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/* 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;
}
/*
* Initializes the Core Root of Trust for Measurements
* in coreboot. The initial code in a chain of trust must measure
* itself.
*
* Summary:
* + Measures the FMAP FMAP partition.
* + Measures bootblock in CBFS or BOOTBLOCK FMAP partition.
* + If vboot starts in romstage, it measures the romstage
* in CBFS.
* + Measure the verstage if it is compiled as separate
* stage.
*
* Takes the current vboot context as parameter for s3 checks.
* returns on success VB2_SUCCESS, else a vboot error.
*/
static 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;
}
struct region_device fmap;
if (fmap_locate_area_as_rdev("FMAP", &fmap) == 0) {
if (tpm_measure_region(&fmap, TPM_CRTM_PCR, "FMAP: FMAP")) {
printk(BIOS_ERR,
"TSPI: Couldn't measure FMAP into CRTM!\n");
return VB2_ERROR_UNKNOWN;
}
} else {
printk(BIOS_ERR, "TSPI: Could not find FMAP!\n");
}
/* 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(const struct region_device *rdev, const char *name,
uint32_t cbfs_type)
{
uint32_t pcr_index;
char tcpa_metadata[TCPA_PCR_HASH_NAME];
if (!tcpa_log_available()) {
if (tspi_init_crtm() != VB2_SUCCESS) {
printk(BIOS_WARNING,
"Initializing CRTM failed!\n");
return 0;
}
printk(BIOS_DEBUG, "CRTM initialized.\n");
}
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;
}
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