[horde] Browser feature

[Otto Stolz]

Hello,

recently, we have introduced new, 2048-bit SSL keys.
Now, complaints/questions from my Webmail customers keep
pouring in, because many of them still use old browsers
that cannot cope with SSL keys of that size.

I have placed a warning on my index.html page (which
comes before the horde/imp/index.php page that must be
accessed via HTTPS). But those users do not understand
that warning, because they havent't ever heard if SSL,
keys, and all that stuff. They also do not understand
the browser's error message either; one browser
(Netscape 6.2) does not even issue an error message,
but simply stays in the page displayed before.

So I'd like to issue a more specific warning, whenever
a user tries Webmail with a browser not supporting 2048-bit
keys. The warning should say something like: "Your XY browser
is way too old, hence does not support current safety techno-
logy. Please get you a better one."

So my question is: How can I determine whether the browser
supports these keys? Appartently, neither Browser::hasFeature(),
nor Browser::hasQuirk()) can provide this info.

Of course, I can always read the AgentString, or use
Browser::getBrowser(), Browser::getIEVersion(),
Browser::getMajor(), and Browser::getMinor(), to see,
which browser I am dealing with -- but how do I know
which browser supports which key size?

Thank you for any hints,
   Otto Stolz