grub/grub-core/kern/efi/tpm.c

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2020-10-29 19:33:00 +00:00
#include <grub/err.h>
#include <grub/i18n.h>
#include <grub/efi/api.h>
#include <grub/efi/efi.h>
#include <grub/efi/tpm.h>
#include <grub/mm.h>
#include <grub/tpm.h>
#include <grub/term.h>
static grub_efi_guid_t tpm_guid = EFI_TPM_GUID;
static grub_efi_guid_t tpm2_guid = EFI_TPM2_GUID;
static grub_efi_boolean_t grub_tpm_present(grub_efi_tpm_protocol_t *tpm)
{
grub_efi_status_t status;
TCG_EFI_BOOT_SERVICE_CAPABILITY caps;
grub_uint32_t flags;
grub_efi_physical_address_t eventlog, lastevent;
caps.Size = (grub_uint8_t)sizeof(caps);
status = efi_call_5(tpm->status_check, tpm, &caps, &flags, &eventlog,
&lastevent);
if (status != GRUB_EFI_SUCCESS || caps.TPMDeactivatedFlag
|| !caps.TPMPresentFlag)
return 0;
return 1;
}
static grub_efi_boolean_t grub_tpm2_present(grub_efi_tpm2_protocol_t *tpm)
{
grub_efi_status_t status;
EFI_TCG2_BOOT_SERVICE_CAPABILITY caps;
caps.Size = (grub_uint8_t)sizeof(caps);
status = efi_call_2(tpm->get_capability, tpm, &caps);
if (status != GRUB_EFI_SUCCESS || !caps.TPMPresentFlag)
return 0;
return 1;
}
static grub_efi_boolean_t grub_tpm_handle_find(grub_efi_handle_t *tpm_handle,
grub_efi_uint8_t *protocol_version)
{
grub_efi_handle_t *handles;
grub_efi_uintn_t num_handles;
handles = grub_efi_locate_handle (GRUB_EFI_BY_PROTOCOL, &tpm_guid, NULL,
&num_handles);
if (handles && num_handles > 0) {
*tpm_handle = handles[0];
*protocol_version = 1;
return 1;
}
handles = grub_efi_locate_handle (GRUB_EFI_BY_PROTOCOL, &tpm2_guid, NULL,
&num_handles);
if (handles && num_handles > 0) {
*tpm_handle = handles[0];
*protocol_version = 2;
return 1;
}
return 0;
}
static grub_err_t
grub_tpm1_execute(grub_efi_handle_t tpm_handle,
PassThroughToTPM_InputParamBlock *inbuf,
PassThroughToTPM_OutputParamBlock *outbuf)
{
grub_efi_status_t status;
grub_efi_tpm_protocol_t *tpm;
grub_uint32_t inhdrsize = sizeof(*inbuf) - sizeof(inbuf->TPMOperandIn);
grub_uint32_t outhdrsize = sizeof(*outbuf) - sizeof(outbuf->TPMOperandOut);
tpm = grub_efi_open_protocol (tpm_handle, &tpm_guid,
GRUB_EFI_OPEN_PROTOCOL_GET_PROTOCOL);
if (!grub_tpm_present(tpm))
return 0;
/* UEFI TPM protocol takes the raw operand block, no param block header */
status = efi_call_5 (tpm->pass_through_to_tpm, tpm,
inbuf->IPBLength - inhdrsize, inbuf->TPMOperandIn,
outbuf->OPBLength - outhdrsize, outbuf->TPMOperandOut);
switch (status) {
case GRUB_EFI_SUCCESS:
return 0;
case GRUB_EFI_DEVICE_ERROR:
return grub_error (GRUB_ERR_IO, N_("Command failed"));
case GRUB_EFI_INVALID_PARAMETER:
return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("Invalid parameter"));
case GRUB_EFI_BUFFER_TOO_SMALL:
return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("Output buffer too small"));
case GRUB_EFI_NOT_FOUND:
return grub_error (GRUB_ERR_UNKNOWN_DEVICE, N_("TPM unavailable"));
default:
return grub_error (GRUB_ERR_UNKNOWN_DEVICE, N_("Unknown TPM error"));
}
}
static grub_err_t
grub_tpm2_execute(grub_efi_handle_t tpm_handle,
PassThroughToTPM_InputParamBlock *inbuf,
PassThroughToTPM_OutputParamBlock *outbuf)
{
grub_efi_status_t status;
grub_efi_tpm2_protocol_t *tpm;
grub_uint32_t inhdrsize = sizeof(*inbuf) - sizeof(inbuf->TPMOperandIn);
grub_uint32_t outhdrsize = sizeof(*outbuf) - sizeof(outbuf->TPMOperandOut);
tpm = grub_efi_open_protocol (tpm_handle, &tpm2_guid,
GRUB_EFI_OPEN_PROTOCOL_GET_PROTOCOL);
if (!grub_tpm2_present(tpm))
return 0;
/* UEFI TPM protocol takes the raw operand block, no param block header */
status = efi_call_5 (tpm->submit_command, tpm,
inbuf->IPBLength - inhdrsize, inbuf->TPMOperandIn,
outbuf->OPBLength - outhdrsize, outbuf->TPMOperandOut);
switch (status) {
case GRUB_EFI_SUCCESS:
return 0;
case GRUB_EFI_DEVICE_ERROR:
return grub_error (GRUB_ERR_IO, N_("Command failed"));
case GRUB_EFI_INVALID_PARAMETER:
return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("Invalid parameter"));
case GRUB_EFI_BUFFER_TOO_SMALL:
return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("Output buffer too small"));
case GRUB_EFI_NOT_FOUND:
return grub_error (GRUB_ERR_UNKNOWN_DEVICE, N_("TPM unavailable"));
default:
return grub_error (GRUB_ERR_UNKNOWN_DEVICE, N_("Unknown TPM error"));
}
}
grub_err_t
grub_tpm_execute(PassThroughToTPM_InputParamBlock *inbuf,
PassThroughToTPM_OutputParamBlock *outbuf)
{
grub_efi_handle_t tpm_handle;
grub_uint8_t protocol_version;
/* It's not a hard failure for there to be no TPM */
if (!grub_tpm_handle_find(&tpm_handle, &protocol_version))
return 0;
if (protocol_version == 1) {
return grub_tpm1_execute(tpm_handle, inbuf, outbuf);
} else {
return grub_tpm2_execute(tpm_handle, inbuf, outbuf);
}
}
static grub_err_t
grub_tpm1_log_event(grub_efi_handle_t tpm_handle, unsigned char *buf,
grub_size_t size, grub_uint8_t pcr,
const char *description)
{
TCG_PCR_EVENT *event;
grub_efi_status_t status;
grub_efi_tpm_protocol_t *tpm;
grub_efi_physical_address_t lastevent;
grub_uint32_t algorithm;
grub_uint32_t eventnum = 0;
tpm = grub_efi_open_protocol (tpm_handle, &tpm_guid,
GRUB_EFI_OPEN_PROTOCOL_GET_PROTOCOL);
if (!grub_tpm_present(tpm))
return 0;
event = grub_zalloc(sizeof (TCG_PCR_EVENT) + grub_strlen(description) + 1);
if (!event)
return grub_error (GRUB_ERR_OUT_OF_MEMORY,
N_("cannot allocate TPM event buffer"));
event->PCRIndex = pcr;
event->EventType = EV_IPL;
event->EventSize = grub_strlen(description) + 1;
grub_memcpy(event->Event, description, event->EventSize);
algorithm = TCG_ALG_SHA;
status = efi_call_7 (tpm->log_extend_event, tpm, (grub_efi_physical_address_t)buf, (grub_uint64_t) size,
algorithm, event, &eventnum, &lastevent);
switch (status) {
case GRUB_EFI_SUCCESS:
return 0;
case GRUB_EFI_DEVICE_ERROR:
return grub_error (GRUB_ERR_IO, N_("Command failed"));
case GRUB_EFI_INVALID_PARAMETER:
return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("Invalid parameter"));
case GRUB_EFI_BUFFER_TOO_SMALL:
return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("Output buffer too small"));
case GRUB_EFI_NOT_FOUND:
return grub_error (GRUB_ERR_UNKNOWN_DEVICE, N_("TPM unavailable"));
default:
return grub_error (GRUB_ERR_UNKNOWN_DEVICE, N_("Unknown TPM error"));
}
}
static grub_err_t
grub_tpm2_log_event(grub_efi_handle_t tpm_handle, unsigned char *buf,
grub_size_t size, grub_uint8_t pcr,
const char *description)
{
EFI_TCG2_EVENT *event;
grub_efi_status_t status;
grub_efi_tpm2_protocol_t *tpm;
tpm = grub_efi_open_protocol (tpm_handle, &tpm2_guid,
GRUB_EFI_OPEN_PROTOCOL_GET_PROTOCOL);
if (!grub_tpm2_present(tpm))
return 0;
event = grub_zalloc(sizeof (EFI_TCG2_EVENT) + grub_strlen(description) + 1);
if (!event)
return grub_error (GRUB_ERR_OUT_OF_MEMORY,
N_("cannot allocate TPM event buffer"));
event->Header.HeaderSize = sizeof(EFI_TCG2_EVENT_HEADER);
event->Header.HeaderVersion = 1;
event->Header.PCRIndex = pcr;
event->Header.EventType = EV_IPL;
event->Size = sizeof(*event) - sizeof(event->Event) + grub_strlen(description) + 1;
grub_memcpy(event->Event, description, grub_strlen(description) + 1);
status = efi_call_5 (tpm->hash_log_extend_event, tpm, 0, (grub_efi_physical_address_t)buf,
(grub_uint64_t) size, event);
switch (status) {
case GRUB_EFI_SUCCESS:
return 0;
case GRUB_EFI_DEVICE_ERROR:
return grub_error (GRUB_ERR_IO, N_("Command failed"));
case GRUB_EFI_INVALID_PARAMETER:
return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("Invalid parameter"));
case GRUB_EFI_BUFFER_TOO_SMALL:
return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("Output buffer too small"));
case GRUB_EFI_NOT_FOUND:
return grub_error (GRUB_ERR_UNKNOWN_DEVICE, N_("TPM unavailable"));
default:
return grub_error (GRUB_ERR_UNKNOWN_DEVICE, N_("Unknown TPM error"));
}
}
grub_err_t
grub_tpm_log_event(unsigned char *buf, grub_size_t size, grub_uint8_t pcr,
const char *description)
{
grub_efi_handle_t tpm_handle;
grub_efi_uint8_t protocol_version;
if (!grub_tpm_handle_find(&tpm_handle, &protocol_version))
return 0;
if (protocol_version == 1) {
return grub_tpm1_log_event(tpm_handle, buf, size, pcr, description);
} else {
return grub_tpm2_log_event(tpm_handle, buf, size, pcr, description);
}
}