]:
cherrypy.session.regenerate()
# I can't actually tell if I need to do this myself or what
email = cherrypy.request.login = cherrypy.session[SESSION_KEY]
authenticated = True
debugprint("Authenticated with session: {}, for user: {}".format(
this_session, email))
except KeyError:
# If the session isn't set, it either wasn't present or wasn't valid.
# Now check if the request includes HTTPBA?
# FFR The auth header looks like: "AUTHORIZATION: Basic <base64shit>"
# TODO: cherrypy has got to handle this for me, right?
authheader = cherrypy.request.headers.get('AUTHORIZATION')
debugprint("Authheader: {}".format(authheader))
if authheader:
#b64data = re.sub("Basic ", "", cherrypy.request.headers.get('AUTHORIZATION'))
# TODO: what happens if you get an auth header that doesn't use basic auth?
b64data = re.sub("Basic ", "", authheader)
decodeddata = base64.b64decode(b64data.encode("ASCII"))
# TODO: test how this handles ':' characters in username/passphrase.
email,passphrase = decodeddata.decode().split(":", 1)
if user_verify(email, passphrase):
cherrypy.session.regenerate()
# This line of code is discussed in doc/sessions-and-auth.markdown
cherrypy.session[SESSION_KEY] = cherrypy.request.login = email
authenticated = True
else:
debugprint ("Attempted to log in with HTTBA username {} but failed.".format(
email))
else:
debugprint ("Auth header was not present.")
except:
debugprint ("Client has no valid session and did not provide HTTPBA credentials.")
debugprint ("TODO: ensure that if I have a failure inside the 'except KeyError'"
+ " section above, it doesn't get to this section... I'd want to"
+ " show a different error message if that happened.")
if authenticated:
for condition in conditions:
if not condition():
debugprint ("Authentication succeeded but authorization failed.")
raise cherrypy.HTTPError("403 Forbidden")
else:
raise cherrypy.HTTPError("401 Unauthorized")
cherrypy.tools.zkauth = cherrypy.Tool('before_handler', protect)
def require(*conditions):
"""A decorator that appends conditions to the auth.require config
variable."""
def decorate(f):
if not hasattr(f, '_cp_config'):
f._cp_config = dict()
if 'auth.require' not in f._cp_config:
f._cp_config['auth.require'] = []
f._cp_config['auth.require'].extend(conditions)
return f
return decorate
#### CONDITIONS
#
# Conditions are callables that return True
# if the user fulfills the conditions they define, False otherwise
#
# They can access the current user as cherrypy.request.login
# TODO: test this function with cookies, I want to make sure that cherrypy.request.login is
# set properly so that this function can use it.
def zkn_admin():
return lambda: user_is_admin(cherrypy.request.login)
def user_is(reqd_email):
return lambda: reqd_email == cherrypy.request.login
#### END CONDITIONS
def logout():
email = cherrypy.session.get(SESSION_KEY, None)
cherrypy.session[SESSION_KEY] = cherrypy.request.login = None
return "Logout successful"
Now all you have to do is enable both builtin sessions and your own cherrypy.tools.WHATEVER in your CherryPy configuration. Again, take care not to enable cherrypy.tools.auth. My configuration ended up looking like this:
config_root = {
'/' : {
'tools.zkauth.on': True,
'tools.sessions.on': True,
'tools.sessions.name': 'zknsrv',
}
}
Related
For my system, my users have their own unique ID (participant_id) that I've provided them.
I have a flask server that registers my users with Fitbit.
#app.route('/fitbit_authorize')
def homepage(): #probably need to send participant_id here
return 'Authenticate with fitbit' % FITBIT_AUTHORIZATION_URL
Fitbit sends a post request regarding the successfulness of my participant registration to the following where I get their user access/refresh tokens for oauth:
#app.route('/fitbit_callback')
def fitbit_callback():
error = request.args.get('error', '')
if error:
return "Error: " + error
state = request.args.get('state', '')
code = request.args.get('code')
token = fitbit_access.get_full_token(code)
I was wondering how can I retrieve the authorizer's original ID (participant_id) in the callback. Is there anyway for me to pass additional information in the fitbit authorization process or what would be the best way for me to retrieve their participant_id?
Good question.
Oauth2 allows for you to include state information in the authorization request---You can include the participant_id in the state parameter: https://dev.fitbit.com/build/reference/web-api/oauth2/
state: Provides any state that might be useful to your application
when the user is redirected back to your application. This parameter
will be added to the redirect URI exactly as your application
specifies. Fitbit strongly recommend including an anti-forgery token
in this parameter and confirming its value in the redirect to mitigate
against cross-site request forgery (CSRF).
In addition to providing the participant_id, you should provide an anti-forgery token to help fight CSRF.
I'm writing a python function to validate a token from an email. In the email, there is a url with the endpoint of it. I have two url parameters, the token and email address. In my endpoint I have to check :
if the parameters are in the URL
if there is a associate token in the database
if it corresponds to the user email
if the token is still valid (expires after 2 days)
if it has already been used
I choose to wrap all those checks in a try except block, I will always return the same error "invalid token" so I don't have to precisely check individual error. I used the function assertFalse and assertEqual that will raise an exception if it's not correct.
try:
# pull from url
email = request.GET['email']
value_token = request.GET['token']
# test if valid
token = EmailValidationToken.objects.get(token=value_token)
assertFalse(token.consumed)
assertEqual(email, token.user.email)
assertFalse(token.is_expired())
except:
pass # return error
I like the way I did it because it's super clean.
Is it a good practice ? Is there other solution for this problem ?
No, using assert for control flow rather than debugging is poor practice, because assertions can be turned off. Just use an ordinary if statement.
# pull from url
email = request.GET['email']
value_token = request.GET['token']
# test if valid
token = EmailValidationToken.objects.get(token=value_token)
if token.consumed or email != token.user.email or token.is_expired():
pass # return error
If you absolutely insist on controlling your program's flow by raising an error (which is a valid thing to do in some cases), do so with raise, e.g. if condition: raise TypeError.
I'm trying to set up token authentication with the Django Rest Framework. I'm currently writing some tests to see if I can get a token returned for a user. Below is the code for the unit test (which is inside of a test case).
def test_create_valid_request(self):
u = User.objects.create(username='test1', password='thisis8chars')
Token.objects.create(user=u)
# these assertions all pass
self.assertEqual(User.objects.get(username='test1'), u)
self.assertEqual(u.username, 'test1')
self.assertEqual(u.password, 'thisis8chars')
data = {'username': 'test1', 'password': 'thisis8chars'}
url = "/api-token-auth/"
response = self.client.post(url, data, format="json")
print response.status_code
print response.content
This prints:
400
{"non_field_errors":["Unable to log in with provided credentials."]}
I understand that there must be something wrong with my credentials, but I can't see it. I create a user, tests its attributes, and make a post request to retrieve the token. I've manually tested this on the Django development server with httpie, and it works and returns the token. Any ideas what the problem could be? Is this a problem with my testing setup? If so, what?
I can post/describe more code if necessary.
Thanks
Okay so the error was very simple: I wanted User.objects.create_user rather than User.objects.create.
The password that I was trying to use with my code above was problematic because it wasn't hashed or salted, and because Django doesn't store or send plain-text passwords, me sending the plain-text password was resulting in a bad credentials error.
As you've already stated, you need to use User.objects.create_user.
To add to this, if you already have a User object instantiated and want to change their password you'll need to call the user.set_password(raw_password) method.
I am trying to create a set on Quizlet.com, using its API found here: https://quizlet.com/api/2.0/docs/sets#add
Here is my code of a set I am trying to create:
import requests
quizkey = my_client_id
authcode = my_secret_code # I'm not sure if I need this or not
data = {"client_id":quizkey, "whitespace":1, "title":"my-api-set",
"lang_terms":"it", "lang_definitions":"en",
"terms":['uno','due'], "definitions":["one","two"]}
apiPrefix = "https://api.quizlet.com/2.0/sets"
r = requests.post(url=apiPrefix, params=data)
print r.text
The response is:
{
"http_code": 401,
"error": "invalid_scope",
"error_title": "Not Allowed",
"error_description": "You do not have sufficient permissions to perform the requested action."
}
I also tried "access_token":authcode instead of "client_id":quizkey, but this resulted in the error: "You do not have sufficient permissions to perform the requested action."
How can I fix this and not get a 401 error?
Alright so 3 and a half years later (!!) I've looked into this again and here's what I've discovered.
To add a set you need an access token - this is different to the client_id (what I call quizkey in my code), and to be quite honest I don't remember what authcode in my code is.
This token is obtained by going through the user authentication flow. To summarise it:
Send a POST request to https://quizlet.com/authorize like so:
https://quizlet.com/authorize?response_type=code&client_id=MY_CLIENT_ID&scope=read&state=RANDOM_STRING
Keep the response_type as code, replace client_id with your client_id, keep the scope as read, and state can be anything
I believe this requires human intervention because you're literally authorising your own account? Not sure of another way...
You'll receive a response back with a code
Let's call this RESPONSE_CODE for now
Send a POST request to https://api.quizlet.com/oauth/token, specifying 4 mandatory parameters:
grant_type="authorization_code" (this never changes)
code=RESPONSE_CODE
redirect_uri=https://yourredirecturi.com (this can be found at your personal API dashboard)
client ID and secret token separated by a colon and then base64-encoded (the user authentication flow link above tells you what this is if you don't want to do any of the encoding)
You'll receive the access_token from this API call
Now you can use that access_token in your call to create a set like I've done above (just replace "client_id":quizkey with "access_token":access_token)
You will need to authenticate in order to make sets. This link gives an overview:
https://quizlet.com/api/2.0/docs/making_api_calls
And this one provides details about the authentication process:
https://quizlet.com/api/2.0/docs/authorization_code_flow
I have asked a few questions about this before, but still haven't solved my problem.
I am trying to allow Salesforce to remotely send commands to a Raspberry Pi via JSON (REST API). The Raspberry Pi controls the power of some RF Plugs via an RF Transmitter called a TellStick. This is all setup, and I can use Python to send these commands. All I need to do now is make the Pi accept JSON, then work out how to send the commands from Salesforce.
Someone kindly forked my repo on GitHub, and provided me with some code which should make it work. But unfortunately it still isn't working.
Here is the previous question: How to accept a JSON POST?
And here is the forked repo: https://github.com/bfagundez/RemotePiControl/blob/master/power.py
What do I need to do? I have sent test JSON messages n the Postman extension and in cURL but keep getting errors.
I just want to be able to send various variables, and let the script work the rest out.
I can currently post to a .py script I have with some URL variables, so /python.py?power=on&device=1&time=10&pass=whatever and it figures it out. Surely there's a simple way to send this in JSON?
Here is the power.py code:
# add flask here
from flask import Flask
app = Flask(__name__)
app.debug = True
# keep your code
import time
import cgi
from tellcore.telldus import TelldusCore
core = TelldusCore()
devices = core.devices()
# define a "power ON api endpoint"
#app.route("/API/v1.0/power-on/<deviceId>",methods=['POST'])
def powerOnDevice(deviceId):
payload = {}
#get the device by id somehow
device = devices[deviceId]
# get some extra parameters
# let's say how long to stay on
params = request.get_json()
try:
device.turn_on()
payload['success'] = True
return payload
except:
payload['success'] = False
# add an exception description here
return payload
# define a "power OFF api endpoint"
#app.route("/API/v1.0/power-off/<deviceId>",methods=['POST'])
def powerOffDevice(deviceId):
payload = {}
#get the device by id somehow
device = devices[deviceId]
try:
device.turn_off()
payload['success'] = True
return payload
except:
payload['success'] = False
# add an exception description here
return payload
app.run()
Your deviceID variable is a string, not an integer; it contains a '1' digit, but that's not yet an integer.
You can either convert it explicitly:
device = devices[int(deviceId)]
or tell Flask you wanted an integer parameter in the route:
#app.route("/API/v1.0/power-on/<int:deviceId>", methods=['POST'])
def powerOnDevice(deviceId):
where the int: part is a URL route converter.
Your views should return a response object, a string or a tuple instead of a dictionary (as you do now), see About Responses. If you wanted to return JSON, use the flask.json.jsonify() function:
# define a "power ON api endpoint"
#app.route("/API/v1.0/power-on/<int:deviceId>", methods=['POST'])
def powerOnDevice(deviceId):
device = devices[deviceId]
# get some extra parameters
# let's say how long to stay on
params = request.get_json()
try:
device.turn_on()
return jsonify(success=True)
except SomeSpecificException as exc:
return jsonify(success=False, exception=str(exc))
where I also altered the exception handler to handle a specific exception only; try to avoid Pokemon exception handling; do not try to catch them all!
To retrieve the Json Post values you must use request.json
if request.json and 'email' in request.json:
request.json['email']