pmac

Documentation

Overview

PMAC message authentication code, defined in http://web.cs.ucdavis.edu/~rogaway/ocb/pmac.pdf

Index

• Constants
• func New(c cipher.Block) (hash.Hash, error)
• func NewWithTagSize(c cipher.Block, tagsize int) (hash.Hash, error)
• func Sum(msg []byte, c cipher.Block, tagsize int) ([]byte, error)
• func Verify(mac, msg []byte, c cipher.Block, tagsize int) bool
• type Block
  • func NewBlock(size int) Block
  • func (b *Block) Clear()
  • func (b *Block) Dbl()
  • func (b *Block) Encrypt(c cipher.Block)

Constants

const (
	// R is the minimal irreducible polynomial for a 128-bit block size
	R = 0x87
)

Functions

func New

func New(c cipher.Block) (hash.Hash, error)

New creates a new PMAC instance using the given cipher

func NewWithTagSize

func NewWithTagSize(c cipher.Block, tagsize int) (hash.Hash, error)

NewWithTagSize returns a hash.Hash computing the PMAC checksum with the given tag size. The tag size must between the 1 and the cipher's block size.

func Sum

func Sum(msg []byte, c cipher.Block, tagsize int) ([]byte, error)

Sum computes the PMAC checksum with the given tagsize of msg using the cipher.Block.

func Verify

func Verify(mac, msg []byte, c cipher.Block, tagsize int) bool

Verify computes the PMAC checksum with the given tagsize of msg and compares it with the given mac. This functions returns true if and only if the given mac is equal to the computed one.

Types

type Block

type Block struct {
	Data []byte

	Size int
}

Block is a 128-bit array used by certain block ciphers (i.e. AES)

func NewBlock

func NewBlock(size int) Block

func (*Block) Clear

func (b *Block) Clear()

Clear zeroes out the contents of the block

func (*Block) Dbl

func (b *Block) Dbl()

Dbl performs a doubling of a block over GF(2^128):

a<<1 if firstbit(a)=0
(a<<1) ⊕ 0¹²⁰10000111 if firstbit(a)=1

func (*Block) Encrypt

func (b *Block) Encrypt(c cipher.Block)

Encrypt a block with the given block cipher