(Bonus points for being able to parse ASN.1 and generate appropriate Haskell datatypes & serialization primitives automatically :-) )
I think there's at least an ASN.1 definition in the crypto library. Dominic might be able to enlighten us on that.
No bonus points I'm afraid. There is an embryonic ASN.1 library here http://hackage.haskell.org/cgi-bin/hackage-scripts/package/ASN1-0.0.1 You can take an ASN.1 definition such as FooBar {1 2 0 0 6 1} DEFINITIONS ::= BEGIN Journey ::= SEQUENCE { origin IA5String, stop1 [0] IA5String OPTIONAL, stop2 [1] IA5String OPTIONAL, destination IA5String } Odyssey ::= SEQUENCE { start Journey, trip1 [0] Journey OPTIONAL, trip2 [1] Journey OPTIONAL, trip3 [2] Journey OPTIONAL, end Journey } END And then create abstract Haskell representations of the ASN.1 types journey = "Journey" ::= AbsSeq Universal 16 Implicit [ Regular (Just "origin" :>: (Nothing :@: absIA5String)), Optional (Just "stop1" :>: (Just 0 :@: absIA5String)), Optional (Just "stop2" :>: (Just 1 :@: absIA5String)), Regular (Just "destination" :>: (Nothing :@: absIA5String)) ] odyssey = "Odyssey" ::= AbsSeq Universal 16 Implicit [ Regular (Just "start" :>: (Nothing :@: journey)), Optional (Just "trip1" :>: (Just 0 :@: journey)), Optional (Just "trip2" :>: (Just 1 :@: journey)), Optional (Just "trip3" :>: (Just 2 :@: journey)), Regular (Just "end" :>: (Nothing :@: journey)) ] The library then allows you to decode BER representations of these types. It's good enough to decode X.509 identity and attribute certificates. There's no encoding routines currently as I didn't need them. I'll try and make some documentation more easily available if I get time at the weekend. I'm working on PER at the moment both encoding and decoding using GADTs. I will extend it at some point for BER but that won't be for some time. I thought I read that someone was working on parsing ASN.1 so I'll try and follow that up (again it will have to be at the weekend). Dominic.