ParagonIE_Sodium_Core_Curve25519::ge_mul_l

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Summery Summery

multiply by the order of the main subgroup l = 2^252+27742317777372353535851937790883648493

Syntax Syntax

ParagonIE_Sodium_Core_Curve25519::ge_mul_l( ParagonIE_Sodium_Core_Curve25519_Ge_P3 $A )

Parameters Parameters

$A

(Required)

Return Return

(ParagonIE_Sodium_Core_Curve25519_Ge_P3)

Source Source

File: wp-includes/sodium_compat/src/Core/Curve25519.php

    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);
    }

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