Re: [lwip-users] tls server, http1.1, pipelining

[address@hidden]

Am 18.06.2019 um 18:29 schrieb Mario Luzeiro:
> I managed to get a TLS server working with lwIP!
>
> I have a webpage with html and images. It loads ok over http.
> My problem is now with TLS it cannot load the images.
>
> If I set the server using HTTP1.0 the browser will send multiple parallel
> TLS connections to get the images.
> So it looks this multiple connections are not supported? in lwIP/mbedTLS?

Multiple connections *are* supported.

> If I set the server to send a HTTP1.1 with keep-alive, the browser will keep
> the connection but will send multiple READs
> but why does it work (multiple readings) with regular HTTP and not over TLS?

You need to configure the server correctly, and you need enough RAM. We
have the lwIP htpd working perfectly as https server on an STM32, of
course with keep-alive. To speed up connection setup for parallel
connections, mbedTLS provides some cookie mechanisms as well.

> I checked and it looks there is no HTTP option to ask client to not perform
> pipelining.

You mean no option to request the client not opening multiple
connections? That's right, but you can greatly reduce mbedTLS memory
consumption when reducing the TX buffer: lwIP only uses a small TX
buffer, so you don't need 16K there. And when you're not expecting large
uploads, you can safely reduce the RX buffer for mbedTLS as well.

Regards,
Simon