Re: [saag] RADIUS is deprecating MD5

[Alan DeKok <[e-mail]>]

On Mar 31, 2024, at 11:00 AM, Viktor Dukhovni <[e-mail]> wrote:
> I appreciate and agree that new protocols should not use MD5, but it is
> not clear that there's a pressing case to deprecate its long-standing
> use in RADIUS.  What attack is that guarding against?

  As Jan-Frederik pointed out, privacy is a huge one.

  In many cases, RADIUS packets are often sent across the net in the clear.  This exposes user identity, location, device information, etc.

  In many cases, Access-Request packets are unauthenticated, and lack all integrity checks.

  The only fix is to switch to TLS transport.

  To be perfectly clear:  There are "cloud" providers which send RADIUS/UDP traffic over the Internet.  In the clear.  Where anyone can see or modify the contents.

  There is absolutely no reason to keep doing this in 2024.  There is every reason to deprecate such behavior with extreme prejudice.  Anyone doing that should stop immediately.

  We've known since the late 1990s that this behavior is terrible.  Yet we're only now thinking of officially deprecating it.  Can we please just agree that sending PII in clear-text across the Internet is bad?

  Alan DeKok.