X25519.php in Automatic Updates 7

File

vendor/paragonie/sodium_compat/src/Core/X25519.php

<?php

if (class_exists('ParagonIE_Sodium_Core_X25519', false)) {
  return;
}

/**
 * Class ParagonIE_Sodium_Core_X25519
 */
abstract class ParagonIE_Sodium_Core_X25519 extends ParagonIE_Sodium_Core_Curve25519 {

  /**
   * Alters the objects passed to this method in place.
   *
   * @internal You should not use this directly from another application
   *
   * @param ParagonIE_Sodium_Core_Curve25519_Fe $f
   * @param ParagonIE_Sodium_Core_Curve25519_Fe $g
   * @param int $b
   * @return void
   * @psalm-suppress MixedAssignment
   */
  public static function fe_cswap(ParagonIE_Sodium_Core_Curve25519_Fe $f, ParagonIE_Sodium_Core_Curve25519_Fe $g, $b = 0) {
    $f0 = (int) $f[0];
    $f1 = (int) $f[1];
    $f2 = (int) $f[2];
    $f3 = (int) $f[3];
    $f4 = (int) $f[4];
    $f5 = (int) $f[5];
    $f6 = (int) $f[6];
    $f7 = (int) $f[7];
    $f8 = (int) $f[8];
    $f9 = (int) $f[9];
    $g0 = (int) $g[0];
    $g1 = (int) $g[1];
    $g2 = (int) $g[2];
    $g3 = (int) $g[3];
    $g4 = (int) $g[4];
    $g5 = (int) $g[5];
    $g6 = (int) $g[6];
    $g7 = (int) $g[7];
    $g8 = (int) $g[8];
    $g9 = (int) $g[9];
    $b = -$b;
    $x0 = ($f0 ^ $g0) & $b;
    $x1 = ($f1 ^ $g1) & $b;
    $x2 = ($f2 ^ $g2) & $b;
    $x3 = ($f3 ^ $g3) & $b;
    $x4 = ($f4 ^ $g4) & $b;
    $x5 = ($f5 ^ $g5) & $b;
    $x6 = ($f6 ^ $g6) & $b;
    $x7 = ($f7 ^ $g7) & $b;
    $x8 = ($f8 ^ $g8) & $b;
    $x9 = ($f9 ^ $g9) & $b;
    $f[0] = $f0 ^ $x0;
    $f[1] = $f1 ^ $x1;
    $f[2] = $f2 ^ $x2;
    $f[3] = $f3 ^ $x3;
    $f[4] = $f4 ^ $x4;
    $f[5] = $f5 ^ $x5;
    $f[6] = $f6 ^ $x6;
    $f[7] = $f7 ^ $x7;
    $f[8] = $f8 ^ $x8;
    $f[9] = $f9 ^ $x9;
    $g[0] = $g0 ^ $x0;
    $g[1] = $g1 ^ $x1;
    $g[2] = $g2 ^ $x2;
    $g[3] = $g3 ^ $x3;
    $g[4] = $g4 ^ $x4;
    $g[5] = $g5 ^ $x5;
    $g[6] = $g6 ^ $x6;
    $g[7] = $g7 ^ $x7;
    $g[8] = $g8 ^ $x8;
    $g[9] = $g9 ^ $x9;
  }

  /**
   * @internal You should not use this directly from another application
   *
   * @param ParagonIE_Sodium_Core_Curve25519_Fe $f
   * @return ParagonIE_Sodium_Core_Curve25519_Fe
   */
  public static function fe_mul121666(ParagonIE_Sodium_Core_Curve25519_Fe $f) {
    $h = array(
      self::mul((int) $f[0], 121666, 17),
      self::mul((int) $f[1], 121666, 17),
      self::mul((int) $f[2], 121666, 17),
      self::mul((int) $f[3], 121666, 17),
      self::mul((int) $f[4], 121666, 17),
      self::mul((int) $f[5], 121666, 17),
      self::mul((int) $f[6], 121666, 17),
      self::mul((int) $f[7], 121666, 17),
      self::mul((int) $f[8], 121666, 17),
      self::mul((int) $f[9], 121666, 17),
    );

    /** @var int $carry9 */
    $carry9 = $h[9] + (1 << 24) >> 25;
    $h[0] += self::mul($carry9, 19, 5);
    $h[9] -= $carry9 << 25;

    /** @var int $carry1 */
    $carry1 = $h[1] + (1 << 24) >> 25;
    $h[2] += $carry1;
    $h[1] -= $carry1 << 25;

    /** @var int $carry3 */
    $carry3 = $h[3] + (1 << 24) >> 25;
    $h[4] += $carry3;
    $h[3] -= $carry3 << 25;

    /** @var int $carry5 */
    $carry5 = $h[5] + (1 << 24) >> 25;
    $h[6] += $carry5;
    $h[5] -= $carry5 << 25;

    /** @var int $carry7 */
    $carry7 = $h[7] + (1 << 24) >> 25;
    $h[8] += $carry7;
    $h[7] -= $carry7 << 25;

    /** @var int $carry0 */
    $carry0 = $h[0] + (1 << 25) >> 26;
    $h[1] += $carry0;
    $h[0] -= $carry0 << 26;

    /** @var int $carry2 */
    $carry2 = $h[2] + (1 << 25) >> 26;
    $h[3] += $carry2;
    $h[2] -= $carry2 << 26;

    /** @var int $carry4 */
    $carry4 = $h[4] + (1 << 25) >> 26;
    $h[5] += $carry4;
    $h[4] -= $carry4 << 26;

    /** @var int $carry6 */
    $carry6 = $h[6] + (1 << 25) >> 26;
    $h[7] += $carry6;
    $h[6] -= $carry6 << 26;

    /** @var int $carry8 */
    $carry8 = $h[8] + (1 << 25) >> 26;
    $h[9] += $carry8;
    $h[8] -= $carry8 << 26;
    foreach ($h as $i => $value) {
      $h[$i] = (int) $value;
    }
    return ParagonIE_Sodium_Core_Curve25519_Fe::fromArray($h);
  }

  /**
   * @internal You should not use this directly from another application
   *
   * Inline comments preceded by # are from libsodium's ref10 code.
   *
   * @param string $n
   * @param string $p
   * @return string
   * @throws SodiumException
   * @throws TypeError
   */
  public static function crypto_scalarmult_curve25519_ref10($n, $p) {

    # for (i = 0;i < 32;++i) e[i] = n[i];
    $e = '' . $n;

    # e[0] &= 248;
    $e[0] = self::intToChr(self::chrToInt($e[0]) & 248);

    # e[31] &= 127;

    # e[31] |= 64;
    $e[31] = self::intToChr(self::chrToInt($e[31]) & 127 | 64);

    # fe_frombytes(x1,p);
    $x1 = self::fe_frombytes($p);

    # fe_1(x2);
    $x2 = self::fe_1();

    # fe_0(z2);
    $z2 = self::fe_0();

    # fe_copy(x3,x1);
    $x3 = self::fe_copy($x1);

    # fe_1(z3);
    $z3 = self::fe_1();

    # swap = 0;

    /** @var int $swap */
    $swap = 0;

    # for (pos = 254;pos >= 0;--pos) {
    for ($pos = 254; $pos >= 0; --$pos) {

      # b = e[pos / 8] >> (pos & 7);

      /** @var int $b */
      $b = self::chrToInt($e[(int) floor($pos / 8)]) >> ($pos & 7);

      # b &= 1;
      $b &= 1;

      # swap ^= b;
      $swap ^= $b;

      # fe_cswap(x2,x3,swap);
      self::fe_cswap($x2, $x3, $swap);

      # fe_cswap(z2,z3,swap);
      self::fe_cswap($z2, $z3, $swap);

      # swap = b;
      $swap = $b;

      # fe_sub(tmp0,x3,z3);
      $tmp0 = self::fe_sub($x3, $z3);

      # fe_sub(tmp1,x2,z2);
      $tmp1 = self::fe_sub($x2, $z2);

      # fe_add(x2,x2,z2);
      $x2 = self::fe_add($x2, $z2);

      # fe_add(z2,x3,z3);
      $z2 = self::fe_add($x3, $z3);

      # fe_mul(z3,tmp0,x2);
      $z3 = self::fe_mul($tmp0, $x2);

      # fe_mul(z2,z2,tmp1);
      $z2 = self::fe_mul($z2, $tmp1);

      # fe_sq(tmp0,tmp1);
      $tmp0 = self::fe_sq($tmp1);

      # fe_sq(tmp1,x2);
      $tmp1 = self::fe_sq($x2);

      # fe_add(x3,z3,z2);
      $x3 = self::fe_add($z3, $z2);

      # fe_sub(z2,z3,z2);
      $z2 = self::fe_sub($z3, $z2);

      # fe_mul(x2,tmp1,tmp0);
      $x2 = self::fe_mul($tmp1, $tmp0);

      # fe_sub(tmp1,tmp1,tmp0);
      $tmp1 = self::fe_sub($tmp1, $tmp0);

      # fe_sq(z2,z2);
      $z2 = self::fe_sq($z2);

      # fe_mul121666(z3,tmp1);
      $z3 = self::fe_mul121666($tmp1);

      # fe_sq(x3,x3);
      $x3 = self::fe_sq($x3);

      # fe_add(tmp0,tmp0,z3);
      $tmp0 = self::fe_add($tmp0, $z3);

      # fe_mul(z3,x1,z2);
      $z3 = self::fe_mul($x1, $z2);

      # fe_mul(z2,tmp1,tmp0);
      $z2 = self::fe_mul($tmp1, $tmp0);
    }

    # fe_cswap(x2,x3,swap);
    self::fe_cswap($x2, $x3, $swap);

    # fe_cswap(z2,z3,swap);
    self::fe_cswap($z2, $z3, $swap);

    # fe_invert(z2,z2);
    $z2 = self::fe_invert($z2);

    # fe_mul(x2,x2,z2);
    $x2 = self::fe_mul($x2, $z2);

    # fe_tobytes(q,x2);
    return self::fe_tobytes($x2);
  }

  /**
   * @internal You should not use this directly from another application
   *
   * @param ParagonIE_Sodium_Core_Curve25519_Fe $edwardsY
   * @param ParagonIE_Sodium_Core_Curve25519_Fe $edwardsZ
   * @return ParagonIE_Sodium_Core_Curve25519_Fe
   */
  public static function edwards_to_montgomery(ParagonIE_Sodium_Core_Curve25519_Fe $edwardsY, ParagonIE_Sodium_Core_Curve25519_Fe $edwardsZ) {
    $tempX = self::fe_add($edwardsZ, $edwardsY);
    $tempZ = self::fe_sub($edwardsZ, $edwardsY);
    $tempZ = self::fe_invert($tempZ);
    return self::fe_mul($tempX, $tempZ);
  }

  /**
   * @internal You should not use this directly from another application
   *
   * @param string $n
   * @return string
   * @throws SodiumException
   * @throws TypeError
   */
  public static function crypto_scalarmult_curve25519_ref10_base($n) {

    # for (i = 0;i < 32;++i) e[i] = n[i];
    $e = '' . $n;

    # e[0] &= 248;
    $e[0] = self::intToChr(self::chrToInt($e[0]) & 248);

    # e[31] &= 127;

    # e[31] |= 64;
    $e[31] = self::intToChr(self::chrToInt($e[31]) & 127 | 64);
    $A = self::ge_scalarmult_base($e);
    if (!$A->Y instanceof ParagonIE_Sodium_Core_Curve25519_Fe || !$A->Z instanceof ParagonIE_Sodium_Core_Curve25519_Fe) {
      throw new TypeError('Null points encountered');
    }
    $pk = self::edwards_to_montgomery($A->Y, $A->Z);
    return self::fe_tobytes($pk);
  }

}

Classes

Name	Description
ParagonIE_Sodium_Core_X25519	Class ParagonIE_Sodium_Core_X25519