Re: PAP [was Re: forging a new pppext charter]

> > How about PAP in EAP-TTLS?
> > (RFC 1334 is carefully not referenced in
> > draft-ietf-pppext-eap-ttls-03.txt, but it has a whole subsection 10.2.5
> > devoted to it.)

Cleartext passwords have been deprecated, and RFC 2284bis makes it clear
that the omission of cleartext password support in EAP was intentional.

PAP within EAP-TTLS was an unfortunate mistake.  RFC 2284bis explains why
support of PAP (even within an encrypted tunnel) is dangerous.  This
exposes a security vulnerability in RADIUS similar to WEP that enables
cracking of the key stream.  If the RADIUS client does not have a
cryptographic quality random number generator (e.g. if the client calls
RAND() to populate the Request Authenticator field in RADIUS), then it
will be possible for an attacker to do a known plaintext attack on
RADIUS, and eventually to decrypt "hidden" fields in RADIUS,
including the User-Password field used to carry PAP passwords.