# Class type Netsys_ciphers.cipher

    class type cipher = object .. end

    method name : string

The name of the cipher

    method mode : string

The mode of the cipher

    method key_lengths : (int * int) list

Supported key lengths as pairs `min,max`. If there is a recommended key length, this is the first.

    method iv_lengths : (int * int) list

Supported iv lengths as pairs `min,max`. If there is a recommended iv length, this is the first.

    method block_constraint : int

The buffers used with encrypt/decrypt must have a length that is a multiple of this number. (In ECB mode this is the block size.)

    method supports_aead : bool

Whether this cipher integrates authentication

    method create : string -> padding -> cipher_ctx

`create c p key`: create a new cipher context for `key`. If not set, the initialization vector is assumed to be zero, and the header the empty string.

The cipher context can be used for either encrypting or decrypting a single message.