xref: /aosp_15_r20/external/fsverity-utils/programs/cmd_measure.c (revision b13c0e4024008a1f948ee8189745cb3371f4ac04)
1*b13c0e40SEric Biggers // SPDX-License-Identifier: MIT
2*b13c0e40SEric Biggers /*
3*b13c0e40SEric Biggers  * The 'fsverity measure' command
4*b13c0e40SEric Biggers  *
5*b13c0e40SEric Biggers  * Copyright 2018 Google LLC
6*b13c0e40SEric Biggers  *
7*b13c0e40SEric Biggers  * Use of this source code is governed by an MIT-style
8*b13c0e40SEric Biggers  * license that can be found in the LICENSE file or at
9*b13c0e40SEric Biggers  * https://opensource.org/licenses/MIT.
10*b13c0e40SEric Biggers  */
11*b13c0e40SEric Biggers 
12*b13c0e40SEric Biggers #include "fsverity.h"
13*b13c0e40SEric Biggers 
14*b13c0e40SEric Biggers #include <fcntl.h>
15*b13c0e40SEric Biggers #include <getopt.h>
16*b13c0e40SEric Biggers #include <sys/ioctl.h>
17*b13c0e40SEric Biggers 
18*b13c0e40SEric Biggers static const struct option longopts[] = {
19*b13c0e40SEric Biggers 	{NULL, 0, NULL, 0}
20*b13c0e40SEric Biggers };
21*b13c0e40SEric Biggers 
22*b13c0e40SEric Biggers /* Display the fs-verity digest of the given verity file(s). */
fsverity_cmd_measure(const struct fsverity_command * cmd,int argc,char * argv[])23*b13c0e40SEric Biggers int fsverity_cmd_measure(const struct fsverity_command *cmd,
24*b13c0e40SEric Biggers 			 int argc, char *argv[])
25*b13c0e40SEric Biggers {
26*b13c0e40SEric Biggers 	struct fsverity_digest *d = NULL;
27*b13c0e40SEric Biggers 	struct filedes file;
28*b13c0e40SEric Biggers 	char digest_hex[FS_VERITY_MAX_DIGEST_SIZE * 2 + 1];
29*b13c0e40SEric Biggers 	char _hash_alg_name[32];
30*b13c0e40SEric Biggers 	const char *hash_alg_name;
31*b13c0e40SEric Biggers 	int status;
32*b13c0e40SEric Biggers 	int i;
33*b13c0e40SEric Biggers 
34*b13c0e40SEric Biggers 	/*
35*b13c0e40SEric Biggers 	 * No supported options, but run getopt_long() with an empty longopts
36*b13c0e40SEric Biggers 	 * array so that any options are rejected and "--" works as expected.
37*b13c0e40SEric Biggers 	 */
38*b13c0e40SEric Biggers 	if (getopt_long(argc, argv, "", longopts, NULL) != -1)
39*b13c0e40SEric Biggers 		goto out_usage;
40*b13c0e40SEric Biggers 
41*b13c0e40SEric Biggers 	argv += optind;
42*b13c0e40SEric Biggers 	argc -= optind;
43*b13c0e40SEric Biggers 
44*b13c0e40SEric Biggers 	if (argc < 1)
45*b13c0e40SEric Biggers 		goto out_usage;
46*b13c0e40SEric Biggers 
47*b13c0e40SEric Biggers 	d = xzalloc(sizeof(*d) + FS_VERITY_MAX_DIGEST_SIZE);
48*b13c0e40SEric Biggers 
49*b13c0e40SEric Biggers 	for (i = 0; i < argc; i++) {
50*b13c0e40SEric Biggers 		d->digest_size = FS_VERITY_MAX_DIGEST_SIZE;
51*b13c0e40SEric Biggers 
52*b13c0e40SEric Biggers 		if (!open_file(&file, argv[i], O_RDONLY, 0))
53*b13c0e40SEric Biggers 			goto out_err;
54*b13c0e40SEric Biggers 		if (ioctl(file.fd, FS_IOC_MEASURE_VERITY, d) != 0) {
55*b13c0e40SEric Biggers 			error_msg_errno("FS_IOC_MEASURE_VERITY failed on '%s'",
56*b13c0e40SEric Biggers 					file.name);
57*b13c0e40SEric Biggers 			filedes_close(&file);
58*b13c0e40SEric Biggers 			goto out_err;
59*b13c0e40SEric Biggers 		}
60*b13c0e40SEric Biggers 		filedes_close(&file);
61*b13c0e40SEric Biggers 
62*b13c0e40SEric Biggers 		ASSERT(d->digest_size <= FS_VERITY_MAX_DIGEST_SIZE);
63*b13c0e40SEric Biggers 		bin2hex(d->digest, d->digest_size, digest_hex);
64*b13c0e40SEric Biggers 		hash_alg_name = libfsverity_get_hash_name(d->digest_algorithm);
65*b13c0e40SEric Biggers 		if (!hash_alg_name) {
66*b13c0e40SEric Biggers 			sprintf(_hash_alg_name, "ALG_%u", d->digest_algorithm);
67*b13c0e40SEric Biggers 			hash_alg_name = _hash_alg_name;
68*b13c0e40SEric Biggers 		}
69*b13c0e40SEric Biggers 		printf("%s:%s %s\n", hash_alg_name, digest_hex, argv[i]);
70*b13c0e40SEric Biggers 	}
71*b13c0e40SEric Biggers 	status = 0;
72*b13c0e40SEric Biggers out:
73*b13c0e40SEric Biggers 	free(d);
74*b13c0e40SEric Biggers 	return status;
75*b13c0e40SEric Biggers 
76*b13c0e40SEric Biggers out_err:
77*b13c0e40SEric Biggers 	status = 1;
78*b13c0e40SEric Biggers 	goto out;
79*b13c0e40SEric Biggers 
80*b13c0e40SEric Biggers out_usage:
81*b13c0e40SEric Biggers 	usage(cmd, stderr);
82*b13c0e40SEric Biggers 	status = 2;
83*b13c0e40SEric Biggers 	goto out;
84*b13c0e40SEric Biggers }
85