/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2021-2023, Juniper Networks, Inc.
* 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 <sys/types.h>
#include <sys/errno.h>
#include <sys/mac.h>
#include <unistd.h>
#include <string.h>
#include <security/mac_veriexec/mac_veriexec.h>
/**
* @brief get veriexec params for a process
*
* @return
* @li 0 if successful
*/
int
veriexec_get_pid_params(pid_t pid,
struct mac_veriexec_syscall_params *params)
{
struct mac_veriexec_syscall_params_args args;
if (params == NULL)
return EINVAL;
args.u.pid = pid;
args.params = params;
return mac_syscall(MAC_VERIEXEC_NAME,
MAC_VERIEXEC_GET_PARAMS_PID_SYSCALL, &args);
}
/**
* @brief get veriexec params for a path
*
* @return
* @li 0 if successful
*/
int
veriexec_get_path_params(const char *file,
struct mac_veriexec_syscall_params *params)
{
struct mac_veriexec_syscall_params_args args;
if (file == NULL || params == NULL)
return EINVAL;
args.u.filename = file;
args.params = params;
return mac_syscall(MAC_VERIEXEC_NAME,
MAC_VERIEXEC_GET_PARAMS_PATH_SYSCALL, &args);
}
/**
* @brief return label associated with a path
*
* @param[in] file
* pathname of file to lookup.
*
* @prarm[in] buf
* if not NULL and big enough copy label to buf.
* otherwise return a copy of label.
*
* @param[in] bufsz
* size of buf, must be greater than found label length.
*
* @return
* @li NULL if no label
* @li pointer to label
*/
char *
veriexec_get_path_label(const char *file, char *buf, size_t bufsz)
{
struct mac_veriexec_syscall_params params;
char *cp;
cp = NULL;
if (veriexec_get_path_params(file, ¶ms) == 0) {
/* Does label contain a label */
if (params.labellen > 0) {
if (buf != NULL && bufsz > params.labellen) {
strlcpy(buf, params.label, bufsz);
cp = buf;
} else
cp = strdup(params.label);
}
}
return cp;
}
/**
* @brief return label of a process
*
*
* @param[in] pid
* process id of interest.
*
* @prarm[in] buf
* if not NULL and big enough copy label to buf.
* otherwise return a copy of label.
*
* @param[in] bufsz
* size of buf, must be greater than found label length.
*
* @return
* @li NULL if no label
* @li pointer to label
*/
char *
veriexec_get_pid_label(pid_t pid, char *buf, size_t bufsz)
{
struct mac_veriexec_syscall_params params;
char *cp;
cp = NULL;
if (veriexec_get_pid_params(pid, ¶ms) == 0) {
/* Does label contain a label */
if (params.labellen > 0) {
if (buf != NULL && bufsz > params.labellen) {
strlcpy(buf, params.label, bufsz);
cp = buf;
} else
cp = strdup(params.label);
}
}
return cp;
}
/*
* we match
* ^want$
* ^want,
* ,want,
* ,want$
*
* and if want ends with / then we match that prefix too.
*/
static int
check_label_want(const char *label, size_t labellen,
const char *want, size_t wantlen)
{
char *cp;
/* Does label contain [,]<want>[,] ? */
if (labellen > 0 && wantlen > 0 &&
(cp = strstr(label, want)) != NULL) {
if (cp == label || cp[-1] == ',') {
if (cp[wantlen] == '\0' || cp[wantlen] == ',' ||
(cp[wantlen-1] == '/' && want[wantlen-1] == '/'))
return 1; /* yes */
}
}
return 0; /* no */
}
/**
* @brief check if a process has label that contains what we want
*
* @param[in] pid
* process id of interest.
*
* @param[in] want
* the label we are looking for
* if want ends with ``/`` it is assumed a prefix
* otherwise we expect it to be followed by ``,`` or end of string.
*
* @return
* @li 0 if no
* @li 1 if yes
*/
int
veriexec_check_pid_label(pid_t pid, const char *want)
{
struct mac_veriexec_syscall_params params;
size_t n;
if (want != NULL &&
(n = strlen(want)) > 0 &&
veriexec_get_pid_params(pid, ¶ms) == 0) {
return check_label_want(params.label, params.labellen,
want, n);
}
return 0; /* no */
}
/**
* @brief check if a path has label that contains what we want
*
* @param[in] path
* pathname of interest.
*
* @param[in] want
* the label we are looking for
* if want ends with ``/`` it is assumed a prefix
* otherwise we expect it to be followed by ``,`` or end of string.
*
* @return
* @li 0 if no
* @li 1 if yes
*/
int
veriexec_check_path_label(const char *file, const char *want)
{
struct mac_veriexec_syscall_params params;
size_t n;
if (want != NULL && file != NULL &&
(n = strlen(want)) > 0 &&
veriexec_get_path_params(file, ¶ms) == 0) {
return check_label_want(params.label, params.labellen,
want, n);
}
return 0; /* no */
}
#ifdef UNIT_TEST
#include <stdlib.h>
#include <stdio.h>
#include <err.h>
static char *
hash2hex(char *type, unsigned char *digest)
{
static char buf[2*MAXFINGERPRINTLEN+1];
size_t n;
int i;
if (strcmp(type, "SHA1") == 0) {
n = 20;
} else if (strcmp(type, "SHA256") == 0) {
n = 32;
} else if (strcmp(type, "SHA384") == 0) {
n = 48;
}
for (i = 0; i < n; i++) {
sprintf(&buf[2*i], "%02x", (unsigned)digest[i]);
}
return buf;
}
int
main(int argc, char *argv[])
{
struct mac_veriexec_syscall_params params;
pid_t pid;
char buf[BUFSIZ];
const char *cp;
char *want = NULL;
int lflag = 0;
int pflag = 0;
int error;
int c;
while ((c = getopt(argc, argv, "lpw:")) != -1) {
switch (c) {
case 'l':
lflag = 1;
break;
case 'p':
pflag = 1;
break;
case 'w':
want = optarg;
break;
default:
break;
}
}
for (; optind < argc; optind++) {
if (pflag) {
pid = atoi(argv[optind]);
if (lflag) {
cp = veriexec_get_pid_label(pid, buf, sizeof(buf));
if (cp)
printf("pid=%d label='%s'\n", pid, cp);
continue;
}
if (want) {
error = veriexec_check_pid_label(pid, want);
printf("pid=%d want='%s': %d\n",
pid, want, error);
continue;
}
error = veriexec_get_pid_params(pid, ¶ms);
} else {
if (lflag) {
cp = veriexec_get_path_label(argv[optind],
buf, sizeof(buf));
if (cp)
printf("path='%s' label='%s'\n",
argv[optind], cp);
continue;
}
if (want) {
error = veriexec_check_path_label(argv[optind], want);
printf("path='%s' want='%s': %d\n",
argv[optind], want, error);
continue;
}
error = veriexec_get_path_params(argv[optind], ¶ms);
}
if (error) {
err(2, "%s, error=%d", argv[optind], error);
}
printf("arg=%s, type=%s, flags=%u, label='%s', fingerprint='%s'\n",
argv[optind], params.fp_type, (unsigned)params.flags,
params.label,
hash2hex(params.fp_type, params.fingerprint));
}
return 0;
}
#endif