[xmlsec] Expanding xmlSecKeyDataFormat enum?

[Dmitry Belyavsky]

Greetings!

We need to load private key from hardware token using our engine.
Analyzing the xmlSecOpenSSLAppKeyLoad function, I think it should be
better to add to the xmlSecKeyDataFormat enum another option,
xmlSecKeyDataFormatEngine or provide a similar function
xmlSecOpenSSLAppKeyLoadEngine accepting the engine name, smth as
filename and not accepting the xmlSecKeyDataFormat arg at all.

Which variant is more acceptable for you?
Thank you!

-- 
SY, Dmitry Belyavsky