I am running into that familiar problem of handling authorization in
nested services. Example:
Application A
Invoke Service "A"
Authorized with permissions "A"
Invokes Service "C" in Application "C"
Authorized with permissions "C"
In order for a user to run Service "A", I have to give them permission
to run Service "A" and Service "C". This might not be desirable because
granting permission "C" to the user could give them access to other
things I didn't intend to give them access to.
So far, we have handled that permission issue with permission service
SECAs - where a second permission service is invoked if the first one
fails. SECA Example:
Invoke permission service for permissions "C"
If permission service fails, invoke permission service for
permissions "A"
Return results of permission service "A"
Else
Return results of permission service "C"
This solves the problem (an example can be found in the Asset Maint
application), but it is cumbersome to implement.
There are other places in the project where the problem is solved by
invoking Service "C" with "system" or "admin" user credentials - which
looks hackish to me.
It seems to me this could be made a lot simpler by having the service
dispatcher keep track of previous authorizations. In other words, move
the authorization tracking (which is currently handled outside the
service dispatcher) into the service dispatcher. Example:
Service invoked
If user previously authorized
Execute service
Else
Execute permission service
If user authorized
Set previously authorized to true
Execute service
Set previously authorized to false
With this change, giving the user permission to run Service "A" will
automatically authorize them to run any services called by the service.
Naturally, this approach does not solve the problem if permission checks
are embedded in service code - it depends on the use of permission services.
So, what do you think?
-Adrian
