Which Property should I use when Sending Additional information in a RequestSecurityToken (RST)

Question

There are a couple of properties that seem to allow this:

Properties (which is a Dictionaty) AdditionalContext and Context...

I cannot find any guidelines as to which would be most appropriate to use...

I basically need the requestor of the token to provide me with a "External User Id" and the STS I am building will include that as a claim in the response (RSTR).

Answer 1

I would use the .Claims property - this passes in the requested claims.

Add the "external user id" claim here to indicate to the STS that you need this claim in the RSTR.

Answer 2

You must have noticed that manipulating RequestSecurityToken.Properties requires custom WSTrust13ResponseSerializer and WSTrust13RequestSerializer classes to be implemented.

Afterwards you should assign these custom classes to SecurityTokenServiceConfiguration class.