The old stream cipher RC4
is as dead as SSL. Soon.
RC4 has been considered fundamentally flawed
a long time.
The deprecation of RC4 in browsers began in November 2013, when Microsoft moved RC4-suites to fallback, by not including RC4 in the ClientHello in the initial handshake in IE11
. This was later described in RFC 7465
: “TLS clients MUST NOT include RC4 cipher suites in the ClientHello message.”
Mozilla followed suit in February 2015, when RC4 was move to fallback in Firefox 36
: “No longer accept insecure RC4 ciphers whenever possible”.
In April 2015 “Move RC4 behind a fallback
” was merged in Chromium, reaching Chrome 43
stable in May and Opera 30
in June. Chromium developers added: “Note that this sort of fallback provides NO security benefit.”
The first real security benefit came when support for RC4 was removed
in Chromium in late October 2015, in Chrome 48
stable in January 2016, and Opera 35
in early February. RC4 was also disabled in Opera 12.18
Mozilla disabled RC4 in Firefox 44
. See also Deprecating the RC4 Cipher
The next step will be taken on patch Tuesday in April, when Microsoft releases updates that disable RC4 in Edge, and in IE11
on Windows 7, 8.1 and 10.
As Dragon and Chromodo are now based on Chromium 48, and IceDragon is based on Firefox 44, RC4 is disabled in them as well.
Test support for RC4: https://rc4.badssl.com/
Apple? Don’t know. All I know is that Safari 9 supports RC4 and includes it in the ClientHello