Cryptokit.Cipher

`sig
type direction = Encrypt | Decrypt
type chaining_mode = ECB | CBC | CFB of int | OFB of int
val aes :
?mode:Cryptokit.Cipher.chaining_mode ->
?pad:Cryptokit.Padding.scheme ->
?iv:string -> string -> Cryptokit.Cipher.direction -> Cryptokit.transform
val des :
?mode:Cryptokit.Cipher.chaining_mode ->
?pad:Cryptokit.Padding.scheme ->
?iv:string -> string -> Cryptokit.Cipher.direction -> Cryptokit.transform
val triple_des :
?mode:Cryptokit.Cipher.chaining_mode ->
?pad:Cryptokit.Padding.scheme ->
?iv:string -> string -> Cryptokit.Cipher.direction -> Cryptokit.transform
val arcfour : string -> Cryptokit.Cipher.direction -> Cryptokit.transform
end`