I have a social media platform and I'm using cognito for auth. When I delete users, they are not logged out, how can i deactivate tokens
The token validity is 1 day. I waited for 1 day but it didn't log out.
I may be wrong, but it sounds like you don't clearly understand what is JWT and how it works.
Here are two types of JWT tokens: access token and refresh token.
access token can't be invalidated for single user until it expires. It is using for user authentication. In other way refresh token is using for new access tokens creation. By default, expiring time of refresh token is 30 days. So, user able generate new access token even if it expired until refresh token is valid.
You have to revoke refresh token when deleting user. Also expiring time of access token should be pretty short (e.g., 30 minutes). In this case user will be able login only 30 minutes at max after refresh token revocation.
Here is no info in your question about token revocation and which of tokens valid until 1 day, so I hope this info will help you figure out how it works.
I am using django rest frameworks JWT library
http://getblimp.github.io/django-rest-framework-jwt/
There are two settings on JWT token expiration
JWT_EXPIRATION_DELTA which is in seconds
The docs on it:
You can turn off expiration time verification by setting JWT_VERIFY_EXPIRATION to False. Without expiration verification, JWTs will last forever meaning a leaked token could be used by an attacker indefinitely.
This is an instance of Python's datetime.timedelta. This will be added to datetime.utcnow() to set the expiration time.
Default is datetime.timedelta(seconds=300)(5 minutes).
and JWT_REFRESH_EXPIRATION_DELTA
Docs:
mit on token refresh, is a datetime.timedelta instance. This is how much time after the original token that future tokens can be refreshed from.
Default is datetime.timedelta(days=7) (7 days).
Im not sure on the different use cases. I set the jwt token expiration delta to 20 seconds.
Then got a token saved it to local waited 20 seconds closed my browser window and re navigated to the site
expecting to not be logged in because the token would of expired but I was logged in.
So then what is the difference between JWT token expiration delta
and JWT Refresh Expiration Delta?
JWT_EXPIRATION_DELTA is the actual time till your JWT token will work. After the time mention in JWT_EXPIRATION_DELTA, whenever you will use this token to access a secure endpoint(that has JWT Auth enabled), it will return a error with message that Your JWT Token has been expired. So you need to keep refreshing JWT Token before it get expired. According to documentation:
Refresh with tokens can be repeated (token1 -> token2 -> token3), but this chain of token stores the time that the original token (obtained with username/password credentials), as orig_iat. You can only keep refreshing tokens up to JWT_REFRESH_EXPIRATION_DELTA
It means that no matter how many times you refresh your tokens, it will always keep the record of the original time when your 1st token was generated(First Time you logged in your user). So if JWT_REFRESH_EXPIRATION_DELTA is set to 1 day, you can't keep refreshing your JWT token after 1 day from when your original token was generated (means your 1st token generated time).
Don't know what mechanism you are using to check in the frontend if the user is authenticated or not. But if you use to check it on the backend (DRF-JWT provides some ready endpoints to verify and refresh tokens), you will find it will not work.
Conceptually, I really like JWT as it is in line with the statelessness of REST etc (no state saved server-side, all relevant data is contained in the token).
What I am unsure about: how would you handle token expiry when not connected (ie, a "remember me" functionality)?
There's an emerging coverage of JWT on the web, but I couldn't find anyone that answered the expiry question yet.
Clarification: I am not asking how to handle a token soon-to-expire, but what to do when a token has already expired (user closed website/app for a while). The simplest solution that comes to my mind is caching the user's credentials, which is rather insecure.
There isn't a black and white answer to the given problem of how to implement the remember-me functionality theoretical wise. Lots of theoretical arguments are given on why something should not be done, while at the same time there is no clear answer given to the problem as for how it should practically be done.
Remember-me implicitly comes with the problem that you need a longer time window of token expiration, there is just no way around this. The most secure way is to have the user login regularly given brief expiry; nobody practically likes this though, so a tradeoff is made where theoretical secure perfection is weighed against practical measures.
The way this tradeoff works is by patching the imperfections that come with having a long expiry for a token. But make no mistake about it, you will need a jwt / cookie with long expiry (whether you use two tokens, implement some secondary refreshing mechanism or whatever, at the end you run into the same problem)!
Based on articles I've read on how others did it, this is how it's done.
The way I will implement this is by offering a 3-month expiry on a jwt stored in an httpOnly / secure cookie when the user checks remember-me.
On logout just clear the cookie.
Obviously protect using https / CSRF measures on top.
If you don't agree with it, stop fussing and offer an alternative solution - which there clearly isn't from the infinite number of discussions I've read on it.
If there were a straightforward solution to the problem, there probably wouldn't be so many discussions about it in the first place.
Edit:
You can use a refresh token mechanism, but it only works if you verify the time intervals when the refresh token gets used. For example, depending on the lifetime of the access token, you can govern how often you allow a user to refresh the token. If the intervals show suspicious activity, you should revoke both the tokens for all clients.
The problem revolves around the idea that either access token or refresh token would theoretically be stolen. So merely having a refreshing mechanism without additional security is essentially useless. If you can steal an access token, you can steal a refresh token too.
I am not so sure if I follow but I will write what I think.
Imagine the token as a hotel card, you pay in advance for 5 days (remember me set to expire on 5 days). I can enter the building, garage, room, etc. within those 5 days, after those 5 days, it won't work anymore.
What to do when token has already expired? Nothing at all.
Imagine I pay those 5 days and meh, I had an urgency and I go back home (with the card on the pocket). The hotel doesn't care at all, when the 5 days pass, the card is just an useless piece of plastic and if you try to use it on the hotel, it will do nothing.
So back to web development. If you offer a remember me service, you can put an expiry date to let's say 7 days. As long as the user has the token, he can access the service without any problem. If he loses the token, he needs to login again. If he uses the token and it have expired, he will need to login again too.
If he login, he gets a token for 7 days, if he doesn't use it anymore and after 20 days he comes again, he would need to login again, the server will just decline your petitions until you do so.
What I would do if you use something like angular on the frontend is to check the token validation on startup so you can have a nice user experience.
What I don't understand about your question is de caching thing though.
In addition to #Jesus answer, you can think about implementing a refresh token system: https://auth0.com/blog/refresh-tokens-what-are-they-and-when-to-use-them/
In the hotel-example, your hotel-card (access-token) would be invalid after time X, but at the reception you can use your passport (refresh-token) to get a new hotel card again.
You could store the refresh token in the database with additional data about the device the user is using, allowing him to disable the device in case it gets stolen.
Example:
first correct client login: Create a refresh token which is valid forever (until it gets deleted or invalidated)
store refresh token in database
return access token (JWT) with expiration time to client ( this token gets not stored in database)
for the next request, the client sends the access token
Now Check if the access token is expired:
5.1 Access Token not expired, all okay
5.2 Access Token expired, check if there is a refresh token in database
5.2.1 Refresh Token is in database, return new Access Token
5.2.2 No Refresh Token in database, return 401 / logout, User has to login again
Hope this helps.
You need to persist the JWT on the client so that it’s available across page loads, the most secure strategy is an HTTPS-only cookie. This will send the JWT to your server on every request and the server can check the validity of the token and reject it if it's expired. How you handle the expiration is dependent on the type of web app you have.
For a single-page application (e.g. Angular.js apps) you would want to structure the application so that it makes an initial request of the server before it bootstraps the rest of the application. If the server sees that the JWT in this request is expired it would issue a 401 response. You application would respond to this response by rendering a login form. Otherwise it would continue with the assumption that the JWT is valid and can be used to access the required resources. If, at any time, the app sees a 401 it should bring the user back to the login form.
For traditional web apps that render their pages on the server: for any request that has an expired JWT (as read from the cookie) the server should issue a 302 redirect to a login form.
I think what you are asking is how to invalidate a JWT server side for long expiry tokens (e.g. "remember me" functionality)?
I ran into this issue myself recently and ended up using a unique user secret to invalidate the token, when the user attempts to validate a token that was produced with an old secret it will fail. The username can be found in the decoded JWT pre verification.
You could probably even use the users password salt for this, that way any current JWT's would be invalidated when a user changes their password (assuming you also change the salt at the same time), this may be problematic though as the password hash and JWT's would become tightly coupled
I can think of one way, but it is not really defined the standard.
What about adding another kind of expiration date with different lifespan to the claims? With two claims, we can treat the shorter one of it as the resource access expiration date, and the longer one as the refresh expiration date, e.g.
{
"iat": /* current time */,
"bbf": /* current time + 1 hour -- expired means no resource access */
"exp": /* current time + 1 week -- expired means cannot refresh */
}
(Note: I use bbf for the shorter expiration date. No specific reason, just because it has 3 characters in length.)
So with "remember me" checked, when the user reconnects, he can use the same token to request for a new one, but not to access the resource. With this, all relevant data is contained within the token -- no extra token required.
And lastly, when "remember me" not checked, just use the same lifespan for bbf and exp.
Is there any way to use the graph api to find out when a page access token, or application token will expire?
Update: There is a new API endpoint to access information about an access token. You can find info here: Debugging Access Tokens and Handling Errors
https://graph.facebook.com/debug_token?input_token=INPUT_TOKEN&access_token=ACCESS_TOKEN
input_token: the Access Token to debug
access_token: your App Access Token or a valid User Access Token from a developer of the app.
--
You should try to make sure that you store each token's expiration time along with the access token when you get it. For a page access token, that means storing the expiration time of the user access token. If you would like to manually discover expiration times for tokens you have today, you should use Facebook's Access Token Debugger tool. However, you should not be relying on expiration times alone -- in practice, many tokens will expire much earlier than their expiration time.
Application access tokens will never expire, unless the application secret key is reset.
Page access tokens last up to 60 days (5184000 seconds), but more importantly, they last as long as the user access token that was used to acquire them. So they will be invalidated as soon as the user that you got them from:
logs out of FB.
changes password.
deauthorizes your application.
Basically, when you lose the user's token, you will lose the page's token. Instead, you should retrieve page access tokens once per user access token. If you throw out a user access token, throw out the page token. You should not be trying to store page access tokens for any significant period of time. Instead you should get them as needed and forget them when a user's session dies.
To get a new page access token:
https://graph.facebook.com/PAGEID?fields=access_token&access_token=USER_ACCESS_TOKEN
Access Token Debugger
https://developers.facebook.com/tools/debug/access_token
Does not use the Graph API... but a very useful tool for manual debugging.
There is now an API version of the debugger tool.
See https://developers.facebook.com/docs/authentication/access-token-debug/
I would like to repeat this question for the current version of the API since I've come to a situation when Facebook doc clearly does not describe what is happening:
no expiry dates when requesting a new long-lived token with fb_exchange_token
no expiry dates when requesting debug_token information (expires_at = 0)
it does reply with an expiration date when redirecting the user to the auth page for the first time, but that does not help as I cannot extract the long-lived expiration date nor it will reply with this information for the second time
The debug tool here: https://developers.facebook.com/tools/debug/accesstoken says "Expires: Never".
Try this, it worked with me. Get the token with your app and paste it in the graph explorer as the token to be used for queries. Click on the info a see the expiration date.
example image
I hope it works for you too.
https://developers.facebook.com/docs/facebook-login/access-tokens/expiration-and-extension
From the page above:
Access tokens on the web often have a lifetime of about two hours, but
will automatically be refreshed when required. If you want to use
access tokens for longer-lived web apps, especially server side, you
need to generate a long-lived token. A long-lived token generally
lasts about 60 days.
In addition to the access token (the
access_token parameter), the response
contains the number of seconds until
the token expires (the expires
parameter).
http://developers.facebook.com/docs/authentication/
The above facebook documentation suggest that along with the access token we also get its expiration.
However, in my case, I only get the token and the state and nothing else.
Am I doing something wrong or did facebook make yet another undocumented API change?