Security of token base authentication

[Michael Dürig]

Hi,

Token based authentication as implemented with JCR-2851 seems to exhibit 
a security issue: the token returned by the server consists of the 
identifier of a (newly created) node in the repository. An attacker who 
is able to guess (or acquire by other means i.e. via log files) that 
identifier will be granted access to the repository. Worse yet, JCR-2857 
introduces sequential node ids. Guessing is a piece of cake in such a 
setup.

I think we should decouple authentication secrets from node ids. A 
simple solution would be to store the secret in a token attribute and 
delegate generation of the secret to a dedicated handler. Such a handler 
can then use a secure random generator, private/public key encryption or 
whatever other method that is deemed appropriate to generate the 
authentication secret.

Michael