Transactional guarantees for CredentialsManager

[groue]

Hello,

Describe the problem you'd like to have solved

CredentialsManager is a very handy ready-made tool. However, it makes it difficult to make sure both credentials AND another piece of data are persisted or read from disk with transactional guarantees.

In particular, I would like to store credentials with a stable ID that identifies the user. No token found in Credentials is able to fulfill this need.

The purpose of this user ID is to help my application strictly isolate users' data, and particularly manage my local cache. In no way a network request authenticated with Alice's access token should be optimized by looking in Bob's cache. In no way the result of this network request should be stored in Bob's cache.

If credentials and user ID are not persisted or read together, with transactional guarantees, it is possible that both pieces of information end up out of sync. And then the above bugs can happen.

CredentialsManager already performs transactional accesses to credentials, by using NSKeyedArchiver and NSKeyedUnarchiver in order to store and read credentials as a whole. This is very good. We just need one more step:

Describe the ideal solution

Please allow CredentialsManager users to provide a userInfo dictionary that would be stored and read at the same time as the credentials:

 public func store(credentials: Credentials) -> Bool
+public func store(credentials: Credentials, userInfo: [String: Any]) -> Bool

 public func credentials(
     withScope scope: String? = nil, 
     minTTL: Int = 0, 
     callback: @escaping (CredentialsManagerError?, Credentials?) -> Void)
+public func extendedCredentials(
+    withScope scope: String? = nil, 
+    minTTL: Int = 0, 
+    callback: @escaping (CredentialsManagerError?, Credentials?, [String: Any]?) -> Void)

Alternatives and current work-arounds

Current work-around involves duplicating CredentialsManager in application code, and modify it in order to provide the needed extra transactional guarantees.

The problem with this duplication of code is that when Auth0 is upgraded and CredentialsManager is improved, application code is not.

Thanks for reading!

[groue]

This feature request may be related to #437, but I'm not quite sure.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. If you have not received a response for our team (apologies for the delay) and this is still a blocker, please reply with additional information or just a ping. Thank you for your contribution! 🙇‍♂️

[groue]

If you have not received a response for our team (apologies for the delay) and this is still a blocker, please reply with additional information or just a ping.

Ping!

[Widcket]

Hi @groue, apologies for the delay.

This is not a feature request we want to proceed with.

We already provide a stable user ID (the sub claim from the ID Token) that you can map to your own. We recently added a user property to the CredentialsManager, that parses the ID Token and returns a UserInfo instance, which has a sub property.

Alternatively, you can also add your own ID via a Rule as a custom claim.

[groue]

Thank you very much @Widcket. TIL about the sub stable user ID, and that's all I needed 👍