change text "handshare failure" to "handshake failure or TLS extension not supported"

[Wikinaut]

I do see "handshake failure" for servers which do not offer TLS, so the text should inform about this possibility.alertHandshakeFailure: "handshake failure. This could mean that the TLS extension is not supported.",

I haven't tested this code change yet.

[FiloSottile]

By TLS extension you mean TLS itself?

[Wikinaut]

@FiloSottile when a server runs an older openssl which do not offer TLS, than your script says "handshake failure", but users then do not know whether this is a "good" or "bad" server (with respect to the Heartbleed bug).

This is why I suggest to show then my proposed text.

You can compare your tool against the competitive tool http://possible.lv/tools/hb/ which in such cases (no TLS implemented) says

Looking for TLS extensions on https://www.example.org

ext 65281 (renegotiation info, length=1)
ext 00035 (session ticket, length=0)
TLS extension 15 (heartbeat) seems disabled, so your server is probably unaffected.

[garrettr]

Test case: https://mozilla.org