Sun Microsystems

/* $Id$ */

/*

 * TODO

 *

 * - deal with overlap between this and sys_auth_allowed_user

 *   sys_auth_record_login and record_failed_login.

 */

/*

 * Copyright 1988-2002 Sun Microsystems, Inc.  All rights reserved.

 * Use is subject to license terms.

 *

 * 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.

 *

 */

/* #pragma ident	"@(#)bsmaudit.c	1.1	01/09/17 SMI" */

#include "includes.h"

#if defined(USE_BSM_AUDIT)

#include "ssh.h"

#include "log.h"

#include "auth.h"

#include "xmalloc.h"

#ifndef AUE_openssh

# define AUE_openssh     32800

#endif

#include <bsm/audit.h>

#include <bsm/libbsm.h>

#include <bsm/audit_uevents.h>

#include <bsm/audit_record.h>

#include <locale.h>

#if defined(HAVE_GETAUDIT_ADDR)

#define	AuditInfoStruct		auditinfo_addr

#define AuditInfoTermID		au_tid_addr_t

#define GetAuditFunc(a,b)	getaudit_addr((a),(b))

#define GetAuditFuncText	"getaudit_addr"

#define SetAuditFunc(a,b)	setaudit_addr((a),(b))

#define SetAuditFuncText	"setaudit_addr"

#define AUToSubjectFunc		au_to_subject_ex

#define AUToReturnFunc(a,b)	au_to_return32((a), (int32_t)(b))

#else

#define	AuditInfoStruct		auditinfo

#define AuditInfoTermID		au_tid_t

#define GetAuditFunc(a,b)	getaudit(a)

#define GetAuditFuncText	"getaudit"

#define SetAuditFunc(a,b)	setaudit(a)

#define SetAuditFuncText	"setaudit"

#define AUToSubjectFunc		au_to_subject

#define AUToReturnFunc(a,b)	au_to_return((a), (u_int)(b))

#endif

extern int	cannot_audit(int);

extern void	aug_init(void);

extern dev_t	aug_get_port(void);

extern int 	aug_get_machine(char *, u_int32_t *, u_int32_t *);

extern void	aug_save_auid(au_id_t);

extern void	aug_save_uid(uid_t);

extern void	aug_save_euid(uid_t);

extern void	aug_save_gid(gid_t);

extern void	aug_save_egid(gid_t);

extern void	aug_save_pid(pid_t);

extern void	aug_save_asid(au_asid_t);

extern void	aug_save_tid(dev_t, unsigned int);

extern void	aug_save_tid_ex(dev_t, u_int32_t *, u_int32_t);

extern int	aug_save_me(void);

extern int	aug_save_namask(void);

extern void	aug_save_event(au_event_t);

extern void	aug_save_sorf(int);

extern void	aug_save_text(char *);

extern void	aug_save_text1(char *);

extern void	aug_save_text2(char *);

extern void	aug_save_na(int);

extern void	aug_save_user(char *);

extern void	aug_save_path(char *);

extern int	aug_save_policy(void);

extern void	aug_save_afunc(int (*)(int));

extern int	aug_audit(void);

extern int	aug_na_selected(void);

extern int	aug_selected(void);

extern int	aug_daemon_session(void);

#ifndef HAVE_GETTEXT

# define gettext(a)	(a)

#endif

extern Authctxt *the_authctxt;

static AuditInfoTermID ssh_bsm_tid;

/* Below is the low-level BSM interface code */

/*

 * Check if the specified event is selected (enabled) for auditting.

 * Returns 1 if the event is selected, 0 if not and -1 on failure.

 */

static int

selected(char *username, uid_t uid, au_event_t event, int sf)

{

	int rc, sorf;

	char naflags[512];

	struct au_mask mask;

	mask.am_success = mask.am_failure = 0;

	if (uid < 0) {

		/* get flags for non-attributable (to a real user) events */

		rc = getacna(naflags, sizeof(naflags));

		if (rc == 0)

			(void) getauditflagsbin(naflags, &mask);

	} else

		rc = au_user_mask(username, &mask);

	sorf = (sf == 0) ? AU_PRS_SUCCESS : AU_PRS_FAILURE;

	return(au_preselect(event, &mask, sorf, AU_PRS_REREAD));

}

static void

bsm_audit_record(int typ, char *string, au_event_t event_no)

{

	int		ad, rc, sel;

	uid_t		uid = -1;

	gid_t		gid = -1;

	pid_t		pid = getpid();

	AuditInfoTermID	tid = ssh_bsm_tid;

	if (the_authctxt != NULL && the_authctxt->valid) {

		uid = the_authctxt->pw->pw_uid;

		gid = the_authctxt->pw->pw_gid;

	}

	rc = (typ == 0) ? 0 : -1;

	sel = selected(the_authctxt->user, uid, event_no, rc);

	debug3("BSM audit: typ %d rc %d \"%s\"", typ, rc, string);

	if (!sel)

		return;	/* audit event does not match mask, do not write */

	debug3("BSM audit: writing audit new record");

	ad = au_open();

	(void) au_write(ad, AUToSubjectFunc(uid, uid, gid, uid, gid,

	    pid, pid, &tid));

	(void) au_write(ad, au_to_text(string));

	(void) au_write(ad, AUToReturnFunc(typ, rc));

	rc = au_close(ad, AU_TO_WRITE, event_no);

	if (rc < 0)

		error("BSM audit: %s failed to write \"%s\" record: %s",

		    __func__, string, strerror(errno));

}

static void

bsm_audit_session_setup(void)

{

	int rc;

	struct AuditInfoStruct info;

	au_mask_t mask;

	if (the_authctxt == NULL) {

		error("BSM audit: session setup internal error (NULL ctxt)");

		return;

	}

	if (the_authctxt->valid)

		info.ai_auid = the_authctxt->pw->pw_uid;

	else

		info.ai_auid = -1;

	info.ai_asid = getpid();

	mask.am_success = 0;

	mask.am_failure = 0;

	(void) au_user_mask(the_authctxt->user, &mask);

	info.ai_mask.am_success  = mask.am_success;

	info.ai_mask.am_failure  = mask.am_failure;

	info.ai_termid = ssh_bsm_tid;

	rc = SetAuditFunc(&info, sizeof(info));

	if (rc < 0)

		error("BSM audit: %s: %s failed: %s", __func__,

		    SetAuditFuncText, strerror(errno));

}

static void

bsm_audit_bad_login(const char *what)

{

	char textbuf[BSM_TEXTBUFSZ];

	if (the_authctxt->valid) {

		(void) snprintf(textbuf, sizeof (textbuf),

			gettext("invalid %s for user %s"),

			    what, the_authctxt->user);

		bsm_audit_record(4, textbuf, AUE_openssh);

	} else {

		(void) snprintf(textbuf, sizeof (textbuf),

			gettext("invalid user name \"%s\""),

			    the_authctxt->user);

		bsm_audit_record(3, textbuf, AUE_openssh);

	}

}

/* Below is the sshd audit API code */

void

audit_connection_from(const char *host, int port)

{

	AuditInfoTermID *tid = &ssh_bsm_tid;

	char buf[1024];

	if (cannot_audit(0))

		return;

	debug3("BSM audit: connection from %.100s port %d", host, port);

	/* populate our terminal id structure */

#if defined(HAVE_GETAUDIT_ADDR)

	tid->at_port = (dev_t)port;

	aug_get_machine((char *)host, &(tid->at_addr[0]), &(tid->at_type));

	snprintf(buf, sizeof(buf), "%08x %08x %08x %08x", tid->at_addr[0],

	    tid->at_addr[1], tid->at_addr[2], tid->at_addr[3]);

	debug3("BSM audit: iptype %d machine ID %s", (int)tid->at_type, buf);

#else

	/* this is used on IPv4-only machines */

	tid->port = (dev_t)port;

	tid->machine = inet_addr(host);

	snprintf(buf, sizeof(buf), "%08x", tid->machine);

	debug3("BSM audit: machine ID %s", buf);

#endif

}

void

audit_run_command(const char *command)

{

	/* not implemented */

}

void

audit_session_open(const char *ttyn)

{

	/* not implemented */

}

void

audit_session_close(const char *ttyn)

{

	/* not implemented */

}

void

audit_event(ssh_audit_event_t event)

{

	char    textbuf[BSM_TEXTBUFSZ];

	static int logged_in = 0;

	const char *user = the_authctxt ? the_authctxt->user : "(unknown user)";

	if (cannot_audit(0))

		return;

	switch(event) {

	case SSH_AUTH_SUCCESS:

		logged_in = 1;

		bsm_audit_session_setup();

		snprintf(textbuf, sizeof(textbuf),

		    gettext("successful login %s"), user);

		bsm_audit_record(0, textbuf, AUE_openssh);

		break;

	case SSH_CONNECTION_CLOSE:

		/*

		 * We can also get a close event if the user attempted auth

		 * but never succeeded.

		 */

		if (logged_in) {

			snprintf(textbuf, sizeof(textbuf),

			    gettext("sshd logout %s"), the_authctxt->user);

			bsm_audit_record(0, textbuf, AUE_logout);

		} else {

			debug("%s: connection closed without authentication",

			    __func__);

		}

		break;

	case SSH_NOLOGIN:

		bsm_audit_record(1,

		    gettext("logins disabled by /etc/nologin"), AUE_openssh);

		break;

	case SSH_LOGIN_EXCEED_MAXTRIES:

		snprintf(textbuf, sizeof(textbuf),

		    gettext("too many tries for user %s"), the_authctxt->user);

		bsm_audit_record(1, textbuf, AUE_openssh);

		break;

	case SSH_LOGIN_ROOT_DENIED:

		bsm_audit_record(2, gettext("not_console"), AUE_openssh);

		break;

	case SSH_AUTH_FAIL_PASSWD:

		bsm_audit_bad_login("password");

		break;

	case SSH_AUTH_FAIL_KBDINT:

		bsm_audit_bad_login("interactive password entry");

		break;

	default:

		debug("%s: unhandled event %d", __func__, event);

	}

}

#endif /* BSM */

AUDIT_MODULE=none

AC_ARG_WITH(audit,

	[  --with-audit=module     Enable EXPERIMENTAL audit support (modules=debug,bsm)],

	[

	  AC_MSG_CHECKING(for supported audit module)

	  case "$withval" in

	  bsm)

		AC_MSG_RESULT(bsm)

		AUDIT_MODULE=bsm

		dnl    Checks for headers, libs and functions

		AC_CHECK_HEADERS(bsm/audit.h, [],

		    [AC_MSG_ERROR(BSM enabled and bsm/audit.h not found)])

		AC_CHECK_LIB(bsm, getaudit, [],

		    [AC_MSG_ERROR(BSM enabled and required library not found)])

		AC_CHECK_FUNCS(getaudit, [],

		    [AC_MSG_ERROR(BSM enabled and required function not found)])

		# These are optional

		AC_CHECK_FUNCS(getaudit_addr gettext)

		AC_DEFINE(USE_BSM_AUDIT, [], [Use BSM audit module])

		;;

	  debug)

		AUDIT_MODULE=debug

		AC_MSG_RESULT(debug)

		AC_DEFINE(SSH_AUDIT_EVENTS, [], Use audit debugging module)

		;;

	  *)

		AC_MSG_ERROR([Unknown audit module $withval])

		;;

	esac ]

)

AC_CHECK_TYPES(in_addr_t,,,[#include <netinet/in.h>])

#ifndef HAVE_IN_ADDR_T

typedef u_int32_t	in_addr_t;

#endif

#ifdef USE_BSM_AUDIT

# define SSH_AUDIT_EVENTS

# define CUSTOM_SSH_AUDIT_EVENTS

#endif