64 

    65     /**

    66      * @internal You should not use this directly from another application

    67      *

    68      * @param string $message

    69      * @param string $nonce

    70      * @param string $key

    71      * @param string $ic

    72      * @return string

    73      * @throws SodiumException

    74      * @throws TypeError

    75      */

    76     public static function ietfStreamXorIc($message, $nonce = '', $key = '', $ic = '')

    77     {

    78         return self::encryptBytes(

    79             new ParagonIE_Sodium_Core32_ChaCha20_IetfCtx(

    80                 self::hChaCha20(self::substr($nonce, 0, 16), $key),

    81                 "\x00\x00\x00\x00" . self::substr($nonce, 16, 8),

    82                 $ic

    83             ),

    84             $message

    85         );

    86     }