ASN1 framework

[Alejandro Perez Mendez]

Hello,

for my GSS preauthentication plugin I should make use of ASN1 for the 
encoding of the PA element. I've being advised to not encode DER by 
hand, but use instead the ASN1 macros that are defined in MIT KRB code. 
However, I've spent a while trying to understand how they work, without 
much success. Is there any documentation available?

I have lots of questions about it, like:

Am I supposed to modify the code in lib/krb5/asn1/ to define the 
encoding of my PA element? (there are lots of PKINIT definitions there)

Are encoding/decoding functions generated automatically based on the DEF 
macros? (some structs have encoding and decoding functions, some only 
have decoding functions, and some seem to have none of them).

Regards,
Alejandro