fix some ssl memory leaks

[ericogr]

I've got memory leak using mqtt with ssl enabled. It occurs when broker restart (using mqtt.connect(...) again to reconnect)

adding ssl_ctx_free(sslContext) when closing and onError apparently worked but I'm not shure if it can cause side effects or best way to do it

[slaff]

Hm.. looking at the axtls code for ssl_ctx_free it seems that the function internally calls ssl_free. Excerpt:

EXP_FUNC void STDCALL ssl_ctx_free(SSL_CTX *ssl_ctx)
{
    SSL *ssl;
    int i;

    if (ssl_ctx == NULL)
        return;

    ssl = ssl_ctx->head;

    /* clear out all the ssl entries */
    while (ssl)
    {
        SSL *next = ssl->next;
        ssl_free(ssl);
        ssl = next;
    }

// ...

Which means that probably just replacing ssl_free(ssl); with ssl_ctx_free(sslContext); should work.

[ericogr]

that's true, I'll try :)

[slaff]

@ericogr May be one last thing - add the following comment behind the ssl_ctx_free(sslContext); // ssl_ctx_free frees the context. Internally it calls ssl_free which frees SSL extension data and SSL itself.

[slaff]

@ericogr Please, delete that line above. The line below should take care to do the right free-ing.

[slaff]

@ericogr Same as above - delete that line above. The line below should take care to do the right free-ing.