    -- KeyInfo.hs: OpenPGP (RFC4880) fingerprinting methods
    -- Copyright © 2012-2013  Clint Adams
    -- This software is released under the terms of the Expat license.
    -- (See the LICENSE file).

    module Codec.Encryption.OpenPGP.KeyInfo (
       keySize
     , pkalgoAbbrev
    ) where

    import qualified Crypto.PubKey.RSA as RSA
    import qualified Crypto.PubKey.DSA as DSA
    import qualified Crypto.Hash.MD5 as MD5
    import qualified Crypto.Hash.SHA1 as SHA1
    import qualified Data.ByteString as B
    import Data.Bits (shiftR)
    import Data.List (unfoldr)

    import Codec.Encryption.OpenPGP.Types

    keySize (RSAPubKey x) = RSA.public_size x * 8
    keySize (DSAPubKey x) = bitcount . DSA.params_p . DSA.public_params $ x
    keySize (ElGamalPubKey x) = bitcount $ head x

    bitcount = (*8) . length . unfoldr (\x -> if x == 0 then Nothing else Just (True, x `shiftR` 8))

    pkalgoAbbrev RSA = "R"
    pkalgoAbbrev DSA = "D"
    pkalgoAbbrev ElgamalEncryptOnly = "g"
    pkalgoAbbrev DeprecatedRSAEncryptOnly = "-"
    pkalgoAbbrev DeprecatedRSASignOnly = "_"
    pkalgoAbbrev EC = "e"
    pkalgoAbbrev ECDSA = "E"
    pkalgoAbbrev ForbiddenElgamal = "f"
    pkalgoAbbrev DH = "d"
    pkalgoAbbrev (OtherPKA _) = "."