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File: src/Core/HSalsa20.php

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  Classes of Scott Arciszewski  >  PHP Sodium Compat  >  src/Core/HSalsa20.php  >  Download  
File: src/Core/HSalsa20.php
Role: Class source
Content type: text/plain
Description: Class source
Class: PHP Sodium Compat
Cryptographic functions of libsodium in pure PHP
Author: By
Last change: Update docblocks.
Date: 3 months ago
Size: 3,673 bytes
 

Contents

Class file image Download
<?php

if (class_exists('ParagonIE_Sodium_Core_HSalsa20', false)) {
    return;
}

/**
 * Class ParagonIE_Sodium_Core_HSalsa20
 */
abstract class ParagonIE_Sodium_Core_HSalsa20 extends ParagonIE_Sodium_Core_Salsa20
{
   
/**
     * Calculate an hsalsa20 hash of a single block
     *
     * HSalsa20 doesn't have a counter and will never be used for more than
     * one block (used to derive a subkey for xsalsa20).
     *
     * @internal You should not use this directly from another application
     *
     * @param string $in
     * @param string $k
     * @param string|null $c
     * @return string
     * @throws TypeError
     */
   
public static function hsalsa20($in, $k, $c = null)
    {
        if (
$c === null) {
           
$x0 = 0x61707865;
           
$x5 = 0x3320646e;
           
$x10 = 0x79622d32;
           
$x15 = 0x6b206574;
        } else {
           
$x0 = self::load_4(self::substr($c, 0, 4));
           
$x5 = self::load_4(self::substr($c, 4, 4));
           
$x10 = self::load_4(self::substr($c, 8, 4));
           
$x15 = self::load_4(self::substr($c, 12, 4));
        }
       
$x1 = self::load_4(self::substr($k, 0, 4));
       
$x2 = self::load_4(self::substr($k, 4, 4));
       
$x3 = self::load_4(self::substr($k, 8, 4));
       
$x4 = self::load_4(self::substr($k, 12, 4));
       
$x11 = self::load_4(self::substr($k, 16, 4));
       
$x12 = self::load_4(self::substr($k, 20, 4));
       
$x13 = self::load_4(self::substr($k, 24, 4));
       
$x14 = self::load_4(self::substr($k, 28, 4));
       
$x6 = self::load_4(self::substr($in, 0, 4));
       
$x7 = self::load_4(self::substr($in, 4, 4));
       
$x8 = self::load_4(self::substr($in, 8, 4));
       
$x9 = self::load_4(self::substr($in, 12, 4));

        for (
$i = self::ROUNDS; $i > 0; $i -= 2) {
           
$x4 ^= self::rotate($x0 + $x12, 7);
           
$x8 ^= self::rotate($x4 + $x0, 9);
           
$x12 ^= self::rotate($x8 + $x4, 13);
           
$x0 ^= self::rotate($x12 + $x8, 18);
           
$x9 ^= self::rotate($x5 + $x1, 7);
           
$x13 ^= self::rotate($x9 + $x5, 9);
           
$x1 ^= self::rotate($x13 + $x9, 13);
           
$x5 ^= self::rotate($x1 + $x13, 18);
           
$x14 ^= self::rotate($x10 + $x6, 7);
           
$x2 ^= self::rotate($x14 + $x10, 9);
           
$x6 ^= self::rotate($x2 + $x14, 13);
           
$x10 ^= self::rotate($x6 + $x2, 18);
           
$x3 ^= self::rotate($x15 + $x11, 7);
           
$x7 ^= self::rotate($x3 + $x15, 9);
           
$x11 ^= self::rotate($x7 + $x3, 13);
           
$x15 ^= self::rotate($x11 + $x7, 18);
           
$x1 ^= self::rotate($x0 + $x3, 7);
           
$x2 ^= self::rotate($x1 + $x0, 9);
           
$x3 ^= self::rotate($x2 + $x1, 13);
           
$x0 ^= self::rotate($x3 + $x2, 18);
           
$x6 ^= self::rotate($x5 + $x4, 7);
           
$x7 ^= self::rotate($x6 + $x5, 9);
           
$x4 ^= self::rotate($x7 + $x6, 13);
           
$x5 ^= self::rotate($x4 + $x7, 18);
           
$x11 ^= self::rotate($x10 + $x9, 7);
           
$x8 ^= self::rotate($x11 + $x10, 9);
           
$x9 ^= self::rotate($x8 + $x11, 13);
           
$x10 ^= self::rotate($x9 + $x8, 18);
           
$x12 ^= self::rotate($x15 + $x14, 7);
           
$x13 ^= self::rotate($x12 + $x15, 9);
           
$x14 ^= self::rotate($x13 + $x12, 13);
           
$x15 ^= self::rotate($x14 + $x13, 18);
        }

        return
self::store32_le($x0) .
           
self::store32_le($x5) .
           
self::store32_le($x10) .
           
self::store32_le($x15) .
           
self::store32_le($x6) .
           
self::store32_le($x7) .
           
self::store32_le($x8) .
           
self::store32_le($x9);
    }
}