FreeBSD Man Pages

krb5_425_conv_principal(3)

NAME

     krb5_425_conv_principal, krb5_425_conv_principal_ext,
     krb5_524_conv_principal -- converts to and from version 4 principals

LIBRARY

     Kerberos 5 Library (libkrb5, -lkrb5)

SYNOPSIS

     #include <krb5.h>

     krb5_error_code
     krb5_425_conv_principal(krb5_context context, const char *name,
	 const char *instance, const char *realm, krb5_principal *principal);

     krb5_error_code
     krb5_425_conv_principal_ext(krb5_context context, const char *name,
	 const char *instance, const char *realm,
	 krb5_boolean (*func)(krb5_context, krb5_principal),
	 krb5_boolean resolve, krb5_principal *principal);

     krb5_error_code
     krb5_524_conv_principal(krb5_context context,
	 const krb5_principal principal, char *name, char *instance,
	 char *realm);

DESCRIPTION

     Converting between version 4 and version 5 principals can at best be
     described as a mess.

     A version 4 principal consists of a name, an instance, and a realm. A
     version 5 principal consists of one or more components, and a realm. In
     some cases also the first component/name will differ between version 4
     and version 5.  Furthermore the second component of a host principal will
     be the fully qualified domain name of the host in question, while the
     instance of a version 4 principal will only contain the first part (short
     hostname).  Because of these problems the conversion between principals
     will have to be site customized.

     krb5_425_conv_principal_ext() will try to convert a version 4 principal,
     given by name, instance, and realm, to a version 5 principal. This can
     result in several possible principals, and if func is non-NULL, it will
     be called for each candidate principal.  func should return true if the
     principal was ``good''.  To accomplish this,
     krb5_425_conv_principal_ext() will look up the name in krb5.conf.	It
     first looks in the v4_name_convert/host subsection, which should contain
     a list of version 4 names whose instance should be treated as a hostname.
     This list can be specified for each realm (in the realms section), or in
     the libdefaults section.  If the name is found the resulting name of the
     principal will be the value of this binding. The instance is then first
     looked up in v4_instance_convert for the specified realm. If found the
     resulting value will be used as instance (this can be used for special
     cases), no further attempts will be made to find a conversion if this
     fails (with func).  If the resolve parameter is true, the instance will
     be looked up with gethostbyname().  This can be a time consuming, error
     prone, and unsafe operation.  Next a list of hostnames will be created
     from the instance and the v4_domains variable, which should contain a
     list of possible domains for the specific realm.
		   host = {
			   ftp = ftp
			   hprop = hprop
			   imap = imap
			   pop = pop
			   rcmd = host
			   smtp = smtp
		   }
	   }

     It will only be used if there isn't an entry for these names in the con-
     fig file, so you can override these defaults.

     krb5_425_conv_principal() will call krb5_425_conv_principal_ext() with
     NULL as func, and the value of v4_instance_resolve (from the libdefaults
     section) as resolve.

     krb5_524_conv_principal() basically does the opposite of
     krb5_425_conv_principal(), it just doesn't have to look up any names, but
     will instead truncate instances found to belong to a host principal. The
     name, instance, and realm should be at least 40 characters long.

EXAMPLES

     Since this is confusing an example is in place.

     Assume that we have the ``foo.com'', and ``bar.com'' domains that have
     shared a single version 4 realm, FOO.COM. The version 4 krb.realms file
     looked like:

	   foo.com	   FOO.COM
	   .foo.com	   FOO.COM
	   .bar.com	   FOO.COM

     A krb5.conf file that covers this case might look like:

	   [libdefaults]
		   v4_instance_resolve = yes
	   [realms]
		   FOO.COM = {
			   kdc = kerberos.foo.com
			   v4_instance_convert = {
				   foo = foo.com
			   }
			   v4_domains = foo.com
		   }

     With this setup and the following host table:

	   foo.com
	   a-host.foo.com
	   b-host.bar.com
     the following conversions will be made:

	   rcmd.a-host	   -> host/a-host.foo.com
	   ftp.b-host	   -> ftp/b-host.bar.com
	   pop.foo	   -> pop/foo.com
	   ftp.other	   -> ftp/other.foo.com
	   other.a-host    -> other/a-host
     resolving.

SEE ALSO

     krb5_build_principal(3), krb5_free_principal(3), krb5_parse_name(3),
     krb5_sname_to_principal(3), krb5_unparse_name(3), krb5.conf(5)

HEIMDAL 			April 11, 1999			       HEIMDAL

SPONSORED LINKS