<?php
if (class_exists('ParagonIE_Sodium_Core_AES_KeySchedule', false)) {
return;
}
/**
* @internal This should only be used by sodium_compat
*/
class ParagonIE_Sodium_Core_AES_KeySchedule
{
/** @var array<int, int> $skey -- has size 120 */
protected $skey;
/** @var bool $expanded */
protected $expanded = false;
/** @var int $numRounds */
private $numRounds;
/**
* @param array $skey
* @param int $numRounds
*/
public function __construct(array $skey, $numRounds = 10)
{
$this->skey = $skey;
$this->numRounds = $numRounds;
}
/**
* Get a value at an arbitrary index. Mostly used for unit testing.
*
* @param int $i
* @return int
*/
public function get($i)
{
return $this->skey[$i];
}
/**
* @return int
*/
public function getNumRounds()
{
return $this->numRounds;
}
/**
* @param int $offset
* @return ParagonIE_Sodium_Core_AES_Block
*/
public function getRoundKey($offset)
{
return ParagonIE_Sodium_Core_AES_Block::fromArray(
array_slice($this->skey, $offset, 8)
);
}
/**
* Return an expanded key schedule
*
* @return ParagonIE_Sodium_Core_AES_Expanded
*/
public function expand()
{
$exp = new ParagonIE_Sodium_Core_AES_Expanded(
array_fill(0, 120, 0),
$this->numRounds
);
$n = ($exp->numRounds + 1) << 2;
for ($u = 0, $v = 0; $u < $n; ++$u, $v += 2) {
$x = $y = $this->skey[$u];
$x &= 0x55555555;
$exp->skey[$v] = ($x | ($x << 1)) & ParagonIE_Sodium_Core_Util::U32_MAX;
$y &= 0xAAAAAAAA;
$exp->skey[$v + 1] = ($y | ($y >> 1)) & ParagonIE_Sodium_Core_Util::U32_MAX;
}
return $exp;
}
}