blake2b

Documentation

Overview

Package blake2b implements the BLAKE2b hash algorithm defined by RFC 7693 and the extendable output function (XOF) BLAKE2Xb.

For a detailed specification of BLAKE2b see https://blake2.net/blake2.pdf and for BLAKE2Xb see https://blake2.net/blake2x.pdf

If you aren't sure which function you need, use BLAKE2b (Sum512 or New512). If you need a secret-key MAC (message authentication code), use the New512 function with a non-nil key.

BLAKE2X is a construction to compute hash values larger than 64 bytes. It can produce hash values between 0 and 4 GiB.

Index

• Constants
• func New(size int, key []byte) (hash.Hash, error)
• func New256(key []byte) (hash.Hash, error)
• func New384(key []byte) (hash.Hash, error)
• func New512(key []byte) (hash.Hash, error)
• func Sum256(data []byte) [Size256]byte
• func Sum384(data []byte) [Size384]byte
• func Sum512(data []byte) [Size]byte
• type XOF
  • func NewXOF(size uint32, key []byte) (XOF, error)

Constants

const (
	// The blocksize of BLAKE2b in bytes.
	BlockSize = 128
	// The hash size of BLAKE2b-512 in bytes.
	Size = 64
	// The hash size of BLAKE2b-384 in bytes.
	Size384 = 48
	// The hash size of BLAKE2b-256 in bytes.
	Size256 = 32
)

const OutputLengthUnknown = 0

OutputLengthUnknown can be used as the size argument to NewXOF to indicate the the length of the output is not known in advance.

Functions

func New

func New(size int, key []byte) (hash.Hash, error)

New returns a new hash.Hash computing the BLAKE2b checksum with a custom length. A non-nil key turns the hash into a MAC. The key must between zero and 64 bytes long. The hash size can be a value between 1 and 64 but it is highly recommended to use values equal or greater than: - 32 if BLAKE2b is used as a hash function (The key is zero bytes long). - 16 if BLAKE2b is used as a MAC function (The key is at least 16 bytes long).

func New256

func New256(key []byte) (hash.Hash, error)

New256 returns a new hash.Hash computing the BLAKE2b-256 checksum. A non-nil key turns the hash into a MAC. The key must between zero and 64 bytes long.

func New384

func New384(key []byte) (hash.Hash, error)

New384 returns a new hash.Hash computing the BLAKE2b-384 checksum. A non-nil key turns the hash into a MAC. The key must between zero and 64 bytes long.

func New512

func New512(key []byte) (hash.Hash, error)

New512 returns a new hash.Hash computing the BLAKE2b-512 checksum. A non-nil key turns the hash into a MAC. The key must between zero and 64 bytes long.

func Sum256

func Sum256(data []byte) [Size256]byte

Sum256 returns the BLAKE2b-256 checksum of the data.

func Sum384

func Sum384(data []byte) [Size384]byte

Sum384 returns the BLAKE2b-384 checksum of the data.

func Sum512

func Sum512(data []byte) [Size]byte

Sum512 returns the BLAKE2b-512 checksum of the data.

Types

type XOF

type XOF interface {
	// Write absorbs more data into the hash's state. It panics if called
	// after Read.
	io.Writer

	// Read reads more output from the hash. It returns io.EOF if the limit
	// has been reached.
	io.Reader

	// Clone returns a copy of the XOF in its current state.
	Clone() XOF

	// Reset resets the XOF to its initial state.
	Reset()
}

XOF defines the interface to hash functions that support arbitrary-length output.

func NewXOF

func NewXOF(size uint32, key []byte) (XOF, error)

NewXOF creates a new variable-output-length hash. The hash either produce a known number of bytes (1 <= size < 2**32-1), or an unknown number of bytes (size == OutputLengthUnknown). In the latter case, an absolute limit of 256GiB applies.

A non-nil key turns the hash into a MAC. The key must between zero and 32 bytes long.