xref: /aosp_15_r20/external/fsverity-utils/programs/cmd_measure.c (revision b13c0e4024008a1f948ee8189745cb3371f4ac04)
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 <getopt.h>
16 #include <sys/ioctl.h>
17 
18 static const struct option longopts[] = {
19 	{NULL, 0, NULL, 0}
20 };
21 
22 /* Display the fs-verity digest of the given verity file(s). */
fsverity_cmd_measure(const struct fsverity_command * cmd,int argc,char * argv[])23 int fsverity_cmd_measure(const struct fsverity_command *cmd,
24 			 int argc, char *argv[])
25 {
26 	struct fsverity_digest *d = NULL;
27 	struct filedes file;
28 	char digest_hex[FS_VERITY_MAX_DIGEST_SIZE * 2 + 1];
29 	char _hash_alg_name[32];
30 	const char *hash_alg_name;
31 	int status;
32 	int i;
33 
34 	/*
35 	 * No supported options, but run getopt_long() with an empty longopts
36 	 * array so that any options are rejected and "--" works as expected.
37 	 */
38 	if (getopt_long(argc, argv, "", longopts, NULL) != -1)
39 		goto out_usage;
40 
41 	argv += optind;
42 	argc -= optind;
43 
44 	if (argc < 1)
45 		goto out_usage;
46 
47 	d = xzalloc(sizeof(*d) + FS_VERITY_MAX_DIGEST_SIZE);
48 
49 	for (i = 0; i < argc; i++) {
50 		d->digest_size = FS_VERITY_MAX_DIGEST_SIZE;
51 
52 		if (!open_file(&file, argv[i], O_RDONLY, 0))
53 			goto out_err;
54 		if (ioctl(file.fd, FS_IOC_MEASURE_VERITY, d) != 0) {
55 			error_msg_errno("FS_IOC_MEASURE_VERITY failed on '%s'",
56 					file.name);
57 			filedes_close(&file);
58 			goto out_err;
59 		}
60 		filedes_close(&file);
61 
62 		ASSERT(d->digest_size <= FS_VERITY_MAX_DIGEST_SIZE);
63 		bin2hex(d->digest, d->digest_size, digest_hex);
64 		hash_alg_name = libfsverity_get_hash_name(d->digest_algorithm);
65 		if (!hash_alg_name) {
66 			sprintf(_hash_alg_name, "ALG_%u", d->digest_algorithm);
67 			hash_alg_name = _hash_alg_name;
68 		}
69 		printf("%s:%s %s\n", hash_alg_name, digest_hex, argv[i]);
70 	}
71 	status = 0;
72 out:
73 	free(d);
74 	return status;
75 
76 out_err:
77 	status = 1;
78 	goto out;
79 
80 out_usage:
81 	usage(cmd, stderr);
82 	status = 2;
83 	goto out;
84 }
85