<?php
if (class_exists('ParagonIE_Sodium_Core_HChaCha20', false)) {
return;
}
/**
* Class ParagonIE_Sodium_Core_HChaCha20
*/
class ParagonIE_Sodium_Core_HChaCha20 extends ParagonIE_Sodium_Core_ChaCha20
{
/**
* @param string $in
* @param string $key
* @param string|null $c
* @return string
* @throws TypeError
*/
public static function hChaCha20($in = '', $key = '', $c = null)
{
$ctx = array();
if ($c === null) {
$ctx[0] = 0x61707865;
$ctx[1] = 0x3320646e;
$ctx[2] = 0x79622d32;
$ctx[3] = 0x6b206574;
} else {
$ctx[0] = self::load_4(self::substr($c, 0, 4));
$ctx[1] = self::load_4(self::substr($c, 4, 4));
$ctx[2] = self::load_4(self::substr($c, 8, 4));
$ctx[3] = self::load_4(self::substr($c, 12, 4));
}
$ctx[4] = self::load_4(self::substr($key, 0, 4));
$ctx[5] = self::load_4(self::substr($key, 4, 4));
$ctx[6] = self::load_4(self::substr($key, 8, 4));
$ctx[7] = self::load_4(self::substr($key, 12, 4));
$ctx[8] = self::load_4(self::substr($key, 16, 4));
$ctx[9] = self::load_4(self::substr($key, 20, 4));
$ctx[10] = self::load_4(self::substr($key, 24, 4));
$ctx[11] = self::load_4(self::substr($key, 28, 4));
$ctx[12] = self::load_4(self::substr($in, 0, 4));
$ctx[13] = self::load_4(self::substr($in, 4, 4));
$ctx[14] = self::load_4(self::substr($in, 8, 4));
$ctx[15] = self::load_4(self::substr($in, 12, 4));
return self::hChaCha20Bytes($ctx);
}
/**
* @param array $ctx
* @return string
* @throws TypeError
*/
protected static function hChaCha20Bytes(array $ctx)
{
$x0 = (int) $ctx[0];
$x1 = (int) $ctx[1];
$x2 = (int) $ctx[2];
$x3 = (int) $ctx[3];
$x4 = (int) $ctx[4];
$x5 = (int) $ctx[5];
$x6 = (int) $ctx[6];
$x7 = (int) $ctx[7];
$x8 = (int) $ctx[8];
$x9 = (int) $ctx[9];
$x10 = (int) $ctx[10];
$x11 = (int) $ctx[11];
$x12 = (int) $ctx[12];
$x13 = (int) $ctx[13];
$x14 = (int) $ctx[14];
$x15 = (int) $ctx[15];
for ($i = 0; $i < 10; ++$i) {
# QUARTERROUND( x0, x4, x8, x12)
list($x0, $x4, $x8, $x12) = self::quarterRound($x0, $x4, $x8, $x12);
# QUARTERROUND( x1, x5, x9, x13)
list($x1, $x5, $x9, $x13) = self::quarterRound($x1, $x5, $x9, $x13);
# QUARTERROUND( x2, x6, x10, x14)
list($x2, $x6, $x10, $x14) = self::quarterRound($x2, $x6, $x10, $x14);
# QUARTERROUND( x3, x7, x11, x15)
list($x3, $x7, $x11, $x15) = self::quarterRound($x3, $x7, $x11, $x15);
# QUARTERROUND( x0, x5, x10, x15)
list($x0, $x5, $x10, $x15) = self::quarterRound($x0, $x5, $x10, $x15);
# QUARTERROUND( x1, x6, x11, x12)
list($x1, $x6, $x11, $x12) = self::quarterRound($x1, $x6, $x11, $x12);
# QUARTERROUND( x2, x7, x8, x13)
list($x2, $x7, $x8, $x13) = self::quarterRound($x2, $x7, $x8, $x13);
# QUARTERROUND( x3, x4, x9, x14)
list($x3, $x4, $x9, $x14) = self::quarterRound($x3, $x4, $x9, $x14);
}
return self::store32_le((int) ($x0 & 0xffffffff)) .
self::store32_le((int) ($x1 & 0xffffffff)) .
self::store32_le((int) ($x2 & 0xffffffff)) .
self::store32_le((int) ($x3 & 0xffffffff)) .
self::store32_le((int) ($x12 & 0xffffffff)) .
self::store32_le((int) ($x13 & 0xffffffff)) .
self::store32_le((int) ($x14 & 0xffffffff)) .
self::store32_le((int) ($x15 & 0xffffffff));
}
}