public static function ParagonIE_Sodium_Core_Curve25519::fe_tobytes in Automatic Updates 8

Same name and namespace in other branches

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

Convert a field element to a byte string.

@internal You should not use this directly from another application

Parameters

ParagonIE_Sodium_Core_Curve25519_Fe $h:

Return value

string

7 calls to ParagonIE_Sodium_Core_Curve25519::fe_tobytes()

ParagonIE_Sodium_Core_Curve25519::fe_isnegative in vendor/paragonie/sodium_compat/src/Core/Curve25519.php

Is a field element negative? (1 = yes, 0 = no. Used in calculations.)

ParagonIE_Sodium_Core_Curve25519::fe_isnonzero in vendor/paragonie/sodium_compat/src/Core/Curve25519.php

Returns 0 if this field element results in all NUL bytes.

ParagonIE_Sodium_Core_Curve25519::ge_p3_tobytes in vendor/paragonie/sodium_compat/src/Core/Curve25519.php

@internal You should not use this directly from another application

ParagonIE_Sodium_Core_Curve25519::ge_tobytes in vendor/paragonie/sodium_compat/src/Core/Curve25519.php

Convert a group element to a byte string.

ParagonIE_Sodium_Core_Ed25519::pk_to_curve25519 in vendor/paragonie/sodium_compat/src/Core/Ed25519.php

... See full list

File

vendor/paragonie/sodium_compat/src/Core/Curve25519.php, line 213

Class

ParagonIE_Sodium_Core_Curve25519

Class ParagonIE_Sodium_Core_Curve25519

Code

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);
}