Documentation

Gmac
in package
Uses NeedsTrait

Class Gmac

Table of Contents

BLOCK_SIZE  = 16
$buf  : ByteArray
$bufLength  : int
$h  : ByteArray
$hf  : ByteArray
$key  : Key
$x  : ByteArray
__construct()  : mixed
Gmac constructor.
finish()  : ByteArray
Finish processing the authentication tag.
flush()  : self
Finish processing any leftover bytes in the internal buffer.
needs()  : mixed
Preconditions, postconditions, and loop invariants are very useful for safe programing. They also document the specifications.
update()  : self
Update the object with some data.
bit()  : int
Get a specific bit from the provided array, at the given index.
blockMultiply()  : ByteArray
Galois Field Multiplication

Constants

BLOCK_SIZE

public mixed BLOCK_SIZE = 16

Properties

$bufLength

protected int $bufLength = 0

Methods

__construct()

Gmac constructor.

public __construct(Key $aesKey, string $nonce[, int $keySize = 256 ]) : mixed
Parameters
$aesKey : Key
$nonce : string
$keySize : int = 256
Return values
mixed —

finish()

Finish processing the authentication tag.

public finish(int $aadLength, int $ciphertextLength) : ByteArray

This method mutates this Gmac object (effectively resetting it).

Parameters
$aadLength : int
$ciphertextLength : int
Return values
ByteArray —

flush()

Finish processing any leftover bytes in the internal buffer.

public flush() : self
Return values
self —

needs()

Preconditions, postconditions, and loop invariants are very useful for safe programing. They also document the specifications.

public static needs( $condition,  $errorMessage[, null $exceptionClass = null ]) : mixed

This function is to help simplify the semantic burden of parsing these constructions.

Instead of constructions like if (!(GOOD CONDITION)) { throw new \Exception('condition not true'); }

you can write: needs(GOOD CONDITION, 'condition not true');

Parameters
$condition :
$errorMessage :
$exceptionClass : null = null
Return values
mixed —

update()

Update the object with some data.

public update(ByteArray $blocks) : self

This method mutates this Gmac object.

Parameters
$blocks : ByteArray
Return values
self —

bit()

Get a specific bit from the provided array, at the given index.

protected bit(ByteArray $x, int $i) : int

[01234567], 8+[01234567], 16+[01234567], ...

Parameters
$x : ByteArray
$i : int
Return values
int —

blockMultiply()

Galois Field Multiplication

protected blockMultiply(ByteArray $x, ByteArray $y) : ByteArray

This function is the critical path that must be constant-time in order to avoid timing side-channels against AES-GCM.

The contents of each are always calculated, regardless of the branching condition, to prevent another kind of timing leak.

Parameters
$x : ByteArray
$y : ByteArray
Return values
ByteArray —

Search results