1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
|
/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include "analyze.h"
#include "analyze-pcrs.h"
#include "fileio.h"
#include "format-table.h"
#include "hexdecoct.h"
#include "terminal-util.h"
#include "tpm2-util.h"
static int get_pcr_alg(const char **ret) {
assert(ret);
FOREACH_STRING(alg, "sha256", "sha1") {
_cleanup_free_ char *p = NULL;
if (asprintf(&p, "/sys/class/tpm/tpm0/pcr-%s/0", alg) < 0)
return log_oom();
if (access(p, F_OK) < 0) {
if (errno != ENOENT)
return log_error_errno(errno, "Failed to determine whether %s exists: %m", p);
} else {
*ret = alg;
return 1;
}
}
log_notice("Kernel does not support reading PCR values.");
*ret = NULL;
return 0;
}
static int get_current_pcr(const char *alg, uint32_t pcr, void **ret, size_t *ret_size) {
_cleanup_free_ char *p = NULL, *s = NULL;
_cleanup_free_ void *buf = NULL;
size_t ss = 0, bufsize = 0;
int r;
assert(alg);
assert(ret);
assert(ret_size);
if (asprintf(&p, "/sys/class/tpm/tpm0/pcr-%s/%" PRIu32, alg, pcr) < 0)
return log_oom();
r = read_virtual_file(p, 4096, &s, &ss);
if (r < 0)
return log_error_errno(r, "Failed to read '%s': %m", p);
r = unhexmem(s, ss, &buf, &bufsize);
if (r < 0)
return log_error_errno(r, "Failed to decode hex PCR data '%s': %m", s);
*ret = TAKE_PTR(buf);
*ret_size = bufsize;
return 0;
}
static int add_pcr_to_table(Table *table, const char *alg, uint32_t pcr) {
_cleanup_free_ char *h = NULL;
const char *color = NULL;
int r;
if (alg) {
_cleanup_free_ void *buf = NULL;
size_t bufsize = 0;
r = get_current_pcr(alg, pcr, &buf, &bufsize);
if (r < 0)
return r;
h = hexmem(buf, bufsize);
if (!h)
return log_oom();
/* Grey out PCRs that are not sensibly initialized */
if (memeqbyte(0, buf, bufsize) ||
memeqbyte(0xFFU, buf, bufsize))
color = ANSI_GREY;
}
r = table_add_many(table,
TABLE_UINT32, pcr,
TABLE_STRING, tpm2_pcr_index_to_string(pcr),
TABLE_STRING, h,
TABLE_SET_COLOR, color);
if (r < 0)
return table_log_add_error(r);
return 0;
}
int verb_pcrs(int argc, char *argv[], void *userdata) {
_cleanup_(table_unrefp) Table *table = NULL;
const char *alg = NULL;
int r;
if (tpm2_support() != TPM2_SUPPORT_FULL)
log_notice("System lacks full TPM2 support, not showing PCR state.");
else {
r = get_pcr_alg(&alg);
if (r < 0)
return r;
}
table = table_new("nr", "name", alg ?: "-");
if (!table)
return log_oom();
(void) table_set_align_percent(table, table_get_cell(table, 0, 0), 100);
(void) table_set_ersatz_string(table, TABLE_ERSATZ_DASH);
if (!alg) /* hide hash column if we couldn't acquire it */
(void) table_set_display(table, 0, 1);
if (strv_isempty(strv_skip(argv, 1)))
for (uint32_t pi = 0; pi < _TPM2_PCR_INDEX_MAX_DEFINED; pi++) {
r = add_pcr_to_table(table, alg, pi);
if (r < 0)
return r;
}
else {
for (int i = 1; i < argc; i++) {
int pi;
pi = tpm2_pcr_index_from_string(argv[i]);
if (pi < 0)
return log_error_errno(pi, "PCR index \"%s\" not known.", argv[i]);
r = add_pcr_to_table(table, alg, pi);
if (r < 0)
return r;
}
(void) table_set_sort(table, (size_t) 0);
}
r = table_print_with_pager(table, arg_json_format_flags, arg_pager_flags, /* show_header= */true);
if (r < 0)
return log_error_errno(r, "Failed to output table: %m");
return EXIT_SUCCESS;
}
|
