public static function ParagonIE_Sodium_Core_Curve25519::ge_double_scalarmult_vartime in Automatic Updates 8

Same name and namespace in other branches

1. 7 vendor/paragonie/sodium_compat/src/Core/Curve25519.php \ParagonIE_Sodium_Core_Curve25519::ge_double_scalarmult_vartime()

@internal You should not use this directly from another application

@psalm-suppress MixedArgument @psalm-suppress MixedArrayAccess

Parameters

string $a:

ParagonIE_Sodium_Core_Curve25519_Ge_P3 $A:

string $b:

Return value

ParagonIE_Sodium_Core_Curve25519_Ge_P2

Throws

SodiumException

TypeError

1 call to ParagonIE_Sodium_Core_Curve25519::ge_double_scalarmult_vartime()

ParagonIE_Sodium_Core_Ed25519::verify_detached in vendor/paragonie/sodium_compat/src/Core/Ed25519.php

@internal You should not use this directly from another application

File

vendor/paragonie/sodium_compat/src/Core/Curve25519.php, line 1813

Class

ParagonIE_Sodium_Core_Curve25519

Class ParagonIE_Sodium_Core_Curve25519

Code

public static function ge_double_scalarmult_vartime($a, ParagonIE_Sodium_Core_Curve25519_Ge_P3 $A, $b) {

  /** @var array<int, ParagonIE_Sodium_Core_Curve25519_Ge_Cached> $Ai */
  $Ai = array();

  /** @var array<int, ParagonIE_Sodium_Core_Curve25519_Ge_Precomp> $Bi */
  static $Bi = array();
  if (!$Bi) {
    for ($i = 0; $i < 8; ++$i) {
      $Bi[$i] = new ParagonIE_Sodium_Core_Curve25519_Ge_Precomp(ParagonIE_Sodium_Core_Curve25519_Fe::fromArray(self::$base2[$i][0]), ParagonIE_Sodium_Core_Curve25519_Fe::fromArray(self::$base2[$i][1]), ParagonIE_Sodium_Core_Curve25519_Fe::fromArray(self::$base2[$i][2]));
    }
  }
  for ($i = 0; $i < 8; ++$i) {
    $Ai[$i] = new ParagonIE_Sodium_Core_Curve25519_Ge_Cached(self::fe_0(), self::fe_0(), self::fe_0(), self::fe_0());
  }

  # slide(aslide,a);

  # slide(bslide,b);

  /** @var array<int, int> $aslide */
  $aslide = self::slide($a);

  /** @var array<int, int> $bslide */
  $bslide = self::slide($b);

  # ge_p3_to_cached(&Ai[0],A);

  # ge_p3_dbl(&t,A); ge_p1p1_to_p3(&A2,&t);
  $Ai[0] = self::ge_p3_to_cached($A);
  $t = self::ge_p3_dbl($A);
  $A2 = self::ge_p1p1_to_p3($t);

  # ge_add(&t,&A2,&Ai[0]); ge_p1p1_to_p3(&u,&t); ge_p3_to_cached(&Ai[1],&u);

  # ge_add(&t,&A2,&Ai[1]); ge_p1p1_to_p3(&u,&t); ge_p3_to_cached(&Ai[2],&u);

  # ge_add(&t,&A2,&Ai[2]); ge_p1p1_to_p3(&u,&t); ge_p3_to_cached(&Ai[3],&u);

  # ge_add(&t,&A2,&Ai[3]); ge_p1p1_to_p3(&u,&t); ge_p3_to_cached(&Ai[4],&u);

  # ge_add(&t,&A2,&Ai[4]); ge_p1p1_to_p3(&u,&t); ge_p3_to_cached(&Ai[5],&u);

  # ge_add(&t,&A2,&Ai[5]); ge_p1p1_to_p3(&u,&t); ge_p3_to_cached(&Ai[6],&u);

  # ge_add(&t,&A2,&Ai[6]); ge_p1p1_to_p3(&u,&t); ge_p3_to_cached(&Ai[7],&u);
  for ($i = 0; $i < 7; ++$i) {
    $t = self::ge_add($A2, $Ai[$i]);
    $u = self::ge_p1p1_to_p3($t);
    $Ai[$i + 1] = self::ge_p3_to_cached($u);
  }

  # ge_p2_0(r);
  $r = self::ge_p2_0();

  # for (i = 255;i >= 0;--i) {

  #     if (aslide[i] || bslide[i]) break;

  # }
  $i = 255;
  for (; $i >= 0; --$i) {
    if ($aslide[$i] || $bslide[$i]) {
      break;
    }
  }

  # for (;i >= 0;--i) {
  for (; $i >= 0; --$i) {

    # ge_p2_dbl(&t,r);
    $t = self::ge_p2_dbl($r);

    # if (aslide[i] > 0) {
    if ($aslide[$i] > 0) {

      # ge_p1p1_to_p3(&u,&t);

      # ge_add(&t,&u,&Ai[aslide[i]/2]);
      $u = self::ge_p1p1_to_p3($t);
      $t = self::ge_add($u, $Ai[(int) floor($aslide[$i] / 2)]);

      # } else if (aslide[i] < 0) {
    }
    elseif ($aslide[$i] < 0) {

      # ge_p1p1_to_p3(&u,&t);

      # ge_sub(&t,&u,&Ai[(-aslide[i])/2]);
      $u = self::ge_p1p1_to_p3($t);
      $t = self::ge_sub($u, $Ai[(int) floor(-$aslide[$i] / 2)]);
    }

    # if (bslide[i] > 0) {
    if ($bslide[$i] > 0) {

      /** @var int $index */
      $index = (int) floor($bslide[$i] / 2);

      # ge_p1p1_to_p3(&u,&t);

      # ge_madd(&t,&u,&Bi[bslide[i]/2]);
      $u = self::ge_p1p1_to_p3($t);
      $t = self::ge_madd($t, $u, $Bi[$index]);

      # } else if (bslide[i] < 0) {
    }
    elseif ($bslide[$i] < 0) {

      /** @var int $index */
      $index = (int) floor(-$bslide[$i] / 2);

      # ge_p1p1_to_p3(&u,&t);

      # ge_msub(&t,&u,&Bi[(-bslide[i])/2]);
      $u = self::ge_p1p1_to_p3($t);
      $t = self::ge_msub($t, $u, $Bi[$index]);
    }

    # ge_p1p1_to_p2(r,&t);
    $r = self::ge_p1p1_to_p2($t);
  }
  return $r;
}