I think the more important change here is that you changed to using SSL_strerror instead of ERR_error_string. Why? The former function seems to be completely undocumented? When was that introduced? Is it meant to work the same way as ERR_error_string?

SSL_strerror is an internal libcurl function, implemented in lib/vtls/openssl.c :-)
It's a wrapper for OpenSSL's ERR_error_string_n

Hah, look at that. I totally blanked on that... thanks!

We should probably rename it to not use a "SSL_" prefix as some OpenSSL functions use that.

thanks!