[krbdev.mit.edu #5425] nonce needs to be random

[Ken Raeburn via RT]

On Feb 1, 2007, at 11:48, Ezra Peisach via RT wrote:
> Be careful... I have another issue on record in the database - the  
> nonce
> is required to be an unsigned int 32 on the wire...

> To make matters worse - I know that Heimdal is also using an  
> integer.  Their
> integer handling code is not as generous as ours... If we send an  
> unsigned integer
> with the high bit set - then ASN.1 needs I believe 5 bytes for an  
> unsigned integer
> and four for a signed... The Heimdal code will reject the encoding.
>
> One solution - which I believe Heimdal uses is that the nonces are  
> randomly
> chosen and the high bit masked off...  Not an ideal solution...

No, it's not, but a 31-bit nonce is better than a fairly predictable  
32-bit timestamp.

Ken