Crash reported on Windows in X509Certificate verification #3221
Description
We've received reports of an enterprise app using an SDK built on Poco that often experiences crashes at this location:
00 (Inline Function) --------`-------- EnterpriseApp!std::_WChar_traits<wchar_t>::length+0xa [C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Tools\MSVC\14.26.28801\include\xstring @ 168]
01 (Inline Function) --------`-------- EnterpriseApp!std::basic_string<wchar_t,std::char_traits<wchar_t>,std::allocator<wchar_t> >::assign+0xa [C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Tools\MSVC\14.26.28801\include\xstring @ 2992]
02 (Inline Function) --------`-------- EnterpriseApp!std::basic_string<wchar_t,std::char_traits<wchar_t>,std::allocator<wchar_t> >::{ctor}+0x1b [C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Tools\MSVC\14.26.28801\include\xstring @ 2344]
03 000000bc`387fe430 00007ff7`e983ae6b EnterpriseApp!Poco::Net::X509Certificate::extractNames+0x2a4 [D:\path\to\poco\NetSSL_Win\src\X509Certificate.cpp @ 262]
04 000000bc`387fe590 00007ff7`e983eee2 EnterpriseApp!Poco::Net::X509Certificate::verify+0x9b [D:\path\to\poco\NetSSL_Win\src\X509Certificate.cpp @ 478]
05 000000bc`387fe6c0 00007ff7`e983eb91 EnterpriseApp!Poco::Net::SecureSocketImpl::clientVerifyCertificate+0x82 [D:\path\to\poco\NetSSL_Win\src\SecureSocketImpl.cpp @ 1173]
This happens with Poco 1.9.4 in production releases using HTTPSClientSession for API calls, but apparently only for a limited subset of users. For them, it is consistent. It seems to be directly correlated with Kaspersky. When users disable Kaspersky, the issue is resolved. We cannot directly reproduce in testing. The app involved is a Win32 app, packaged without MSIX, running on Windows 10.
https://github.com/pocoproject/poco/blob/poco-1.9.4/NetSSL_Win/src/X509Certificate.cpp#L262
I wonder if it is possible for rgAltEntry[i].pwszDNSName to be NULL. I don't see any significant difference there between 1.9.4 and the 1.10 releases or the master branch. I could contribute a PR with a NULL check, but I don't know if that is the issue.
Any advice or assistance is appreciated. Thank you.