summaryrefslogtreecommitdiff
path: root/src/security/tpm/tspi/log.c
blob: 8a9cc888279fb2d04cffd041033e603fa49d969a (plain)
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
/*
 * This file is part of the coreboot project.
 *
 * Copyright 2018 Facebook Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <console/console.h>
#include <security/tpm/tspi.h>
#include <region_file.h>
#include <string.h>
#include <security/vboot/symbols.h>
#include <cbmem.h>
#include <bootstate.h>
#include <vb2_sha.h>

static struct tcpa_table *tcpa_cbmem_init(void)
{
	MAYBE_STATIC_BSS struct tcpa_table *tclt = NULL;
	if (tclt)
		return tclt;

	if (cbmem_possibly_online()) {
		tclt = cbmem_find(CBMEM_ID_TCPA_LOG);
		if (!tclt) {
			size_t tcpa_log_len = sizeof(struct tcpa_table) +
			MAX_TCPA_LOG_ENTRIES * sizeof(struct tcpa_entry);
			tclt = cbmem_add(CBMEM_ID_TCPA_LOG, tcpa_log_len);
			if (tclt) {
				tclt->max_entries = MAX_TCPA_LOG_ENTRIES;
				tclt->num_entries = 0;
			}
		}
	}
	return tclt;
}

static struct tcpa_table *tcpa_log_init(void)
{
	MAYBE_STATIC_BSS struct tcpa_table *tclt = NULL;

	/* We are dealing here with pre CBMEM environment.
	 * If cbmem isn't available use CAR or SRAM */
	if (!cbmem_possibly_online() &&
		!CONFIG(VBOOT_RETURN_FROM_VERSTAGE))
		return (struct tcpa_table *)_vboot2_tpm_log;
	else if (ENV_ROMSTAGE &&
		!CONFIG(VBOOT_RETURN_FROM_VERSTAGE)) {
		tclt = tcpa_cbmem_init();
		if (!tclt)
			return (struct tcpa_table *)_vboot2_tpm_log;
	} else {
		tclt = tcpa_cbmem_init();
	}

	return tclt;
}

void tcpa_log_dump(void *unused)
{
	int i, j;
	struct tcpa_table *tclt;

	tclt = tcpa_log_init();
	if (!tclt)
		return;

	printk(BIOS_INFO, "coreboot TCPA measurements:\n\n");
	for (i = 0; i < tclt->num_entries; i++) {
		struct tcpa_entry *tce = &tclt->entries[i];
		if (tce) {
			printk(BIOS_INFO, " PCR-%u ", tce->pcr);

			for (j = 0; j < tce->digest_length; j++)
				printk(BIOS_INFO, "%02x", tce->digest[j]);

			printk(BIOS_INFO, " %s [%s]\n",
				   tce->digest_type, tce->name);
		}
	}
	printk(BIOS_INFO, "\n");
}

void tcpa_log_add_table_entry(const char *name, const uint32_t pcr,
			enum vb2_hash_algorithm digest_algo,
			const uint8_t *digest,
			const size_t digest_len)
{
	struct tcpa_table *tclt = tcpa_log_init();
	if (!tclt) {
		printk(BIOS_WARNING, "TCPA: Log non-existent!\n");
		return;
	}

	if (tclt->num_entries >= tclt->max_entries) {
		printk(BIOS_WARNING, "TCPA: TCPA log table is full\n");
		return;
	}

	if (!name) {
		printk(BIOS_WARNING, "TCPA: TCPA entry name not set\n");
		return;
	}

	struct tcpa_entry *tce = &tclt->entries[tclt->num_entries++];
	strncpy(tce->name, name, TCPA_PCR_HASH_NAME - 1);
	tce->pcr = pcr;

	if (digest_len > TCPA_DIGEST_MAX_LENGTH) {
		printk(BIOS_WARNING, "TCPA: PCR digest too long for TCPA log entry\n");
		return;
	}

	strncpy(tce->digest_type,
			vb2_get_hash_algorithm_name(digest_algo),
			TCPA_PCR_HASH_LEN - 1);
	tce->digest_length = digest_len;
	memcpy(tce->digest, digest, tce->digest_length);
}

void tcpa_preram_log_clear(void)
{
	printk(BIOS_INFO, "TCPA: Clearing coreboot TCPA log\n");
	struct tcpa_table *tclt = (struct tcpa_table *)_vboot2_tpm_log;
	tclt->max_entries = MAX_TCPA_LOG_ENTRIES;
	tclt->num_entries = 0;
}

#if !CONFIG(VBOOT_RETURN_FROM_VERSTAGE)
static void recover_tcpa_log(int is_recovery)
{
	struct tcpa_table *preram_log = (struct tcpa_table *)_vboot2_tpm_log;
	struct tcpa_table *ram_log = NULL;
	int i;

	if (preram_log->num_entries > MAX_PRERAM_TCPA_LOG_ENTRIES) {
		printk(BIOS_WARNING, "TCPA: Pre-RAM TCPA log is too full, possible corruption\n");
		return;
	}

	ram_log = tcpa_cbmem_init();
	if (!ram_log) {
		printk(BIOS_WARNING, "TCPA: CBMEM not available something went wrong\n");
		return;
	}

	for (i = 0; i < preram_log->num_entries; i++) {
		struct tcpa_entry *tce = &ram_log->entries[ram_log->num_entries++];
		strncpy(tce->name, preram_log->entries[i].name, TCPA_PCR_HASH_NAME - 1);
		tce->pcr = preram_log->entries[i].pcr;

		if (preram_log->entries[i].digest_length > TCPA_DIGEST_MAX_LENGTH) {
			printk(BIOS_WARNING, "TCPA: PCR digest too long for TCPA log entry\n");
			return;
		}

		strncpy(tce->digest_type, preram_log->entries[i].digest_type, TCPA_PCR_HASH_LEN - 1);
		tce->digest_length = MIN(preram_log->entries[i].digest_length, TCPA_DIGEST_MAX_LENGTH);
		memcpy(tce->digest, preram_log->entries[i].digest, tce->digest_length);
	}
}
ROMSTAGE_CBMEM_INIT_HOOK(recover_tcpa_log);
#endif

BOOT_STATE_INIT_ENTRY(BS_PAYLOAD_BOOT, BS_ON_ENTRY, tcpa_log_dump, NULL);