> Stunnel version is 5.48 with OpenSSL 1.0.2o-fips. (in this very case I need to use 32bit version, so no possibility to upgrade).
Actually, you can upgrade your Windows 32-bit stunnel. Either, you compile your own, or you can get the latest from here:
https://github.com/josealf/stunnel-win32/blob/master/stunnel-testing-win32-5.56-ossl-1.1.1g-installer.exe
Regards,
Jose