2 * Copyright (c) 1997 - 2001 Kungliga Tekniska Högskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
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34 #include "krb5_locl.h"
37 RCSID("$Id: get_host_realm.c,v 1.28 2001/05/14 06:14:47 assar Exp $");
39 /* To automagically find the correct realm of a host (without
40 * [domain_realm] in krb5.conf) add a text record for your domain with
41 * the name of your realm, like this:
43 * krb5-realm IN TXT FOO.SE
45 * The search is recursive, so you can add entries for specific
46 * hosts. To find the realm of host a.b.c, it first tries
47 * krb5-realm.a.b.c, then krb5-realm.b.c and so on.
49 * Also supported is _kerberos (following draft-ietf-cat-krb-dns-locate-01.txt)
54 copy_txt_to_realms (struct resource_record *head,
57 struct resource_record *rr;
60 for(n = 0, rr = head; rr; rr = rr->next)
61 if (rr->type == T_TXT)
67 *realms = malloc ((n + 1) * sizeof(krb5_realm));
71 for (i = 0; i < n + 1; ++i)
74 for (i = 0, rr = head; rr; rr = rr->next) {
75 if (rr->type == T_TXT) {
78 tmp = strdup(rr->u.txt);
80 for (i = 0; i < n; ++i)
93 dns_find_realm(krb5_context context,
95 const char *dom_string,
98 char dom[MAXHOSTNAMELEN];
104 snprintf(dom, sizeof(dom), "%s.%s.", dom_string, domain);
105 r = dns_lookup(dom, "TXT");
109 ret = copy_txt_to_realms (r->head, realms);
115 * Try to figure out what realms host in `domain' belong to from the
116 * configuration file.
120 config_find_realm(krb5_context context,
124 char **tmp = krb5_config_get_strings (context, NULL,
136 * This function assumes that `host' is a FQDN (and doesn't handle the
137 * special case of host == NULL either).
138 * Try to find mapping in the config file or DNS and it that fails,
139 * fall back to guessing
143 krb5_get_host_realm_int (krb5_context context,
145 krb5_boolean use_dns,
150 for (p = host; p != NULL; p = strchr (p + 1, '.')) {
151 if(config_find_realm(context, p, realms) == 0)
154 if(dns_find_realm(context, p, "krb5-realm", realms) == 0)
156 if(dns_find_realm(context, p, "_kerberos", realms) == 0)
160 p = strchr(host, '.');
163 *realms = malloc(2 * sizeof(krb5_realm));
164 if (*realms == NULL) {
165 krb5_set_error_string(context, "malloc: out of memory");
169 (*realms)[0] = strdup(p);
170 if((*realms)[0] == NULL) {
172 krb5_set_error_string(context, "malloc: out of memory");
175 strupr((*realms)[0]);
179 krb5_set_error_string(context, "unable to find realm of host %s", host);
180 return KRB5_ERR_HOST_REALM_UNKNOWN;
184 * Return the realm(s) of `host' as a NULL-terminated list in `realms'.
188 krb5_get_host_realm(krb5_context context,
192 char hostname[MAXHOSTNAMELEN];
195 if (gethostname (hostname, sizeof(hostname)))
200 return krb5_get_host_realm_int (context, host, 1, realms);