https://www.openssl.org/docs/man1.0.2/crypto/X509_VERIFY_PARAM_set1_host.html
They say they NEED this because they can delete a whole load of code that could have security bugs. Perhaps I am wrong but upon a quick glance, doesn't this just boil down to some simple ORing? How does this sit with https://www.openbsd.org/papers/eurobsdcon2014-libressl.html The ressl API does provide one noteworthy feature. Hostname verification. In order to make a secure TLS connection, you must do two things. Validate the certificate and its trust chain. Then verify that the hostname in the cert matches the hostname you've connected to. Lots of people don't do the latter because OpenSSL doesn't do that latter. You have to do it yourself, which requires knowing about things like CommonNames and SubjectAltNames. The good news is that popular bindings for languages like python and ruby include a function to verify the hostname. The bad news is if you pick a python or ruby project at random, they probably forget to do it. Another funny fact is that since everybody has to write this code themselves, everybody does it a little bit differently. Especially regarding handling of wildcard certificates and everybody's favorite, embedded nul bytes. Hostname verification is on by default in ressl, and the API is designed so that you always provide a hostname; there's no way to accidentally call the function that doesn't do verification.
