RE: iSCSI: Decimal encoding - why 64 bits ?

[Paul Koning <ni1d@arrl.net>]

Excerpt of message (sent 2 July 2002) by THALER,PAT (A-Roseville,ex1):
> 10.4 SRP: N,g,s,A,B,M and H(A | M | K) are binary-values
> 10.5 CHAP: C and R are binary-values
> 
> 10.2 and 10.3 use large-binary-value instead of binary-value and I
> can't find any other use of binary-value.
> 
> Normally, the values defined as binary-values for SRP and CHAP would
> be 64 bits or longer anyway, but someone could send short keys and
> encode them in decimal according to the current draft. This should be
> eliminated.

I agree.

Actually, H(A|M|K) in SRP and R in CHAP both can only be
large-binary-value since their length is always greater than 8 bytes.
The same goes for N and g in SRP (since these systems are all based on
modular arithmetic with a modulus of at least several hundred bits).

The probability of the other SRP items coming out small enough
numerically to fit in 64 bits is essentially zero.  It makes no sense
for the spec to allow it.

In CHAP, C should not be short for the same reason that the password
should not be short.

So I conclude that there are good technical reasons why all these
items must be large-binary-value.

      paul