public static function ParagonIE_Sodium_Core32_Int64::ctSelect in Automatic Updates 8

Same name and namespace in other branches

1. 7 vendor/paragonie/sodium_compat/src/Core32/Int64.php \ParagonIE_Sodium_Core32_Int64::ctSelect()

@psalm-suppress MixedInferredReturnType

Parameters

ParagonIE_Sodium_Core32_Int64 $A:

ParagonIE_Sodium_Core32_Int64 $B:

Return value

array<int, ParagonIE_Sodium_Core32_Int64>

Throws

SodiumException

TypeError

1 call to ParagonIE_Sodium_Core32_Int64::ctSelect()

ParagonIE_Sodium_Core32_Int64::mulInt64 in vendor/paragonie/sodium_compat/src/Core32/Int64.php

@psalm-suppress MixedAssignment

File

vendor/paragonie/sodium_compat/src/Core32/Int64.php, line 290

Class

ParagonIE_Sodium_Core32_Int64

Class ParagonIE_Sodium_Core32_Int64

Code

public static function ctSelect(ParagonIE_Sodium_Core32_Int64 $A, ParagonIE_Sodium_Core32_Int64 $B) {
  $a = clone $A;
  $b = clone $B;

  /** @var int $aNeg */
  $aNeg = $a->limbs[0] >> 15 & 1;

  /** @var int $bNeg */
  $bNeg = $b->limbs[0] >> 15 & 1;

  /** @var int $m */
  $m = -($aNeg & $bNeg) | 1;

  /** @var int $swap */
  $swap = $bNeg & ~$aNeg;

  /** @var int $d */
  $d = -$swap;

  /*
          if ($bNeg && !$aNeg) {
     $a = clone $int;
     $b = clone $this;
          } elseif($bNeg && $aNeg) {
     $a = $this->mulInt(-1);
     $b = $int->mulInt(-1);
          }
  */
  $x = $a
    ->xorInt64($b)
    ->mask64($d, $d);
  return array(
    $a
      ->xorInt64($x)
      ->mulInt($m),
    $b
      ->xorInt64($x)
      ->mulInt($m),
  );
}