ocb3

Documentation

Index

• Constants
• func New(b cipher.Block) (cipher.AEAD, error)
• func NewWithNonceAndTagSize(b cipher.Block, nonceSize, tagSize int) (cipher.AEAD, error)
• func NewWithNonceSize(block cipher.Block, nonceSize int) (cipher.AEAD, error)
• func NewWithTagSize(block cipher.Block, tagSize int) (cipher.AEAD, error)

Constants

const (
	// BlockSize is the size in bytes of an OCB3 block.
	BlockSize = 16
)

Functions

func New

func New(b cipher.Block) (cipher.AEAD, error)

New creates an OCB3 AEAD from a secure block cipher.

The AEAD uses a 96-bit nonce and 128-bit tag.

Nonces can either be random or a counter. Like many AEAD modes, they need not be secret.

Like many AEAD modes, (nonce, key) pairs must never be used to encrypt multiple messages (multiple calls to Seal). Doing so is catastrophic for both confidentiality and authenticity. It cannot be stressed enough: never allow (nonce, key) pairs to repeat while encrypting. It is a fatal error.

OCB3's confidentiality and authenticity claims degrade as the number of blocks, s, approaches s^2 / 2^128. Therefore, it is recommended that each key generate no more than 2^48 ciphertext blocks (about 4 PB), including associated data.

It is an error if the cipher's block size is not exactly BlockSize.

func NewWithNonceAndTagSize

func NewWithNonceAndTagSize(b cipher.Block, nonceSize, tagSize int) (cipher.AEAD, error)

func NewWithNonceSize

func NewWithNonceSize(block cipher.Block, nonceSize int) (cipher.AEAD, error)

func NewWithTagSize

func NewWithTagSize(block cipher.Block, tagSize int) (cipher.AEAD, error)