Re: http.sslVersion only specifies minimum TLS version, later versions are allowed

> > Just looking at how the curl binary does it, "--tlsv1.2" means "1.2 or
> > greater" (which is not at all surprising; the library interface tends to
> > mirror their command-line and vice versa, and our behavior is influenced
> > by the library interface here).  But that implies to me that curl folks
> > considered this and though the "or greater" behavior was useful (which
> > makes sense -- the main goal is probably to avoid insecurities in older
> > versions of the protocol).
> > 
> > Anyway, the binary also has --tls-max for capping the maximum version.
> > That seems more flexible in general than "use this version exactly" (if
> > you only care that 1.3 is broken, then setting "max=1.2" lets you talk
> > to servers that support 1.1 or 1.2).
> > 
> > -Peff
> 
> I agree that the current behaviour is better for most users, and that
> some kind of separate "max" config option would work for anyone in my
> situation.
> 
> Another idea would be to keep the current behaviour for
> `http.sslVersion`, but use an exact match with the environment
> variable only. That already takes priority, and I imagine its main
> appeal over the config option is for users that want to try something
> with a specific TLS version.