ParagonIE_Sodium_Core_Curve25519::fe_normalize( ParagonIE_Sodium_Core_Curve25519_Fe $f ): ParagonIE_Sodium_Core_Curve25519_Fe

3809    public static function fe_normalize(ParagonIE_Sodium_Core_Curve25519_Fe $f)3810    {3811        $x = (PHP_INT_SIZE << 3) - 1; // 31 or 633812 3813        $g = self::fe_copy($f);3814        for ($i = 0; $i < 10; ++$i) {3815            $mask = -(($g[$i] >> $x) & 1);3816 3817            /*3818             * Get two candidate normalized values for $g[$i], depending on the sign of $g[$i]:3819             */3820            $a = $g[$i] & 0x7ffffff;3821            $b = -((-$g[$i]) & 0x7ffffff);3822 3823            /*3824             * Return the appropriate candidate value, based on the sign of the original input:3825             *3826             * The following is equivalent to this ternary:3827             *3828             * $g[$i] = (($g[$i] >> $x) & 1) ? $a : $b;3829             *3830             * Except what's written doesn't contain timing leaks.3831             */3832            $g[$i] = ($a ^ (($a ^ $b) & $mask));3833        }3834        return $g;3835    }