1 <?php

     2 

     3 if (class_exists('ParagonIE_Sodium_Core_HSalsa20', false)) {

     4     return;

     5 }

     6 

     7 /**

     8  * Class ParagonIE_Sodium_Core_HSalsa20

     9  */

    10 abstract class ParagonIE_Sodium_Core_HSalsa20 extends ParagonIE_Sodium_Core_Salsa20

    11 {

    12     /**

    13      * Calculate an hsalsa20 hash of a single block

    14      *

    15      * HSalsa20 doesn't have a counter and will never be used for more than

    16      * one block (used to derive a subkey for xsalsa20).

    17      *

    18      * @internal You should not use this directly from another application

    19      *

    20      * @param string $in

    21      * @param string $k

    22      * @param string|null $c

    23      * @return string

    24      * @throws TypeError

    25      */

    26     public static function hsalsa20($in, $k, $c = null)

    27     {

    28         if ($c === null) {

    29             $x0  = 0x61707865;

    30             $x5  = 0x3320646e;

    31             $x10 = 0x79622d32;

    32             $x15 = 0x6b206574;

    33         } else {

    34             $x0  = self::load_4(self::substr($c, 0, 4));

    35             $x5  = self::load_4(self::substr($c, 4, 4));

    36             $x10 = self::load_4(self::substr($c, 8, 4));

    37             $x15 = self::load_4(self::substr($c, 12, 4));

    38         }

    39         $x1  = self::load_4(self::substr($k, 0, 4));

    40         $x2  = self::load_4(self::substr($k, 4, 4));

    41         $x3  = self::load_4(self::substr($k, 8, 4));

    42         $x4  = self::load_4(self::substr($k, 12, 4));

    43         $x11 = self::load_4(self::substr($k, 16, 4));

    44         $x12 = self::load_4(self::substr($k, 20, 4));

    45         $x13 = self::load_4(self::substr($k, 24, 4));

    46         $x14 = self::load_4(self::substr($k, 28, 4));

    47         $x6  = self::load_4(self::substr($in, 0, 4));

    48         $x7  = self::load_4(self::substr($in, 4, 4));

    49         $x8  = self::load_4(self::substr($in, 8, 4));

    50         $x9  = self::load_4(self::substr($in, 12, 4));

    51 

    52         for ($i = self::ROUNDS; $i > 0; $i -= 2) {

    53             $x4 ^= self::rotate($x0 + $x12, 7);

    54             $x8 ^= self::rotate($x4 + $x0, 9);

    55             $x12 ^= self::rotate($x8 + $x4, 13);

    56             $x0 ^= self::rotate($x12 + $x8, 18);

    57             $x9 ^= self::rotate($x5 + $x1, 7);

    58             $x13 ^= self::rotate($x9 + $x5, 9);

    59             $x1 ^= self::rotate($x13 + $x9, 13);

    60             $x5 ^= self::rotate($x1 + $x13, 18);

    61             $x14 ^= self::rotate($x10 + $x6, 7);

    62             $x2 ^= self::rotate($x14 + $x10, 9);

    63             $x6 ^= self::rotate($x2 + $x14, 13);

    64             $x10 ^= self::rotate($x6 + $x2, 18);

    65             $x3 ^= self::rotate($x15 + $x11, 7);

    66             $x7 ^= self::rotate($x3 + $x15, 9);

    67             $x11 ^= self::rotate($x7 + $x3, 13);

    68             $x15 ^= self::rotate($x11 + $x7, 18);

    69             $x1 ^= self::rotate($x0 + $x3, 7);

    70             $x2 ^= self::rotate($x1 + $x0, 9);

    71             $x3 ^= self::rotate($x2 + $x1, 13);

    72             $x0 ^= self::rotate($x3 + $x2, 18);

    73             $x6 ^= self::rotate($x5 + $x4, 7);

    74             $x7 ^= self::rotate($x6 + $x5, 9);

    75             $x4 ^= self::rotate($x7 + $x6, 13);

    76             $x5 ^= self::rotate($x4 + $x7, 18);

    77             $x11 ^= self::rotate($x10 + $x9, 7);

    78             $x8 ^= self::rotate($x11 + $x10, 9);

    79             $x9 ^= self::rotate($x8 + $x11, 13);

    80             $x10 ^= self::rotate($x9 + $x8, 18);

    81             $x12 ^= self::rotate($x15 + $x14, 7);

    82             $x13 ^= self::rotate($x12 + $x15, 9);

    83             $x14 ^= self::rotate($x13 + $x12, 13);

    84             $x15 ^= self::rotate($x14 + $x13, 18);

    85         }

    86 

    87         return self::store32_le($x0) .

    88             self::store32_le($x5) .

    89             self::store32_le($x10) .

    90             self::store32_le($x15) .

    91             self::store32_le($x6) .

    92             self::store32_le($x7) .

    93             self::store32_le($x8) .

    94             self::store32_le($x9);

    95     }

    96 }