1// SPDX-License-Identifier: MIT
2/*
3 * The 'fsverity measure' command
4 *
5 * Copyright 2018 Google LLC
6 *
7 * Use of this source code is governed by an MIT-style
8 * license that can be found in the LICENSE file or at
9 * https://opensource.org/licenses/MIT.
10 */
11
12#include "fsverity.h"
13
14#include <fcntl.h>
15#include <sys/ioctl.h>
16
17/* Display the fs-verity digest of the given verity file(s). */
18int fsverity_cmd_measure(const struct fsverity_command *cmd,
19			 int argc, char *argv[])
20{
21	struct fsverity_digest *d = NULL;
22	struct filedes file;
23	char digest_hex[FS_VERITY_MAX_DIGEST_SIZE * 2 + 1];
24	char _hash_alg_name[32];
25	const char *hash_alg_name;
26	int status;
27	int i;
28
29	if (argc < 2)
30		goto out_usage;
31
32	d = xzalloc(sizeof(*d) + FS_VERITY_MAX_DIGEST_SIZE);
33
34	for (i = 1; i < argc; i++) {
35		d->digest_size = FS_VERITY_MAX_DIGEST_SIZE;
36
37		if (!open_file(&file, argv[i], O_RDONLY, 0))
38			goto out_err;
39		if (ioctl(file.fd, FS_IOC_MEASURE_VERITY, d) != 0) {
40			error_msg_errno("FS_IOC_MEASURE_VERITY failed on '%s'",
41					file.name);
42			filedes_close(&file);
43			goto out_err;
44		}
45		filedes_close(&file);
46
47		ASSERT(d->digest_size <= FS_VERITY_MAX_DIGEST_SIZE);
48		bin2hex(d->digest, d->digest_size, digest_hex);
49		hash_alg_name = libfsverity_get_hash_name(d->digest_algorithm);
50		if (!hash_alg_name) {
51			sprintf(_hash_alg_name, "ALG_%u", d->digest_algorithm);
52			hash_alg_name = _hash_alg_name;
53		}
54		printf("%s:%s %s\n", hash_alg_name, digest_hex, argv[i]);
55	}
56	status = 0;
57out:
58	free(d);
59	return status;
60
61out_err:
62	status = 1;
63	goto out;
64
65out_usage:
66	usage(cmd, stderr);
67	status = 2;
68	goto out;
69}
70