[xmlsec] Key Requirements

[Aleksey Sanin]

There are two ways to specify a key for signing (or encryption).
The first option is to put a pointer to xmlSecKey in signature
(encryption) context. The second option is to put key information
(for example, key name) in the template and let xmlsec search
the key in keys manager. In case of signature verification (decryption)
you also have the same two options: specify key in context object
or let xmlsec figure out the key from the input document.

xmlSecKeyReq structure is used by xmlsec to hold all the information
about a key required for keys search in the keys manager. Transform
(say, signature or encryption) fills in this structure and xmlsec passes it
to keys manager. Keys manager must return a key that matches all
requirements specified in xmlSecKeyReq structure.


Aleksey