r8302: import mini HEIMDAL into the tree

(This used to be commit 118be28a7aef233799956615a99d1a2a74dac175)

1 files changed, 220 insertions, 0 deletions

diff --git a/source4/heimdal/lib/krb5/get_host_realm.c b/source4/heimdal/lib/krb5/get_host_realm.c
new file mode 100644
index 0000000000..d9c5bd5dc1
--- /dev/null
+++ b/source4/heimdal/lib/krb5/get_host_realm.c
@@ -0,0 +1,220 @@
+/*
+ * Copyright (c) 1997 - 2005 Kungliga Tekniska Högskolan
+ * (Royal Institute of Technology, Stockholm, Sweden). 
+ * All rights reserved. 
+ *
+ * Redistribution and use in source and binary forms, with or without 
+ * modification, are permitted provided that the following conditions 
+ * are met: 
+ *
+ * 1. Redistributions of source code must retain the above copyright 
+ *    notice, this list of conditions and the following disclaimer. 
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright 
+ *    notice, this list of conditions and the following disclaimer in the 
+ *    documentation and/or other materials provided with the distribution. 
+ *
+ * 3. Neither the name of the Institute nor the names of its contributors 
+ *    may be used to endorse or promote products derived from this software 
+ *    without specific prior written permission. 
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 
+ * SUCH DAMAGE. 
+ */
+
+#include "krb5_locl.h"
+#include <resolve.h>
+
+RCSID("$Id: get_host_realm.c,v 1.34 2005/04/19 18:52:51 lha Exp $");
+
+/* To automagically find the correct realm of a host (without
+ * [domain_realm] in krb5.conf) add a text record for your domain with
+ * the name of your realm, like this:
+ *
+ * _kerberos	IN	TXT	"FOO.SE"
+ *
+ * The search is recursive, so you can add entries for specific
+ * hosts. To find the realm of host a.b.c, it first tries
+ * _kerberos.a.b.c, then _kerberos.b.c and so on.
+ *
+ * This method is described in draft-ietf-cat-krb-dns-locate-03.txt.
+ *
+ */
+
+static int
+copy_txt_to_realms (struct resource_record *head,
+		    krb5_realm **realms)
+{
+    struct resource_record *rr;
+    int n, i;
+
+    for(n = 0, rr = head; rr; rr = rr->next)
+	if (rr->type == T_TXT)
+	    ++n;
+
+    if (n == 0)
+	return -1;
+
+    *realms = malloc ((n + 1) * sizeof(krb5_realm));
+    if (*realms == NULL)
+	return -1;
+
+    for (i = 0; i < n + 1; ++i)
+	(*realms)[i] = NULL;
+
+    for (i = 0, rr = head; rr; rr = rr->next) {
+	if (rr->type == T_TXT) {
+	    char *tmp;
+
+	    tmp = strdup(rr->u.txt);
+	    if (tmp == NULL) {
+		for (i = 0; i < n; ++i)
+		    free ((*realms)[i]);
+		free (*realms);
+		return -1;
+	    }
+	    (*realms)[i] = tmp;
+	    ++i;
+	}
+    }
+    return 0;
+}
+
+static int
+dns_find_realm(krb5_context context,
+	       const char *domain,
+	       krb5_realm **realms)
+{
+    static char *default_labels[] = { "_kerberos", NULL };
+    char dom[MAXHOSTNAMELEN];
+    struct dns_reply *r;
+    char **labels;
+    int i, ret;
+    
+    labels = krb5_config_get_strings(context, NULL, "libdefaults",
+	"dns_lookup_realm_labels", NULL);
+    if(labels == NULL)
+	labels = default_labels;
+    if(*domain == '.')
+	domain++;
+    for (i = 0; labels[i] != NULL; i++) {
+	ret = snprintf(dom, sizeof(dom), "%s.%s.", labels[i], domain);
+	if(ret < 0 || ret >= sizeof(dom))
+	    return -1;
+    	r = dns_lookup(dom, "TXT");
+    	if(r != NULL) {
+	    ret = copy_txt_to_realms (r->head, realms);
+	    dns_free_data(r);
+	    if(ret == 0)
+		return 0;
+	}
+    }
+    return -1;
+}
+
+/*
+ * Try to figure out what realms host in `domain' belong to from the
+ * configuration file.
+ */
+
+static int
+config_find_realm(krb5_context context, 
+		  const char *domain, 
+		  krb5_realm **realms)
+{
+    char **tmp = krb5_config_get_strings (context, NULL,
+					  "domain_realm",
+					  domain,
+					  NULL);
+
+    if (tmp == NULL)
+	return -1;
+    *realms = tmp;
+    return 0;
+}
+
+/*
+ * This function assumes that `host' is a FQDN (and doesn't handle the
+ * special case of host == NULL either).
+ * Try to find mapping in the config file or DNS and it that fails,
+ * fall back to guessing
+ */
+
+krb5_error_code KRB5_LIB_FUNCTION
+_krb5_get_host_realm_int (krb5_context context,
+			  const char *host,
+			  krb5_boolean use_dns,
+			  krb5_realm **realms)
+{
+    const char *p, *q;
+    krb5_boolean dns_locate_enable;
+
+    dns_locate_enable = krb5_config_get_bool_default(context, NULL, TRUE,
+	"libdefaults", "dns_lookup_realm", NULL);
+    for (p = host; p != NULL; p = strchr (p + 1, '.')) {
+	if(config_find_realm(context, p, realms) == 0) {
+	    if(strcasecmp(*realms[0], "dns_locate") == 0) {
+		if(use_dns)
+		    for (q = host; q != NULL; q = strchr(q + 1, '.'))
+			if(dns_find_realm(context, q, realms) == 0)
+			    return 0;
+		continue; 
+	    } else 
+	    	return 0;
+	}
+	else if(use_dns && dns_locate_enable) {
+	    if(dns_find_realm(context, p, realms) == 0)
+		return 0;
+	}
+    }
+    p = strchr(host, '.');
+    if(p != NULL) {
+	p++;
+	*realms = malloc(2 * sizeof(krb5_realm));
+	if (*realms == NULL) {
+	    krb5_set_error_string(context, "malloc: out of memory");
+	    return ENOMEM;
+	}
+
+	(*realms)[0] = strdup(p);
+	if((*realms)[0] == NULL) {
+	    free(*realms);
+	    krb5_set_error_string(context, "malloc: out of memory");
+	    return ENOMEM;
+	}
+	strupr((*realms)[0]);
+	(*realms)[1] = NULL;
+	return 0;
+    }
+    krb5_set_error_string(context, "unable to find realm of host %s", host);
+    return KRB5_ERR_HOST_REALM_UNKNOWN;
+}
+
+/*
+ * Return the realm(s) of `host' as a NULL-terminated list in `realms'.
+ */
+
+krb5_error_code KRB5_LIB_FUNCTION
+krb5_get_host_realm(krb5_context context,
+		    const char *host,
+		    krb5_realm **realms)
+{
+    char hostname[MAXHOSTNAMELEN];
+
+    if (host == NULL) {
+	if (gethostname (hostname, sizeof(hostname)))
+	    return errno;
+	host = hostname;
+    }
+
+    return _krb5_get_host_realm_int (context, host, 1, realms);
+}