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
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
|
/* SPDX-License-Identifier: GPL-2.0-only */
#include <console/console.h>
#include <fmap.h>
#include <cbfs.h>
#include "crtm.h"
#include <string.h>
/*
* This function sets the TCPA log namespace
* for the cbfs file (region) lookup.
*/
static int create_tcpa_metadata(const struct region_device *rdev,
const char *cbfs_name, char log_string[TCPA_PCR_HASH_NAME])
{
int i;
struct region_device fmap;
static const char *const fmap_cbfs_names[] = {
"COREBOOT",
"FW_MAIN_A",
"FW_MAIN_B",
"RW_LEGACY"
};
for (i = 0; i < ARRAY_SIZE(fmap_cbfs_names); i++) {
if (fmap_locate_area_as_rdev(fmap_cbfs_names[i], &fmap) == 0) {
if (region_is_subregion(region_device_region(&fmap),
region_device_region(rdev))) {
snprintf(log_string, TCPA_PCR_HASH_NAME,
"FMAP: %s CBFS: %s",
fmap_cbfs_names[i], cbfs_name);
return 0;
}
}
}
return -1;
}
static int tcpa_log_initialized;
static inline int tcpa_log_available(void)
{
if (ENV_BOOTBLOCK)
return tcpa_log_initialized;
return 1;
}
uint32_t tspi_init_crtm(void)
{
struct prog bootblock = PROG_INIT(PROG_BOOTBLOCK, "bootblock");
/* Initialize TCPA PRERAM log. */
if (!tcpa_log_available()) {
tcpa_preram_log_clear();
tcpa_log_initialized = 1;
} else {
printk(BIOS_WARNING, "TSPI: CRTM already initialized!\n");
return VB2_SUCCESS;
}
/* measure bootblock from RO */
struct cbfsf bootblock_data;
struct region_device bootblock_fmap;
if (fmap_locate_area_as_rdev("BOOTBLOCK", &bootblock_fmap) == 0) {
if (tpm_measure_region(&bootblock_fmap,
TPM_CRTM_PCR,
"FMAP: BOOTBLOCK"))
return VB2_ERROR_UNKNOWN;
} else {
if (cbfs_boot_locate(&bootblock_data,
prog_name(&bootblock), NULL)) {
/*
* measurement is done in
* tspi_measure_cbfs_hook()
*/
printk(BIOS_INFO,
"TSPI: Couldn't measure bootblock into CRTM!\n");
return VB2_ERROR_UNKNOWN;
}
}
return VB2_SUCCESS;
}
static bool is_runtime_data(const char *name)
{
const char *allowlist = CONFIG_TPM_MEASURED_BOOT_RUNTIME_DATA;
size_t allowlist_len = sizeof(CONFIG_TPM_MEASURED_BOOT_RUNTIME_DATA) - 1;
size_t name_len = strlen(name);
const char *end;
if (!allowlist_len || !name_len)
return false;
while ((end = strchr(allowlist, ' '))) {
if (end - allowlist == name_len && !strncmp(allowlist, name, name_len))
return true;
allowlist = end + 1;
}
return !strcmp(allowlist, name);
}
uint32_t tspi_measure_cbfs_hook(struct cbfsf *fh, const char *name)
{
uint32_t pcr_index;
uint32_t cbfs_type;
struct region_device rdev;
char tcpa_metadata[TCPA_PCR_HASH_NAME];
if (!tcpa_log_available()) {
if (tspi_init_crtm() != VB2_SUCCESS) {
printk(BIOS_WARNING,
"Initializing CRTM failed!");
return 0;
}
printk(BIOS_DEBUG, "CRTM initialized.");
}
cbfsf_file_type(fh, &cbfs_type);
cbfs_file_data(&rdev, fh);
switch (cbfs_type) {
case CBFS_TYPE_MRC_CACHE:
pcr_index = TPM_RUNTIME_DATA_PCR;
break;
/*
* mrc.bin is code executed on CPU, so it
* should not be considered runtime data
*/
case CBFS_TYPE_MRC:
case CBFS_TYPE_STAGE:
case CBFS_TYPE_SELF:
case CBFS_TYPE_FIT:
pcr_index = TPM_CRTM_PCR;
break;
default:
if (is_runtime_data(name))
pcr_index = TPM_RUNTIME_DATA_PCR;
else
pcr_index = TPM_CRTM_PCR;
break;
}
if (create_tcpa_metadata(&rdev, name, tcpa_metadata) < 0)
return VB2_ERROR_UNKNOWN;
return tpm_measure_region(&rdev, pcr_index, tcpa_metadata);
}
int tspi_measure_cache_to_pcr(void)
{
int i;
enum vb2_hash_algorithm hash_alg;
struct tcpa_table *tclt = tcpa_log_init();
if (!tclt) {
printk(BIOS_WARNING, "TCPA: Log non-existent!\n");
return VB2_ERROR_UNKNOWN;
}
if (CONFIG(TPM1)) {
hash_alg = VB2_HASH_SHA1;
} else { /* CONFIG_TPM2 */
hash_alg = VB2_HASH_SHA256;
}
printk(BIOS_DEBUG, "TPM: Write digests cached in TCPA log to PCR\n");
for (i = 0; i < tclt->num_entries; i++) {
struct tcpa_entry *tce = &tclt->entries[i];
if (tce) {
printk(BIOS_DEBUG, "TPM: Write digest for"
" %s into PCR %d\n",
tce->name, tce->pcr);
int result = tlcl_extend(tce->pcr,
tce->digest,
NULL);
if (result != TPM_SUCCESS) {
printk(BIOS_ERR, "TPM: Writing digest"
" of %s into PCR failed with error"
" %d\n",
tce->name, result);
return VB2_ERROR_UNKNOWN;
}
}
}
return VB2_SUCCESS;
}
|
