shishi_realm_for_server_dns(3)					      shishi					    shishi_realm_for_server_dns(3)

NAME

       shishi_realm_for_server_dns - API function

SYNOPSIS

       #include <shishi.h>

       char * shishi_realm_for_server_dns(Shishi * handle, char * server);

ARGUMENTS

       Shishi * handle
		   Shishi library handle create by shishi_init().

       char * server
		   hostname to find realm for.

DESCRIPTION

       Find  realm  for a host using DNS lookups, according to draft-ietf-krb-wg-krb-dns-locate-03.txt.  Since DNS lookups may be spoofed, relying
       on the realm information may result in a redirection attack.  In a single-realm scenario, this only achieves a denial of service, but  with
       cross-realm  trust  it  may redirect you to a compromised realm.  For this reason, Shishi prints a warning, suggesting that the user should
       add the proper 'server-realm' configuration tokens instead.

       To illustrate the DNS information used, here is an extract from a zone file for the domain ASDF.COM:

       _kerberos.asdf.com.	       IN      TXT	"ASDF.COM"  _kerberos.mrkserver.asdf.com.    IN       TXT      "MARKETING.ASDF.COM"  _ker-
       beros.salesserver.asdf.com. IN	   TXT	   "SALES.ASDF.COM"

       Let us suppose that in this case, a client wishes to use a service on the host foo.asdf.com.  It would first query:

       _kerberos.foo.asdf.com. IN TXT

       Finding no match, it would then query:

       _kerberos.asdf.com. IN TXT

RETURN VALUE

       Returns realm for host, or NULL if not found.

REPORTING BUGS

       Report bugs to <bug-shishi@gnu.org>.

COPYRIGHT

       Copyright (C) 2002-2010 Simon Josefsson.
       Copying	and  distribution  of  this file, with or without modification, are permitted in any medium without royalty provided the copyright
       notice and this notice are preserved.

SEE ALSO

       The full documentation for shishi is maintained as a Texinfo manual.  If the info and shishi programs are properly installed at your  site,
       the command

	      info shishi

       should give you access to the complete manual.

shishi								       1.0.1					    shishi_realm_for_server_dns(3)