[Summary view] [Print] [Text view]

   1  <?php
   2  
   3  if (class_exists('ParagonIE_Sodium_Core_AES_KeySchedule', false)) {
   4      return;
   5  }
   6  
   7  /**
   8   * @internal This should only be used by sodium_compat
   9   */
  10  class ParagonIE_Sodium_Core_AES_KeySchedule
  11  {
  12      /** @var array<int, int> $skey -- has size 120 */
  13      protected $skey;
  14  
  15      /** @var bool $expanded */
  16      protected $expanded = false;
  17  
  18      /** @var int $numRounds */
  19      private $numRounds;
  20  
  21      /**
  22       * @param array $skey
  23       * @param int $numRounds
  24       */
  25      public function __construct(array $skey, $numRounds = 10)
  26      {
  27          $this->skey = $skey;
  28          $this->numRounds = $numRounds;
  29      }
  30  
  31      /**
  32       * Get a value at an arbitrary index. Mostly used for unit testing.
  33       *
  34       * @param int $i
  35       * @return int
  36       */
  37      public function get($i)
  38      {
  39          return $this->skey[$i];
  40      }
  41  
  42      /**
  43       * @return int
  44       */
  45      public function getNumRounds()
  46      {
  47          return $this->numRounds;
  48      }
  49  
  50      /**
  51       * @param int $offset
  52       * @return ParagonIE_Sodium_Core_AES_Block
  53       */
  54      public function getRoundKey($offset)
  55      {
  56          return ParagonIE_Sodium_Core_AES_Block::fromArray(
  57              array_slice($this->skey, $offset, 8)
  58          );
  59      }
  60  
  61      /**
  62       * Return an expanded key schedule
  63       *
  64       * @return ParagonIE_Sodium_Core_AES_Expanded
  65       */
  66      public function expand()
  67      {
  68          $exp = new ParagonIE_Sodium_Core_AES_Expanded(
  69              array_fill(0, 120, 0),
  70              $this->numRounds
  71          );
  72          $n = ($exp->numRounds + 1) << 2;
  73          for ($u = 0, $v = 0; $u < $n; ++$u, $v += 2) {
  74              $x = $y = $this->skey[$u];
  75              $x &= 0x55555555;
  76              $exp->skey[$v] = ($x | ($x << 1)) & ParagonIE_Sodium_Core_Util::U32_MAX;
  77              $y &= 0xAAAAAAAA;
  78              $exp->skey[$v + 1] = ($y | ($y >> 1)) & ParagonIE_Sodium_Core_Util::U32_MAX;
  79          }
  80          return $exp;
  81      }
  82  }