ietfStream example

 {
        /** @var int $adlen - Length of associated data */
        $adlen = ParagonIE_Sodium_Core_Util::strlen($ad);

        /** @var int $len - Length of message (ciphertext + MAC) */
        $len = ParagonIE_Sodium_Core_Util::strlen($message);

        /** @var int $clen - Length of ciphertext */
        $clen = $len - self::aead_chacha20poly1305_IETF_ABYTES;

        /** @var string The first block of the chacha20 keystream, used as a poly1305 key */
        $block0 = ParagonIE_Sodium_Core_ChaCha20::ietfStream(
            32,
            $nonce,
            $key
        );

        /** @var string $mac - Message authentication code */
        $mac = ParagonIE_Sodium_Core_Util::substr(
            $message,
            $len - self::aead_chacha20poly1305_IETF_ABYTES,
            self::aead_chacha20poly1305_IETF_ABYTES
        );

        

 {
        /** @var int $adlen - Length of associated data */
        $adlen = ParagonIE_Sodium_Core32_Util::strlen($ad);

        /** @var int $len - Length of message (ciphertext + MAC) */
        $len = ParagonIE_Sodium_Core32_Util::strlen($message);

        /** @var int $clen - Length of ciphertext */
        $clen = $len - self::aead_chacha20poly1305_IETF_ABYTES;

        /** @var string The first block of the chacha20 keystream, used as a poly1305 key */
        $block0 = ParagonIE_Sodium_Core32_ChaCha20::ietfStream(
            32,
            $nonce,
            $key
        );

        /** @var string $mac - Message authentication code */
        $mac = ParagonIE_Sodium_Core32_Util::substr(
            $message,
            $len - self::aead_chacha20poly1305_IETF_ABYTES,
            self::aead_chacha20poly1305_IETF_ABYTES
        );