/**
* Split a key using a variant of HKDF that used a keyed BLAKE2b hash rather
* than an HMAC construct
*
* @param \ParagonIE\Halite\Key $master
* @param string $salt
* @return array
*/
public static function splitKeys(Key $master, $salt = null)
{
$binary = $master->get();
return [CryptoUtil::hkdfBlake2b($binary, \Sodium\CRYPTO_SECRETBOX_KEYBYTES, Config::HKDF_SBOX, $salt), CryptoUtil::hkdfBlake2b($binary, \Sodium\CRYPTO_AUTH_KEYBYTES, Config::HKDF_AUTH, $salt)];
}
/**
* Save a key to a file
*
* @param Key|KeyPair $key
* @param string $filename
* @return int|boolean
*/
public static function save($key, $filename = '')
{
if ($key instanceof KeyPair) {
return self::saveKeyFile($filename, $key->getSecretKey()->get());
}
return self::saveKeyFile($filename, $key->get());
}
