Schannel tls implementation doesn't work about libstrophe

[pasis]

SEC_E_INCOMPLETE_MESSAGE is not critical error and ideally should be handled in the code (according to [1] and [2]).

But the actual problem is in sock_read(). select() returns 1 indicating that there is a descriptor ready to read. But reading with recv() returns 0 which means the connection is shutdown from server side.

Update: connection is closed after the 1st sock_write() to the socket:

libstrophe/src/tls_schannel.c

Line 271 in 111659c

sent = sock_write(tls->sock, writebuff, writelen);

[pasis]

Root cause of the problem is in the SupportedAlgs. Seems, my server doesn't like RC4. As these fields are optional I left cSupportedAlgs/palgSupportedAlgs zeroed to use default system configuration and tls_start() returned without errors. But 1st tls_read() (after a tls_write()) returns SEC_E_UNSUPPORTED_FUNCTION.

There is question on stackoverflow, but without solution: http://stackoverflow.com/questions/24204082/decryptmessage-returning-sec-e-unsupported-function

[pasis]

I backported a patch from a libstrophe fork which is related to the incomplete message issue: 886f455 .

[pasis]

With the patch from the previous comment, schannel implementation works on VS2017/Win10. However, I needed to fix few compilation errors and LoadLibrary() didn't load any dll for unknown reason.

I couldn't make it work in VS6/WinXP though. InitializeSecurityContext() returned 0x80090318 repeatedly.

Closing this issue.