ParagonIE_Sodium_Core_Salsa20::salsa20_xor_ic() public WP 1.0

{} It's a method of the class: ParagonIE_Sodium_Core_Salsa20{}

No Hooks.

Return

String.

Usage

$result = ParagonIE_Sodium_Core_Salsa20::salsa20_xor_ic( $m, $n, $ic, $k );

$m(string) (required)

-

$n(string) (required)

-

$ic(int) (required)

-

$k(string) (required)

-

Code of ParagonIE_Sodium_Core_Salsa20::salsa20_xor_ic() ParagonIE Sodium Core Salsa20::salsa20 xor ic ^{WP 5.8.2}

public static function salsa20_xor_ic($m, $n, $ic, $k)
{
    $mlen = self::strlen($m);
    if ($mlen < 1) {
        return '';
    }
    $kcopy = self::substr($k, 0, 32);
    $in = self::substr($n, 0, 8);
    // Initialize the counter
    $in .= ParagonIE_Sodium_Core_Util::store64_le($ic);

    $c = '';
    while ($mlen >= 64) {
        $block = self::core_salsa20($in, $kcopy, null);
        $c .= self::xorStrings(
            self::substr($m, 0, 64),
            self::substr($block, 0, 64)
        );
        $u = 1;
        for ($i = 8; $i < 16; ++$i) {
            $u += self::chrToInt($in[$i]);
            $in[$i] = self::intToChr($u & 0xff);
            $u >>= 8;
        }

        $mlen -= 64;
        $m = self::substr($m, 64);
    }

    if ($mlen) {
        $block = self::core_salsa20($in, $kcopy, null);
        $c .= self::xorStrings(
            self::substr($m, 0, $mlen),
            self::substr($block, 0, $mlen)
        );
    }
    try {
        ParagonIE_Sodium_Compat::memzero($block);
        ParagonIE_Sodium_Compat::memzero($kcopy);
    } catch (SodiumException $ex) {
        $block = null;
        $kcopy = null;
    }

    return $c;
}