Hi thanks for getting back to me,

That's fine if it doesn't work in future releases, I will most likely stay on 3.0.0.

Unfortunately when trying to add this line to the dtls_server example I get:

error: dereferencing pointer to incomplete type 'mbedtls_ssl_handshake_params' {aka 'struct mbedtls_ssl_handshake_params'}

int resumed = ssl.MBEDTLS_PRIVATE(handshake)->resume;

                                                                                  ^~

If I try to use .resume instead of ->resume it also complains because `handshake` is a pointer and I must use -> instead.

My use case for this is to test a client's ability to connect to the server and use session caching, I want to essentially send messages to the server from a client with session caching enabled, and have the server send a message back either 'session cache was used' or 'session cache was not used.

On Tue, 8 Mar 2022 at 18:02, Paul Elliott <Paul.Elliott@arm.com> wrote:

Hi,

As a temporary workaround for the you can use:

ssl.MBEDTLS_PRIVATE(handshake).resume

But please be aware that this is something that could break with any
future release, so should only be used as a very temporary workaround.

We made these members private in 3.0.0, and thus need to know if
anyone's code paths have been broken as a result, so we can add
accessors or new methods as required. Regarding this, may I enquire the
reason for your needing to know if the session has been resumed - is
this only a debug thing, or do you have a requirement in your codebase
to know this?

Regards,

Paul.

On Mon, 2022-03-07 at 20:55 +0000, eoin.mcmahon.dev--- via mbed-tls
wrote:
> I am trying to modify the dtls_server.c example to keep track of
> whether session caching was used for a given connection.
>
> Ideally I would have an interget value i.e `session_resumed = #1 or
> 0`
>
> One way I tried to do this was by reading the value of the
> mbedtls_ssl_context struct `ssl`:
> ```
>     /*
>      * 5. Handshake
>      */
>     do ret = mbedtls_ssl_handshake( &ssl );
>     while( ret == MBEDTLS_ERR_SSL_WANT_READ || ret ==
> MBEDTLS_ERR_SSL_WANT_WRITE );
>
>     if( ret == MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED ) {
>         printf( " hello verification requested\n" );
>         ret = 0;
>         goto reset;
>     }
>     else if( ret != 0 ) {
>         printf( " failed\n  ! mbedtls_ssl_handshake returned -
> 0x%x\n\n", (unsigned int) -ret );
>         goto reset;
>     }
>     printf( " session cache status:  %d\n", ssl.handshake.resume );
> ```
>
> The issue with this is that the ssl struct is set to private, so the
> code fails to compile with the error: 'struct mbedtls_ssl_context'
> has no member named 'handshake'
>
> Can somebody help me with some example code that would make this
> possible?