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   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  }