Magicloud Magiclouds wrote:
I am trying to work with some binary data that encrypted by field instead of the result of serialization. I'd like to use Data.Serialize to wrap the data structure. But I could not figure out how to apply an runtime specified cipher method to the bytestring.
Are you using the set of crypto libraries written by Victor Hanquez, such as cryptocipher-types, crypto-pubkey-types, and cryptohash? Or the set of libraries written by Thomas DuBuisson, such as crypto-api, cipher-aes128, etc.? Here is an example of decoding for Victor's libraries. Encoding would be similar using Put instead of Get. Thomas' libraries would be similar using the other API. Let's say you have a type like this: data MyCipher = MyAES | MyBlowfish | ... Then in your cereal code you would have a Get monad expression something like this (assuming you have written all of the functions called parseSomething): getStuff = do cipher <- parseCipher :: Get MyCipher clearText <- case cipher of MyAES -> do keyBS <- parseAESKey :: Get ByteString let key = either (error "bad AES key") id $ makeKey keyBS cipher = cipherInit key cipherText <- parseAESCipherText :: Get ByteString return $ ecbDecrypt cipher cipherText MyBlowfish -> do ... etc. Hope this helps, Yitz