xoodyak

Documentation

Index

• Constants
• func CryptoDecryptAEAD(in, key, id, ad, tag []byte) (pt []byte, valid bool, err error)
• func CryptoEncryptAEAD(in, key, id, ad []byte) (ct, tag []byte, err error)
• func HashXoodyak(in []byte) []byte
• func HashXoodyakLen(in []byte, hLen uint) []byte
• func MACXoodyak(key, msg []byte, macLen uint) []byte
• func NewXoodyakAEAD(key []byte) (cipher.AEAD, error)
• func NewXoodyakHash() hash.Hash
• func NewXoodyakMac(key []byte) hash.Hash
• type CryptMode
• type CyclistMode
• type CyclistPhase
• type Xoodyak
  • func Instantiate(key, id, counter []byte) *Xoodyak
  • func (xk *Xoodyak) Absorb(x []byte)
  • func (xk *Xoodyak) AbsorbAny(x []byte, r uint, cd uint8)
  • func (xk *Xoodyak) AbsorbBlock(x []byte, cd uint8)
  • func (xk *Xoodyak) AbsorbKey(key, id, counter []byte)
  • func (xk *Xoodyak) Crypt(msg []byte, cm CryptMode) []byte
  • func (xk *Xoodyak) Decrypt(ct []byte) []byte
  • func (xk *Xoodyak) Down(Xi []byte, Cd byte)
  • func (xk *Xoodyak) Encrypt(pt []byte) []byte
  • func (xk *Xoodyak) Ratchet()
  • func (xk *Xoodyak) Squeeze(outLen uint) []byte
  • func (xk *Xoodyak) SqueezeAny(YLen uint, Cu uint8) []byte
  • func (xk *Xoodyak) SqueezeKey(keyLen uint) []byte
  • func (xk *Xoodyak) Up(Cu byte, Yilen uint) []byte

Examples

• HashXoodyak
• HashXoodyakLen

Constants

const (
	AbsorbCdInit  uint8 = 0x03
	AbsorbCdMain  uint8 = 0x00
	SqueezeCuInit uint8 = 0x40
	CryptCuInit   uint8 = 0x80
	CryptCuMain   uint8 = 0x00
	CryptCd       uint8 = 0x00
	RatchetCu     uint8 = 0x10
)

Functions

func CryptoDecryptAEAD

func CryptoDecryptAEAD(in, key, id, ad, tag []byte) (pt []byte, valid bool, err error)

CryptoDecryptAEAD decrypts and authenticates a ciphertext message given a 16-byte key, 16-byte nonce. optional associated metadata bytes, and a 16 byte authentication tag generated at encryption. A plaintext message is only returned if authentication is successful. This decryption process is compatible with the Xoodyak LWC AEAD implementation.

func CryptoEncryptAEAD

func CryptoEncryptAEAD(in, key, id, ad []byte) (ct, tag []byte, err error)

CryptoEncryptAEAD encrypts a plaintext message given a 16-byte key, 16-bytes nonce, and optional associated metadata bytes. Along with a cipher text, a 16-byte authentication tag is also generated The ciphertext and tag data is compatible with the Xoodyak LWC AEAD implementation.

func HashXoodyak

func HashXoodyak(in []byte) []byte

HashXoodyak calculates a 32-byte hash on a provided slice of bytes. The output is compatible with the Xoodyak LWC definition

Example

package main

import (
	"fmt"

	"github.com/inmcm/xoodoo/xoodyak"
)

func main() {
	myMsg := []byte("hello xoodoo")
	myHash := xoodyak.HashXoodyak(myMsg)
	fmt.Printf("Msg:'%s'\nHash:%x\n", myMsg, myHash)
}

Output:

Msg:hello xoodoo
Hash:5c9a95363d79b2157cbdfff49dddaf1f20562dc64644f2d28211478537e6b29a

func HashXoodyakLen

func HashXoodyakLen(in []byte, hLen uint) []byte

HashXoodyakLen calculates a cryptographic hash of arbitrary length on a provided slice of bytes

Example

package main

import (
	"fmt"

	"github.com/inmcm/xoodoo/xoodyak"
)

func main() {
	myMsg := []byte("hello xoodoo")
	myHash := xoodyak.HashXoodyakLen(myMsg, 64)
	fmt.Printf("Msg:%s\nHash:%x\n", myMsg, myHash)
}

Output:

Msg:hello xoodoo
Hash:5c9a95363d79b2157cbdfff49dddaf1f20562dc64644f2d28211478537e6b29a5675a6d4a3fe18b985e7ae018133c118a44c5f82b3672492a30408937e5712cb

func MACXoodyak

func MACXoodyak(key, msg []byte, macLen uint) []byte

MACXoodyak generates a message authentication code of the desired length in bytes for the provided message based on the provided key data. This implements the MAC behavior described in section 1.3.2 of the Xoodyak specification.

func NewXoodyakAEAD

func NewXoodyakAEAD(key []byte) (cipher.AEAD, error)

NewXoodyakAEAD accepts a set of key bytes and returns object compatible with the stdlib crypto/cipher AEAD interface

func NewXoodyakHash

func NewXoodyakHash() hash.Hash

NewXoodyakHash returns a initialized Xoodyak digest object compatible with the stdlib Hash interface

func NewXoodyakMac

func NewXoodyakMac(key []byte) hash.Hash

NewXoodyakMac generates a new hashing object with the provided key data already baked in. Writing Any data then written to the hash object is part of the MAC check. Note that the length of the resulting MAC matches that of the offical Xoodyak hash output: 32 bytes

Types

type CryptMode

type CryptMode int

CryptMode defines if a Xoodyak instance (already running in keyed mode) is encrypting or decrypting provided message data

const (
	Encrypting CryptMode = iota + 1
	Decrypting
)

type CyclistMode

type CyclistMode int

CyclistMode defines if a Xoodyak instance should be running in hashing mode or encryption (keyed) modes

const (
	Hash CyclistMode = iota + 1
	Keyed
)

type CyclistPhase

type CyclistPhase int

CyclistPhase defines if a Xoodyak instance should perform the Up or Down method in the current Cyclist iteration

const (
	Down CyclistPhase = iota + 1
	Up
)

type Xoodyak

type Xoodyak struct {
	Instance    *xoodoo.Xoodoo
	Mode        CyclistMode
	Phase       CyclistPhase
	AbsorbSize  uint
	SqueezeSize uint
}

Xoodyak is a cryptographic object that allows execution of the Cyclist operating mode on the Xoodoo permutation primitive. Xoodyak allows for construction of a variety of hashing, encryption and authentication schemes through assembly of its various operating methods

func Instantiate

func Instantiate(key, id, counter []byte) *Xoodyak

Instantiate generate a new Xoodoo object initialized for hashing or keyed operations

func (*Xoodyak) Absorb

func (xk *Xoodyak) Absorb(x []byte)

Absorb ingests a provided message at the rate of the Xoodyak instance's absorption size

func (*Xoodyak) AbsorbAny

func (xk *Xoodyak) AbsorbAny(x []byte, r uint, cd uint8)

AbsorbAny allow input of any size number of bytes into the Xoodoo state

func (*Xoodyak) AbsorbBlock

func (xk *Xoodyak) AbsorbBlock(x []byte, cd uint8)

AbsorbBlock ingests a single block of bytes encompassing a single iteration of the Cyclist sequence

func (*Xoodyak) AbsorbKey

func (xk *Xoodyak) AbsorbKey(key, id, counter []byte)

AbsorbKey is special Xoodyak method that ingests provided key, id (nonce), and counter messages into the Xoodoo state enabling the keyed mode of operation typically used for authenticated encryption

func (*Xoodyak) Crypt

func (xk *Xoodyak) Crypt(msg []byte, cm CryptMode) []byte

Crypt is core encryption function of Xoodyak/Cyclist. It accepts a byte message of arbitrary length and generates either a ciphertext or plaintext based on the mode provided. Encryption or decryption is accomplished via XOR against a keystream generated from the Xoodoo primitive

func (*Xoodyak) Decrypt

func (xk *Xoodyak) Decrypt(ct []byte) []byte

Decrypt transforms the provided ciphertext message into a plainext message of equal size based on the Xoodyak instance provided (key, nonce, counter have already been processed)

func (*Xoodyak) Down

func (xk *Xoodyak) Down(Xi []byte, Cd byte)

Down injects the provided slice of bytes into the provided Xoodoo state via xor with the existing state

func (*Xoodyak) Encrypt

func (xk *Xoodyak) Encrypt(pt []byte) []byte

Encrypt transforms the provided plaintext message into a ciphertext message of equal size based on the Xoodyak instance provided (key, nonce, counter have already been processed)

func (*Xoodyak) Ratchet

func (xk *Xoodyak) Ratchet()

Ratchet performs a irreversible transformation of the underlying Xoodoo state to prevent key recovery

func (*Xoodyak) Squeeze

func (xk *Xoodyak) Squeeze(outLen uint) []byte

Squeeze outputs a provided stream of pseudo-random bytes at the rate of the Xoodyak instance's squeeze size

func (*Xoodyak) SqueezeAny

func (xk *Xoodyak) SqueezeAny(YLen uint, Cu uint8) []byte

SqueezeAny allow generation of a message of pseudo-random bytes of any size based on permutating the underlying Xoodoo state

func (*Xoodyak) SqueezeKey

func (xk *Xoodyak) SqueezeKey(keyLen uint) []byte

SqueezeKey can generate a new encryption key from the existing Xoodyak state

func (*Xoodyak) Up

func (xk *Xoodyak) Up(Cu byte, Yilen uint) []byte

Up applies the Xoodoo permutation to the Xoodoo state and returns the requested number of bytes