Curve25519.php in Automatic Updates 8

File

vendor/paragonie/sodium_compat/src/Core/Curve25519.php

<?php

if (class_exists('ParagonIE_Sodium_Core_Curve25519', false)) {
  return;
}

/**
 * Class ParagonIE_Sodium_Core_Curve25519
 *
 * Implements Curve25519 core functions
 *
 * Based on the ref10 curve25519 code provided by libsodium
 *
 * @ref https://github.com/jedisct1/libsodium/blob/master/src/libsodium/crypto_core/curve25519/ref10/curve25519_ref10.c
 */
abstract class ParagonIE_Sodium_Core_Curve25519 extends ParagonIE_Sodium_Core_Curve25519_H {

  /**
   * Get a field element of size 10 with a value of 0
   *
   * @internal You should not use this directly from another application
   *
   * @return ParagonIE_Sodium_Core_Curve25519_Fe
   */
  public static function fe_0() {
    return ParagonIE_Sodium_Core_Curve25519_Fe::fromArray(array(
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
    ));
  }

  /**
   * Get a field element of size 10 with a value of 1
   *
   * @internal You should not use this directly from another application
   *
   * @return ParagonIE_Sodium_Core_Curve25519_Fe
   */
  public static function fe_1() {
    return ParagonIE_Sodium_Core_Curve25519_Fe::fromArray(array(
      1,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
    ));
  }

  /**
   * Add two field elements.
   *
   * @internal You should not use this directly from another application
   *
   * @param ParagonIE_Sodium_Core_Curve25519_Fe $f
   * @param ParagonIE_Sodium_Core_Curve25519_Fe $g
   * @return ParagonIE_Sodium_Core_Curve25519_Fe
   * @psalm-suppress MixedAssignment
   * @psalm-suppress MixedOperand
   */
  public static function fe_add(ParagonIE_Sodium_Core_Curve25519_Fe $f, ParagonIE_Sodium_Core_Curve25519_Fe $g) {

    /** @var array<int, int> $arr */
    $arr = array();
    for ($i = 0; $i < 10; ++$i) {
      $arr[$i] = (int) ($f[$i] + $g[$i]);
    }
    return ParagonIE_Sodium_Core_Curve25519_Fe::fromArray($arr);
  }

  /**
   * Constant-time conditional move.
   *
   * @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 ParagonIE_Sodium_Core_Curve25519_Fe
   * @psalm-suppress MixedAssignment
   */
  public static function fe_cmov(ParagonIE_Sodium_Core_Curve25519_Fe $f, ParagonIE_Sodium_Core_Curve25519_Fe $g, $b = 0) {

    /** @var array<int, int> $h */
    $h = array();
    $b *= -1;
    for ($i = 0; $i < 10; ++$i) {

      /** @var int $x */
      $x = ($f[$i] ^ $g[$i]) & $b;
      $h[$i] = (int) ((int) $f[$i] ^ $x);
    }
    return ParagonIE_Sodium_Core_Curve25519_Fe::fromArray($h);
  }

  /**
   * Create a copy of a field element.
   *
   * @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_copy(ParagonIE_Sodium_Core_Curve25519_Fe $f) {
    $h = clone $f;
    return $h;
  }

  /**
   * Give: 32-byte string.
   * Receive: A field element object to use for internal calculations.
   *
   * @internal You should not use this directly from another application
   *
   * @param string $s
   * @return ParagonIE_Sodium_Core_Curve25519_Fe
   * @throws RangeException
   * @throws TypeError
   */
  public static function fe_frombytes($s) {
    if (self::strlen($s) !== 32) {
      throw new RangeException('Expected a 32-byte string.');
    }

    /** @var int $h0 */
    $h0 = self::load_4($s);

    /** @var int $h1 */
    $h1 = self::load_3(self::substr($s, 4, 3)) << 6;

    /** @var int $h2 */
    $h2 = self::load_3(self::substr($s, 7, 3)) << 5;

    /** @var int $h3 */
    $h3 = self::load_3(self::substr($s, 10, 3)) << 3;

    /** @var int $h4 */
    $h4 = self::load_3(self::substr($s, 13, 3)) << 2;

    /** @var int $h5 */
    $h5 = self::load_4(self::substr($s, 16, 4));

    /** @var int $h6 */
    $h6 = self::load_3(self::substr($s, 20, 3)) << 7;

    /** @var int $h7 */
    $h7 = self::load_3(self::substr($s, 23, 3)) << 5;

    /** @var int $h8 */
    $h8 = self::load_3(self::substr($s, 26, 3)) << 4;

    /** @var int $h9 */
    $h9 = (self::load_3(self::substr($s, 29, 3)) & 8388607) << 2;

    /** @var int $carry9 */
    $carry9 = $h9 + (1 << 24) >> 25;
    $h0 += self::mul($carry9, 19, 5);
    $h9 -= $carry9 << 25;

    /** @var int $carry1 */
    $carry1 = $h1 + (1 << 24) >> 25;
    $h2 += $carry1;
    $h1 -= $carry1 << 25;

    /** @var int $carry3 */
    $carry3 = $h3 + (1 << 24) >> 25;
    $h4 += $carry3;
    $h3 -= $carry3 << 25;

    /** @var int $carry5 */
    $carry5 = $h5 + (1 << 24) >> 25;
    $h6 += $carry5;
    $h5 -= $carry5 << 25;

    /** @var int $carry7 */
    $carry7 = $h7 + (1 << 24) >> 25;
    $h8 += $carry7;
    $h7 -= $carry7 << 25;

    /** @var int $carry0 */
    $carry0 = $h0 + (1 << 25) >> 26;
    $h1 += $carry0;
    $h0 -= $carry0 << 26;

    /** @var int $carry2 */
    $carry2 = $h2 + (1 << 25) >> 26;
    $h3 += $carry2;
    $h2 -= $carry2 << 26;

    /** @var int $carry4 */
    $carry4 = $h4 + (1 << 25) >> 26;
    $h5 += $carry4;
    $h4 -= $carry4 << 26;

    /** @var int $carry6 */
    $carry6 = $h6 + (1 << 25) >> 26;
    $h7 += $carry6;
    $h6 -= $carry6 << 26;

    /** @var int $carry8 */
    $carry8 = $h8 + (1 << 25) >> 26;
    $h9 += $carry8;
    $h8 -= $carry8 << 26;
    return ParagonIE_Sodium_Core_Curve25519_Fe::fromArray(array(
      (int) $h0,
      (int) $h1,
      (int) $h2,
      (int) $h3,
      (int) $h4,
      (int) $h5,
      (int) $h6,
      (int) $h7,
      (int) $h8,
      (int) $h9,
    ));
  }

  /**
   * Convert a field element to a byte string.
   *
   * @internal You should not use this directly from another application
   *
   * @param ParagonIE_Sodium_Core_Curve25519_Fe $h
   * @return string
   */
  public static function fe_tobytes(ParagonIE_Sodium_Core_Curve25519_Fe $h) {

    /** @var int $h0 */
    $h0 = (int) $h[0];

    /** @var int $h1 */
    $h1 = (int) $h[1];

    /** @var int $h2 */
    $h2 = (int) $h[2];

    /** @var int $h3 */
    $h3 = (int) $h[3];

    /** @var int $h4 */
    $h4 = (int) $h[4];

    /** @var int $h5 */
    $h5 = (int) $h[5];

    /** @var int $h6 */
    $h6 = (int) $h[6];

    /** @var int $h7 */
    $h7 = (int) $h[7];

    /** @var int $h8 */
    $h8 = (int) $h[8];

    /** @var int $h9 */
    $h9 = (int) $h[9];

    /** @var int $q */
    $q = self::mul($h9, 19, 5) + (1 << 24) >> 25;

    /** @var int $q */
    $q = $h0 + $q >> 26;

    /** @var int $q */
    $q = $h1 + $q >> 25;

    /** @var int $q */
    $q = $h2 + $q >> 26;

    /** @var int $q */
    $q = $h3 + $q >> 25;

    /** @var int $q */
    $q = $h4 + $q >> 26;

    /** @var int $q */
    $q = $h5 + $q >> 25;

    /** @var int $q */
    $q = $h6 + $q >> 26;

    /** @var int $q */
    $q = $h7 + $q >> 25;

    /** @var int $q */
    $q = $h8 + $q >> 26;

    /** @var int $q */
    $q = $h9 + $q >> 25;
    $h0 += self::mul($q, 19, 5);

    /** @var int $carry0 */
    $carry0 = $h0 >> 26;
    $h1 += $carry0;
    $h0 -= $carry0 << 26;

    /** @var int $carry1 */
    $carry1 = $h1 >> 25;
    $h2 += $carry1;
    $h1 -= $carry1 << 25;

    /** @var int $carry2 */
    $carry2 = $h2 >> 26;
    $h3 += $carry2;
    $h2 -= $carry2 << 26;

    /** @var int $carry3 */
    $carry3 = $h3 >> 25;
    $h4 += $carry3;
    $h3 -= $carry3 << 25;

    /** @var int $carry4 */
    $carry4 = $h4 >> 26;
    $h5 += $carry4;
    $h4 -= $carry4 << 26;

    /** @var int $carry5 */
    $carry5 = $h5 >> 25;
    $h6 += $carry5;
    $h5 -= $carry5 << 25;

    /** @var int $carry6 */
    $carry6 = $h6 >> 26;
    $h7 += $carry6;
    $h6 -= $carry6 << 26;

    /** @var int $carry7 */
    $carry7 = $h7 >> 25;
    $h8 += $carry7;
    $h7 -= $carry7 << 25;

    /** @var int $carry8 */
    $carry8 = $h8 >> 26;
    $h9 += $carry8;
    $h8 -= $carry8 << 26;

    /** @var int $carry9 */
    $carry9 = $h9 >> 25;
    $h9 -= $carry9 << 25;

    /**
     * @var array<int, int>
     */
    $s = array(
      (int) ($h0 >> 0 & 0xff),
      (int) ($h0 >> 8 & 0xff),
      (int) ($h0 >> 16 & 0xff),
      (int) (($h0 >> 24 | $h1 << 2) & 0xff),
      (int) ($h1 >> 6 & 0xff),
      (int) ($h1 >> 14 & 0xff),
      (int) (($h1 >> 22 | $h2 << 3) & 0xff),
      (int) ($h2 >> 5 & 0xff),
      (int) ($h2 >> 13 & 0xff),
      (int) (($h2 >> 21 | $h3 << 5) & 0xff),
      (int) ($h3 >> 3 & 0xff),
      (int) ($h3 >> 11 & 0xff),
      (int) (($h3 >> 19 | $h4 << 6) & 0xff),
      (int) ($h4 >> 2 & 0xff),
      (int) ($h4 >> 10 & 0xff),
      (int) ($h4 >> 18 & 0xff),
      (int) ($h5 >> 0 & 0xff),
      (int) ($h5 >> 8 & 0xff),
      (int) ($h5 >> 16 & 0xff),
      (int) (($h5 >> 24 | $h6 << 1) & 0xff),
      (int) ($h6 >> 7 & 0xff),
      (int) ($h6 >> 15 & 0xff),
      (int) (($h6 >> 23 | $h7 << 3) & 0xff),
      (int) ($h7 >> 5 & 0xff),
      (int) ($h7 >> 13 & 0xff),
      (int) (($h7 >> 21 | $h8 << 4) & 0xff),
      (int) ($h8 >> 4 & 0xff),
      (int) ($h8 >> 12 & 0xff),
      (int) (($h8 >> 20 | $h9 << 6) & 0xff),
      (int) ($h9 >> 2 & 0xff),
      (int) ($h9 >> 10 & 0xff),
      (int) ($h9 >> 18 & 0xff),
    );
    return self::intArrayToString($s);
  }

  /**
   * Is a field element negative? (1 = yes, 0 = no. Used in calculations.)
   *
   * @internal You should not use this directly from another application
   *
   * @param ParagonIE_Sodium_Core_Curve25519_Fe $f
   * @return int
   * @throws SodiumException
   * @throws TypeError
   */
  public static function fe_isnegative(ParagonIE_Sodium_Core_Curve25519_Fe $f) {
    $str = self::fe_tobytes($f);
    return (int) (self::chrToInt($str[0]) & 1);
  }

  /**
   * Returns 0 if this field element results in all NUL bytes.
   *
   * @internal You should not use this directly from another application
   *
   * @param ParagonIE_Sodium_Core_Curve25519_Fe $f
   * @return bool
   * @throws SodiumException
   * @throws TypeError
   */
  public static function fe_isnonzero(ParagonIE_Sodium_Core_Curve25519_Fe $f) {
    static $zero;
    if ($zero === null) {
      $zero = str_repeat("\0", 32);
    }

    /** @var string $zero */

    /** @var string $str */
    $str = self::fe_tobytes($f);
    return !self::verify_32($str, (string) $zero);
  }

  /**
   * Multiply two field elements
   *
   * h = f * g
   *
   * @internal You should not use this directly from another application
   *
   * @security Is multiplication a source of timing leaks? If so, can we do
   *           anything to prevent that from happening?
   *
   * @param ParagonIE_Sodium_Core_Curve25519_Fe $f
   * @param ParagonIE_Sodium_Core_Curve25519_Fe $g
   * @return ParagonIE_Sodium_Core_Curve25519_Fe
   */
  public static function fe_mul(ParagonIE_Sodium_Core_Curve25519_Fe $f, ParagonIE_Sodium_Core_Curve25519_Fe $g) {

    /** @var int $f0 */
    $f0 = $f[0];

    /** @var int $f1 */
    $f1 = $f[1];

    /** @var int $f2 */
    $f2 = $f[2];

    /** @var int $f3 */
    $f3 = $f[3];

    /** @var int $f4 */
    $f4 = $f[4];

    /** @var int $f5 */
    $f5 = $f[5];

    /** @var int $f6 */
    $f6 = $f[6];

    /** @var int $f7 */
    $f7 = $f[7];

    /** @var int $f8 */
    $f8 = $f[8];

    /** @var int $f9 */
    $f9 = $f[9];

    /** @var int $g0 */
    $g0 = $g[0];

    /** @var int $g1 */
    $g1 = $g[1];

    /** @var int $g2 */
    $g2 = $g[2];

    /** @var int $g3 */
    $g3 = $g[3];

    /** @var int $g4 */
    $g4 = $g[4];

    /** @var int $g5 */
    $g5 = $g[5];

    /** @var int $g6 */
    $g6 = $g[6];

    /** @var int $g7 */
    $g7 = $g[7];

    /** @var int $g8 */
    $g8 = $g[8];

    /** @var int $g9 */
    $g9 = $g[9];
    $g1_19 = self::mul($g1, 19, 5);
    $g2_19 = self::mul($g2, 19, 5);
    $g3_19 = self::mul($g3, 19, 5);
    $g4_19 = self::mul($g4, 19, 5);
    $g5_19 = self::mul($g5, 19, 5);
    $g6_19 = self::mul($g6, 19, 5);
    $g7_19 = self::mul($g7, 19, 5);
    $g8_19 = self::mul($g8, 19, 5);
    $g9_19 = self::mul($g9, 19, 5);

    /** @var int $f1_2 */
    $f1_2 = $f1 << 1;

    /** @var int $f3_2 */
    $f3_2 = $f3 << 1;

    /** @var int $f5_2 */
    $f5_2 = $f5 << 1;

    /** @var int $f7_2 */
    $f7_2 = $f7 << 1;

    /** @var int $f9_2 */
    $f9_2 = $f9 << 1;
    $f0g0 = self::mul($f0, $g0, 26);
    $f0g1 = self::mul($f0, $g1, 25);
    $f0g2 = self::mul($f0, $g2, 26);
    $f0g3 = self::mul($f0, $g3, 25);
    $f0g4 = self::mul($f0, $g4, 26);
    $f0g5 = self::mul($f0, $g5, 25);
    $f0g6 = self::mul($f0, $g6, 26);
    $f0g7 = self::mul($f0, $g7, 25);
    $f0g8 = self::mul($f0, $g8, 26);
    $f0g9 = self::mul($f0, $g9, 26);
    $f1g0 = self::mul($f1, $g0, 26);
    $f1g1_2 = self::mul($f1_2, $g1, 25);
    $f1g2 = self::mul($f1, $g2, 26);
    $f1g3_2 = self::mul($f1_2, $g3, 25);
    $f1g4 = self::mul($f1, $g4, 26);
    $f1g5_2 = self::mul($f1_2, $g5, 25);
    $f1g6 = self::mul($f1, $g6, 26);
    $f1g7_2 = self::mul($f1_2, $g7, 25);
    $f1g8 = self::mul($f1, $g8, 26);
    $f1g9_38 = self::mul($g9_19, $f1_2, 26);
    $f2g0 = self::mul($f2, $g0, 26);
    $f2g1 = self::mul($f2, $g1, 25);
    $f2g2 = self::mul($f2, $g2, 26);
    $f2g3 = self::mul($f2, $g3, 25);
    $f2g4 = self::mul($f2, $g4, 26);
    $f2g5 = self::mul($f2, $g5, 25);
    $f2g6 = self::mul($f2, $g6, 26);
    $f2g7 = self::mul($f2, $g7, 25);
    $f2g8_19 = self::mul($g8_19, $f2, 26);
    $f2g9_19 = self::mul($g9_19, $f2, 26);
    $f3g0 = self::mul($f3, $g0, 26);
    $f3g1_2 = self::mul($f3_2, $g1, 25);
    $f3g2 = self::mul($f3, $g2, 26);
    $f3g3_2 = self::mul($f3_2, $g3, 25);
    $f3g4 = self::mul($f3, $g4, 26);
    $f3g5_2 = self::mul($f3_2, $g5, 25);
    $f3g6 = self::mul($f3, $g6, 26);
    $f3g7_38 = self::mul($g7_19, $f3_2, 26);
    $f3g8_19 = self::mul($g8_19, $f3, 25);
    $f3g9_38 = self::mul($g9_19, $f3_2, 26);
    $f4g0 = self::mul($f4, $g0, 26);
    $f4g1 = self::mul($f4, $g1, 25);
    $f4g2 = self::mul($f4, $g2, 26);
    $f4g3 = self::mul($f4, $g3, 25);
    $f4g4 = self::mul($f4, $g4, 26);
    $f4g5 = self::mul($f4, $g5, 25);
    $f4g6_19 = self::mul($g6_19, $f4, 26);
    $f4g7_19 = self::mul($g7_19, $f4, 26);
    $f4g8_19 = self::mul($g8_19, $f4, 26);
    $f4g9_19 = self::mul($g9_19, $f4, 26);
    $f5g0 = self::mul($f5, $g0, 26);
    $f5g1_2 = self::mul($f5_2, $g1, 25);
    $f5g2 = self::mul($f5, $g2, 26);
    $f5g3_2 = self::mul($f5_2, $g3, 25);
    $f5g4 = self::mul($f5, $g4, 26);
    $f5g5_38 = self::mul($g5_19, $f5_2, 26);
    $f5g6_19 = self::mul($g6_19, $f5, 25);
    $f5g7_38 = self::mul($g7_19, $f5_2, 26);
    $f5g8_19 = self::mul($g8_19, $f5, 25);
    $f5g9_38 = self::mul($g9_19, $f5_2, 26);
    $f6g0 = self::mul($f6, $g0, 26);
    $f6g1 = self::mul($f6, $g1, 25);
    $f6g2 = self::mul($f6, $g2, 26);
    $f6g3 = self::mul($f6, $g3, 25);
    $f6g4_19 = self::mul($g4_19, $f6, 26);
    $f6g5_19 = self::mul($g5_19, $f6, 26);
    $f6g6_19 = self::mul($g6_19, $f6, 26);
    $f6g7_19 = self::mul($g7_19, $f6, 26);
    $f6g8_19 = self::mul($g8_19, $f6, 26);
    $f6g9_19 = self::mul($g9_19, $f6, 26);
    $f7g0 = self::mul($f7, $g0, 26);
    $f7g1_2 = self::mul($f7_2, $g1, 25);
    $f7g2 = self::mul($f7, $g2, 26);
    $f7g3_38 = self::mul($g3_19, $f7_2, 26);
    $f7g4_19 = self::mul($g4_19, $f7, 26);
    $f7g5_38 = self::mul($g5_19, $f7_2, 26);
    $f7g6_19 = self::mul($g6_19, $f7, 25);
    $f7g7_38 = self::mul($g7_19, $f7_2, 26);
    $f7g8_19 = self::mul($g8_19, $f7, 25);
    $f7g9_38 = self::mul($g9_19, $f7_2, 26);
    $f8g0 = self::mul($f8, $g0, 26);
    $f8g1 = self::mul($f8, $g1, 25);
    $f8g2_19 = self::mul($g2_19, $f8, 26);
    $f8g3_19 = self::mul($g3_19, $f8, 26);
    $f8g4_19 = self::mul($g4_19, $f8, 26);
    $f8g5_19 = self::mul($g5_19, $f8, 26);
    $f8g6_19 = self::mul($g6_19, $f8, 26);
    $f8g7_19 = self::mul($g7_19, $f8, 26);
    $f8g8_19 = self::mul($g8_19, $f8, 26);
    $f8g9_19 = self::mul($g9_19, $f8, 26);
    $f9g0 = self::mul($f9, $g0, 26);
    $f9g1_38 = self::mul($g1_19, $f9_2, 26);
    $f9g2_19 = self::mul($g2_19, $f9, 25);
    $f9g3_38 = self::mul($g3_19, $f9_2, 26);
    $f9g4_19 = self::mul($g4_19, $f9, 25);
    $f9g5_38 = self::mul($g5_19, $f9_2, 26);
    $f9g6_19 = self::mul($g6_19, $f9, 25);
    $f9g7_38 = self::mul($g7_19, $f9_2, 26);
    $f9g8_19 = self::mul($g8_19, $f9, 25);
    $f9g9_38 = self::mul($g9_19, $f9_2, 26);
    $h0 = $f0g0 + $f1g9_38 + $f2g8_19 + $f3g7_38 + $f4g6_19 + $f5g5_38 + $f6g4_19 + $f7g3_38 + $f8g2_19 + $f9g1_38;
    $h1 = $f0g1 + $f1g0 + $f2g9_19 + $f3g8_19 + $f4g7_19 + $f5g6_19 + $f6g5_19 + $f7g4_19 + $f8g3_19 + $f9g2_19;
    $h2 = $f0g2 + $f1g1_2 + $f2g0 + $f3g9_38 + $f4g8_19 + $f5g7_38 + $f6g6_19 + $f7g5_38 + $f8g4_19 + $f9g3_38;
    $h3 = $f0g3 + $f1g2 + $f2g1 + $f3g0 + $f4g9_19 + $f5g8_19 + $f6g7_19 + $f7g6_19 + $f8g5_19 + $f9g4_19;
    $h4 = $f0g4 + $f1g3_2 + $f2g2 + $f3g1_2 + $f4g0 + $f5g9_38 + $f6g8_19 + $f7g7_38 + $f8g6_19 + $f9g5_38;
    $h5 = $f0g5 + $f1g4 + $f2g3 + $f3g2 + $f4g1 + $f5g0 + $f6g9_19 + $f7g8_19 + $f8g7_19 + $f9g6_19;
    $h6 = $f0g6 + $f1g5_2 + $f2g4 + $f3g3_2 + $f4g2 + $f5g1_2 + $f6g0 + $f7g9_38 + $f8g8_19 + $f9g7_38;
    $h7 = $f0g7 + $f1g6 + $f2g5 + $f3g4 + $f4g3 + $f5g2 + $f6g1 + $f7g0 + $f8g9_19 + $f9g8_19;
    $h8 = $f0g8 + $f1g7_2 + $f2g6 + $f3g5_2 + $f4g4 + $f5g3_2 + $f6g2 + $f7g1_2 + $f8g0 + $f9g9_38;
    $h9 = $f0g9 + $f1g8 + $f2g7 + $f3g6 + $f4g5 + $f5g4 + $f6g3 + $f7g2 + $f8g1 + $f9g0;

    /** @var int $carry0 */
    $carry0 = $h0 + (1 << 25) >> 26;
    $h1 += $carry0;
    $h0 -= $carry0 << 26;

    /** @var int $carry4 */
    $carry4 = $h4 + (1 << 25) >> 26;
    $h5 += $carry4;
    $h4 -= $carry4 << 26;

    /** @var int $carry1 */
    $carry1 = $h1 + (1 << 24) >> 25;
    $h2 += $carry1;
    $h1 -= $carry1 << 25;

    /** @var int $carry5 */
    $carry5 = $h5 + (1 << 24) >> 25;
    $h6 += $carry5;
    $h5 -= $carry5 << 25;

    /** @var int $carry2 */
    $carry2 = $h2 + (1 << 25) >> 26;
    $h3 += $carry2;
    $h2 -= $carry2 << 26;

    /** @var int $carry6 */
    $carry6 = $h6 + (1 << 25) >> 26;
    $h7 += $carry6;
    $h6 -= $carry6 << 26;

    /** @var int $carry3 */
    $carry3 = $h3 + (1 << 24) >> 25;
    $h4 += $carry3;
    $h3 -= $carry3 << 25;

    /** @var int $carry7 */
    $carry7 = $h7 + (1 << 24) >> 25;
    $h8 += $carry7;
    $h7 -= $carry7 << 25;

    /** @var int $carry4 */
    $carry4 = $h4 + (1 << 25) >> 26;
    $h5 += $carry4;
    $h4 -= $carry4 << 26;

    /** @var int $carry8 */
    $carry8 = $h8 + (1 << 25) >> 26;
    $h9 += $carry8;
    $h8 -= $carry8 << 26;

    /** @var int $carry9 */
    $carry9 = $h9 + (1 << 24) >> 25;
    $h0 += self::mul($carry9, 19, 5);
    $h9 -= $carry9 << 25;

    /** @var int $carry0 */
    $carry0 = $h0 + (1 << 25) >> 26;
    $h1 += $carry0;
    $h0 -= $carry0 << 26;
    return ParagonIE_Sodium_Core_Curve25519_Fe::fromArray(array(
      (int) $h0,
      (int) $h1,
      (int) $h2,
      (int) $h3,
      (int) $h4,
      (int) $h5,
      (int) $h6,
      (int) $h7,
      (int) $h8,
      (int) $h9,
    ));
  }

  /**
   * Get the negative values for each piece of the field element.
   *
   * h = -f
   *
   * @internal You should not use this directly from another application
   *
   * @param ParagonIE_Sodium_Core_Curve25519_Fe $f
   * @return ParagonIE_Sodium_Core_Curve25519_Fe
   * @psalm-suppress MixedAssignment
   */
  public static function fe_neg(ParagonIE_Sodium_Core_Curve25519_Fe $f) {
    $h = new ParagonIE_Sodium_Core_Curve25519_Fe();
    for ($i = 0; $i < 10; ++$i) {
      $h[$i] = -$f[$i];
    }
    return $h;
  }

  /**
   * Square a field element
   *
   * h = f * f
   *
   * @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_sq(ParagonIE_Sodium_Core_Curve25519_Fe $f) {
    $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];

    /** @var int $f0_2 */
    $f0_2 = $f0 << 1;

    /** @var int $f1_2 */
    $f1_2 = $f1 << 1;

    /** @var int $f2_2 */
    $f2_2 = $f2 << 1;

    /** @var int $f3_2 */
    $f3_2 = $f3 << 1;

    /** @var int $f4_2 */
    $f4_2 = $f4 << 1;

    /** @var int $f5_2 */
    $f5_2 = $f5 << 1;

    /** @var int $f6_2 */
    $f6_2 = $f6 << 1;

    /** @var int $f7_2 */
    $f7_2 = $f7 << 1;
    $f5_38 = self::mul($f5, 38, 6);
    $f6_19 = self::mul($f6, 19, 5);
    $f7_38 = self::mul($f7, 38, 6);
    $f8_19 = self::mul($f8, 19, 5);
    $f9_38 = self::mul($f9, 38, 6);
    $f0f0 = self::mul($f0, $f0, 25);
    $f0f1_2 = self::mul($f0_2, $f1, 24);
    $f0f2_2 = self::mul($f0_2, $f2, 25);
    $f0f3_2 = self::mul($f0_2, $f3, 24);
    $f0f4_2 = self::mul($f0_2, $f4, 25);
    $f0f5_2 = self::mul($f0_2, $f5, 25);
    $f0f6_2 = self::mul($f0_2, $f6, 25);
    $f0f7_2 = self::mul($f0_2, $f7, 24);
    $f0f8_2 = self::mul($f0_2, $f8, 25);
    $f0f9_2 = self::mul($f0_2, $f9, 25);
    $f1f1_2 = self::mul($f1_2, $f1, 24);
    $f1f2_2 = self::mul($f1_2, $f2, 25);
    $f1f3_4 = self::mul($f1_2, $f3_2, 25);
    $f1f4_2 = self::mul($f1_2, $f4, 25);
    $f1f5_4 = self::mul($f1_2, $f5_2, 26);
    $f1f6_2 = self::mul($f1_2, $f6, 25);
    $f1f7_4 = self::mul($f1_2, $f7_2, 25);
    $f1f8_2 = self::mul($f1_2, $f8, 25);
    $f1f9_76 = self::mul($f9_38, $f1_2, 25);
    $f2f2 = self::mul($f2, $f2, 25);
    $f2f3_2 = self::mul($f2_2, $f3, 24);
    $f2f4_2 = self::mul($f2_2, $f4, 25);
    $f2f5_2 = self::mul($f2_2, $f5, 25);
    $f2f6_2 = self::mul($f2_2, $f6, 25);
    $f2f7_2 = self::mul($f2_2, $f7, 24);
    $f2f8_38 = self::mul($f8_19, $f2_2, 26);
    $f2f9_38 = self::mul($f9_38, $f2, 25);
    $f3f3_2 = self::mul($f3_2, $f3, 24);
    $f3f4_2 = self::mul($f3_2, $f4, 25);
    $f3f5_4 = self::mul($f3_2, $f5_2, 26);
    $f3f6_2 = self::mul($f3_2, $f6, 25);
    $f3f7_76 = self::mul($f7_38, $f3_2, 25);
    $f3f8_38 = self::mul($f8_19, $f3_2, 25);
    $f3f9_76 = self::mul($f9_38, $f3_2, 25);
    $f4f4 = self::mul($f4, $f4, 25);
    $f4f5_2 = self::mul($f4_2, $f5, 25);
    $f4f6_38 = self::mul($f6_19, $f4_2, 26);
    $f4f7_38 = self::mul($f7_38, $f4, 25);
    $f4f8_38 = self::mul($f8_19, $f4_2, 26);
    $f4f9_38 = self::mul($f9_38, $f4, 25);
    $f5f5_38 = self::mul($f5_38, $f5, 25);
    $f5f6_38 = self::mul($f6_19, $f5_2, 26);
    $f5f7_76 = self::mul($f7_38, $f5_2, 26);
    $f5f8_38 = self::mul($f8_19, $f5_2, 26);
    $f5f9_76 = self::mul($f9_38, $f5_2, 26);
    $f6f6_19 = self::mul($f6_19, $f6, 25);
    $f6f7_38 = self::mul($f7_38, $f6, 25);
    $f6f8_38 = self::mul($f8_19, $f6_2, 26);
    $f6f9_38 = self::mul($f9_38, $f6, 25);
    $f7f7_38 = self::mul($f7_38, $f7, 24);
    $f7f8_38 = self::mul($f8_19, $f7_2, 25);
    $f7f9_76 = self::mul($f9_38, $f7_2, 25);
    $f8f8_19 = self::mul($f8_19, $f8, 25);
    $f8f9_38 = self::mul($f9_38, $f8, 25);
    $f9f9_38 = self::mul($f9_38, $f9, 25);
    $h0 = $f0f0 + $f1f9_76 + $f2f8_38 + $f3f7_76 + $f4f6_38 + $f5f5_38;
    $h1 = $f0f1_2 + $f2f9_38 + $f3f8_38 + $f4f7_38 + $f5f6_38;
    $h2 = $f0f2_2 + $f1f1_2 + $f3f9_76 + $f4f8_38 + $f5f7_76 + $f6f6_19;
    $h3 = $f0f3_2 + $f1f2_2 + $f4f9_38 + $f5f8_38 + $f6f7_38;
    $h4 = $f0f4_2 + $f1f3_4 + $f2f2 + $f5f9_76 + $f6f8_38 + $f7f7_38;
    $h5 = $f0f5_2 + $f1f4_2 + $f2f3_2 + $f6f9_38 + $f7f8_38;
    $h6 = $f0f6_2 + $f1f5_4 + $f2f4_2 + $f3f3_2 + $f7f9_76 + $f8f8_19;
    $h7 = $f0f7_2 + $f1f6_2 + $f2f5_2 + $f3f4_2 + $f8f9_38;
    $h8 = $f0f8_2 + $f1f7_4 + $f2f6_2 + $f3f5_4 + $f4f4 + $f9f9_38;
    $h9 = $f0f9_2 + $f1f8_2 + $f2f7_2 + $f3f6_2 + $f4f5_2;

    /** @var int $carry0 */
    $carry0 = $h0 + (1 << 25) >> 26;
    $h1 += $carry0;
    $h0 -= $carry0 << 26;

    /** @var int $carry4 */
    $carry4 = $h4 + (1 << 25) >> 26;
    $h5 += $carry4;
    $h4 -= $carry4 << 26;

    /** @var int $carry1 */
    $carry1 = $h1 + (1 << 24) >> 25;
    $h2 += $carry1;
    $h1 -= $carry1 << 25;

    /** @var int $carry5 */
    $carry5 = $h5 + (1 << 24) >> 25;
    $h6 += $carry5;
    $h5 -= $carry5 << 25;

    /** @var int $carry2 */
    $carry2 = $h2 + (1 << 25) >> 26;
    $h3 += $carry2;
    $h2 -= $carry2 << 26;

    /** @var int $carry6 */
    $carry6 = $h6 + (1 << 25) >> 26;
    $h7 += $carry6;
    $h6 -= $carry6 << 26;

    /** @var int $carry3 */
    $carry3 = $h3 + (1 << 24) >> 25;
    $h4 += $carry3;
    $h3 -= $carry3 << 25;

    /** @var int $carry7 */
    $carry7 = $h7 + (1 << 24) >> 25;
    $h8 += $carry7;
    $h7 -= $carry7 << 25;

    /** @var int $carry4 */
    $carry4 = $h4 + (1 << 25) >> 26;
    $h5 += $carry4;
    $h4 -= $carry4 << 26;

    /** @var int $carry8 */
    $carry8 = $h8 + (1 << 25) >> 26;
    $h9 += $carry8;
    $h8 -= $carry8 << 26;

    /** @var int $carry9 */
    $carry9 = $h9 + (1 << 24) >> 25;
    $h0 += self::mul($carry9, 19, 5);
    $h9 -= $carry9 << 25;

    /** @var int $carry0 */
    $carry0 = $h0 + (1 << 25) >> 26;
    $h1 += $carry0;
    $h0 -= $carry0 << 26;
    return ParagonIE_Sodium_Core_Curve25519_Fe::fromArray(array(
      (int) $h0,
      (int) $h1,
      (int) $h2,
      (int) $h3,
      (int) $h4,
      (int) $h5,
      (int) $h6,
      (int) $h7,
      (int) $h8,
      (int) $h9,
    ));
  }

  /**
   * Square and double a field element
   *
   * h = 2 * f * f
   *
   * @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_sq2(ParagonIE_Sodium_Core_Curve25519_Fe $f) {
    $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];

    /** @var int $f0_2 */
    $f0_2 = $f0 << 1;

    /** @var int $f1_2 */
    $f1_2 = $f1 << 1;

    /** @var int $f2_2 */
    $f2_2 = $f2 << 1;

    /** @var int $f3_2 */
    $f3_2 = $f3 << 1;

    /** @var int $f4_2 */
    $f4_2 = $f4 << 1;

    /** @var int $f5_2 */
    $f5_2 = $f5 << 1;

    /** @var int $f6_2 */
    $f6_2 = $f6 << 1;

    /** @var int $f7_2 */
    $f7_2 = $f7 << 1;
    $f5_38 = self::mul($f5, 38, 6);

    /* 1.959375*2^30 */
    $f6_19 = self::mul($f6, 19, 5);

    /* 1.959375*2^30 */
    $f7_38 = self::mul($f7, 38, 6);

    /* 1.959375*2^30 */
    $f8_19 = self::mul($f8, 19, 5);

    /* 1.959375*2^30 */
    $f9_38 = self::mul($f9, 38, 6);

    /* 1.959375*2^30 */
    $f0f0 = self::mul($f0, $f0, 24);
    $f0f1_2 = self::mul($f0_2, $f1, 24);
    $f0f2_2 = self::mul($f0_2, $f2, 24);
    $f0f3_2 = self::mul($f0_2, $f3, 24);
    $f0f4_2 = self::mul($f0_2, $f4, 24);
    $f0f5_2 = self::mul($f0_2, $f5, 24);
    $f0f6_2 = self::mul($f0_2, $f6, 24);
    $f0f7_2 = self::mul($f0_2, $f7, 24);
    $f0f8_2 = self::mul($f0_2, $f8, 24);
    $f0f9_2 = self::mul($f0_2, $f9, 24);
    $f1f1_2 = self::mul($f1_2, $f1, 24);
    $f1f2_2 = self::mul($f1_2, $f2, 24);
    $f1f3_4 = self::mul($f1_2, $f3_2, 24);
    $f1f4_2 = self::mul($f1_2, $f4, 24);
    $f1f5_4 = self::mul($f1_2, $f5_2, 24);
    $f1f6_2 = self::mul($f1_2, $f6, 24);
    $f1f7_4 = self::mul($f1_2, $f7_2, 24);
    $f1f8_2 = self::mul($f1_2, $f8, 24);
    $f1f9_76 = self::mul($f9_38, $f1_2, 24);
    $f2f2 = self::mul($f2, $f2, 24);
    $f2f3_2 = self::mul($f2_2, $f3, 24);
    $f2f4_2 = self::mul($f2_2, $f4, 24);
    $f2f5_2 = self::mul($f2_2, $f5, 24);
    $f2f6_2 = self::mul($f2_2, $f6, 24);
    $f2f7_2 = self::mul($f2_2, $f7, 24);
    $f2f8_38 = self::mul($f8_19, $f2_2, 25);
    $f2f9_38 = self::mul($f9_38, $f2, 24);
    $f3f3_2 = self::mul($f3_2, $f3, 24);
    $f3f4_2 = self::mul($f3_2, $f4, 24);
    $f3f5_4 = self::mul($f3_2, $f5_2, 24);
    $f3f6_2 = self::mul($f3_2, $f6, 24);
    $f3f7_76 = self::mul($f7_38, $f3_2, 24);
    $f3f8_38 = self::mul($f8_19, $f3_2, 24);
    $f3f9_76 = self::mul($f9_38, $f3_2, 24);
    $f4f4 = self::mul($f4, $f4, 24);
    $f4f5_2 = self::mul($f4_2, $f5, 24);
    $f4f6_38 = self::mul($f6_19, $f4_2, 25);
    $f4f7_38 = self::mul($f7_38, $f4, 24);
    $f4f8_38 = self::mul($f8_19, $f4_2, 25);
    $f4f9_38 = self::mul($f9_38, $f4, 24);
    $f5f5_38 = self::mul($f5_38, $f5, 24);
    $f5f6_38 = self::mul($f6_19, $f5_2, 24);
    $f5f7_76 = self::mul($f7_38, $f5_2, 24);
    $f5f8_38 = self::mul($f8_19, $f5_2, 24);
    $f5f9_76 = self::mul($f9_38, $f5_2, 24);
    $f6f6_19 = self::mul($f6_19, $f6, 24);
    $f6f7_38 = self::mul($f7_38, $f6, 24);
    $f6f8_38 = self::mul($f8_19, $f6_2, 25);
    $f6f9_38 = self::mul($f9_38, $f6, 24);
    $f7f7_38 = self::mul($f7_38, $f7, 24);
    $f7f8_38 = self::mul($f8_19, $f7_2, 24);
    $f7f9_76 = self::mul($f9_38, $f7_2, 24);
    $f8f8_19 = self::mul($f8_19, $f8, 24);
    $f8f9_38 = self::mul($f9_38, $f8, 24);
    $f9f9_38 = self::mul($f9_38, $f9, 24);

    /** @var int $h0 */
    $h0 = (int) ($f0f0 + $f1f9_76 + $f2f8_38 + $f3f7_76 + $f4f6_38 + $f5f5_38) << 1;

    /** @var int $h1 */
    $h1 = (int) ($f0f1_2 + $f2f9_38 + $f3f8_38 + $f4f7_38 + $f5f6_38) << 1;

    /** @var int $h2 */
    $h2 = (int) ($f0f2_2 + $f1f1_2 + $f3f9_76 + $f4f8_38 + $f5f7_76 + $f6f6_19) << 1;

    /** @var int $h3 */
    $h3 = (int) ($f0f3_2 + $f1f2_2 + $f4f9_38 + $f5f8_38 + $f6f7_38) << 1;

    /** @var int $h4 */
    $h4 = (int) ($f0f4_2 + $f1f3_4 + $f2f2 + $f5f9_76 + $f6f8_38 + $f7f7_38) << 1;

    /** @var int $h5 */
    $h5 = (int) ($f0f5_2 + $f1f4_2 + $f2f3_2 + $f6f9_38 + $f7f8_38) << 1;

    /** @var int $h6 */
    $h6 = (int) ($f0f6_2 + $f1f5_4 + $f2f4_2 + $f3f3_2 + $f7f9_76 + $f8f8_19) << 1;

    /** @var int $h7 */
    $h7 = (int) ($f0f7_2 + $f1f6_2 + $f2f5_2 + $f3f4_2 + $f8f9_38) << 1;

    /** @var int $h8 */
    $h8 = (int) ($f0f8_2 + $f1f7_4 + $f2f6_2 + $f3f5_4 + $f4f4 + $f9f9_38) << 1;

    /** @var int $h9 */
    $h9 = (int) ($f0f9_2 + $f1f8_2 + $f2f7_2 + $f3f6_2 + $f4f5_2) << 1;

    /** @var int $carry0 */
    $carry0 = $h0 + (1 << 25) >> 26;
    $h1 += $carry0;
    $h0 -= $carry0 << 26;

    /** @var int $carry4 */
    $carry4 = $h4 + (1 << 25) >> 26;
    $h5 += $carry4;
    $h4 -= $carry4 << 26;

    /** @var int $carry1 */
    $carry1 = $h1 + (1 << 24) >> 25;
    $h2 += $carry1;
    $h1 -= $carry1 << 25;

    /** @var int $carry5 */
    $carry5 = $h5 + (1 << 24) >> 25;
    $h6 += $carry5;
    $h5 -= $carry5 << 25;

    /** @var int $carry2 */
    $carry2 = $h2 + (1 << 25) >> 26;
    $h3 += $carry2;
    $h2 -= $carry2 << 26;

    /** @var int $carry6 */
    $carry6 = $h6 + (1 << 25) >> 26;
    $h7 += $carry6;
    $h6 -= $carry6 << 26;

    /** @var int $carry3 */
    $carry3 = $h3 + (1 << 24) >> 25;
    $h4 += $carry3;
    $h3 -= $carry3 << 25;

    /** @var int $carry7 */
    $carry7 = $h7 + (1 << 24) >> 25;
    $h8 += $carry7;
    $h7 -= $carry7 << 25;

    /** @var int $carry4 */
    $carry4 = $h4 + (1 << 25) >> 26;
    $h5 += $carry4;
    $h4 -= $carry4 << 26;

    /** @var int $carry8 */
    $carry8 = $h8 + (1 << 25) >> 26;
    $h9 += $carry8;
    $h8 -= $carry8 << 26;

    /** @var int $carry9 */
    $carry9 = $h9 + (1 << 24) >> 25;
    $h0 += self::mul($carry9, 19, 5);
    $h9 -= $carry9 << 25;

    /** @var int $carry0 */
    $carry0 = $h0 + (1 << 25) >> 26;
    $h1 += $carry0;
    $h0 -= $carry0 << 26;
    return ParagonIE_Sodium_Core_Curve25519_Fe::fromArray(array(
      (int) $h0,
      (int) $h1,
      (int) $h2,
      (int) $h3,
      (int) $h4,
      (int) $h5,
      (int) $h6,
      (int) $h7,
      (int) $h8,
      (int) $h9,
    ));
  }

  /**
   * @internal You should not use this directly from another application
   *
   * @param ParagonIE_Sodium_Core_Curve25519_Fe $Z
   * @return ParagonIE_Sodium_Core_Curve25519_Fe
   */
  public static function fe_invert(ParagonIE_Sodium_Core_Curve25519_Fe $Z) {
    $z = clone $Z;
    $t0 = self::fe_sq($z);
    $t1 = self::fe_sq($t0);
    $t1 = self::fe_sq($t1);
    $t1 = self::fe_mul($z, $t1);
    $t0 = self::fe_mul($t0, $t1);
    $t2 = self::fe_sq($t0);
    $t1 = self::fe_mul($t1, $t2);
    $t2 = self::fe_sq($t1);
    for ($i = 1; $i < 5; ++$i) {
      $t2 = self::fe_sq($t2);
    }
    $t1 = self::fe_mul($t2, $t1);
    $t2 = self::fe_sq($t1);
    for ($i = 1; $i < 10; ++$i) {
      $t2 = self::fe_sq($t2);
    }
    $t2 = self::fe_mul($t2, $t1);
    $t3 = self::fe_sq($t2);
    for ($i = 1; $i < 20; ++$i) {
      $t3 = self::fe_sq($t3);
    }
    $t2 = self::fe_mul($t3, $t2);
    $t2 = self::fe_sq($t2);
    for ($i = 1; $i < 10; ++$i) {
      $t2 = self::fe_sq($t2);
    }
    $t1 = self::fe_mul($t2, $t1);
    $t2 = self::fe_sq($t1);
    for ($i = 1; $i < 50; ++$i) {
      $t2 = self::fe_sq($t2);
    }
    $t2 = self::fe_mul($t2, $t1);
    $t3 = self::fe_sq($t2);
    for ($i = 1; $i < 100; ++$i) {
      $t3 = self::fe_sq($t3);
    }
    $t2 = self::fe_mul($t3, $t2);
    $t2 = self::fe_sq($t2);
    for ($i = 1; $i < 50; ++$i) {
      $t2 = self::fe_sq($t2);
    }
    $t1 = self::fe_mul($t2, $t1);
    $t1 = self::fe_sq($t1);
    for ($i = 1; $i < 5; ++$i) {
      $t1 = self::fe_sq($t1);
    }
    return self::fe_mul($t1, $t0);
  }

  /**
   * @internal You should not use this directly from another application
   *
   * @ref https://github.com/jedisct1/libsodium/blob/68564326e1e9dc57ef03746f85734232d20ca6fb/src/libsodium/crypto_core/curve25519/ref10/curve25519_ref10.c#L1054-L1106
   *
   * @param ParagonIE_Sodium_Core_Curve25519_Fe $z
   * @return ParagonIE_Sodium_Core_Curve25519_Fe
   */
  public static function fe_pow22523(ParagonIE_Sodium_Core_Curve25519_Fe $z) {

    # fe_sq(t0, z);

    # fe_sq(t1, t0);

    # fe_sq(t1, t1);

    # fe_mul(t1, z, t1);

    # fe_mul(t0, t0, t1);

    # fe_sq(t0, t0);

    # fe_mul(t0, t1, t0);

    # fe_sq(t1, t0);
    $t0 = self::fe_sq($z);
    $t1 = self::fe_sq($t0);
    $t1 = self::fe_sq($t1);
    $t1 = self::fe_mul($z, $t1);
    $t0 = self::fe_mul($t0, $t1);
    $t0 = self::fe_sq($t0);
    $t0 = self::fe_mul($t1, $t0);
    $t1 = self::fe_sq($t0);

    # for (i = 1; i < 5; ++i) {

    #     fe_sq(t1, t1);

    # }
    for ($i = 1; $i < 5; ++$i) {
      $t1 = self::fe_sq($t1);
    }

    # fe_mul(t0, t1, t0);

    # fe_sq(t1, t0);
    $t0 = self::fe_mul($t1, $t0);
    $t1 = self::fe_sq($t0);

    # for (i = 1; i < 10; ++i) {

    #     fe_sq(t1, t1);

    # }
    for ($i = 1; $i < 10; ++$i) {
      $t1 = self::fe_sq($t1);
    }

    # fe_mul(t1, t1, t0);

    # fe_sq(t2, t1);
    $t1 = self::fe_mul($t1, $t0);
    $t2 = self::fe_sq($t1);

    # for (i = 1; i < 20; ++i) {

    #     fe_sq(t2, t2);

    # }
    for ($i = 1; $i < 20; ++$i) {
      $t2 = self::fe_sq($t2);
    }

    # fe_mul(t1, t2, t1);

    # fe_sq(t1, t1);
    $t1 = self::fe_mul($t2, $t1);
    $t1 = self::fe_sq($t1);

    # for (i = 1; i < 10; ++i) {

    #     fe_sq(t1, t1);

    # }
    for ($i = 1; $i < 10; ++$i) {
      $t1 = self::fe_sq($t1);
    }

    # fe_mul(t0, t1, t0);

    # fe_sq(t1, t0);
    $t0 = self::fe_mul($t1, $t0);
    $t1 = self::fe_sq($t0);

    # for (i = 1; i < 50; ++i) {

    #     fe_sq(t1, t1);

    # }
    for ($i = 1; $i < 50; ++$i) {
      $t1 = self::fe_sq($t1);
    }

    # fe_mul(t1, t1, t0);

    # fe_sq(t2, t1);
    $t1 = self::fe_mul($t1, $t0);
    $t2 = self::fe_sq($t1);

    # for (i = 1; i < 100; ++i) {

    #     fe_sq(t2, t2);

    # }
    for ($i = 1; $i < 100; ++$i) {
      $t2 = self::fe_sq($t2);
    }

    # fe_mul(t1, t2, t1);

    # fe_sq(t1, t1);
    $t1 = self::fe_mul($t2, $t1);
    $t1 = self::fe_sq($t1);

    # for (i = 1; i < 50; ++i) {

    #     fe_sq(t1, t1);

    # }
    for ($i = 1; $i < 50; ++$i) {
      $t1 = self::fe_sq($t1);
    }

    # fe_mul(t0, t1, t0);

    # fe_sq(t0, t0);

    # fe_sq(t0, t0);

    # fe_mul(out, t0, z);
    $t0 = self::fe_mul($t1, $t0);
    $t0 = self::fe_sq($t0);
    $t0 = self::fe_sq($t0);
    return self::fe_mul($t0, $z);
  }

  /**
   * Subtract two field elements.
   *
   * h = f - g
   *
   * Preconditions:
   * |f| bounded by 1.1*2^25,1.1*2^24,1.1*2^25,1.1*2^24,etc.
   * |g| bounded by 1.1*2^25,1.1*2^24,1.1*2^25,1.1*2^24,etc.
   *
   * Postconditions:
   * |h| bounded by 1.1*2^26,1.1*2^25,1.1*2^26,1.1*2^25,etc.
   *
   * @internal You should not use this directly from another application
   *
   * @param ParagonIE_Sodium_Core_Curve25519_Fe $f
   * @param ParagonIE_Sodium_Core_Curve25519_Fe $g
   * @return ParagonIE_Sodium_Core_Curve25519_Fe
   * @psalm-suppress MixedOperand
   */
  public static function fe_sub(ParagonIE_Sodium_Core_Curve25519_Fe $f, ParagonIE_Sodium_Core_Curve25519_Fe $g) {
    return ParagonIE_Sodium_Core_Curve25519_Fe::fromArray(array(
      (int) ($f[0] - $g[0]),
      (int) ($f[1] - $g[1]),
      (int) ($f[2] - $g[2]),
      (int) ($f[3] - $g[3]),
      (int) ($f[4] - $g[4]),
      (int) ($f[5] - $g[5]),
      (int) ($f[6] - $g[6]),
      (int) ($f[7] - $g[7]),
      (int) ($f[8] - $g[8]),
      (int) ($f[9] - $g[9]),
    ));
  }

  /**
   * Add two group elements.
   *
   * r = p + q
   *
   * @internal You should not use this directly from another application
   *
   * @param ParagonIE_Sodium_Core_Curve25519_Ge_P3 $p
   * @param ParagonIE_Sodium_Core_Curve25519_Ge_Cached $q
   * @return ParagonIE_Sodium_Core_Curve25519_Ge_P1p1
   */
  public static function ge_add(ParagonIE_Sodium_Core_Curve25519_Ge_P3 $p, ParagonIE_Sodium_Core_Curve25519_Ge_Cached $q) {
    $r = new ParagonIE_Sodium_Core_Curve25519_Ge_P1p1();
    $r->X = self::fe_add($p->Y, $p->X);
    $r->Y = self::fe_sub($p->Y, $p->X);
    $r->Z = self::fe_mul($r->X, $q->YplusX);
    $r->Y = self::fe_mul($r->Y, $q->YminusX);
    $r->T = self::fe_mul($q->T2d, $p->T);
    $r->X = self::fe_mul($p->Z, $q->Z);
    $t0 = self::fe_add($r->X, $r->X);
    $r->X = self::fe_sub($r->Z, $r->Y);
    $r->Y = self::fe_add($r->Z, $r->Y);
    $r->Z = self::fe_add($t0, $r->T);
    $r->T = self::fe_sub($t0, $r->T);
    return $r;
  }

  /**
   * @internal You should not use this directly from another application
   *
   * @ref https://github.com/jedisct1/libsodium/blob/157c4a80c13b117608aeae12178b2d38825f9f8f/src/libsodium/crypto_core/curve25519/ref10/curve25519_ref10.c#L1185-L1215
   * @param string $a
   * @return array<int, mixed>
   * @throws SodiumException
   * @throws TypeError
   */
  public static function slide($a) {
    if (self::strlen($a) < 256) {
      if (self::strlen($a) < 16) {
        $a = str_pad($a, 256, '0', STR_PAD_RIGHT);
      }
    }

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

    /** @var int $i */
    for ($i = 0; $i < 256; ++$i) {
      $r[$i] = (int) (1 & self::chrToInt($a[(int) ($i >> 3)]) >> ($i & 7));
    }
    for ($i = 0; $i < 256; ++$i) {
      if ($r[$i]) {
        for ($b = 1; $b <= 6 && $i + $b < 256; ++$b) {
          if ($r[$i + $b]) {
            if ($r[$i] + ($r[$i + $b] << $b) <= 15) {
              $r[$i] += $r[$i + $b] << $b;
              $r[$i + $b] = 0;
            }
            elseif ($r[$i] - ($r[$i + $b] << $b) >= -15) {
              $r[$i] -= $r[$i + $b] << $b;
              for ($k = $i + $b; $k < 256; ++$k) {
                if (!$r[$k]) {
                  $r[$k] = 1;
                  break;
                }
                $r[$k] = 0;
              }
            }
            else {
              break;
            }
          }
        }
      }
    }
    return $r;
  }

  /**
   * @internal You should not use this directly from another application
   *
   * @param string $s
   * @return ParagonIE_Sodium_Core_Curve25519_Ge_P3
   * @throws SodiumException
   * @throws TypeError
   */
  public static function ge_frombytes_negate_vartime($s) {
    static $d = null;
    if (!$d) {
      $d = ParagonIE_Sodium_Core_Curve25519_Fe::fromArray(self::$d);
    }

    # fe_frombytes(h->Y,s);

    # fe_1(h->Z);
    $h = new ParagonIE_Sodium_Core_Curve25519_Ge_P3(self::fe_0(), self::fe_frombytes($s), self::fe_1());

    # fe_sq(u,h->Y);

    # fe_mul(v,u,d);

    # fe_sub(u,u,h->Z);       /* u = y^2-1 */

    # fe_add(v,v,h->Z);       /* v = dy^2+1 */
    $u = self::fe_sq($h->Y);

    /** @var ParagonIE_Sodium_Core_Curve25519_Fe $d */
    $v = self::fe_mul($u, $d);
    $u = self::fe_sub($u, $h->Z);

    /* u =  y^2 - 1 */
    $v = self::fe_add($v, $h->Z);

    /* v = dy^2 + 1 */

    # fe_sq(v3,v);

    # fe_mul(v3,v3,v);        /* v3 = v^3 */

    # fe_sq(h->X,v3);

    # fe_mul(h->X,h->X,v);

    # fe_mul(h->X,h->X,u);    /* x = uv^7 */
    $v3 = self::fe_sq($v);
    $v3 = self::fe_mul($v3, $v);

    /* v3 = v^3 */
    $h->X = self::fe_sq($v3);
    $h->X = self::fe_mul($h->X, $v);
    $h->X = self::fe_mul($h->X, $u);

    /* x = uv^7 */

    # fe_pow22523(h->X,h->X); /* x = (uv^7)^((q-5)/8) */

    # fe_mul(h->X,h->X,v3);

    # fe_mul(h->X,h->X,u);    /* x = uv^3(uv^7)^((q-5)/8) */
    $h->X = self::fe_pow22523($h->X);

    /* x = (uv^7)^((q-5)/8) */
    $h->X = self::fe_mul($h->X, $v3);
    $h->X = self::fe_mul($h->X, $u);

    /* x = uv^3(uv^7)^((q-5)/8) */

    # fe_sq(vxx,h->X);

    # fe_mul(vxx,vxx,v);

    # fe_sub(check,vxx,u);    /* vx^2-u */
    $vxx = self::fe_sq($h->X);
    $vxx = self::fe_mul($vxx, $v);
    $check = self::fe_sub($vxx, $u);

    /* vx^2 - u */

    # if (fe_isnonzero(check)) {

    #     fe_add(check,vxx,u);  /* vx^2+u */

    #     if (fe_isnonzero(check)) {

    #         return -1;

    #     }

    #     fe_mul(h->X,h->X,sqrtm1);

    # }
    if (self::fe_isnonzero($check)) {
      $check = self::fe_add($vxx, $u);

      /* vx^2 + u */
      if (self::fe_isnonzero($check)) {
        throw new RangeException('Internal check failed.');
      }
      $h->X = self::fe_mul($h->X, ParagonIE_Sodium_Core_Curve25519_Fe::fromArray(self::$sqrtm1));
    }

    # if (fe_isnegative(h->X) == (s[31] >> 7)) {

    #     fe_neg(h->X,h->X);

    # }
    $i = self::chrToInt($s[31]);
    if (self::fe_isnegative($h->X) === $i >> 7) {
      $h->X = self::fe_neg($h->X);
    }

    # fe_mul(h->T,h->X,h->Y);
    $h->T = self::fe_mul($h->X, $h->Y);
    return $h;
  }

  /**
   * @internal You should not use this directly from another application
   *
   * @param ParagonIE_Sodium_Core_Curve25519_Ge_P1p1 $R
   * @param ParagonIE_Sodium_Core_Curve25519_Ge_P3 $p
   * @param ParagonIE_Sodium_Core_Curve25519_Ge_Precomp $q
   * @return ParagonIE_Sodium_Core_Curve25519_Ge_P1p1
   */
  public static function ge_madd(ParagonIE_Sodium_Core_Curve25519_Ge_P1p1 $R, ParagonIE_Sodium_Core_Curve25519_Ge_P3 $p, ParagonIE_Sodium_Core_Curve25519_Ge_Precomp $q) {
    $r = clone $R;
    $r->X = self::fe_add($p->Y, $p->X);
    $r->Y = self::fe_sub($p->Y, $p->X);
    $r->Z = self::fe_mul($r->X, $q->yplusx);
    $r->Y = self::fe_mul($r->Y, $q->yminusx);
    $r->T = self::fe_mul($q->xy2d, $p->T);
    $t0 = self::fe_add(clone $p->Z, clone $p->Z);
    $r->X = self::fe_sub($r->Z, $r->Y);
    $r->Y = self::fe_add($r->Z, $r->Y);
    $r->Z = self::fe_add($t0, $r->T);
    $r->T = self::fe_sub($t0, $r->T);
    return $r;
  }

  /**
   * @internal You should not use this directly from another application
   *
   * @param ParagonIE_Sodium_Core_Curve25519_Ge_P1p1 $R
   * @param ParagonIE_Sodium_Core_Curve25519_Ge_P3 $p
   * @param ParagonIE_Sodium_Core_Curve25519_Ge_Precomp $q
   * @return ParagonIE_Sodium_Core_Curve25519_Ge_P1p1
   */
  public static function ge_msub(ParagonIE_Sodium_Core_Curve25519_Ge_P1p1 $R, ParagonIE_Sodium_Core_Curve25519_Ge_P3 $p, ParagonIE_Sodium_Core_Curve25519_Ge_Precomp $q) {
    $r = clone $R;
    $r->X = self::fe_add($p->Y, $p->X);
    $r->Y = self::fe_sub($p->Y, $p->X);
    $r->Z = self::fe_mul($r->X, $q->yminusx);
    $r->Y = self::fe_mul($r->Y, $q->yplusx);
    $r->T = self::fe_mul($q->xy2d, $p->T);
    $t0 = self::fe_add($p->Z, $p->Z);
    $r->X = self::fe_sub($r->Z, $r->Y);
    $r->Y = self::fe_add($r->Z, $r->Y);
    $r->Z = self::fe_sub($t0, $r->T);
    $r->T = self::fe_add($t0, $r->T);
    return $r;
  }

  /**
   * @internal You should not use this directly from another application
   *
   * @param ParagonIE_Sodium_Core_Curve25519_Ge_P1p1 $p
   * @return ParagonIE_Sodium_Core_Curve25519_Ge_P2
   */
  public static function ge_p1p1_to_p2(ParagonIE_Sodium_Core_Curve25519_Ge_P1p1 $p) {
    $r = new ParagonIE_Sodium_Core_Curve25519_Ge_P2();
    $r->X = self::fe_mul($p->X, $p->T);
    $r->Y = self::fe_mul($p->Y, $p->Z);
    $r->Z = self::fe_mul($p->Z, $p->T);
    return $r;
  }

  /**
   * @internal You should not use this directly from another application
   *
   * @param ParagonIE_Sodium_Core_Curve25519_Ge_P1p1 $p
   * @return ParagonIE_Sodium_Core_Curve25519_Ge_P3
   */
  public static function ge_p1p1_to_p3(ParagonIE_Sodium_Core_Curve25519_Ge_P1p1 $p) {
    $r = new ParagonIE_Sodium_Core_Curve25519_Ge_P3();
    $r->X = self::fe_mul($p->X, $p->T);
    $r->Y = self::fe_mul($p->Y, $p->Z);
    $r->Z = self::fe_mul($p->Z, $p->T);
    $r->T = self::fe_mul($p->X, $p->Y);
    return $r;
  }

  /**
   * @internal You should not use this directly from another application
   *
   * @return ParagonIE_Sodium_Core_Curve25519_Ge_P2
   */
  public static function ge_p2_0() {
    return new ParagonIE_Sodium_Core_Curve25519_Ge_P2(self::fe_0(), self::fe_1(), self::fe_1());
  }

  /**
   * @internal You should not use this directly from another application
   *
   * @param ParagonIE_Sodium_Core_Curve25519_Ge_P2 $p
   * @return ParagonIE_Sodium_Core_Curve25519_Ge_P1p1
   */
  public static function ge_p2_dbl(ParagonIE_Sodium_Core_Curve25519_Ge_P2 $p) {
    $r = new ParagonIE_Sodium_Core_Curve25519_Ge_P1p1();
    $r->X = self::fe_sq($p->X);
    $r->Z = self::fe_sq($p->Y);
    $r->T = self::fe_sq2($p->Z);
    $r->Y = self::fe_add($p->X, $p->Y);
    $t0 = self::fe_sq($r->Y);
    $r->Y = self::fe_add($r->Z, $r->X);
    $r->Z = self::fe_sub($r->Z, $r->X);
    $r->X = self::fe_sub($t0, $r->Y);
    $r->T = self::fe_sub($r->T, $r->Z);
    return $r;
  }

  /**
   * @internal You should not use this directly from another application
   *
   * @return ParagonIE_Sodium_Core_Curve25519_Ge_P3
   */
  public static function ge_p3_0() {
    return new ParagonIE_Sodium_Core_Curve25519_Ge_P3(self::fe_0(), self::fe_1(), self::fe_1(), self::fe_0());
  }

  /**
   * @internal You should not use this directly from another application
   *
   * @param ParagonIE_Sodium_Core_Curve25519_Ge_P3 $p
   * @return ParagonIE_Sodium_Core_Curve25519_Ge_Cached
   */
  public static function ge_p3_to_cached(ParagonIE_Sodium_Core_Curve25519_Ge_P3 $p) {
    static $d2 = null;
    if ($d2 === null) {
      $d2 = ParagonIE_Sodium_Core_Curve25519_Fe::fromArray(self::$d2);
    }

    /** @var ParagonIE_Sodium_Core_Curve25519_Fe $d2 */
    $r = new ParagonIE_Sodium_Core_Curve25519_Ge_Cached();
    $r->YplusX = self::fe_add($p->Y, $p->X);
    $r->YminusX = self::fe_sub($p->Y, $p->X);
    $r->Z = self::fe_copy($p->Z);
    $r->T2d = self::fe_mul($p->T, $d2);
    return $r;
  }

  /**
   * @internal You should not use this directly from another application
   *
   * @param ParagonIE_Sodium_Core_Curve25519_Ge_P3 $p
   * @return ParagonIE_Sodium_Core_Curve25519_Ge_P2
   */
  public static function ge_p3_to_p2(ParagonIE_Sodium_Core_Curve25519_Ge_P3 $p) {
    return new ParagonIE_Sodium_Core_Curve25519_Ge_P2($p->X, $p->Y, $p->Z);
  }

  /**
   * @internal You should not use this directly from another application
   *
   * @param ParagonIE_Sodium_Core_Curve25519_Ge_P3 $h
   * @return string
   * @throws SodiumException
   * @throws TypeError
   */
  public static function ge_p3_tobytes(ParagonIE_Sodium_Core_Curve25519_Ge_P3 $h) {
    $recip = self::fe_invert($h->Z);
    $x = self::fe_mul($h->X, $recip);
    $y = self::fe_mul($h->Y, $recip);
    $s = self::fe_tobytes($y);
    $s[31] = self::intToChr(self::chrToInt($s[31]) ^ self::fe_isnegative($x) << 7);
    return $s;
  }

  /**
   * @internal You should not use this directly from another application
   *
   * @param ParagonIE_Sodium_Core_Curve25519_Ge_P3 $p
   * @return ParagonIE_Sodium_Core_Curve25519_Ge_P1p1
   */
  public static function ge_p3_dbl(ParagonIE_Sodium_Core_Curve25519_Ge_P3 $p) {
    $q = self::ge_p3_to_p2($p);
    return self::ge_p2_dbl($q);
  }

  /**
   * @return ParagonIE_Sodium_Core_Curve25519_Ge_Precomp
   */
  public static function ge_precomp_0() {
    return new ParagonIE_Sodium_Core_Curve25519_Ge_Precomp(self::fe_1(), self::fe_1(), self::fe_0());
  }

  /**
   * @internal You should not use this directly from another application
   *
   * @param int $b
   * @param int $c
   * @return int
   */
  public static function equal($b, $c) {
    return (int) ((($b ^ $c) - 1 & 0xffffffff) >> 31);
  }

  /**
   * @internal You should not use this directly from another application
   *
   * @param int|string $char
   * @return int (1 = yes, 0 = no)
   * @throws SodiumException
   * @throws TypeError
   */
  public static function negative($char) {
    if (is_int($char)) {
      return $char < 0 ? 1 : 0;
    }
    $x = self::chrToInt(self::substr($char, 0, 1));
    return (int) ($x >> 63);
  }

  /**
   * Conditional move
   *
   * @internal You should not use this directly from another application
   *
   * @param ParagonIE_Sodium_Core_Curve25519_Ge_Precomp $t
   * @param ParagonIE_Sodium_Core_Curve25519_Ge_Precomp $u
   * @param int $b
   * @return ParagonIE_Sodium_Core_Curve25519_Ge_Precomp
   */
  public static function cmov(ParagonIE_Sodium_Core_Curve25519_Ge_Precomp $t, ParagonIE_Sodium_Core_Curve25519_Ge_Precomp $u, $b) {
    if (!is_int($b)) {
      throw new InvalidArgumentException('Expected an integer.');
    }
    return new ParagonIE_Sodium_Core_Curve25519_Ge_Precomp(self::fe_cmov($t->yplusx, $u->yplusx, $b), self::fe_cmov($t->yminusx, $u->yminusx, $b), self::fe_cmov($t->xy2d, $u->xy2d, $b));
  }

  /**
   * @internal You should not use this directly from another application
   *
   * @param int $pos
   * @param int $b
   * @return ParagonIE_Sodium_Core_Curve25519_Ge_Precomp
   * @throws SodiumException
   * @throws TypeError
   * @psalm-suppress MixedArgument
   * @psalm-suppress MixedArrayAccess
   * @psalm-suppress MixedArrayOffset
   */
  public static function ge_select($pos = 0, $b = 0) {
    static $base = null;
    if ($base === null) {
      $base = array();

      /** @var int $i */
      foreach (self::$base as $i => $bas) {
        for ($j = 0; $j < 8; ++$j) {
          $base[$i][$j] = new ParagonIE_Sodium_Core_Curve25519_Ge_Precomp(ParagonIE_Sodium_Core_Curve25519_Fe::fromArray($bas[$j][0]), ParagonIE_Sodium_Core_Curve25519_Fe::fromArray($bas[$j][1]), ParagonIE_Sodium_Core_Curve25519_Fe::fromArray($bas[$j][2]));
        }
      }
    }

    /** @var array<int, array<int, ParagonIE_Sodium_Core_Curve25519_Ge_Precomp>> $base */
    if (!is_int($pos)) {
      throw new InvalidArgumentException('Position must be an integer');
    }
    if ($pos < 0 || $pos > 31) {
      throw new RangeException('Position is out of range [0, 31]');
    }

    /** @var int $bnegative */
    $bnegative = self::negative($b);

    /** @var int $babs */
    $babs = $b - ((-$bnegative & $b) << 1);
    $t = self::ge_precomp_0();
    for ($i = 0; $i < 8; ++$i) {
      $t = self::cmov($t, $base[$pos][$i], self::equal($babs, $i + 1));
    }
    $minusT = new ParagonIE_Sodium_Core_Curve25519_Ge_Precomp(self::fe_copy($t->yminusx), self::fe_copy($t->yplusx), self::fe_neg($t->xy2d));
    return self::cmov($t, $minusT, $bnegative);
  }

  /**
   * Subtract two group elements.
   *
   * r = p - q
   *
   * @internal You should not use this directly from another application
   *
   * @param ParagonIE_Sodium_Core_Curve25519_Ge_P3 $p
   * @param ParagonIE_Sodium_Core_Curve25519_Ge_Cached $q
   * @return ParagonIE_Sodium_Core_Curve25519_Ge_P1p1
   */
  public static function ge_sub(ParagonIE_Sodium_Core_Curve25519_Ge_P3 $p, ParagonIE_Sodium_Core_Curve25519_Ge_Cached $q) {
    $r = new ParagonIE_Sodium_Core_Curve25519_Ge_P1p1();
    $r->X = self::fe_add($p->Y, $p->X);
    $r->Y = self::fe_sub($p->Y, $p->X);
    $r->Z = self::fe_mul($r->X, $q->YminusX);
    $r->Y = self::fe_mul($r->Y, $q->YplusX);
    $r->T = self::fe_mul($q->T2d, $p->T);
    $r->X = self::fe_mul($p->Z, $q->Z);
    $t0 = self::fe_add($r->X, $r->X);
    $r->X = self::fe_sub($r->Z, $r->Y);
    $r->Y = self::fe_add($r->Z, $r->Y);
    $r->Z = self::fe_sub($t0, $r->T);
    $r->T = self::fe_add($t0, $r->T);
    return $r;
  }

  /**
   * Convert a group element to a byte string.
   *
   * @param ParagonIE_Sodium_Core_Curve25519_Ge_P2 $h
   * @return string
   * @throws SodiumException
   * @throws TypeError
   */
  public static function ge_tobytes(ParagonIE_Sodium_Core_Curve25519_Ge_P2 $h) {
    $recip = self::fe_invert($h->Z);
    $x = self::fe_mul($h->X, $recip);
    $y = self::fe_mul($h->Y, $recip);
    $s = self::fe_tobytes($y);
    $s[31] = self::intToChr(self::chrToInt($s[31]) ^ self::fe_isnegative($x) << 7);
    return $s;
  }

  /**
   * @internal You should not use this directly from another application
   *
   * @param string $a
   * @param ParagonIE_Sodium_Core_Curve25519_Ge_P3 $A
   * @param string $b
   * @return ParagonIE_Sodium_Core_Curve25519_Ge_P2
   * @throws SodiumException
   * @throws TypeError
   * @psalm-suppress MixedArgument
   * @psalm-suppress MixedArrayAccess
   */
  public static function ge_double_scalarmult_vartime($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;
  }

  /**
   * @internal You should not use this directly from another application
   *
   * @param string $a
   * @return ParagonIE_Sodium_Core_Curve25519_Ge_P3
   * @throws SodiumException
   * @throws TypeError
   * @psalm-suppress MixedAssignment
   * @psalm-suppress MixedOperand
   */
  public static function ge_scalarmult_base($a) {

    /** @var array<int, int> $e */
    $e = array();
    $r = new ParagonIE_Sodium_Core_Curve25519_Ge_P1p1();
    for ($i = 0; $i < 32; ++$i) {

      /** @var int $dbl */
      $dbl = (int) $i << 1;
      $e[$dbl] = (int) self::chrToInt($a[$i]) & 15;
      $e[$dbl + 1] = (int) (self::chrToInt($a[$i]) >> 4) & 15;
    }

    /** @var int $carry */
    $carry = 0;
    for ($i = 0; $i < 63; ++$i) {
      $e[$i] += $carry;

      /** @var int $carry */
      $carry = $e[$i] + 8;

      /** @var int $carry */
      $carry >>= 4;
      $e[$i] -= $carry << 4;
    }

    /** @var array<int, int> $e */
    $e[63] += (int) $carry;
    $h = self::ge_p3_0();
    for ($i = 1; $i < 64; $i += 2) {
      $t = self::ge_select((int) floor($i / 2), (int) $e[$i]);
      $r = self::ge_madd($r, $h, $t);
      $h = self::ge_p1p1_to_p3($r);
    }
    $r = self::ge_p3_dbl($h);
    $s = self::ge_p1p1_to_p2($r);
    $r = self::ge_p2_dbl($s);
    $s = self::ge_p1p1_to_p2($r);
    $r = self::ge_p2_dbl($s);
    $s = self::ge_p1p1_to_p2($r);
    $r = self::ge_p2_dbl($s);
    $h = self::ge_p1p1_to_p3($r);
    for ($i = 0; $i < 64; $i += 2) {
      $t = self::ge_select($i >> 1, (int) $e[$i]);
      $r = self::ge_madd($r, $h, $t);
      $h = self::ge_p1p1_to_p3($r);
    }
    return $h;
  }

  /**
   * Calculates (ab + c) mod l
   * where l = 2^252 + 27742317777372353535851937790883648493
   *
   * @internal You should not use this directly from another application
   *
   * @param string $a
   * @param string $b
   * @param string $c
   * @return string
   * @throws TypeError
   */
  public static function sc_muladd($a, $b, $c) {

    /** @var int $a0 */
    $a0 = 2097151 & self::load_3(self::substr($a, 0, 3));

    /** @var int $a1 */
    $a1 = 2097151 & self::load_4(self::substr($a, 2, 4)) >> 5;

    /** @var int $a2 */
    $a2 = 2097151 & self::load_3(self::substr($a, 5, 3)) >> 2;

    /** @var int $a3 */
    $a3 = 2097151 & self::load_4(self::substr($a, 7, 4)) >> 7;

    /** @var int $a4 */
    $a4 = 2097151 & self::load_4(self::substr($a, 10, 4)) >> 4;

    /** @var int $a5 */
    $a5 = 2097151 & self::load_3(self::substr($a, 13, 3)) >> 1;

    /** @var int $a6 */
    $a6 = 2097151 & self::load_4(self::substr($a, 15, 4)) >> 6;

    /** @var int $a7 */
    $a7 = 2097151 & self::load_3(self::substr($a, 18, 3)) >> 3;

    /** @var int $a8 */
    $a8 = 2097151 & self::load_3(self::substr($a, 21, 3));

    /** @var int $a9 */
    $a9 = 2097151 & self::load_4(self::substr($a, 23, 4)) >> 5;

    /** @var int $a10 */
    $a10 = 2097151 & self::load_3(self::substr($a, 26, 3)) >> 2;

    /** @var int $a11 */
    $a11 = self::load_4(self::substr($a, 28, 4)) >> 7;

    /** @var int $b0 */
    $b0 = 2097151 & self::load_3(self::substr($b, 0, 3));

    /** @var int $b1 */
    $b1 = 2097151 & self::load_4(self::substr($b, 2, 4)) >> 5;

    /** @var int $b2 */
    $b2 = 2097151 & self::load_3(self::substr($b, 5, 3)) >> 2;

    /** @var int $b3 */
    $b3 = 2097151 & self::load_4(self::substr($b, 7, 4)) >> 7;

    /** @var int $b4 */
    $b4 = 2097151 & self::load_4(self::substr($b, 10, 4)) >> 4;

    /** @var int $b5 */
    $b5 = 2097151 & self::load_3(self::substr($b, 13, 3)) >> 1;

    /** @var int $b6 */
    $b6 = 2097151 & self::load_4(self::substr($b, 15, 4)) >> 6;

    /** @var int $b7 */
    $b7 = 2097151 & self::load_3(self::substr($b, 18, 3)) >> 3;

    /** @var int $b8 */
    $b8 = 2097151 & self::load_3(self::substr($b, 21, 3));

    /** @var int $b9 */
    $b9 = 2097151 & self::load_4(self::substr($b, 23, 4)) >> 5;

    /** @var int $b10 */
    $b10 = 2097151 & self::load_3(self::substr($b, 26, 3)) >> 2;

    /** @var int $b11 */
    $b11 = self::load_4(self::substr($b, 28, 4)) >> 7;

    /** @var int $c0 */
    $c0 = 2097151 & self::load_3(self::substr($c, 0, 3));

    /** @var int $c1 */
    $c1 = 2097151 & self::load_4(self::substr($c, 2, 4)) >> 5;

    /** @var int $c2 */
    $c2 = 2097151 & self::load_3(self::substr($c, 5, 3)) >> 2;

    /** @var int $c3 */
    $c3 = 2097151 & self::load_4(self::substr($c, 7, 4)) >> 7;

    /** @var int $c4 */
    $c4 = 2097151 & self::load_4(self::substr($c, 10, 4)) >> 4;

    /** @var int $c5 */
    $c5 = 2097151 & self::load_3(self::substr($c, 13, 3)) >> 1;

    /** @var int $c6 */
    $c6 = 2097151 & self::load_4(self::substr($c, 15, 4)) >> 6;

    /** @var int $c7 */
    $c7 = 2097151 & self::load_3(self::substr($c, 18, 3)) >> 3;

    /** @var int $c8 */
    $c8 = 2097151 & self::load_3(self::substr($c, 21, 3));

    /** @var int $c9 */
    $c9 = 2097151 & self::load_4(self::substr($c, 23, 4)) >> 5;

    /** @var int $c10 */
    $c10 = 2097151 & self::load_3(self::substr($c, 26, 3)) >> 2;

    /** @var int $c11 */
    $c11 = self::load_4(self::substr($c, 28, 4)) >> 7;

    /* Can't really avoid the pyramid here: */
    $s0 = $c0 + self::mul($a0, $b0, 24);
    $s1 = $c1 + self::mul($a0, $b1, 24) + self::mul($a1, $b0, 24);
    $s2 = $c2 + self::mul($a0, $b2, 24) + self::mul($a1, $b1, 24) + self::mul($a2, $b0, 24);
    $s3 = $c3 + self::mul($a0, $b3, 24) + self::mul($a1, $b2, 24) + self::mul($a2, $b1, 24) + self::mul($a3, $b0, 24);
    $s4 = $c4 + self::mul($a0, $b4, 24) + self::mul($a1, $b3, 24) + self::mul($a2, $b2, 24) + self::mul($a3, $b1, 24) + self::mul($a4, $b0, 24);
    $s5 = $c5 + self::mul($a0, $b5, 24) + self::mul($a1, $b4, 24) + self::mul($a2, $b3, 24) + self::mul($a3, $b2, 24) + self::mul($a4, $b1, 24) + self::mul($a5, $b0, 24);
    $s6 = $c6 + self::mul($a0, $b6, 24) + self::mul($a1, $b5, 24) + self::mul($a2, $b4, 24) + self::mul($a3, $b3, 24) + self::mul($a4, $b2, 24) + self::mul($a5, $b1, 24) + self::mul($a6, $b0, 24);
    $s7 = $c7 + self::mul($a0, $b7, 24) + self::mul($a1, $b6, 24) + self::mul($a2, $b5, 24) + self::mul($a3, $b4, 24) + self::mul($a4, $b3, 24) + self::mul($a5, $b2, 24) + self::mul($a6, $b1, 24) + self::mul($a7, $b0, 24);
    $s8 = $c8 + self::mul($a0, $b8, 24) + self::mul($a1, $b7, 24) + self::mul($a2, $b6, 24) + self::mul($a3, $b5, 24) + self::mul($a4, $b4, 24) + self::mul($a5, $b3, 24) + self::mul($a6, $b2, 24) + self::mul($a7, $b1, 24) + self::mul($a8, $b0, 24);
    $s9 = $c9 + self::mul($a0, $b9, 24) + self::mul($a1, $b8, 24) + self::mul($a2, $b7, 24) + self::mul($a3, $b6, 24) + self::mul($a4, $b5, 24) + self::mul($a5, $b4, 24) + self::mul($a6, $b3, 24) + self::mul($a7, $b2, 24) + self::mul($a8, $b1, 24) + self::mul($a9, $b0, 24);
    $s10 = $c10 + self::mul($a0, $b10, 24) + self::mul($a1, $b9, 24) + self::mul($a2, $b8, 24) + self::mul($a3, $b7, 24) + self::mul($a4, $b6, 24) + self::mul($a5, $b5, 24) + self::mul($a6, $b4, 24) + self::mul($a7, $b3, 24) + self::mul($a8, $b2, 24) + self::mul($a9, $b1, 24) + self::mul($a10, $b0, 24);
    $s11 = $c11 + self::mul($a0, $b11, 24) + self::mul($a1, $b10, 24) + self::mul($a2, $b9, 24) + self::mul($a3, $b8, 24) + self::mul($a4, $b7, 24) + self::mul($a5, $b6, 24) + self::mul($a6, $b5, 24) + self::mul($a7, $b4, 24) + self::mul($a8, $b3, 24) + self::mul($a9, $b2, 24) + self::mul($a10, $b1, 24) + self::mul($a11, $b0, 24);
    $s12 = self::mul($a1, $b11, 24) + self::mul($a2, $b10, 24) + self::mul($a3, $b9, 24) + self::mul($a4, $b8, 24) + self::mul($a5, $b7, 24) + self::mul($a6, $b6, 24) + self::mul($a7, $b5, 24) + self::mul($a8, $b4, 24) + self::mul($a9, $b3, 24) + self::mul($a10, $b2, 24) + self::mul($a11, $b1, 24);
    $s13 = self::mul($a2, $b11, 24) + self::mul($a3, $b10, 24) + self::mul($a4, $b9, 24) + self::mul($a5, $b8, 24) + self::mul($a6, $b7, 24) + self::mul($a7, $b6, 24) + self::mul($a8, $b5, 24) + self::mul($a9, $b4, 24) + self::mul($a10, $b3, 24) + self::mul($a11, $b2, 24);
    $s14 = self::mul($a3, $b11, 24) + self::mul($a4, $b10, 24) + self::mul($a5, $b9, 24) + self::mul($a6, $b8, 24) + self::mul($a7, $b7, 24) + self::mul($a8, $b6, 24) + self::mul($a9, $b5, 24) + self::mul($a10, $b4, 24) + self::mul($a11, $b3, 24);
    $s15 = self::mul($a4, $b11, 24) + self::mul($a5, $b10, 24) + self::mul($a6, $b9, 24) + self::mul($a7, $b8, 24) + self::mul($a8, $b7, 24) + self::mul($a9, $b6, 24) + self::mul($a10, $b5, 24) + self::mul($a11, $b4, 24);
    $s16 = self::mul($a5, $b11, 24) + self::mul($a6, $b10, 24) + self::mul($a7, $b9, 24) + self::mul($a8, $b8, 24) + self::mul($a9, $b7, 24) + self::mul($a10, $b6, 24) + self::mul($a11, $b5, 24);
    $s17 = self::mul($a6, $b11, 24) + self::mul($a7, $b10, 24) + self::mul($a8, $b9, 24) + self::mul($a9, $b8, 24) + self::mul($a10, $b7, 24) + self::mul($a11, $b6, 24);
    $s18 = self::mul($a7, $b11, 24) + self::mul($a8, $b10, 24) + self::mul($a9, $b9, 24) + self::mul($a10, $b8, 24) + self::mul($a11, $b7, 24);
    $s19 = self::mul($a8, $b11, 24) + self::mul($a9, $b10, 24) + self::mul($a10, $b9, 24) + self::mul($a11, $b8, 24);
    $s20 = self::mul($a9, $b11, 24) + self::mul($a10, $b10, 24) + self::mul($a11, $b9, 24);
    $s21 = self::mul($a10, $b11, 24) + self::mul($a11, $b10, 24);
    $s22 = self::mul($a11, $b11, 24);
    $s23 = 0;

    /** @var int $carry0 */
    $carry0 = $s0 + (1 << 20) >> 21;
    $s1 += $carry0;
    $s0 -= $carry0 << 21;

    /** @var int $carry2 */
    $carry2 = $s2 + (1 << 20) >> 21;
    $s3 += $carry2;
    $s2 -= $carry2 << 21;

    /** @var int $carry4 */
    $carry4 = $s4 + (1 << 20) >> 21;
    $s5 += $carry4;
    $s4 -= $carry4 << 21;

    /** @var int $carry6 */
    $carry6 = $s6 + (1 << 20) >> 21;
    $s7 += $carry6;
    $s6 -= $carry6 << 21;

    /** @var int $carry8 */
    $carry8 = $s8 + (1 << 20) >> 21;
    $s9 += $carry8;
    $s8 -= $carry8 << 21;

    /** @var int $carry10 */
    $carry10 = $s10 + (1 << 20) >> 21;
    $s11 += $carry10;
    $s10 -= $carry10 << 21;

    /** @var int $carry12 */
    $carry12 = $s12 + (1 << 20) >> 21;
    $s13 += $carry12;
    $s12 -= $carry12 << 21;

    /** @var int $carry14 */
    $carry14 = $s14 + (1 << 20) >> 21;
    $s15 += $carry14;
    $s14 -= $carry14 << 21;

    /** @var int $carry16 */
    $carry16 = $s16 + (1 << 20) >> 21;
    $s17 += $carry16;
    $s16 -= $carry16 << 21;

    /** @var int $carry18 */
    $carry18 = $s18 + (1 << 20) >> 21;
    $s19 += $carry18;
    $s18 -= $carry18 << 21;

    /** @var int $carry20 */
    $carry20 = $s20 + (1 << 20) >> 21;
    $s21 += $carry20;
    $s20 -= $carry20 << 21;

    /** @var int $carry22 */
    $carry22 = $s22 + (1 << 20) >> 21;
    $s23 += $carry22;
    $s22 -= $carry22 << 21;

    /** @var int $carry1 */
    $carry1 = $s1 + (1 << 20) >> 21;
    $s2 += $carry1;
    $s1 -= $carry1 << 21;

    /** @var int $carry3 */
    $carry3 = $s3 + (1 << 20) >> 21;
    $s4 += $carry3;
    $s3 -= $carry3 << 21;

    /** @var int $carry5 */
    $carry5 = $s5 + (1 << 20) >> 21;
    $s6 += $carry5;
    $s5 -= $carry5 << 21;

    /** @var int $carry7 */
    $carry7 = $s7 + (1 << 20) >> 21;
    $s8 += $carry7;
    $s7 -= $carry7 << 21;

    /** @var int $carry9 */
    $carry9 = $s9 + (1 << 20) >> 21;
    $s10 += $carry9;
    $s9 -= $carry9 << 21;

    /** @var int $carry11 */
    $carry11 = $s11 + (1 << 20) >> 21;
    $s12 += $carry11;
    $s11 -= $carry11 << 21;

    /** @var int $carry13 */
    $carry13 = $s13 + (1 << 20) >> 21;
    $s14 += $carry13;
    $s13 -= $carry13 << 21;

    /** @var int $carry15 */
    $carry15 = $s15 + (1 << 20) >> 21;
    $s16 += $carry15;
    $s15 -= $carry15 << 21;

    /** @var int $carry17 */
    $carry17 = $s17 + (1 << 20) >> 21;
    $s18 += $carry17;
    $s17 -= $carry17 << 21;

    /** @var int $carry19 */
    $carry19 = $s19 + (1 << 20) >> 21;
    $s20 += $carry19;
    $s19 -= $carry19 << 21;

    /** @var int $carry21 */
    $carry21 = $s21 + (1 << 20) >> 21;
    $s22 += $carry21;
    $s21 -= $carry21 << 21;
    $s11 += self::mul($s23, 666643, 20);
    $s12 += self::mul($s23, 470296, 19);
    $s13 += self::mul($s23, 654183, 20);
    $s14 -= self::mul($s23, 997805, 20);
    $s15 += self::mul($s23, 136657, 18);
    $s16 -= self::mul($s23, 683901, 20);
    $s10 += self::mul($s22, 666643, 20);
    $s11 += self::mul($s22, 470296, 19);
    $s12 += self::mul($s22, 654183, 20);
    $s13 -= self::mul($s22, 997805, 20);
    $s14 += self::mul($s22, 136657, 18);
    $s15 -= self::mul($s22, 683901, 20);
    $s9 += self::mul($s21, 666643, 20);
    $s10 += self::mul($s21, 470296, 19);
    $s11 += self::mul($s21, 654183, 20);
    $s12 -= self::mul($s21, 997805, 20);
    $s13 += self::mul($s21, 136657, 18);
    $s14 -= self::mul($s21, 683901, 20);
    $s8 += self::mul($s20, 666643, 20);
    $s9 += self::mul($s20, 470296, 19);
    $s10 += self::mul($s20, 654183, 20);
    $s11 -= self::mul($s20, 997805, 20);
    $s12 += self::mul($s20, 136657, 18);
    $s13 -= self::mul($s20, 683901, 20);
    $s7 += self::mul($s19, 666643, 20);
    $s8 += self::mul($s19, 470296, 19);
    $s9 += self::mul($s19, 654183, 20);
    $s10 -= self::mul($s19, 997805, 20);
    $s11 += self::mul($s19, 136657, 18);
    $s12 -= self::mul($s19, 683901, 20);
    $s6 += self::mul($s18, 666643, 20);
    $s7 += self::mul($s18, 470296, 19);
    $s8 += self::mul($s18, 654183, 20);
    $s9 -= self::mul($s18, 997805, 20);
    $s10 += self::mul($s18, 136657, 18);
    $s11 -= self::mul($s18, 683901, 20);

    /** @var int $carry6 */
    $carry6 = $s6 + (1 << 20) >> 21;
    $s7 += $carry6;
    $s6 -= $carry6 << 21;

    /** @var int $carry8 */
    $carry8 = $s8 + (1 << 20) >> 21;
    $s9 += $carry8;
    $s8 -= $carry8 << 21;

    /** @var int $carry10 */
    $carry10 = $s10 + (1 << 20) >> 21;
    $s11 += $carry10;
    $s10 -= $carry10 << 21;

    /** @var int $carry12 */
    $carry12 = $s12 + (1 << 20) >> 21;
    $s13 += $carry12;
    $s12 -= $carry12 << 21;

    /** @var int $carry14 */
    $carry14 = $s14 + (1 << 20) >> 21;
    $s15 += $carry14;
    $s14 -= $carry14 << 21;

    /** @var int $carry16 */
    $carry16 = $s16 + (1 << 20) >> 21;
    $s17 += $carry16;
    $s16 -= $carry16 << 21;

    /** @var int $carry7 */
    $carry7 = $s7 + (1 << 20) >> 21;
    $s8 += $carry7;
    $s7 -= $carry7 << 21;

    /** @var int $carry9 */
    $carry9 = $s9 + (1 << 20) >> 21;
    $s10 += $carry9;
    $s9 -= $carry9 << 21;

    /** @var int $carry11 */
    $carry11 = $s11 + (1 << 20) >> 21;
    $s12 += $carry11;
    $s11 -= $carry11 << 21;

    /** @var int $carry13 */
    $carry13 = $s13 + (1 << 20) >> 21;
    $s14 += $carry13;
    $s13 -= $carry13 << 21;

    /** @var int $carry15 */
    $carry15 = $s15 + (1 << 20) >> 21;
    $s16 += $carry15;
    $s15 -= $carry15 << 21;
    $s5 += self::mul($s17, 666643, 20);
    $s6 += self::mul($s17, 470296, 19);
    $s7 += self::mul($s17, 654183, 20);
    $s8 -= self::mul($s17, 997805, 20);
    $s9 += self::mul($s17, 136657, 18);
    $s10 -= self::mul($s17, 683901, 20);
    $s4 += self::mul($s16, 666643, 20);
    $s5 += self::mul($s16, 470296, 19);
    $s6 += self::mul($s16, 654183, 20);
    $s7 -= self::mul($s16, 997805, 20);
    $s8 += self::mul($s16, 136657, 18);
    $s9 -= self::mul($s16, 683901, 20);
    $s3 += self::mul($s15, 666643, 20);
    $s4 += self::mul($s15, 470296, 19);
    $s5 += self::mul($s15, 654183, 20);
    $s6 -= self::mul($s15, 997805, 20);
    $s7 += self::mul($s15, 136657, 18);
    $s8 -= self::mul($s15, 683901, 20);
    $s2 += self::mul($s14, 666643, 20);
    $s3 += self::mul($s14, 470296, 19);
    $s4 += self::mul($s14, 654183, 20);
    $s5 -= self::mul($s14, 997805, 20);
    $s6 += self::mul($s14, 136657, 18);
    $s7 -= self::mul($s14, 683901, 20);
    $s1 += self::mul($s13, 666643, 20);
    $s2 += self::mul($s13, 470296, 19);
    $s3 += self::mul($s13, 654183, 20);
    $s4 -= self::mul($s13, 997805, 20);
    $s5 += self::mul($s13, 136657, 18);
    $s6 -= self::mul($s13, 683901, 20);
    $s0 += self::mul($s12, 666643, 20);
    $s1 += self::mul($s12, 470296, 19);
    $s2 += self::mul($s12, 654183, 20);
    $s3 -= self::mul($s12, 997805, 20);
    $s4 += self::mul($s12, 136657, 18);
    $s5 -= self::mul($s12, 683901, 20);
    $s12 = 0;

    /** @var int $carry0 */
    $carry0 = $s0 + (1 << 20) >> 21;
    $s1 += $carry0;
    $s0 -= $carry0 << 21;

    /** @var int $carry2 */
    $carry2 = $s2 + (1 << 20) >> 21;
    $s3 += $carry2;
    $s2 -= $carry2 << 21;

    /** @var int $carry4 */
    $carry4 = $s4 + (1 << 20) >> 21;
    $s5 += $carry4;
    $s4 -= $carry4 << 21;

    /** @var int $carry6 */
    $carry6 = $s6 + (1 << 20) >> 21;
    $s7 += $carry6;
    $s6 -= $carry6 << 21;

    /** @var int $carry8 */
    $carry8 = $s8 + (1 << 20) >> 21;
    $s9 += $carry8;
    $s8 -= $carry8 << 21;

    /** @var int $carry10 */
    $carry10 = $s10 + (1 << 20) >> 21;
    $s11 += $carry10;
    $s10 -= $carry10 << 21;

    /** @var int $carry1 */
    $carry1 = $s1 + (1 << 20) >> 21;
    $s2 += $carry1;
    $s1 -= $carry1 << 21;

    /** @var int $carry3 */
    $carry3 = $s3 + (1 << 20) >> 21;
    $s4 += $carry3;
    $s3 -= $carry3 << 21;

    /** @var int $carry5 */
    $carry5 = $s5 + (1 << 20) >> 21;
    $s6 += $carry5;
    $s5 -= $carry5 << 21;

    /** @var int $carry7 */
    $carry7 = $s7 + (1 << 20) >> 21;
    $s8 += $carry7;
    $s7 -= $carry7 << 21;

    /** @var int $carry9 */
    $carry9 = $s9 + (1 << 20) >> 21;
    $s10 += $carry9;
    $s9 -= $carry9 << 21;

    /** @var int $carry11 */
    $carry11 = $s11 + (1 << 20) >> 21;
    $s12 += $carry11;
    $s11 -= $carry11 << 21;
    $s0 += self::mul($s12, 666643, 20);
    $s1 += self::mul($s12, 470296, 19);
    $s2 += self::mul($s12, 654183, 20);
    $s3 -= self::mul($s12, 997805, 20);
    $s4 += self::mul($s12, 136657, 18);
    $s5 -= self::mul($s12, 683901, 20);
    $s12 = 0;

    /** @var int $carry0 */
    $carry0 = $s0 >> 21;
    $s1 += $carry0;
    $s0 -= $carry0 << 21;

    /** @var int $carry1 */
    $carry1 = $s1 >> 21;
    $s2 += $carry1;
    $s1 -= $carry1 << 21;

    /** @var int $carry2 */
    $carry2 = $s2 >> 21;
    $s3 += $carry2;
    $s2 -= $carry2 << 21;

    /** @var int $carry3 */
    $carry3 = $s3 >> 21;
    $s4 += $carry3;
    $s3 -= $carry3 << 21;

    /** @var int $carry4 */
    $carry4 = $s4 >> 21;
    $s5 += $carry4;
    $s4 -= $carry4 << 21;

    /** @var int $carry5 */
    $carry5 = $s5 >> 21;
    $s6 += $carry5;
    $s5 -= $carry5 << 21;

    /** @var int $carry6 */
    $carry6 = $s6 >> 21;
    $s7 += $carry6;
    $s6 -= $carry6 << 21;

    /** @var int $carry7 */
    $carry7 = $s7 >> 21;
    $s8 += $carry7;
    $s7 -= $carry7 << 21;

    /** @var int $carry8 */
    $carry8 = $s8 >> 21;
    $s9 += $carry8;
    $s8 -= $carry8 << 21;

    /** @var int $carry9 */
    $carry9 = $s9 >> 21;
    $s10 += $carry9;
    $s9 -= $carry9 << 21;

    /** @var int $carry10 */
    $carry10 = $s10 >> 21;
    $s11 += $carry10;
    $s10 -= $carry10 << 21;

    /** @var int $carry11 */
    $carry11 = $s11 >> 21;
    $s12 += $carry11;
    $s11 -= $carry11 << 21;
    $s0 += self::mul($s12, 666643, 20);
    $s1 += self::mul($s12, 470296, 19);
    $s2 += self::mul($s12, 654183, 20);
    $s3 -= self::mul($s12, 997805, 20);
    $s4 += self::mul($s12, 136657, 18);
    $s5 -= self::mul($s12, 683901, 20);

    /** @var int $carry0 */
    $carry0 = $s0 >> 21;
    $s1 += $carry0;
    $s0 -= $carry0 << 21;

    /** @var int $carry1 */
    $carry1 = $s1 >> 21;
    $s2 += $carry1;
    $s1 -= $carry1 << 21;

    /** @var int $carry2 */
    $carry2 = $s2 >> 21;
    $s3 += $carry2;
    $s2 -= $carry2 << 21;

    /** @var int $carry3 */
    $carry3 = $s3 >> 21;
    $s4 += $carry3;
    $s3 -= $carry3 << 21;

    /** @var int $carry4 */
    $carry4 = $s4 >> 21;
    $s5 += $carry4;
    $s4 -= $carry4 << 21;

    /** @var int $carry5 */
    $carry5 = $s5 >> 21;
    $s6 += $carry5;
    $s5 -= $carry5 << 21;

    /** @var int $carry6 */
    $carry6 = $s6 >> 21;
    $s7 += $carry6;
    $s6 -= $carry6 << 21;

    /** @var int $carry7 */
    $carry7 = $s7 >> 21;
    $s8 += $carry7;
    $s7 -= $carry7 << 21;

    /** @var int $carry8 */
    $carry8 = $s8 >> 21;
    $s9 += $carry8;
    $s8 -= $carry8 << 21;

    /** @var int $carry9 */
    $carry9 = $s9 >> 21;
    $s10 += $carry9;
    $s9 -= $carry9 << 21;

    /** @var int $carry10 */
    $carry10 = $s10 >> 21;
    $s11 += $carry10;
    $s10 -= $carry10 << 21;

    /**
     * @var array<int, int>
     */
    $arr = array(
      (int) (0xff & $s0 >> 0),
      (int) (0xff & $s0 >> 8),
      (int) (0xff & ($s0 >> 16 | $s1 << 5)),
      (int) (0xff & $s1 >> 3),
      (int) (0xff & $s1 >> 11),
      (int) (0xff & ($s1 >> 19 | $s2 << 2)),
      (int) (0xff & $s2 >> 6),
      (int) (0xff & ($s2 >> 14 | $s3 << 7)),
      (int) (0xff & $s3 >> 1),
      (int) (0xff & $s3 >> 9),
      (int) (0xff & ($s3 >> 17 | $s4 << 4)),
      (int) (0xff & $s4 >> 4),
      (int) (0xff & $s4 >> 12),
      (int) (0xff & ($s4 >> 20 | $s5 << 1)),
      (int) (0xff & $s5 >> 7),
      (int) (0xff & ($s5 >> 15 | $s6 << 6)),
      (int) (0xff & $s6 >> 2),
      (int) (0xff & $s6 >> 10),
      (int) (0xff & ($s6 >> 18 | $s7 << 3)),
      (int) (0xff & $s7 >> 5),
      (int) (0xff & $s7 >> 13),
      (int) (0xff & $s8 >> 0),
      (int) (0xff & $s8 >> 8),
      (int) (0xff & ($s8 >> 16 | $s9 << 5)),
      (int) (0xff & $s9 >> 3),
      (int) (0xff & $s9 >> 11),
      (int) (0xff & ($s9 >> 19 | $s10 << 2)),
      (int) (0xff & $s10 >> 6),
      (int) (0xff & ($s10 >> 14 | $s11 << 7)),
      (int) (0xff & $s11 >> 1),
      (int) (0xff & $s11 >> 9),
      0xff & $s11 >> 17,
    );
    return self::intArrayToString($arr);
  }

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

    /** @var int $s0 */
    $s0 = 2097151 & self::load_3(self::substr($s, 0, 3));

    /** @var int $s1 */
    $s1 = 2097151 & self::load_4(self::substr($s, 2, 4)) >> 5;

    /** @var int $s2 */
    $s2 = 2097151 & self::load_3(self::substr($s, 5, 3)) >> 2;

    /** @var int $s3 */
    $s3 = 2097151 & self::load_4(self::substr($s, 7, 4)) >> 7;

    /** @var int $s4 */
    $s4 = 2097151 & self::load_4(self::substr($s, 10, 4)) >> 4;

    /** @var int $s5 */
    $s5 = 2097151 & self::load_3(self::substr($s, 13, 3)) >> 1;

    /** @var int $s6 */
    $s6 = 2097151 & self::load_4(self::substr($s, 15, 4)) >> 6;

    /** @var int $s7 */
    $s7 = 2097151 & self::load_3(self::substr($s, 18, 4)) >> 3;

    /** @var int $s8 */
    $s8 = 2097151 & self::load_3(self::substr($s, 21, 3));

    /** @var int $s9 */
    $s9 = 2097151 & self::load_4(self::substr($s, 23, 4)) >> 5;

    /** @var int $s10 */
    $s10 = 2097151 & self::load_3(self::substr($s, 26, 3)) >> 2;

    /** @var int $s11 */
    $s11 = 2097151 & self::load_4(self::substr($s, 28, 4)) >> 7;

    /** @var int $s12 */
    $s12 = 2097151 & self::load_4(self::substr($s, 31, 4)) >> 4;

    /** @var int $s13 */
    $s13 = 2097151 & self::load_3(self::substr($s, 34, 3)) >> 1;

    /** @var int $s14 */
    $s14 = 2097151 & self::load_4(self::substr($s, 36, 4)) >> 6;

    /** @var int $s15 */
    $s15 = 2097151 & self::load_3(self::substr($s, 39, 4)) >> 3;

    /** @var int $s16 */
    $s16 = 2097151 & self::load_3(self::substr($s, 42, 3));

    /** @var int $s17 */
    $s17 = 2097151 & self::load_4(self::substr($s, 44, 4)) >> 5;

    /** @var int $s18 */
    $s18 = 2097151 & self::load_3(self::substr($s, 47, 3)) >> 2;

    /** @var int $s19 */
    $s19 = 2097151 & self::load_4(self::substr($s, 49, 4)) >> 7;

    /** @var int $s20 */
    $s20 = 2097151 & self::load_4(self::substr($s, 52, 4)) >> 4;

    /** @var int $s21 */
    $s21 = 2097151 & self::load_3(self::substr($s, 55, 3)) >> 1;

    /** @var int $s22 */
    $s22 = 2097151 & self::load_4(self::substr($s, 57, 4)) >> 6;

    /** @var int $s23 */
    $s23 = self::load_4(self::substr($s, 60, 4)) >> 3;
    $s11 += self::mul($s23, 666643, 20);
    $s12 += self::mul($s23, 470296, 19);
    $s13 += self::mul($s23, 654183, 20);
    $s14 -= self::mul($s23, 997805, 20);
    $s15 += self::mul($s23, 136657, 18);
    $s16 -= self::mul($s23, 683901, 20);
    $s10 += self::mul($s22, 666643, 20);
    $s11 += self::mul($s22, 470296, 19);
    $s12 += self::mul($s22, 654183, 20);
    $s13 -= self::mul($s22, 997805, 20);
    $s14 += self::mul($s22, 136657, 18);
    $s15 -= self::mul($s22, 683901, 20);
    $s9 += self::mul($s21, 666643, 20);
    $s10 += self::mul($s21, 470296, 19);
    $s11 += self::mul($s21, 654183, 20);
    $s12 -= self::mul($s21, 997805, 20);
    $s13 += self::mul($s21, 136657, 18);
    $s14 -= self::mul($s21, 683901, 20);
    $s8 += self::mul($s20, 666643, 20);
    $s9 += self::mul($s20, 470296, 19);
    $s10 += self::mul($s20, 654183, 20);
    $s11 -= self::mul($s20, 997805, 20);
    $s12 += self::mul($s20, 136657, 18);
    $s13 -= self::mul($s20, 683901, 20);
    $s7 += self::mul($s19, 666643, 20);
    $s8 += self::mul($s19, 470296, 19);
    $s9 += self::mul($s19, 654183, 20);
    $s10 -= self::mul($s19, 997805, 20);
    $s11 += self::mul($s19, 136657, 18);
    $s12 -= self::mul($s19, 683901, 20);
    $s6 += self::mul($s18, 666643, 20);
    $s7 += self::mul($s18, 470296, 19);
    $s8 += self::mul($s18, 654183, 20);
    $s9 -= self::mul($s18, 997805, 20);
    $s10 += self::mul($s18, 136657, 18);
    $s11 -= self::mul($s18, 683901, 20);

    /** @var int $carry6 */
    $carry6 = $s6 + (1 << 20) >> 21;
    $s7 += $carry6;
    $s6 -= $carry6 << 21;

    /** @var int $carry8 */
    $carry8 = $s8 + (1 << 20) >> 21;
    $s9 += $carry8;
    $s8 -= $carry8 << 21;

    /** @var int $carry10 */
    $carry10 = $s10 + (1 << 20) >> 21;
    $s11 += $carry10;
    $s10 -= $carry10 << 21;

    /** @var int $carry12 */
    $carry12 = $s12 + (1 << 20) >> 21;
    $s13 += $carry12;
    $s12 -= $carry12 << 21;

    /** @var int $carry14 */
    $carry14 = $s14 + (1 << 20) >> 21;
    $s15 += $carry14;
    $s14 -= $carry14 << 21;

    /** @var int $carry16 */
    $carry16 = $s16 + (1 << 20) >> 21;
    $s17 += $carry16;
    $s16 -= $carry16 << 21;

    /** @var int $carry7 */
    $carry7 = $s7 + (1 << 20) >> 21;
    $s8 += $carry7;
    $s7 -= $carry7 << 21;

    /** @var int $carry9 */
    $carry9 = $s9 + (1 << 20) >> 21;
    $s10 += $carry9;
    $s9 -= $carry9 << 21;

    /** @var int $carry11 */
    $carry11 = $s11 + (1 << 20) >> 21;
    $s12 += $carry11;
    $s11 -= $carry11 << 21;

    /** @var int $carry13 */
    $carry13 = $s13 + (1 << 20) >> 21;
    $s14 += $carry13;
    $s13 -= $carry13 << 21;

    /** @var int $carry15 */
    $carry15 = $s15 + (1 << 20) >> 21;
    $s16 += $carry15;
    $s15 -= $carry15 << 21;
    $s5 += self::mul($s17, 666643, 20);
    $s6 += self::mul($s17, 470296, 19);
    $s7 += self::mul($s17, 654183, 20);
    $s8 -= self::mul($s17, 997805, 20);
    $s9 += self::mul($s17, 136657, 18);
    $s10 -= self::mul($s17, 683901, 20);
    $s4 += self::mul($s16, 666643, 20);
    $s5 += self::mul($s16, 470296, 19);
    $s6 += self::mul($s16, 654183, 20);
    $s7 -= self::mul($s16, 997805, 20);
    $s8 += self::mul($s16, 136657, 18);
    $s9 -= self::mul($s16, 683901, 20);
    $s3 += self::mul($s15, 666643, 20);
    $s4 += self::mul($s15, 470296, 19);
    $s5 += self::mul($s15, 654183, 20);
    $s6 -= self::mul($s15, 997805, 20);
    $s7 += self::mul($s15, 136657, 18);
    $s8 -= self::mul($s15, 683901, 20);
    $s2 += self::mul($s14, 666643, 20);
    $s3 += self::mul($s14, 470296, 19);
    $s4 += self::mul($s14, 654183, 20);
    $s5 -= self::mul($s14, 997805, 20);
    $s6 += self::mul($s14, 136657, 18);
    $s7 -= self::mul($s14, 683901, 20);
    $s1 += self::mul($s13, 666643, 20);
    $s2 += self::mul($s13, 470296, 19);
    $s3 += self::mul($s13, 654183, 20);
    $s4 -= self::mul($s13, 997805, 20);
    $s5 += self::mul($s13, 136657, 18);
    $s6 -= self::mul($s13, 683901, 20);
    $s0 += self::mul($s12, 666643, 20);
    $s1 += self::mul($s12, 470296, 19);
    $s2 += self::mul($s12, 654183, 20);
    $s3 -= self::mul($s12, 997805, 20);
    $s4 += self::mul($s12, 136657, 18);
    $s5 -= self::mul($s12, 683901, 20);
    $s12 = 0;

    /** @var int $carry0 */
    $carry0 = $s0 + (1 << 20) >> 21;
    $s1 += $carry0;
    $s0 -= $carry0 << 21;

    /** @var int $carry2 */
    $carry2 = $s2 + (1 << 20) >> 21;
    $s3 += $carry2;
    $s2 -= $carry2 << 21;

    /** @var int $carry4 */
    $carry4 = $s4 + (1 << 20) >> 21;
    $s5 += $carry4;
    $s4 -= $carry4 << 21;

    /** @var int $carry6 */
    $carry6 = $s6 + (1 << 20) >> 21;
    $s7 += $carry6;
    $s6 -= $carry6 << 21;

    /** @var int $carry8 */
    $carry8 = $s8 + (1 << 20) >> 21;
    $s9 += $carry8;
    $s8 -= $carry8 << 21;

    /** @var int $carry10 */
    $carry10 = $s10 + (1 << 20) >> 21;
    $s11 += $carry10;
    $s10 -= $carry10 << 21;

    /** @var int $carry1 */
    $carry1 = $s1 + (1 << 20) >> 21;
    $s2 += $carry1;
    $s1 -= $carry1 << 21;

    /** @var int $carry3 */
    $carry3 = $s3 + (1 << 20) >> 21;
    $s4 += $carry3;
    $s3 -= $carry3 << 21;

    /** @var int $carry5 */
    $carry5 = $s5 + (1 << 20) >> 21;
    $s6 += $carry5;
    $s5 -= $carry5 << 21;

    /** @var int $carry7 */
    $carry7 = $s7 + (1 << 20) >> 21;
    $s8 += $carry7;
    $s7 -= $carry7 << 21;

    /** @var int $carry9 */
    $carry9 = $s9 + (1 << 20) >> 21;
    $s10 += $carry9;
    $s9 -= $carry9 << 21;

    /** @var int $carry11 */
    $carry11 = $s11 + (1 << 20) >> 21;
    $s12 += $carry11;
    $s11 -= $carry11 << 21;
    $s0 += self::mul($s12, 666643, 20);
    $s1 += self::mul($s12, 470296, 19);
    $s2 += self::mul($s12, 654183, 20);
    $s3 -= self::mul($s12, 997805, 20);
    $s4 += self::mul($s12, 136657, 18);
    $s5 -= self::mul($s12, 683901, 20);
    $s12 = 0;

    /** @var int $carry0 */
    $carry0 = $s0 >> 21;
    $s1 += $carry0;
    $s0 -= $carry0 << 21;

    /** @var int $carry1 */
    $carry1 = $s1 >> 21;
    $s2 += $carry1;
    $s1 -= $carry1 << 21;

    /** @var int $carry2 */
    $carry2 = $s2 >> 21;
    $s3 += $carry2;
    $s2 -= $carry2 << 21;

    /** @var int $carry3 */
    $carry3 = $s3 >> 21;
    $s4 += $carry3;
    $s3 -= $carry3 << 21;

    /** @var int $carry4 */
    $carry4 = $s4 >> 21;
    $s5 += $carry4;
    $s4 -= $carry4 << 21;

    /** @var int $carry5 */
    $carry5 = $s5 >> 21;
    $s6 += $carry5;
    $s5 -= $carry5 << 21;

    /** @var int $carry6 */
    $carry6 = $s6 >> 21;
    $s7 += $carry6;
    $s6 -= $carry6 << 21;

    /** @var int $carry7 */
    $carry7 = $s7 >> 21;
    $s8 += $carry7;
    $s7 -= $carry7 << 21;

    /** @var int $carry8 */
    $carry8 = $s8 >> 21;
    $s9 += $carry8;
    $s8 -= $carry8 << 21;

    /** @var int $carry9 */
    $carry9 = $s9 >> 21;
    $s10 += $carry9;
    $s9 -= $carry9 << 21;

    /** @var int $carry10 */
    $carry10 = $s10 >> 21;
    $s11 += $carry10;
    $s10 -= $carry10 << 21;

    /** @var int $carry11 */
    $carry11 = $s11 >> 21;
    $s12 += $carry11;
    $s11 -= $carry11 << 21;
    $s0 += self::mul($s12, 666643, 20);
    $s1 += self::mul($s12, 470296, 19);
    $s2 += self::mul($s12, 654183, 20);
    $s3 -= self::mul($s12, 997805, 20);
    $s4 += self::mul($s12, 136657, 18);
    $s5 -= self::mul($s12, 683901, 20);

    /** @var int $carry0 */
    $carry0 = $s0 >> 21;
    $s1 += $carry0;
    $s0 -= $carry0 << 21;

    /** @var int $carry1 */
    $carry1 = $s1 >> 21;
    $s2 += $carry1;
    $s1 -= $carry1 << 21;

    /** @var int $carry2 */
    $carry2 = $s2 >> 21;
    $s3 += $carry2;
    $s2 -= $carry2 << 21;

    /** @var int $carry3 */
    $carry3 = $s3 >> 21;
    $s4 += $carry3;
    $s3 -= $carry3 << 21;

    /** @var int $carry4 */
    $carry4 = $s4 >> 21;
    $s5 += $carry4;
    $s4 -= $carry4 << 21;

    /** @var int $carry5 */
    $carry5 = $s5 >> 21;
    $s6 += $carry5;
    $s5 -= $carry5 << 21;

    /** @var int $carry6 */
    $carry6 = $s6 >> 21;
    $s7 += $carry6;
    $s6 -= $carry6 << 21;

    /** @var int $carry7 */
    $carry7 = $s7 >> 21;
    $s8 += $carry7;
    $s7 -= $carry7 << 21;

    /** @var int $carry8 */
    $carry8 = $s8 >> 21;
    $s9 += $carry8;
    $s8 -= $carry8 << 21;

    /** @var int $carry9 */
    $carry9 = $s9 >> 21;
    $s10 += $carry9;
    $s9 -= $carry9 << 21;

    /** @var int $carry10 */
    $carry10 = $s10 >> 21;
    $s11 += $carry10;
    $s10 -= $carry10 << 21;

    /**
     * @var array<int, int>
     */
    $arr = array(
      (int) ($s0 >> 0),
      (int) ($s0 >> 8),
      (int) ($s0 >> 16 | $s1 << 5),
      (int) ($s1 >> 3),
      (int) ($s1 >> 11),
      (int) ($s1 >> 19 | $s2 << 2),
      (int) ($s2 >> 6),
      (int) ($s2 >> 14 | $s3 << 7),
      (int) ($s3 >> 1),
      (int) ($s3 >> 9),
      (int) ($s3 >> 17 | $s4 << 4),
      (int) ($s4 >> 4),
      (int) ($s4 >> 12),
      (int) ($s4 >> 20 | $s5 << 1),
      (int) ($s5 >> 7),
      (int) ($s5 >> 15 | $s6 << 6),
      (int) ($s6 >> 2),
      (int) ($s6 >> 10),
      (int) ($s6 >> 18 | $s7 << 3),
      (int) ($s7 >> 5),
      (int) ($s7 >> 13),
      (int) ($s8 >> 0),
      (int) ($s8 >> 8),
      (int) ($s8 >> 16 | $s9 << 5),
      (int) ($s9 >> 3),
      (int) ($s9 >> 11),
      (int) ($s9 >> 19 | $s10 << 2),
      (int) ($s10 >> 6),
      (int) ($s10 >> 14 | $s11 << 7),
      (int) ($s11 >> 1),
      (int) ($s11 >> 9),
      (int) $s11 >> 17,
    );
    return self::intArrayToString($arr);
  }

  /**
   * multiply by the order of the main subgroup l = 2^252+27742317777372353535851937790883648493
   *
   * @param ParagonIE_Sodium_Core_Curve25519_Ge_P3 $A
   * @return ParagonIE_Sodium_Core_Curve25519_Ge_P3
   */
  public static function ge_mul_l(ParagonIE_Sodium_Core_Curve25519_Ge_P3 $A) {

    /** @var array<int, int> $aslide */
    $aslide = array(
      13,
      0,
      0,
      0,
      0,
      -1,
      0,
      0,
      0,
      0,
      -11,
      0,
      0,
      0,
      0,
      0,
      0,
      -5,
      0,
      0,
      0,
      0,
      0,
      0,
      -3,
      0,
      0,
      0,
      0,
      -13,
      0,
      0,
      0,
      0,
      7,
      0,
      0,
      0,
      0,
      0,
      3,
      0,
      0,
      0,
      0,
      -13,
      0,
      0,
      0,
      0,
      5,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      11,
      0,
      0,
      0,
      0,
      0,
      11,
      0,
      0,
      0,
      0,
      -13,
      0,
      0,
      0,
      0,
      0,
      0,
      -3,
      0,
      0,
      0,
      0,
      0,
      -1,
      0,
      0,
      0,
      0,
      3,
      0,
      0,
      0,
      0,
      -11,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      15,
      0,
      0,
      0,
      0,
      0,
      -1,
      0,
      0,
      0,
      0,
      -1,
      0,
      0,
      0,
      0,
      7,
      0,
      0,
      0,
      0,
      5,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      1,
    );

    /** @var array<int, ParagonIE_Sodium_Core_Curve25519_Ge_Cached> $Ai size 8 */
    $Ai = array();

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

    # ge_p3_dbl(&t, A);
    $t = self::ge_p3_dbl($A);

    # ge_p1p1_to_p3(&A2, &t);
    $A2 = self::ge_p1p1_to_p3($t);
    for ($i = 1; $i < 8; ++$i) {

      # ge_add(&t, &A2, &Ai[0]);
      $t = self::ge_add($A2, $Ai[$i - 1]);

      # ge_p1p1_to_p3(&u, &t);
      $u = self::ge_p1p1_to_p3($t);

      # ge_p3_to_cached(&Ai[i], &u);
      $Ai[$i] = self::ge_p3_to_cached($u);
    }
    $r = self::ge_p3_0();
    for ($i = 252; $i >= 0; --$i) {
      $t = self::ge_p3_dbl($r);
      if ($aslide[$i] > 0) {

        # ge_p1p1_to_p3(&u, &t);
        $u = self::ge_p1p1_to_p3($t);

        # ge_add(&t, &u, &Ai[aslide[i] / 2]);
        $t = self::ge_add($u, $Ai[(int) ($aslide[$i] / 2)]);
      }
      elseif ($aslide[$i] < 0) {

        # ge_p1p1_to_p3(&u, &t);
        $u = self::ge_p1p1_to_p3($t);

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

    # ge_p1p1_to_p3(r, &t);
    return self::ge_p1p1_to_p3($t);
  }

}

Classes

Name	Description
ParagonIE_Sodium_Core_Curve25519	Class ParagonIE_Sodium_Core_Curve25519