blob: 084cc3f008fbd3e0347351cd0d757f19b9c59475 [file] [log] [blame]
/*
* (C) Copyright 2015 Google Inc.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* 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; either version 2 of
* the License, or (at your option) any later version.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <common.h>
#include <tpm_lite/tlcl.h>
#include <secure_boot.h>
#define RETURN_ON_FAILURE(tpm_cmd) do { \
uint32_t result_; \
if ((result_ = (tpm_cmd)) != TPM_SUCCESS) { \
printk(KERN_DEBUG "TPM: %08x returned by " #tpm_cmd \
"\n", (int)result_); \
return result_; \
} \
} while (0)
#define PCR_DIGEST_LENGTH 20
#define SHA1_NON_SECURE_BOOT 0
#define SHA1_SECURE_BOOT 1
static const uint8_t bootmode_digests[2][PCR_DIGEST_LENGTH] = {
/* non-secure boot [0, 0, 2] */
{0x1e, 0xf6, 0x24, 0x48, 0x2d, 0x62, 0x0e, 0x43, 0xe6, 0xd3,
0x4d, 0xa1, 0xaf, 0xe4, 0x62, 0x67, 0xfc, 0x69, 0x5d, 0x9b},
/* secure boot [0, 0, 1] */
{0x25, 0x47, 0xcc, 0x73, 0x6e, 0x95, 0x1f, 0xa4, 0x91, 0x98,
0x53, 0xc4, 0x3a, 0xe8, 0x90, 0x86, 0x1a, 0x3b, 0x32, 0x64}
};
static const uint8_t sha256_gfsc100[PCR_DIGEST_LENGTH] = {
0x4f, 0x8c, 0x4d, 0xaf, 0x4d, 0xf3, 0x2e, 0xaf, 0xb5, 0x57,
0xff, 0x76, 0x58, 0x86, 0x02, 0x94, 0x42, 0xdc, 0xce, 0x06
};
static const uint8_t PCR_uninitialized[PCR_DIGEST_LENGTH] = {
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
uint32_t tpm_init(void) {
uint32_t result;
uint8_t disable;
uint8_t deactivated;
uint8_t pcr_value[PCR_DIGEST_LENGTH];
TPM_STCLEAR_FLAGS sflags;
RETURN_ON_FAILURE(tlcl_lib_init());
result = tlcl_startup();
if ((result != TPM_SUCCESS) &&
(result != TPM_E_INVALID_POSTINIT)) {
/* Invalid postinit indicates that TPM_Startup has already been
executed. This situation occurs on reboots on the GFSC100
platform because a reboot does not powercycle the TPM */
printk(KERN_WARNING "TPM_Startup failed: 0x%08x\n", result);
return result;
}
/* Continue or start the self-test of all TPM functions. Untested
functions will return TPM_NEEDS_SELFTEST otherwise */
RETURN_ON_FAILURE(tlcl_continue_self_test());
RETURN_ON_FAILURE(tlcl_get_flags(&disable, &deactivated, NULL));
if (disable || deactivated) {
printk(KERN_DEBUG "TPM: disabled (%d) or deactivated (%d). "
"Fixing...\n", disable, deactivated);
RETURN_ON_FAILURE(tlcl_assert_physical_presence());
RETURN_ON_FAILURE(tlcl_set_enable());
RETURN_ON_FAILURE(tlcl_set_deactivated(0));
}
RETURN_ON_FAILURE(tlcl_get_stclear_flags(&sflags));
if (sflags.deactivated) {
printk(KERN_DEBUG "TPM: Must reboot to re-enable\n");
return TPM_E_MUST_REBOOT;
}
RETURN_ON_FAILURE(tlcl_read_pcr(0, pcr_value));
if (!memcmp(pcr_value, PCR_uninitialized, PCR_DIGEST_LENGTH)) {
/* PCR0 not initialized, extend it with the boot mode */
const uint8_t *digest;
if (get_secure_boot_mode() == SECURE) {
digest = bootmode_digests[SHA1_SECURE_BOOT];
} else {
digest = bootmode_digests[SHA1_NON_SECURE_BOOT];
}
RETURN_ON_FAILURE(tlcl_extend(0, digest, NULL));
}
RETURN_ON_FAILURE(tlcl_read_pcr(1, pcr_value));
if (!memcmp(pcr_value, PCR_uninitialized, PCR_DIGEST_LENGTH)) {
/* PCR1 not initialized, extend it with the platform name */
RETURN_ON_FAILURE(tlcl_extend(1, sha256_gfsc100, NULL));
}
printk(KERN_DEBUG "TPM: Initialization successful\n");
return TPM_SUCCESS;
}
EXPORT_SYMBOL(tpm_init)