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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Unlike log.c this implements TPM log according to TPM2.0 specification
* rather then using coreboot-specific log format.
*
* First entry is in TPM1.2 format and serves as a header, the rest are in
* a newer (agile) format which supports SHA256 and multiple hashes, but we
* store only one hash.
*
* This is defined in "TCG EFI Protocol Specification".
*/
#include <endian.h>
#include <console/console.h>
#include <security/tpm/tspi.h>
#include <security/tpm/tspi/crtm.h>
#include <security/tpm/tspi/logs.h>
#include <region_file.h>
#include <string.h>
#include <symbols.h>
#include <cbmem.h>
#include <vb2_sha.h>
static uint16_t tpmalg_from_vb2_hash(enum vb2_hash_algorithm hash_type)
{
switch (hash_type) {
case VB2_HASH_SHA1:
return TPM2_ALG_SHA1;
case VB2_HASH_SHA256:
return TPM2_ALG_SHA256;
case VB2_HASH_SHA384:
return TPM2_ALG_SHA384;
case VB2_HASH_SHA512:
return TPM2_ALG_SHA512;
default:
return 0xFF;
}
}
void *tpm2_log_cbmem_init(void)
{
static struct tpm_2_log_table *tclt;
if (tclt)
return tclt;
if (cbmem_possibly_online()) {
size_t tpm_log_len;
struct tcg_efi_spec_id_event *hdr;
tclt = cbmem_find(CBMEM_ID_TPM2_TCG_LOG);
if (tclt)
return tclt;
tpm_log_len = sizeof(struct tpm_2_log_table) +
MAX_TPM_LOG_ENTRIES * sizeof(struct tpm_2_log_entry);
tclt = cbmem_add(CBMEM_ID_TPM2_TCG_LOG, tpm_log_len);
if (!tclt)
return NULL;
memset(tclt, 0, tpm_log_len);
hdr = &tclt->header;
hdr->event_type = htole32(EV_NO_ACTION);
hdr->event_size = htole32(33 + sizeof(tclt->vendor));
strcpy((char *)hdr->signature, TPM_20_SPEC_ID_EVENT_SIGNATURE);
hdr->platform_class = htole32(0x00); // client platform
hdr->spec_version_minor = 0x00;
hdr->spec_version_major = 0x02;
hdr->spec_errata = 0x00;
hdr->uintn_size = 0x02; // 64-bit UINT
hdr->num_of_algorithms = htole32(1);
hdr->digest_sizes[0].alg_id = htole16(tpmalg_from_vb2_hash(TPM_MEASURE_ALGO));
hdr->digest_sizes[0].digest_size = htole16(vb2_digest_size(TPM_MEASURE_ALGO));
tclt->vendor_info_size = sizeof(tclt->vendor);
tclt->vendor.reserved = 0;
tclt->vendor.version_major = TPM_20_LOG_VI_MAJOR;
tclt->vendor.version_minor = TPM_20_LOG_VI_MINOR;
tclt->vendor.magic = htole32(TPM_20_LOG_VI_MAGIC);
tclt->vendor.max_entries = htole16(MAX_TPM_LOG_ENTRIES);
tclt->vendor.num_entries = htole16(0);
tclt->vendor.entry_size = htole32(sizeof(struct tpm_2_log_entry));
}
return tclt;
}
void tpm2_log_dump(void)
{
int i, j;
struct tpm_2_log_table *tclt;
int hash_size;
const char *alg_name;
tclt = tpm_log_init();
if (!tclt)
return;
hash_size = vb2_digest_size(TPM_MEASURE_ALGO);
alg_name = vb2_get_hash_algorithm_name(TPM_MEASURE_ALGO);
printk(BIOS_INFO, "coreboot TPM 2.0 measurements:\n\n");
for (i = 0; i < le16toh(tclt->vendor.num_entries); i++) {
struct tpm_2_log_entry *tce = &tclt->entries[i];
printk(BIOS_INFO, " PCR-%u ", le32toh(tce->pcr));
for (j = 0; j < hash_size; j++)
printk(BIOS_INFO, "%02x", tce->digest[j]);
printk(BIOS_INFO, " %s [%s]\n", alg_name, tce->data);
}
printk(BIOS_INFO, "\n");
}
void tpm2_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 tpm_2_log_table *tclt;
struct tpm_2_log_entry *tce;
tclt = tpm_log_init();
if (!tclt) {
printk(BIOS_WARNING, "TPM LOG: non-existent!\n");
return;
}
if (!name) {
printk(BIOS_WARNING, "TPM LOG: entry name not set\n");
return;
}
if (digest_algo != TPM_MEASURE_ALGO) {
printk(BIOS_WARNING, "TPM LOG: digest is of unsupported type: %s\n",
vb2_get_hash_algorithm_name(digest_algo));
return;
}
if (digest_len != vb2_digest_size(TPM_MEASURE_ALGO)) {
printk(BIOS_WARNING, "TPM LOG: digest has invalid length: %d\n",
(int)digest_len);
return;
}
if (le16toh(tclt->vendor.num_entries) >= le16toh(tclt->vendor.max_entries)) {
printk(BIOS_WARNING, "TPM LOG: log table is full\n");
return;
}
tce = &tclt->entries[le16toh(tclt->vendor.num_entries)];
tclt->vendor.num_entries = htole16(le16toh(tclt->vendor.num_entries) + 1);
tce->pcr = htole32(pcr);
tce->event_type = htole32(EV_ACTION);
tce->digest_count = htole32(1);
tce->digest_type = htole16(tpmalg_from_vb2_hash(TPM_MEASURE_ALGO));
memcpy(tce->digest, digest, vb2_digest_size(TPM_MEASURE_ALGO));
tce->data_length = htole32(sizeof(tce->data));
strncpy((char *)tce->data, name, sizeof(tce->data) - 1);
tce->data[sizeof(tce->data) - 1] = '\0';
}
int tpm2_log_get(int entry_idx, int *pcr, const uint8_t **digest_data,
enum vb2_hash_algorithm *digest_algo, const char **event_name)
{
struct tpm_2_log_table *tclt;
struct tpm_2_log_entry *tce;
tclt = tpm_log_init();
if (!tclt)
return 1;
if (entry_idx < 0 || entry_idx >= le16toh(tclt->vendor.num_entries))
return 1;
tce = &tclt->entries[entry_idx];
*pcr = le32toh(tce->pcr);
*digest_data = tce->digest;
*digest_algo = TPM_MEASURE_ALGO; /* We validate algorithm on addition */
*event_name = (char *)tce->data;
return 0;
}
uint16_t tpm2_log_get_size(const void *log_table)
{
const struct tpm_2_log_table *tclt = log_table;
return le16toh(tclt->vendor.num_entries);
}
void tpm2_preram_log_clear(void)
{
printk(BIOS_INFO, "TPM LOG: clearing the log\n");
/*
* Pre-RAM log is only for internal use and isn't exported anywhere, hence it's header
* is not initialized.
*/
struct tpm_2_log_table *tclt = (struct tpm_2_log_table *)_tpm_log;
tclt->vendor.max_entries = htole16(MAX_TPM_LOG_ENTRIES);
tclt->vendor.num_entries = htole16(0);
}
void tpm2_log_copy_entries(const void *from, void *to)
{
const struct tpm_2_log_table *from_log = from;
struct tpm_2_log_table *to_log = to;
int i;
for (i = 0; i < le16toh(from_log->vendor.num_entries); i++) {
struct tpm_2_log_entry *tce =
&to_log->entries[le16toh(to_log->vendor.num_entries)];
to_log->vendor.num_entries = htole16(le16toh(to_log->vendor.num_entries) + 1);
tce->pcr = from_log->entries[i].pcr;
tce->event_type = from_log->entries[i].event_type;
tce->digest_count = from_log->entries[i].digest_count;
tce->digest_type = from_log->entries[i].digest_type;
memcpy(tce->digest, from_log->entries[i].digest, sizeof(tce->digest));
tce->data_length = from_log->entries[i].data_length;
memcpy(tce->data, from_log->entries[i].data, sizeof(tce->data));
}
}
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