diff --git a/lib/asn1/der_length.c b/lib/asn1/der_length.c
new file mode 100644
index 000000000..b02e0d818
--- /dev/null
+++ b/lib/asn1/der_length.c
@@ -0,0 +1,63 @@
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+RCSID("$Id$");
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "der.h"
+
+static size_t
+length_int (unsigned val)
+{
+  size_t ret = 0;
+
+  do {
+    ++ret;
+    val /= 256;
+  } while (val);
+  return ret;
+}
+
+size_t
+length_len (int len)
+{
+  if (len < 128)
+    return 1;
+  else
+    return length_int (len) + 1;
+}
+
+size_t
+length_integer (unsigned *data)
+{
+  size_t len = length_int (*data);
+
+  return 1 + length_len(len) + len;
+}
+
+size_t
+length_general_string (char **data)
+{
+  char *str = *data;
+  size_t len = strlen(str);
+  return 1 + length_len(len) + len;
+}
+
+size_t
+length_octet_string (krb5_data *k)
+{
+  return 1 + length_len(k->len) + k->len;
+}
+
+size_t
+length_generalized_time (time_t *t)
+{
+  krb5_data k;
+  size_t ret;
+
+  time2generalizedtime (*t, &k);
+  ret = 1 + length_len(k.len) + k.len;
+  free (k.data);
+  return ret;
+}