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/*
* Copyright 2016 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include <commonlib/endian.h>
#include <console/console.h>
#include <stdlib.h>
#include <string.h>
#include "tpm2_marshaling.h"
static uint16_t tpm_tag; /* Depends on the command type. */
/*
* Each unmarshaling function receives a pointer to the buffer pointer and a
* pointer to the size of data still in the buffer. The function extracts data
* from the buffer and adjusts both buffer pointer and remaining data size.
*
* Should there be not enough data in the buffer to unmarshal the required
* object, the remaining data size is set to -1 to indicate the error. The
* remaining data size is expected to be set to zero once the last data item
* has been extracted from the receive buffer.
*/
static uint16_t unmarshal_u16(void **buffer, int *buffer_space)
{
uint16_t value;
if (*buffer_space < 0)
return 0;
if (*buffer_space < sizeof(value)) {
*buffer_space = -1; /* Indicate a failure. */
return 0;
}
value = read_be16(*buffer);
*buffer = (void *) ((uintptr_t) (*buffer) + sizeof(value));
*buffer_space -= sizeof(value);
return value;
}
static uint16_t unmarshal_u32(void **buffer, int *buffer_space)
{
uint32_t value;
if (*buffer_space < 0)
return 0;
if (*buffer_space < sizeof(value)) {
*buffer_space = -1; /* Indicate a failure. */
return 0;
}
value = read_be32(*buffer);
*buffer = (void *) ((uintptr_t) (*buffer) + sizeof(value));
*buffer_space -= sizeof(value);
return value;
}
static uint8_t unmarshal_u8(void **buffer, int *buffer_space)
{
uint8_t value;
if (*buffer_space < 0)
return 0;
if (*buffer_space < sizeof(value)) {
*buffer_space = -1; /* Indicate a failure. */
return 0;
}
value = ((uint8_t *)(*buffer))[0];
*buffer = (void *) ((uintptr_t) (*buffer) + sizeof(value));
*buffer_space -= sizeof(value);
return value;
}
#define unmarshal_TPM_CAP(a, b) unmarshal_u32(a, b)
#define unmarshal_TPM_CC(a, b) unmarshal_u32(a, b)
#define unmarshal_TPM_PT(a, b) unmarshal_u32(a, b)
#define unmarshal_TPM_HANDLE(a, b) unmarshal_u32(a, b)
/*
* Each marshaling function receives a pointer to the buffer to marshal into,
* a pointer to the data item to be marshaled, and a pointer to the remaining
* room in the buffer.
*/
/*
* Marshaling an arbitrary blob requires its size in addition to common
* parameter set.
*/
static void marshal_blob(void **buffer, void *blob,
size_t blob_size, size_t *buffer_space)
{
if (*buffer_space < blob_size) {
*buffer_space = -1;
return;
}
memcpy(*buffer, blob, blob_size);
*buffer_space -= blob_size;
*buffer = (void *)((uintptr_t)(*buffer) + blob_size);
}
static void marshal_u8(void **buffer, uint8_t value, size_t *buffer_space)
{
uint8_t *bp = *buffer;
if (*buffer_space < sizeof(value)) {
*buffer_space = 0;
return;
}
*bp++ = value;
*buffer = bp;
*buffer_space -= sizeof(value);
}
static void marshal_u16(void **buffer, uint16_t value, size_t *buffer_space)
{
if (*buffer_space < sizeof(value)) {
*buffer_space = 0;
return;
}
write_be16(*buffer, value);
*buffer = (void *)((uintptr_t)(*buffer) + sizeof(value));
*buffer_space -= sizeof(value);
}
static void marshal_u32(void **buffer, uint32_t value, size_t *buffer_space)
{
if (*buffer_space < sizeof(value)) {
*buffer_space = 0;
return;
}
write_be32(*buffer, value);
*buffer = (void *)((uintptr_t)(*buffer) + sizeof(value));
*buffer_space -= sizeof(value);
}
#define marshal_TPM_HANDLE(a, b, c) marshal_u32(a, b, c)
#define marshal_TPMI_RH_NV_AUTH(a, b, c) marshal_TPM_HANDLE(a, b, c)
#define marshal_TPMI_RH_NV_INDEX(a, b, c) marshal_TPM_HANDLE(a, b, c)
#define marshal_TPMI_SH_AUTH_SESSION(a, b, c) marshal_TPM_HANDLE(a, b, c)
#define marshal_TPMI_ALG_HASH(a, b, c) marshal_u16(a, b, c)
static void marshal_startup(void **buffer,
struct tpm2_startup *cmd_body,
size_t *buffer_space)
{
marshal_u16(buffer, cmd_body->startup_type, buffer_space);
}
static void marshal_get_capability(void **buffer,
struct tpm2_get_capability *cmd_body,
size_t *buffer_space)
{
marshal_u32(buffer, cmd_body->capability, buffer_space);
marshal_u32(buffer, cmd_body->property, buffer_space);
marshal_u32(buffer, cmd_body->propertyCount, buffer_space);
}
static void marshal_TPM2B(void **buffer,
TPM2B *data,
size_t *buffer_space)
{
size_t total_size = data->size + sizeof(data->size);
if (total_size > *buffer_space) {
*buffer_space = 0;
return;
}
marshal_u16(buffer, data->size, buffer_space);
memcpy(*buffer, data->buffer, data->size);
*buffer = ((uint8_t *)(*buffer)) + data->size;
*buffer_space -= data->size;
}
static void marshal_TPMA_NV(void **buffer,
TPMA_NV *nv,
size_t *buffer_space)
{
marshal_u32(buffer, *((uint32_t *)nv), buffer_space);
}
static void marshal_TPMS_NV_PUBLIC(void **buffer,
TPMS_NV_PUBLIC *nvpub,
size_t *buffer_space)
{
marshal_TPM_HANDLE(buffer, nvpub->nvIndex, buffer_space);
marshal_TPMI_ALG_HASH(buffer, nvpub->nameAlg, buffer_space);
marshal_TPMA_NV(buffer, &nvpub->attributes, buffer_space);
marshal_TPM2B(buffer, &nvpub->authPolicy.b, buffer_space);
marshal_u16(buffer, nvpub->dataSize, buffer_space);
}
static void marshal_session_header(void **buffer,
struct tpm2_session_header *session_header,
size_t *buffer_space)
{
size_t base_size;
void *size_location = *buffer;
/* Skip room for the session header size. */
if (*buffer_space < sizeof(uint32_t)) {
*buffer_space = 0;
return;
}
*buffer_space -= sizeof(uint32_t);
*buffer = (void *)(((uintptr_t) *buffer) + sizeof(uint32_t));
base_size = *buffer_space;
marshal_u32(buffer, session_header->session_handle, buffer_space);
marshal_u16(buffer, session_header->nonce_size, buffer_space);
marshal_blob(buffer, session_header->nonce,
session_header->nonce_size, buffer_space);
marshal_u8(buffer, session_header->session_attrs, buffer_space);
marshal_u16(buffer, session_header->auth_size, buffer_space);
marshal_blob(buffer, session_header->auth,
session_header->auth_size, buffer_space);
if (!*buffer_space)
return; /* The structure did not fit. */
/* Paste in the session size. */
marshal_u32(&size_location, base_size - *buffer_space, &base_size);
}
static void marshal_nv_define_space(void **buffer,
struct tpm2_nv_define_space_cmd *nvd_in,
size_t *buffer_space)
{
void *size_location;
size_t base_size;
size_t sizeof_nv_public_size = sizeof(uint16_t);
struct tpm2_session_header session_header;
marshal_TPM_HANDLE(buffer, TPM_RH_PLATFORM, buffer_space);
memset(&session_header, 0, sizeof(session_header));
session_header.session_handle = TPM_RS_PW;
marshal_session_header(buffer, &session_header, buffer_space);
tpm_tag = TPM_ST_SESSIONS;
marshal_TPM2B(buffer, &nvd_in->auth.b, buffer_space);
/* This is where the TPMS_NV_PUBLIC size will be stored. */
size_location = *buffer;
/* Allocate room for the size. */
*buffer = ((uint8_t *)(*buffer)) + sizeof(uint16_t);
if (*buffer_space < sizeof_nv_public_size) {
*buffer_space = 0;
return;
}
*buffer_space -= sizeof_nv_public_size;
base_size = *buffer_space;
marshal_TPMS_NV_PUBLIC(buffer, &nvd_in->publicInfo, buffer_space);
if (!*buffer_space)
return;
base_size = base_size - *buffer_space;
marshal_u16(&size_location, base_size, &sizeof_nv_public_size);
}
static void marshal_nv_write(void **buffer,
struct tpm2_nv_write_cmd *command_body,
size_t *buffer_space)
{
struct tpm2_session_header session_header;
marshal_TPM_HANDLE(buffer, TPM_RH_PLATFORM, buffer_space);
marshal_TPM_HANDLE(buffer, command_body->nvIndex, buffer_space);
memset(&session_header, 0, sizeof(session_header));
session_header.session_handle = TPM_RS_PW;
marshal_session_header(buffer, &session_header, buffer_space);
tpm_tag = TPM_ST_SESSIONS;
marshal_TPM2B(buffer, &command_body->data.b, buffer_space);
marshal_u16(buffer, command_body->offset, buffer_space);
}
static void marshal_nv_read(void **buffer,
struct tpm2_nv_read_cmd *command_body,
size_t *buffer_space)
{
struct tpm2_session_header session_header;
marshal_TPM_HANDLE(buffer, TPM_RH_PLATFORM, buffer_space);
marshal_TPM_HANDLE(buffer, command_body->nvIndex, buffer_space);
memset(&session_header, 0, sizeof(session_header));
session_header.session_handle = TPM_RS_PW;
marshal_session_header(buffer, &session_header, buffer_space);
tpm_tag = TPM_ST_SESSIONS;
marshal_u16(buffer, command_body->size, buffer_space);
marshal_u16(buffer, command_body->offset, buffer_space);
}
static void marshal_selftest(void **buffer,
struct tpm2_self_test *command_body,
size_t *buffer_space)
{
marshal_u8(buffer, command_body->yes_no, buffer_space);
}
int tpm_marshal_command(TPM_CC command, void *tpm_command_body,
void *buffer, size_t buffer_size)
{
void *cmd_body = (uint8_t *)buffer + sizeof(struct tpm_header);
size_t max_body_size = buffer_size - sizeof(struct tpm_header);
size_t body_size = max_body_size;
/* Will be modified when marshaling some commands. */
tpm_tag = TPM_ST_NO_SESSIONS;
switch (command) {
case TPM2_Startup:
marshal_startup(&cmd_body, tpm_command_body, &body_size);
break;
case TPM2_GetCapability:
marshal_get_capability(&cmd_body, tpm_command_body,
&body_size);
break;
case TPM2_NV_Read:
marshal_nv_read(&cmd_body, tpm_command_body, &body_size);
break;
case TPM2_NV_DefineSpace:
marshal_nv_define_space(&cmd_body,
tpm_command_body, &body_size);
break;
case TPM2_NV_Write:
marshal_nv_write(&cmd_body, tpm_command_body, &body_size);
break;
case TPM2_SelfTest:
marshal_selftest(&cmd_body, tpm_command_body, &body_size);
break;
default:
body_size = 0;
printk(BIOS_INFO, "%s:%d:Request to marshal unsupported command %#x\n",
__FILE__, __LINE__, command);
}
if (body_size > 0) {
/* See how much room was taken by marshaling. */
body_size = max_body_size - body_size;
body_size += sizeof(struct tpm_header);
marshal_u16(&buffer, tpm_tag, &max_body_size);
marshal_u32(&buffer, body_size, &max_body_size);
marshal_u32(&buffer, command, &max_body_size);
}
return body_size;
}
static void unmarshal_get_capability(void **buffer, int *size,
struct get_cap_response *gcr)
{
int i;
gcr->more_data = unmarshal_u8(buffer, size);
gcr->cd.capability = unmarshal_TPM_CAP(buffer, size);
if (*size < 0)
return;
switch (gcr->cd.capability) {
case TPM_CAP_TPM_PROPERTIES:
gcr->cd.data.tpmProperties.count =
unmarshal_u32(buffer, size);
if (*size < 0)
return;
if (gcr->cd.data.tpmProperties.count > ARRAY_SIZE
(gcr->cd.data.tpmProperties.tpmProperty)) {
printk(BIOS_INFO, "%s:%s:%d - %d - too many properties\n",
__FILE__, __func__, __LINE__,
gcr->cd.data.tpmProperties.count);
*size = -1;
return;
}
for (i = 0; i < gcr->cd.data.tpmProperties.count; i++) {
TPMS_TAGGED_PROPERTY *pp;
pp = gcr->cd.data.tpmProperties.tpmProperty + i;
pp->property = unmarshal_TPM_PT(buffer, size);
pp->value = unmarshal_u32(buffer, size);
}
break;
default:
printk(BIOS_ERR,
"%s:%d - unable to unmarshal capability response",
__func__, __LINE__);
printk(BIOS_ERR, " for %d\n", gcr->cd.capability);
*size = -1;
break;
}
}
static void unmarshal_TPM2B_MAX_NV_BUFFER(void **buffer,
int *size,
TPM2B_MAX_NV_BUFFER *nv_buffer)
{
nv_buffer->t.size = unmarshal_u16(buffer, size);
if ((*size < 0) || (nv_buffer->t.size > *size)) {
printk(BIOS_ERR, "%s:%d - "
"size mismatch: expected %d, remaining %d\n",
__func__, __LINE__, nv_buffer->t.size, *size);
*size = -1;
return;
}
nv_buffer->t.buffer = *buffer;
*buffer = ((uint8_t *)(*buffer)) + nv_buffer->t.size;
*size -= nv_buffer->t.size;
}
static void unmarshal_nv_read(void **buffer, int *size,
struct nv_read_response *nvr)
{
/* Total size of the parameter field. */
nvr->params_size = unmarshal_u32(buffer, size);
unmarshal_TPM2B_MAX_NV_BUFFER(buffer, size, &nvr->buffer);
if (nvr->params_size !=
(nvr->buffer.t.size + sizeof(nvr->buffer.t.size))) {
printk(BIOS_ERR,
"%s:%d - parameter/buffer %d/%d size mismatch",
__func__, __LINE__, nvr->params_size,
nvr->buffer.t.size);
return;
}
if (*size < 0)
return;
/*
* Let's ignore the authorisation section. It should be 5 bytes total,
* just confirm that this is the case and report any discrepancy.
*/
if (*size != 5)
printk(BIOS_ERR,
"%s:%d - unexpected authorisation seciton size %d\n",
__func__, __LINE__, *size);
*buffer = ((uint8_t *)(*buffer)) + *size;
*size = 0;
}
struct tpm2_response *tpm_unmarshal_response(TPM_CC command,
void *response_body,
size_t in_size)
{
static struct tpm2_response tpm2_resp;
/*
* Should be 0 when done, positive and negaitive values indicate
* unmarshaling errors.
*/
int cr_size = in_size;
if ((cr_size < 0) || (in_size < sizeof(struct tpm_header)))
return NULL;
tpm2_resp.hdr.tpm_tag = unmarshal_u16(&response_body, &cr_size);
tpm2_resp.hdr.tpm_size = unmarshal_u32(&response_body, &cr_size);
tpm2_resp.hdr.tpm_code = unmarshal_TPM_CC(&response_body, &cr_size);
if (!cr_size) {
if (tpm2_resp.hdr.tpm_size != sizeof(tpm2_resp.hdr))
printk(BIOS_ERR,
"%s: size mismatch in response to command %#x\n",
__func__, command);
return &tpm2_resp;
}
switch (command) {
case TPM2_Startup:
break;
case TPM2_GetCapability:
unmarshal_get_capability(&response_body, &cr_size,
&tpm2_resp.gc);
break;
case TPM2_NV_Read:
unmarshal_nv_read(&response_body, &cr_size,
&tpm2_resp.nvr);
break;
case TPM2_NV_DefineSpace:
case TPM2_NV_Write:
/* Session data included in response can be safely ignored. */
cr_size = 0;
break;
default:
{
int i;
printk(BIOS_INFO, "%s:%d:"
"Request to unmarshal unexpected command %#x,"
" code %#x",
__func__, __LINE__, command,
tpm2_resp.hdr.tpm_code);
for (i = 0; i < cr_size; i++) {
if (!(i % 16))
printk(BIOS_INFO, "\n");
printk(BIOS_INFO, "%2.2x ",
((uint8_t *)response_body)[i]);
}
}
printk(BIOS_INFO, "\n");
return NULL;
}
if (cr_size) {
printk(BIOS_INFO,
"%s:%d got %d bytes back in response to %#x,"
" failed to parse (%d)\n",
__func__, __LINE__, tpm2_resp.hdr.tpm_size,
command, cr_size);
return NULL;
}
/* The entire message have been parsed. */
return &tpm2_resp;
}
|