diff --git a/lib/asn1/check-gen.c b/lib/asn1/check-gen.c
new file mode 100644
index 000000000..f37a8d9cf
--- /dev/null
+++ b/lib/asn1/check-gen.c
@@ -0,0 +1,126 @@
+/*
+ * Copyright (c) 1999 - 2003 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. 
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+#include <stdio.h>
+#include <string.h>
+#include <err.h>
+#include <roken.h>
+
+#include <asn1-common.h>
+#include <asn1_err.h>
+#include <der.h>
+#include <krb5_asn1.h>
+
+#include "check-common.h"
+
+RCSID("$Id$");
+
+#define COMPARE_STRING(ac,bc,e) \
+	do { if (strcmp((ac)->e, (bc)->e) != 0) return 1; } while(0)
+#define COMPARE_INTEGER(ac,bc,e) \
+	do { if ((ac)->e != (bc)->e) return 1; } while(0)
+#define COMPARE_MEM(ac,bc,e,len) \
+	do { if (memcmp((ac)->e, (bc)->e,len) != 0) return 1; } while(0)
+
+static int
+cmp_Principal (void *a, void *b)
+{
+    Principal *pa = a;
+    Principal *pb = b;
+    int i;
+
+    COMPARE_STRING(pa,pb,realm);
+    COMPARE_INTEGER(pa,pb,name.name_type);
+    COMPARE_INTEGER(pa,pb,name.name_string.len);
+
+    for (i = 0; i < pa->name.name_string.len; i++)
+	COMPARE_STRING(pa,pb,name.name_string.val[i]);
+
+    return 0;
+}
+
+static int
+test_principal (void)
+{
+    struct test_case tests[] = {
+	{ NULL, 29, 
+	  "0\e \0200\016 \003\002\001\001¡\a0\005\e\003"
+	  "lha¡\a\e\005SU.SE" 
+	},
+	{ NULL, 35,
+	  "0! \0260\024 \003\002\001\001¡\r0\013\e\003"
+	  "lha\e\004root¡\a\e\005SU.SE"
+	},
+	{ NULL, 54, 
+	  "04 &0$ \003\002\001\003¡\0350\e\e\004"
+	  "host\e\023nutcracker.e.kth.se¡\n\e\bE.KTH.SE"
+	},
+    };
+
+
+    char *lha[] = { "lha" };
+    char *lharoot[] = { "lha", "root" };
+    char *datan[] = { "host", "nutcracker.e.kth.se" };
+
+    Principal values[] = { 
+	{ { KRB5_NT_PRINCIPAL, { 1, lha } },  "SU.SE" },
+	{ { KRB5_NT_PRINCIPAL, { 2, lharoot } },  "SU.SE" },
+	{ { KRB5_NT_SRV_HST, { 2, datan } },  "E.KTH.SE" }
+    };
+    int i;
+    int ntests = sizeof(tests) / sizeof(*tests);
+
+    for (i = 0; i < ntests; ++i) {
+	tests[i].val = &values[i];
+	asprintf (&tests[i].name, "Principal %d", i);
+    }
+
+    return generic_test (tests, ntests, sizeof(int),
+			 (generic_encode)encode_Principal,
+			 (generic_length)length_Principal,
+			 (generic_decode)decode_Principal,
+			 cmp_Principal);
+}
+
+int
+main(int argc, char **argv)
+{
+    int ret = 0;
+
+    ret += test_principal ();
+
+    return ret;
+}