Documentation for sct-issuer-config

[Dennis Sosnoski]

Is there any documentation of the sct-issuer-config and 
token-canceler-config configuration options? The Rampart sample04 
configuration includes some comments:

           <!--
              Key computation mechanism
              1 - Use Request Entropy
              2 - Provide Entropy
              3 - Use Own Key
           -->
     <keyComputation>3</keyComputation>
           <!--
              proofKeyType element is valid only if the keyComputation 
is set to 3
              i.e. Use Own Key

              Valid values are: EncryptedKey & BinarySecret
           -->
     <proofKeyType>BinarySecret</proofKeyType>

But it's not clear (at least to me) exactly what these mean. For 
example, if keyComputation is set to 3 does that mean client entropy 
supplied in the request is not used as part of generating the key? And 
what parameters are used for the token-canceler-config?

I've checked the Rampart docs and searched online, but have not found 
documentation other than the Rampart samples.

Thanks,

 - Dennis