ParagonIE_Sodium_Core_Curve25519::ge_sub() public WP 1.0

Subtract two group elements.

r = p - q

{} It's a method of the class: ParagonIE_Sodium_Core_Curve25519{}

No Hooks.

Return

ParagonIE_Sodium_Core_Curve25519_Ge_P1p1. Null. Nothing.

Usage

$result = ParagonIE_Sodium_Core_Curve25519::ge_sub(;

Code of ParagonIE_Sodium_Core_Curve25519::ge_sub() ParagonIE Sodium Core Curve25519::ge sub ^{WP 5.7}

<?php
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;
}