Limited Azure Active Directory access? - azure

Is there a way to have usernames/passwords only work for 1 hour to an Azure website? I've looked into expiring tokens, but I'm not sure if that's the right idea.

Great question. But right now - no, there is no way to make an AAD user be only active for given period of time. Tokens always expire. An application typically only needs the token at first authentication step (when the user came from the Security Token Service) - to validate it and extract claims and eventually a refresh token. After that the original token is no longer used anyway.

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Access Token invalidation in DocuSign API

I'm looking into DocuSign's eSignature API. Trying out their 0Auth using a demo account (https://developers.docusign.com/platform/auth/authcode/authcode-get-token/).
In some 0Auth systems, the access token of a given user gets invalidated after requesting another accessToken for the same user. But it seems previous token continues to be valid as long as it hasn't expire.
Is this a behaviour just for the Demo/Sandbox account or it is possible to rely on behaviour for live accounts as well? (Where several access tokens can be used for the same DocuSign user?
Can each of these accessTokens be refreshed with their respective refreshTokens without limitations/problems?
in this regard, Demo and Production behave the same - you can generate multiple valid tokens for the same user.
That said, this is not a good practice - while the Account Server does not currently have throttles related to token generation, it may in the future. A token should be re-used throughout its lifespan - continuously generating unnecessary tokens is not an appropriate workflow.

Shall JWT expires in mobile apps?

I've implemented lots of Restful APIs and web applications, I used to generate a JWT and give some time for expiration.
Currently I am developing mobile apps, and they all work on the same Restful APIs, but I am a bit confused of should the token expires in mobile apps and log out the user?
On many places, websites and as I do know JWT should never ever live eternally and the time for expiration must be kinda short period of time, maybe one day or less.
But if the mobile logs out the user, would it be considered bad User Experience
On the other hand, the user might click Remember me check box, so how would the JWT get expired?
Any idea would be appreciated.
There are several different ways to handle JWT expiration. First thing is to determine the value of your token. If you're using the token as a log-in to a game server, you might not be as worried about having a week-long expiration as you would for a banking app.
There are lots of ways to handle token expiration, but the most common I find below.
Automatic time-based expiration. This is a best practice, because a hijacked JWT will have less value. As you mention, logging the user out unexpectedly can be a poor experience, so one option are to include a "refresh" token, that can be exchanged once for a new, fresh, valid JWT token when the shorter-lived token expires. Refresh tokens have a longer lifetime, and may be bound to additional details such as a secure element on the device, or a policy such as in-session only (e.g. must obtain a new refresh token on app restart).
Policy-based revocation - instead of relying on a baked-in timeout, you can issue a revocation of the JWT. This relies on your services deciding when to revoke a login, and publishing the revocation somewhere it can be checked. This basically is what opaque tokens do, and thus you've just thrown away one of the advantages of JWT, but you can time out a session based on activity observed by your services.
Generally, these token management policies operate independently from the "remember me" function, which is usually a special "long-lived" (e.g. forever, 30 days, 90 days etc) token that is secured behind a secure element (e.g. fingerprint recognition, password etc) on the device that's used to obtain session tokens when a user starts a new app session.

Does the retrieved OAuth2.0 authorization code for Azure AD web applications expire?

In order to access resources in Azure AD web applications we retrieve an authorization code using the following workflow:
https://learn.microsoft.com/en-us/azure/active-directory/develop/v1-protocols-oauth-code
Now my questions is, does this retrieved code also have a specific lifetime (like tokens have) or will it never expire? I guess it won't expire but I need to be sure about that.
Yes, the authorization code has a lifetime of 10 minutes I think.
You use it to get the tokens you need and then throw it away.
You'll get refresh tokens so you can use them to get more tokens later.
ADAL.NET for example handles the token refresh for you, assuming you properly implement a token cache.
Reference: https://learn.microsoft.com/en-us/azure/active-directory/develop/v2-id-and-access-tokens (scroll all the way down) (it's for the v2.0 endpoint, but codes are similarly short-lived in v1)
Authorization codes (work or school accounts)
10 minutes
Authorization codes are purposely short-lived, and should be immediately redeemed for access tokens and refresh tokens when the tokens are received.

How to generate access token without any expiration

I need to get access token with expiration date as infinite.
I am using AcquireToken method which generates token with expiration time as 1hour based on UTC.
I need to use this access token for Add-AzureRmAccount command (Need example command for this too for successful login)
How to generate access token without any expiration in c#.
Please help me to work on this scenario.
Thanks in advance.
As Gaurav mantri mentioned that access token without any expiry is a major security risk. And it is not allowed in the Auzre. From Configurable token lifetimes in Azure Active Directory (Public Preview) document, we could know that the default expiration of access
token is 1 hour, and the max is 1 day.
How to generate access token without any expiration in c#.
Simple answer is that you can't and you shouldn't. Access tokens are returned by Azure AD and their expiration is set there only i.e. it is not in your control.
Also, getting an access token without any expiry is a major security risk (that's why "you shouldn't" remark above).
If you're using any Azure AD SDK (ADAL for example), it takes care of automatically renewing your access token so you don't have to worry about renewing that.

Should I reuse OAuth 2.0 access tokens?

I am building an Authorization Server in terms of OAuth 2.0.
There is also a 3rd party web application (Client) which is using my Authorization Server. It's a regular web application, and the user may have several active sessions established with this application (for example, office and home machine, or just several web browsers on the same machine).
My Authorization Server issues an access token #1 (with or without the refresh token, that's not so important here) for Client once. When the user starts a new session with the Client, should the Authorization Server give the Client app the same access token #1 for that new session or should it issue a new #2 token?
My thougts:
From security point of view the new token might sound better, but then if the user wants to manage his authorizations, he will see a separate entry for each Client session, which might be messy.
For example, GitHub returns the same token for previously authorized clients, and on the "applications" page in my GitHub account I see only one entry per application, no matter how many sessions I've started, which is convenient.
However, this approach means that I have to store access tokens in Authorization or Resource server in the reversible way (plain-text or encrypted with some known key) instead of using irreversible hashing (like you usually do with passwords, storing salt and password hash from bcrypt, pbkdf2 or something similar).
Please be advised that I am not a security expert and this explanation
is my general idea of oauth. Reason why I mentioned this in the
beginning is because I see you are CREATING YOUR OWN AUTH SERVER based
on oauth 2.0 protocol, which means down the road some people might be
using your server for authentication, and thus I don't want you to
have the wrong concept.
The session-oauth mismatch
I want to clear this first that don't mix sessions and oauth. These are two separate things usually found working together IMHO.
Oauth protocol simply gives the apps/users with an access token via which the app/user can query your server for data associated with the token.
Session on the other hand depends on the application itself. Once some app received the token, they make a session out of it. When user logs in or logs out, the session is destroyed, not the oauth.
So what is the fate of oauth token?
Well from a server standpoint, each of your token should expire after a certain time period. That is it. Server does not know anything else. It gives you the token, then expires it after 'n' seconds.
However, the app may decide that it wants to revoke the access token. Maybe their website was hacked, or maybe they are done with all api calls. Then they can send a special request to your server telling you to force-expire the token.
So what should I do about user opening multiple sessions?
ABSOLUTELY NOTHING. As an oauth service provider, you are not concerned with sessions at all. All you know is that if the app asks you for a token, you give them one.
However, I will answer you question about sessions as well. Should you spawn different sessions for the same user? I would say yes. If you have same session, then if you log out from one machine, and refresh the page in second machine, since the session has expired, your other browser/machines will also log out naturally.
So how does github manages to not show extra entries?
Well I do not work for them so I don't know. But I guess that they will check each session, and if two or more sessions are associate with the same user, they know the user must be using many devices. Then when one of your devices sends some request to github, they can guess from the IP address your location, and if many of your machines are making requests from same place, you got to be using multiple machines. If not, then maybe some attacker is using your account as well.
This is how AFAIK banks predict malicious users - well not the only way, they sometimes also predict the pattern you are using to access bank records, and if that pattern is different, there are good chances that your account was compromised.
So now you may ask me, are you really sure that I should create as many tokens as the app demands me?
This is the part where I am not so sure. From what I have seen, oauth has two things. Google these two terms for more info:
Refresh Token: This token is not your access token. This token never expires, and once your access token is expired, you can use this token to get a new access token. This token is also to be kept secret.
Offline access type: Many oauth providers such as google and facebook also support this mode. This mode basically allows you to extend the expiry time of your access token. E.g. instead of normal expiry time of access token (e.g. 1 hour), for offline tokens you might have the expiry time of 1 year or so.
Answer to the question "Should I reuse OAuth 2.0 access tokens?"
Yes, the token is supposed to be used as many times as you need within the given expiry time (google sets it to 1 hour).
After it has expired, use the refresh token to get another access token and use it as many times as you need. Keep repeating the process.
If your users won't be online for you to start the oauth process, and you don't have the refresh token, then the app needs to have "offline" tokens.
Should I store my auth tokens?
You can if your app demands it, but it is nowhere recommended because of the potential to be leaked. Tokens are supposed to extract data within the given time limit and reissue the token when needed again. However, you surely can store them if you want.
"Offline" tokens, on the other hand, are expected to be stored. You can encrypt them if you like, but if the scopes are not too broad, I wouldn't bother at all.

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