freebsd-dev/usr.bin/login/login_audit.c

/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 2005 Apple Computer, Inc.
 * All rights reserved.
 *
 * @APPLE_BSD_LICENSE_HEADER_START@
 *
 * 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 Apple Computer, Inc. ("Apple") 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 APPLE AND ITS 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 APPLE OR ITS 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.
 *
 * @APPLE_BSD_LICENSE_HEADER_END@
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <sys/types.h>

#include <bsm/libbsm.h>
#include <bsm/audit_uevents.h>

#include <err.h>
#include <errno.h>
#include <pwd.h>
#include <stdio.h>
#include <strings.h>
#include <unistd.h>

#include "login.h"

/*
 * Audit data
 */
static au_tid_t tid;

/*
 * The following tokens are included in the audit record for a successful
 * login: header, subject, return.
 */
void
au_login_success(void)
{
	token_t *tok;
	int aufd;
	au_mask_t aumask;
	auditinfo_t auinfo;
	uid_t uid = pwd->pw_uid;
	gid_t gid = pwd->pw_gid;
	pid_t pid = getpid();
	int au_cond;

	/* If we are not auditing, don't cut an audit record; just return. */
 	if (auditon(A_GETCOND, &au_cond, sizeof(au_cond)) < 0) {
		if (errno == ENOSYS)
			return;
		errx(1, "could not determine audit condition");
	}
	if (au_cond == AUC_NOAUDIT)
		return;

	/* Compute and set the user's preselection mask. */
	if (au_user_mask(pwd->pw_name, &aumask) == -1)
		errx(1, "could not calculate audit mask");

	/* Set the audit info for the user. */
	auinfo.ai_auid = uid;
	auinfo.ai_asid = pid;
	bcopy(&tid, &auinfo.ai_termid, sizeof(auinfo.ai_termid));
	bcopy(&aumask, &auinfo.ai_mask, sizeof(auinfo.ai_mask));
	if (setaudit(&auinfo) != 0)
		err(1, "setaudit failed");

	if ((aufd = au_open()) == -1)
		errx(1, "audit error: au_open() failed");

	if ((tok = au_to_subject32(uid, geteuid(), getegid(), uid, gid, pid,
	    pid, &tid)) == NULL)
		errx(1, "audit error: au_to_subject32() failed");
	au_write(aufd, tok);

	if ((tok = au_to_return32(0, 0)) == NULL)
		errx(1, "audit error: au_to_return32() failed");
	au_write(aufd, tok);

	if (au_close(aufd, 1, AUE_login) == -1)
		errx(1, "audit record was not committed.");
}

/*
 * The following tokens are included in the audit record for failed
 * login attempts: header, subject, text, return.
 */
void
au_login_fail(const char *errmsg, int na)
{
	token_t *tok;
	int aufd;
	int au_cond;
	uid_t uid;
	gid_t gid;
	pid_t pid = getpid();

	/* If we are not auditing, don't cut an audit record; just return. */
 	if (auditon(A_GETCOND, &au_cond, sizeof(au_cond)) < 0) {
		if (errno == ENOSYS)
			return;
		errx(1, "could not determine audit condition");
	}
	if (au_cond == AUC_NOAUDIT)
		return;

	if ((aufd = au_open()) == -1)
		errx(1, "audit error: au_open() failed");

	if (na) {
		/*
		 * Non attributable event.  Assuming that login is not called
		 * within a user's session => auid,asid == -1.
		 */
		if ((tok = au_to_subject32(-1, geteuid(), getegid(), -1, -1,
		    pid, -1, &tid)) == NULL)
			errx(1, "audit error: au_to_subject32() failed");
	} else {
		/* We know the subject -- so use its value instead. */
		uid = pwd->pw_uid;
		gid = pwd->pw_gid;
		if ((tok = au_to_subject32(uid, geteuid(), getegid(), uid,
		    gid, pid, pid, &tid)) == NULL)
			errx(1, "audit error: au_to_subject32() failed");
	}
	au_write(aufd, tok);

	/* Include the error message. */
	if ((tok = au_to_text(errmsg)) == NULL)
		errx(1, "audit error: au_to_text() failed");
	au_write(aufd, tok);

	if ((tok = au_to_return32(1, errno)) == NULL)
		errx(1, "audit error: au_to_return32() failed");
	au_write(aufd, tok);

	if (au_close(aufd, 1, AUE_login) == -1)
		errx(1, "audit error: au_close() was not committed");
}

/*
 * The following tokens are included in the audit record for a logout:
 * header, subject, return.
 */
void
audit_logout(void)
{
	token_t *tok;
	int aufd;
	uid_t uid = pwd->pw_uid;
	gid_t gid = pwd->pw_gid;
	pid_t pid = getpid();
	int au_cond;

	/* If we are not auditing, don't cut an audit record; just return. */
 	if (auditon(A_GETCOND, &au_cond, sizeof(int)) < 0) {
		if (errno == ENOSYS)
			return;
		errx(1, "could not determine audit condition");
	}
	if (au_cond == AUC_NOAUDIT)
		return;

	if ((aufd = au_open()) == -1)
		errx(1, "audit error: au_open() failed");

	/* The subject that is created (euid, egid of the current process). */
	if ((tok = au_to_subject32(uid, geteuid(), getegid(), uid, gid, pid,
	    pid, &tid)) == NULL)
		errx(1, "audit error: au_to_subject32() failed");
	au_write(aufd, tok);

	if ((tok = au_to_return32(0, 0)) == NULL)
		errx(1, "audit error: au_to_return32() failed");
	au_write(aufd, tok);

	if (au_close(aufd, 1, AUE_logout) == -1)
		errx(1, "audit record was not committed.");
}