1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2021-2023, Juniper Networks, Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 */
29
30#include <sys/types.h>
31#include <sys/errno.h>
32#include <sys/mac.h>
33
34#include <unistd.h>
35#include <string.h>
36
37#include <security/mac_veriexec/mac_veriexec.h>
38
39/**
40 * @brief get veriexec params for a process
41 *
42 * @return
43 * @li 0 if successful
44 */
45int
46veriexec_get_pid_params(pid_t pid,
47    struct mac_veriexec_syscall_params *params)
48{
49	struct mac_veriexec_syscall_params_args args;
50
51	if (params == NULL)
52		return EINVAL;
53
54	args.u.pid = pid;
55	args.params = params;
56	return mac_syscall(MAC_VERIEXEC_NAME,
57	    MAC_VERIEXEC_GET_PARAMS_PID_SYSCALL, &args);
58}
59
60/**
61 * @brief get veriexec params for a path
62 *
63 * @return
64 * @li 0 if successful
65 */
66int
67veriexec_get_path_params(const char *file,
68    struct mac_veriexec_syscall_params *params)
69{
70	struct mac_veriexec_syscall_params_args args;
71
72	if (file == NULL || params == NULL)
73		return EINVAL;
74
75	args.u.filename = file;
76	args.params = params;
77	return mac_syscall(MAC_VERIEXEC_NAME,
78	    MAC_VERIEXEC_GET_PARAMS_PATH_SYSCALL, &args);
79}
80
81/**
82 * @brief return label associated with a path
83 *
84 * @param[in] file
85 *	pathname of file to lookup.
86 *
87 * @prarm[in] buf
88 *	if not NULL and big enough copy label to buf.
89 *	otherwise return a copy of label.
90 *
91 * @param[in] bufsz
92 *	size of buf, must be greater than found label length.
93 *
94 * @return
95 * @li NULL if no label
96 * @li pointer to label
97 */
98char *
99veriexec_get_path_label(const char *file, char *buf, size_t bufsz)
100{
101	struct mac_veriexec_syscall_params params;
102	char *cp;
103
104	cp = NULL;
105	if (veriexec_get_path_params(file, &params) == 0) {
106		/* Does label contain a label */
107		if (params.labellen > 0) {
108			if (buf != NULL && bufsz > params.labellen) {
109				strlcpy(buf, params.label, bufsz);
110				cp = buf;
111			} else
112				cp = strdup(params.label);
113		}
114	}
115	return cp;
116}
117
118/**
119 * @brief return label of a process
120 *
121 *
122 * @param[in] pid
123 *	process id of interest.
124 *
125 * @prarm[in] buf
126 *	if not NULL and big enough copy label to buf.
127 *	otherwise return a copy of label.
128 *
129 * @param[in] bufsz
130 *	size of buf, must be greater than found label length.
131 *
132 * @return
133 * @li NULL if no label
134 * @li pointer to label
135 */
136char *
137veriexec_get_pid_label(pid_t pid, char *buf, size_t bufsz)
138{
139	struct mac_veriexec_syscall_params params;
140	char *cp;
141
142	cp = NULL;
143	if (veriexec_get_pid_params(pid, &params) == 0) {
144		/* Does label contain a label */
145		if (params.labellen > 0) {
146			if (buf != NULL && bufsz > params.labellen) {
147				strlcpy(buf, params.label, bufsz);
148				cp = buf;
149			} else
150				cp = strdup(params.label);
151		}
152	}
153	return cp;
154}
155
156/*
157 * we match
158 * ^want$
159 * ^want,
160 * ,want,
161 * ,want$
162 *
163 * and if want ends with / then we match that prefix too.
164 */
165static int
166check_label_want(const char *label, size_t labellen,
167    const char *want, size_t wantlen)
168{
169	char *cp;
170
171	/* Does label contain [,]<want>[,] ? */
172	if (labellen > 0 && wantlen > 0 &&
173	    (cp = strstr(label, want)) != NULL) {
174		if (cp == label || cp[-1] == ',') {
175			if (cp[wantlen] == '\0' || cp[wantlen] == ',' ||
176			    (cp[wantlen-1] == '/' && want[wantlen-1] == '/'))
177				return 1; /* yes */
178		}
179	}
180	return 0;			/* no */
181}
182
183/**
184 * @brief check if a process has label that contains what we want
185 *
186 * @param[in] pid
187 *	process id of interest.
188 *
189 * @param[in] want
190 *	the label we are looking for
191 *	if want ends with ``/`` it is assumed a prefix
192 *	otherwise we expect it to be followed by ``,`` or end of string.
193 *
194 * @return
195 * @li 0 if no
196 * @li 1 if yes
197 */
198int
199veriexec_check_pid_label(pid_t pid, const char *want)
200{
201	struct mac_veriexec_syscall_params params;
202	size_t n;
203
204	if (want != NULL &&
205	    (n = strlen(want)) > 0 &&
206	    veriexec_get_pid_params(pid, &params) == 0) {
207		return check_label_want(params.label, params.labellen,
208		    want, n);
209	}
210	return 0;			/* no */
211}
212
213/**
214 * @brief check if a path has label that contains what we want
215 *
216 * @param[in] path
217 *	pathname of interest.
218 *
219 * @param[in] want
220 *	the label we are looking for
221 *	if want ends with ``/`` it is assumed a prefix
222 *	otherwise we expect it to be followed by ``,`` or end of string.
223 *
224 * @return
225 * @li 0 if no
226 * @li 1 if yes
227 */
228int
229veriexec_check_path_label(const char *file, const char *want)
230{
231	struct mac_veriexec_syscall_params params;
232	size_t n;
233
234	if (want != NULL && file != NULL &&
235	    (n = strlen(want)) > 0 &&
236	    veriexec_get_path_params(file, &params) == 0) {
237		return check_label_want(params.label, params.labellen,
238		    want, n);
239	}
240	return 0;			/* no */
241}
242
243#ifdef UNIT_TEST
244#include <stdlib.h>
245#include <stdio.h>
246#include <err.h>
247
248static char *
249hash2hex(char *type, unsigned char *digest)
250{
251	static char buf[2*MAXFINGERPRINTLEN+1];
252	size_t n;
253	int i;
254
255	if (strcmp(type, "SHA1") == 0) {
256		n = 20;
257	} else if (strcmp(type, "SHA256") == 0) {
258		n = 32;
259	} else if (strcmp(type, "SHA384") == 0) {
260		n = 48;
261	}
262	for (i = 0; i < n; i++) {
263		sprintf(&buf[2*i], "%02x", (unsigned)digest[i]);
264	}
265	return buf;
266}
267
268int
269main(int argc, char *argv[])
270{
271	struct mac_veriexec_syscall_params params;
272	pid_t pid;
273	char buf[BUFSIZ];
274	const char *cp;
275	char *want = NULL;
276	int lflag = 0;
277	int pflag = 0;
278	int error;
279	int c;
280
281	while ((c = getopt(argc, argv, "lpw:")) != -1) {
282		switch (c) {
283		case 'l':
284			lflag = 1;
285			break;
286		case 'p':
287			pflag = 1;
288			break;
289		case 'w':
290			want = optarg;
291			break;
292		default:
293			break;
294		}
295	}
296	for (; optind < argc; optind++) {
297
298		if (pflag) {
299			pid = atoi(argv[optind]);
300			if (lflag) {
301				cp = veriexec_get_pid_label(pid, buf, sizeof(buf));
302				if (cp)
303					printf("pid=%d label='%s'\n", pid, cp);
304				continue;
305			}
306			if (want) {
307				error = veriexec_check_pid_label(pid, want);
308				printf("pid=%d want='%s': %d\n",
309				    pid, want, error);
310				continue;
311			}
312			error = veriexec_get_pid_params(pid, &params);
313		} else {
314			if (lflag) {
315				cp = veriexec_get_path_label(argv[optind],
316				    buf, sizeof(buf));
317				if (cp)
318					printf("path='%s' label='%s'\n",
319					    argv[optind], cp);
320				continue;
321			}
322			if (want) {
323				error = veriexec_check_path_label(argv[optind], want);
324				printf("path='%s' want='%s': %d\n",
325				    argv[optind], want, error);
326				continue;
327			}
328			error = veriexec_get_path_params(argv[optind], &params);
329		}
330		if (error) {
331			err(2, "%s, error=%d", argv[optind], error);
332		}
333
334		printf("arg=%s, type=%s, flags=%u, label='%s', fingerprint='%s'\n",
335		    argv[optind], params.fp_type, (unsigned)params.flags,
336		    params.label,
337		    hash2hex(params.fp_type, params.fingerprint));
338	}
339	return 0;
340}
341#endif
342