diff --git a/lib/asn1/gen_maybe.c b/lib/asn1/gen_maybe.c
new file mode 100644
index 000000000..46e4e4a63
--- /dev/null
+++ b/lib/asn1/gen_maybe.c
@@ -0,0 +1,57 @@
+#include "asn1_locl.h"
+
+RCSID("$Id$");
+
+void
+generate_type_maybe (Symbol *s)
+{
+    fprintf (headerfile,
+	     "int maybe_%s(unsigned char *, int);\n",
+	     s->gen_name);
+
+    fprintf (codefile, "int\n"
+	     "maybe_%s(unsigned char *p, int len)\n"
+	     "{\n    ", 
+	     s->gen_name);
+  
+    switch (s->type->type) {
+    case TInteger:
+	fprintf (codefile, "return der_match_tag (p, len, UNIV, "
+		 "PRIM, UT_Integer) >= 0;\n");
+	break;
+    case TOctetString:
+	fprintf (codefile, "return der_match_tag (p, len, UNIV, "
+		 "PRIM, UT_OctetString) >= 0;\n");
+	break;
+    case TGeneralizedTime:
+	fprintf (codefile, "return der_match_tag (p, len, UNIV, "
+		 "PRIM, UT_GeneralizedTime) >= 0;\n");
+	break;
+    case TGeneralString:
+	fprintf (codefile, "return der_match_tag (p, len, UNIV, "
+		 "PRIM, UT_GeneralString) >= 0;\n");
+	break;
+    case TBitString:
+	fprintf (codefile, "return der_match_tag (p, len, UNIV, "
+		 "PRIM, UT_BitString) >= 0;\n");
+	break;
+	
+    case TSequence:
+    case TSequenceOf:
+	fprintf (codefile, "return der_match_tag (p, len, UNIV, "
+		 "CONS, UT_Sequence) >= 0;\n");
+	break;
+    case TApplication:
+	fprintf (codefile, "return der_match_tag (p, len, APPL, "
+		 "CONS, %d) >= 0;\n", s->type->application);
+	break;
+    case TType:
+	fprintf (codefile, "return maybe_%s(p, len) >= 0;\n", 
+		 s->type->symbol->gen_name);
+	break;
+    default:
+	abort ();
+    }
+    fprintf (codefile, "}\n\n");
+}
+