(_kdc_get_preferred_key): new function, Use the order list of

preferred encryption types and sort the available keys and return the
most preferred key.


git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@17907 ec53bebd-3082-4978-b11e-865c3cabbd6b

kdc/misc.c

@@ -84,3 +84,39 @@ _kdc_free_ent(krb5_context context, hdb_entry_ex *ent)
     free (ent);
 }
 
+/*
+ * Use the order list of preferred encryption types and sort the
+ * available keys and return the most preferred key.
+ */
+
+krb5_error_code
+_kdc_get_preferred_key(krb5_context context,
+		       krb5_kdc_configuration *config,
+		       hdb_entry_ex *h,
+		       const char *name,
+		       krb5_enctype *enctype,
+		       Key **key)
+{
+    const krb5_enctype *p;
+    krb5_error_code ret;
+    int i;
+
+    p = krb5_kerberos_enctypes(context);
+
+    for (i = 0; p[i] != ETYPE_NULL; i++) {
+	if (krb5_enctype_valid(context, p[i]) != 0)
+	    continue;
+	ret = hdb_enctype2key(context, 
+			      &h->entry,
+			      p[i],
+			      key);
+	if (ret == 0) {
+	    *enctype = p[i];
+	    return 0;
+	}
+    }
+
+    krb5_set_error_string(context, "No valid kerberos key found for %s", name);
+    return EINVAL;
+}
+