public static function ParagonIE_Sodium_Core_Curve25519::ge_scalarmult_base in Automatic Updates 8

Same name and namespace in other branches

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

@internal You should not use this directly from another application

@psalm-suppress MixedAssignment @psalm-suppress MixedOperand

Parameters

string $a:

Return value

ParagonIE_Sodium_Core_Curve25519_Ge_P3

Throws

SodiumException

TypeError

3 calls to ParagonIE_Sodium_Core_Curve25519::ge_scalarmult_base()

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

@internal You should not use this directly from another application

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

@internal You should not use this directly from another application

ParagonIE_Sodium_Core_X25519::crypto_scalarmult_curve25519_ref10_base in vendor/paragonie/sodium_compat/src/Core/X25519.php

@internal You should not use this directly from another application

File

vendor/paragonie/sodium_compat/src/Core/Curve25519.php, line 1938

Class

ParagonIE_Sodium_Core_Curve25519

Class ParagonIE_Sodium_Core_Curve25519

Code

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;
}