diff --git a/audit.c b/audit.c
new file mode 100644
index 000000000..13852a05e
--- /dev/null
+++ b/audit.c
@@ -0,0 +1,181 @@
+/* $Id: audit.c,v 1.1 2005/02/02 13:37:14 dtucker Exp $ */
+
+/*
+ * Copyright (c) 2004, 2005 Darren Tucker.  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"
+
+#ifdef AUDIT_EVENTS
+
+#include "audit.h"
+#include "log.h"
+#include "auth.h"
+
+/*
+ * Care must be taken when using this since it WILL NOT be initialized when
+ * audit_connection_from() is called and MAY NOT be initialized when
+ * audit_event(CONNECTION_ABANDON) is called.  Test for NULL before using.
+ */
+extern Authctxt *the_authctxt;
+
+/* Maybe add the audit class to struct Authmethod? */
+ssh_audit_event_t
+audit_classify_auth(const char *method)
+{
+	if (strcmp(method, "none") == 0)
+		return AUTH_FAIL_NONE;
+	else if (strcmp(method, "password") == 0)
+		return AUTH_FAIL_PASSWD;
+	else if (strcmp(method, "publickey") == 0 ||
+	    strcmp(method, "rsa") == 0)
+		return AUTH_FAIL_PUBKEY;
+	else if (strncmp(method, "keyboard-interactive", 20) == 0 ||
+	    strcmp(method, "challenge-response") == 0)
+		return AUTH_FAIL_KBDINT;
+	else if (strcmp(method, "hostbased") == 0 ||
+	    strcmp(method, "rhosts-rsa") == 0)
+		return AUTH_FAIL_HOSTBASED;
+	else if (strcmp(method, "gssapi-with-mic") == 0)
+		return AUTH_FAIL_GSSAPI;
+	else
+		return AUDIT_UNKNOWN;
+}
+
+/* helper to return supplied username */
+const char *
+audit_username(void)
+{
+	static const char unknownuser[] = "(unknown user)";
+	static const char invaliduser[] = "(invalid user)";
+
+	if (the_authctxt == NULL || the_authctxt->user == NULL)
+		return (unknownuser);
+	if (!the_authctxt->valid)
+		return (invaliduser);
+	return (the_authctxt->user);
+}
+
+const char *
+audit_event_lookup(ssh_audit_event_t ev)
+{
+	int i;
+	static struct event_lookup_struct {
+		ssh_audit_event_t event;
+		const char *name;
+	} event_lookup[] = {
+		{LOGIN_EXCEED_MAXTRIES,	"LOGIN_EXCEED_MAXTRIES"},
+		{LOGIN_ROOT_DENIED,	"LOGIN_ROOT_DENIED"},
+		{AUTH_SUCCESS,		"AUTH_SUCCESS"},
+		{AUTH_FAIL_NONE,	"AUTH_FAIL_NONE"},
+		{AUTH_FAIL_PASSWD,	"AUTH_FAIL_PASSWD"},
+		{AUTH_FAIL_KBDINT,	"AUTH_FAIL_KBDINT"},
+		{AUTH_FAIL_PUBKEY,	"AUTH_FAIL_PUBKEY"},
+		{AUTH_FAIL_HOSTBASED,	"AUTH_FAIL_HOSTBASED"},
+		{AUTH_FAIL_GSSAPI,	"AUTH_FAIL_GSSAPI"},
+		{INVALID_USER,		"INVALID_USER"},
+		{NOLOGIN,		"NOLOGIN"},
+		{CONNECTION_CLOSE,	"CONNECTION_CLOSE"},
+		{CONNECTION_ABANDON,	"CONNECTION_ABANDON"},
+		{AUDIT_UNKNOWN,		"AUDIT_UNKNOWN"}
+	};
+
+	for (i = 0; event_lookup[i].event != AUDIT_UNKNOWN; i++)
+		if (event_lookup[i].event == ev)
+			break;
+	return(event_lookup[i].name);
+}
+
+# ifndef CUSTOM_AUDIT_EVENTS
+/*
+ * Null implementations of audit functions.
+ * These get used if AUDIT_EVENTS is defined but no audit module is enabled.
+ */
+
+/*
+ * Called after a connection has been accepted but before any authentication
+ * has been attempted.
+ */
+void
+audit_connection_from(const char *host, int port)
+{
+	debug("audit connection from %s port %d euid %d", host, port,
+	   (int)geteuid());
+}
+
+/*
+ * Called when various events occur (see audit.h for a list of possible
+ * events and what they mean).
+ */
+void
+audit_event(ssh_audit_event_t event)
+{
+	debug("audit event euid %d user %s event %d (%s)", geteuid(),
+	    audit_username(), event, audit_event_lookup(event));
+}
+
+/*
+ * Called when a user session is started.  Argument is the tty allocated to
+ * the session, or NULL if no tty was allocated.
+ *
+ * Note that this may be called multiple times if multiple sessions are used
+ * within a single connection.
+ */
+void
+audit_session_open(const char *ttyn)
+{
+	const char *t = ttyn ? ttyn : "(no tty)";
+
+	debug("audit session open euid %d user %s tty name %s", geteuid(),
+	     audit_username(), t);
+}
+
+/*
+ * Called when a user session is closed.  Argument is the tty allocated to
+ * the session, or NULL if no tty was allocated.
+ *
+ * Note that this may be called multiple times if multiple sessions are used
+ * within a single connection.
+ */
+void
+audit_session_close(const char *ttyn)
+{
+	const char *t = ttyn ? ttyn : "(no tty)";
+
+	debug("audit session close euid %d user %s tty name %s", geteuid(),
+	     audit_username(), t);
+}
+
+/*
+ * This will be called when a user runs a non-interactive command.  Note that
+ * it may be called multiple times for a single connection since SSH2 allows
+ * multiple sessions within a single connection.
+ */
+void
+audit_run_command(const char *command)
+{
+	debug("audit run command euid %d user %s command '%.200s'", geteuid(),
+	    audit_username(), command);
+}
+# endif  /* !defined CUSTOM_AUDIT_EVENTS */
+#endif /* AUDIT_EVENTS */
diff --git a/audit.h b/audit.h
new file mode 100644
index 000000000..2c1437391
--- /dev/null
+++ b/audit.h
@@ -0,0 +1,56 @@
+/* $Id: audit.h,v 1.1 2005/02/02 13:37:14 dtucker Exp $ */
+
+/*
+ * Copyright (c) 2004, 2005 Darren Tucker.  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 "auth.h"
+
+#ifndef _SSH_AUDIT_H
+# define _SSH_AUDIT_H
+enum ssh_audit_event_type {
+	LOGIN_EXCEED_MAXTRIES,
+	LOGIN_ROOT_DENIED,
+	AUTH_SUCCESS,
+	AUTH_FAIL_NONE,
+	AUTH_FAIL_PASSWD,
+	AUTH_FAIL_KBDINT,	/* keyboard-interactive or challenge-response */
+	AUTH_FAIL_PUBKEY,	/* ssh2 pubkey or ssh1 rsa */
+	AUTH_FAIL_HOSTBASED,	/* ssh2 hostbased or ssh1 rhostsrsa */
+	AUTH_FAIL_GSSAPI,
+	INVALID_USER,
+	NOLOGIN,		/* denied by /etc/nologin, not implemented */
+	CONNECTION_CLOSE,	/* closed after attempting auth or session */
+	CONNECTION_ABANDON,	/* closed without completing auth */
+	AUDIT_UNKNOWN
+};
+typedef enum ssh_audit_event_type ssh_audit_event_t;
+
+void	audit_connection_from(const char *, int);
+void	audit_event(ssh_audit_event_t);
+void	audit_session_open(const char *);
+void	audit_session_close(const char *);
+void	audit_run_command(const char *);
+ssh_audit_event_t audit_classify_auth(const char *);
+
+#endif /* _SSH_AUDIT_H */