libbind ns_sign() and ns_verify() parameter in_timesigned not documented

[Mark Andrews]

In message <4AE58FD9.8020508 at sun.com>, Stacey Jonathan Marshall writes:
> The tsig manual page description for ns_sign() and ns_verify() include a 
> parameter named in_timesigned of type time_t.  However there is no 
> description of this parameter as there is for the others:
> 
> $ less libbind-6.0/doc/tsig.cat3
> TSIG                                 LOCAL                                TSI
> G
> 
> NAME
>      ns_sign, ns_sign_tcp, ns_sign_tcp_init, ns_verify, ns_verify_tcp,
>      ns_verify_tcp_init, ns_find_tsig -- TSIG system
> 
> SYNOPSIS
>      int
>      ns_sign(u_char *msg, int *msglen, int msgsize, int error, void *k,
>          const u_char *querysig, int querysiglen, u_char *sig, int *siglen,
>          time_t in_timesigned);
> 
> ...
>      int
>      ns_verify(u_char *msg, int *msglen, void *k, const u_char *querysig,
>          int querysiglen, u_char *sig, int *siglen, time_t in_timesigned,
>          int nostrip);
> 
> 
>  From a cursory review it does not seem to be used unless error == 
> ns_r_badtime.
> Could someone describe the purpose of parameter? 

Theoretically a client can take the bad time response and compute
a time delta and use it to adjust the timestamp in future communications
to the server.  This allows the client to correct for clock skew
if it wants.
 
Mark
-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: marka at isc.org