Quote Originally Posted by reexre View Post
[https-based secure transfers sometimes work - sometimes not (on older systems)]

UserControl_AsyncReadComplete if fired with SratusCode = 0 just when trying to Connect.
It's basically the same problem we've already discussed some time ago - in a different thread
(and which is still brought up by others - any 2 months or so)...

The SSL/TLS stack of those older systems is sometimes enough (when the sites SSL-certificate is satisfied with "old enough" security-methods/algos) -
but for newer SSL-certs (which specify and require more modern crypto-algos in usually higher bit-length) the https requests might fail on such older systems.

There is not much one can do, other than suggesting to install the newest SSL-Upgrades (along with the newest available IE-install for that system).

An alternative to all the "builtin-MS-crypto- and MS-http-libs" would be libCurl.dll (which comes with its own, usually OpenSSL-based crypto-implementations).
This would then support proper https-requests "down to Win98" - but libCurl (in its Win-Version) is quite large binary-wise - and it comes with a few additional Dll-dependencies -
and has a completely different API.

Olaf