https://bugs.winehq.org/show_bug.cgi?id=37500
--- Comment #10 from Bruno Jesus 00cpxxx@gmail.com ---
From the log:
trace:secur32:schan_QueryContextAttributesW Using 256 mac bytes, message size 16384, block size 16
The default max message size is indeed 16384 as specified in the gnutls source code. This value may be changed during the client->server negotiation. I don't know if it's possible to know if it was changed by the server or not.