CODEWITHSUNDEEP
c++windowssslwinhttp
Jose Peiro Pardo
Jose Peiro Pardo

Reputation: 21

Problem with Winhttp SSL under Windows 10

I'm currently trying to implement a soap client under Windows in C++. Due to some technical requirements, the http and communication layer have been implemented using the Winhttp API. Everything seems to work ok but, as soon as TLS 1.1 or 1.2 are enabled the software is unable to perform the SSL handshake. It just keeps sending TCP connection packets to the server.

I made several tests in order to find out what's happening and, so far, this is what I already know:

The winhttp code can be found here. I only added this modification at lines 351-352:

 DWORD dwOpt =  WINHTTP_FLAG_SECURE_PROTOCOL_ALL | WINHTTP_FLAG_SECURE_PROTOCOL_TLS1_1 |WINHTTP_FLAG_SECURE_PROTOCOL_TLS1_2;
 int res = WinHttpSetOption(pData->hInternet, WINHTTP_OPTION_SECURE_PROTOCOLS, &dwOpt, sizeof(dwOpt));

Thanks

Upvotes: 0

Views: 1171

Answers (1)

Jose Peiro Pardo
Jose Peiro Pardo

Reputation: 21

I already found what was going on there. It turns out that the secure protocol flags does not behave the same way in Windows 10 Pro and Windows 10 2016 ltsb.

The code snippet included in the questions works as expected under Windows 10 Pro but, in Windows 10 2016 ltsb it must be: 

DWORD dwOpt = WINHTTP_FLAG_SECURE_PROTOCOL_TLS1_1 |WINHTTP_FLAG_SECURE_PROTOCOL_TLS1_2;
int res = WinHttpSetOption(pData->hInternet, WINHTTP_OPTION_SECURE_PROTOCOLS, &dwOpt, sizeof(dwOpt));

I hope this helps anyone who is struggling with similar issues.

Upvotes: 1

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