Resolve users according to userstore preference order if configured.

[mpmadhavig]

Proposed changes in this pull request

Changes proposed in this PR contains resolving users according to the user store preference order if configured. Note that, if the userstore domain is appended to the login identifier of the user, user store preference will not be taken into consideration.

Support Flows

When multi attribute is enabled, you can configure a particular SP to be authenticated only by one userstore. This is called userstore binding. No other SPs can be authenticated with the users in this userstore. Other SPs can be authenticated with the rest of the userstores as usual.

Note:

• Users with the same loginidentifier across userstores considered as duplicate users and will not be authentictaed. It is considered as a not supported flow. This is the default behaviour of the multi attribute login even without userstore preference support.

When should this PR be merged

After the wso2/carbon-kernel#3682 got merged and released.

Peer verification steps:

Pre-requisits

1. Enable multi-attribute login to use claims http://wso2.org/claims/username,http://wso2.org/claims/mobile,http://wso2.org/claims/emailaddress.
2. Add two secondary user stores called SECONDARY and TERTIARY.
3. Create two users in PRIMARY and SECONDARY user stores, having the same mobile number 0711234567.
4. Create an admin user in the secondary userstore.
5. Create three admin users with the same username as test in all 3 userstores.
6. Configure the user store preference order extension[1] and bind one user store to a service provider.
   • Bind SECONDARY userstore to My Account application.
   • [2] contains the above specified logic. Therefore build the default branch of [2] and add the jar to the dropins folder.

Test Cases:

1. Try to login to My Account using the PRIMARY user store user 0711234567.
   • Can be login using users from the binded userstore SECONDARY.
   • Should Fail.
2. Try to login to My Account using the SECONDARY user store user 0711234567.
   • Login using a user from the binded userstore SECONDARY.
   • Should succesfully authenticate.
3. Try to login to Console using the PRIMARY user store admin's credentials.
   • Login by only PRIMARY and TERTIARY admins.
   • Should succesfully authenticate.
4. Try to login to Console using the SECONDARY user store admin's credentials.
   • Can be login by only PRIMARY and TERTIARY admins.
   • Should Fail.
5. Try to login to Console using the PRIMARY user store user test.
   • test user available in both PRIMARY and TERTIARY userstores.
   • Should Fail.

Try the same test flows without the user preference order.

[1] https://medium.com/@nilasini/user-store-preference-order-per-service-provider-available-from-5-9-0-onwards-bcd7648a485c
[2] https://github.com/mpmadhavig/user-store-order-callback-handler

Resolves wso2/product-is#12503

[mpmadhavig]

Applies https://github.com/wso2/product-is/actions/runs/6492452822