diff --git a/auth-chall.c b/auth-chall.c
new file mode 100644
index 0000000..e02e99d
--- /dev/null
+++ b/auth-chall.c
@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2001 Markus Friedl. 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 "includes.h"
+RCSID("$OpenBSD: auth-chall.c,v 1.1 2001/01/18 17:12:43 markus Exp $");
+
+#include "ssh.h"
+#include "auth.h"
+
+#ifdef SKEY
+char *
+get_challenge(Authctxt *authctxt, char *devs)
+{
+	static char challenge[1024];
+        struct skey skey;
+	if (skeychallenge(&skey, authctxt->user, challenge) == -1)
+		return NULL;
+	strlcat(challenge, "\nS/Key Password: ", sizeof challenge);
+	return challenge;
+}
+int
+verify_response(Authctxt *authctxt, char *response)
+{
+	return (authctxt->valid &&
+	    skey_haskey(authctxt->pw->pw_name) == 0 &&
+	    skey_passcheck(authctxt->pw->pw_name, response) != -1);
+}
+#else
+/* not available */
+char *
+get_challenge(Authctxt *authctxt, char *devs)
+{
+	return NULL;
+}
+int
+verify_response(Authctxt *authctxt, char *response)
+{
+	return 0;
+}
+#endif