limoncello-php-dist / crypt

     *

     * @return string

     */

    protected function readIV(string $data, int $ivLength): string

    {

        $vector = substr($data, 0, $ivLength);

        $isOk   = $vector !== false && strlen($vector) === $ivLength;

        $isOk === true ?: $this->throwException(new CryptException($this->getReadVectorErrorMessage()));

        return $vector;

    }

    /**

     * @param string $data

     *

     * @return string

     */

    protected function readTag(string $data, int $tagLength): string

    {

        $tag  = substr($data, 0, $tagLength);

        $isOk = $tag !== false && strlen($tag) === $tagLength;

        $isOk === true ?: $this->throwException(new CryptException($this->getReadTagErrorMessage()));

        return $tag;

    }

    /**

     * @param string $data

     *

     * @return string

     */

    protected function extractData(string $data, int $ivLength): string

    {

        $result = substr($data, $ivLength);

        $isOk = $result !== false && empty($result) === false;

        $isOk === true ?: $this->throwException(new CryptException($this->getExtractDataErrorMessage()));

        return $result;

    }

    /**

     * @param string $data