u-boot/lib/tpm.c

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/*
* Copyright (c) 2013 The Chromium OS Authors.
*
* 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 <stdarg.h>
#include <tpm.h>
#include <asm/unaligned.h>
/* Internal error of TPM command library */
#define TPM_LIB_ERROR ((uint32_t)~0u)
/* Useful constants */
enum {
COMMAND_BUFFER_SIZE = 256,
TPM_PUBEK_SIZE = 256,
TPM_REQUEST_HEADER_LENGTH = 10,
TPM_RESPONSE_HEADER_LENGTH = 10,
PCR_DIGEST_LENGTH = 20,
};
/**
* Pack data into a byte string. The data types are specified in
* the format string: 'b' means unsigned byte, 'w' unsigned word,
* 'd' unsigned double word, and 's' byte string. The data are a
* series of offsets and values (for type byte string there are also
* lengths). The data values are packed into the byte string
* sequentially, and so a latter value could over-write a former
* value.
*
* @param str output string
* @param size size of output string
* @param format format string
* @param ... data points
* @return 0 on success, non-0 on error
*/
int pack_byte_string(uint8_t *str, size_t size, const char *format, ...)
{
va_list args;
size_t offset = 0, length = 0;
uint8_t *data = NULL;
uint32_t value = 0;
va_start(args, format);
for (; *format; format++) {
switch (*format) {
case 'b':
offset = va_arg(args, size_t);
value = va_arg(args, int);
length = 1;
break;
case 'w':
offset = va_arg(args, size_t);
value = va_arg(args, int);
length = 2;
break;
case 'd':
offset = va_arg(args, size_t);
value = va_arg(args, uint32_t);
length = 4;
break;
case 's':
offset = va_arg(args, size_t);
data = va_arg(args, uint8_t *);
length = va_arg(args, uint32_t);
break;
default:
debug("Couldn't recognize format string\n");
return -1;
}
if (offset + length > size)
return -1;
switch (*format) {
case 'b':
str[offset] = value;
break;
case 'w':
put_unaligned_be16(value, str + offset);
break;
case 'd':
put_unaligned_be32(value, str + offset);
break;
case 's':
memcpy(str + offset, data, length);
break;
}
}
va_end(args);
return 0;
}
/**
* Unpack data from a byte string. The data types are specified in
* the format string: 'b' means unsigned byte, 'w' unsigned word,
* 'd' unsigned double word, and 's' byte string. The data are a
* series of offsets and pointers (for type byte string there are also
* lengths).
*
* @param str output string
* @param size size of output string
* @param format format string
* @param ... data points
* @return 0 on success, non-0 on error
*/
int unpack_byte_string(const uint8_t *str, size_t size, const char *format, ...)
{
va_list args;
size_t offset = 0, length = 0;
uint8_t *ptr8 = NULL;
uint16_t *ptr16 = NULL;
uint32_t *ptr32 = NULL;
va_start(args, format);
for (; *format; format++) {
switch (*format) {
case 'b':
offset = va_arg(args, size_t);
ptr8 = va_arg(args, uint8_t *);
length = 1;
break;
case 'w':
offset = va_arg(args, size_t);
ptr16 = va_arg(args, uint16_t *);
length = 2;
break;
case 'd':
offset = va_arg(args, size_t);
ptr32 = va_arg(args, uint32_t *);
length = 4;
break;
case 's':
offset = va_arg(args, size_t);
ptr8 = va_arg(args, uint8_t *);
length = va_arg(args, uint32_t);
break;
default:
debug("Couldn't recognize format string\n");
return -1;
}
if (offset + length > size)
return -1;
switch (*format) {
case 'b':
*ptr8 = str[offset];
break;
case 'w':
*ptr16 = get_unaligned_be16(str + offset);
break;
case 'd':
*ptr32 = get_unaligned_be32(str + offset);
break;
case 's':
memcpy(ptr8, str + offset, length);
break;
}
}
va_end(args);
return 0;
}
/**
* Get TPM command size.
*
* @param command byte string of TPM command
* @return command size of the TPM command
*/
static uint32_t tpm_command_size(const void *command)
{
const size_t command_size_offset = 2;
return get_unaligned_be32(command + command_size_offset);
}
/**
* Get TPM response return code, which is one of TPM_RESULT values.
*
* @param response byte string of TPM response
* @return return code of the TPM response
*/
static uint32_t tpm_return_code(const void *response)
{
const size_t return_code_offset = 6;
return get_unaligned_be32(response + return_code_offset);
}
/**
* Send a TPM command and return response's return code, and optionally
* return response to caller.
*
* @param command byte string of TPM command
* @param response output buffer for TPM response, or NULL if the
* caller does not care about it
* @param size_ptr output buffer size (input parameter) and TPM
* response length (output parameter); this parameter
* is a bidirectional
* @return return code of the TPM response
*/
static uint32_t tpm_sendrecv_command(const void *command,
void *response, size_t *size_ptr)
{
uint8_t response_buffer[COMMAND_BUFFER_SIZE];
size_t response_length;
uint32_t err;
if (response) {
response_length = *size_ptr;
} else {
response = response_buffer;
response_length = sizeof(response_buffer);
}
err = tis_sendrecv(command, tpm_command_size(command),
response, &response_length);
if (err)
return TPM_LIB_ERROR;
if (response)
*size_ptr = response_length;
return tpm_return_code(response);
}
uint32_t tpm_init(void)
{
uint32_t err;
err = tis_init();
if (err)
return err;
return tis_open();
}
uint32_t tpm_startup(enum tpm_startup_type mode)
{
const uint8_t command[12] = {
0x0, 0xc1, 0x0, 0x0, 0x0, 0xc, 0x0, 0x0, 0x0, 0x99, 0x0, 0x0,
};
const size_t mode_offset = 10;
uint8_t buf[COMMAND_BUFFER_SIZE];
if (pack_byte_string(buf, sizeof(buf), "sw",
0, command, sizeof(command),
mode_offset, mode))
return TPM_LIB_ERROR;
return tpm_sendrecv_command(buf, NULL, NULL);
}
uint32_t tpm_self_test_full(void)
{
const uint8_t command[10] = {
0x0, 0xc1, 0x0, 0x0, 0x0, 0xa, 0x0, 0x0, 0x0, 0x50,
};
return tpm_sendrecv_command(command, NULL, NULL);
}
uint32_t tpm_continue_self_test(void)
{
const uint8_t command[10] = {
0x0, 0xc1, 0x0, 0x0, 0x0, 0xa, 0x0, 0x0, 0x0, 0x53,
};
return tpm_sendrecv_command(command, NULL, NULL);
}
uint32_t tpm_nv_define_space(uint32_t index, uint32_t perm, uint32_t size)
{
const uint8_t command[101] = {
0x0, 0xc1, /* TPM_TAG */
0x0, 0x0, 0x0, 0x65, /* parameter size */
0x0, 0x0, 0x0, 0xcc, /* TPM_COMMAND_CODE */
/* TPM_NV_DATA_PUBLIC->... */
0x0, 0x18, /* ...->TPM_STRUCTURE_TAG */
0, 0, 0, 0, /* ...->TPM_NV_INDEX */
/* TPM_NV_DATA_PUBLIC->TPM_PCR_INFO_SHORT */
0x0, 0x3,
0, 0, 0,
0x1f,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
/* TPM_NV_DATA_PUBLIC->TPM_PCR_INFO_SHORT */
0x0, 0x3,
0, 0, 0,
0x1f,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
/* TPM_NV_ATTRIBUTES->... */
0x0, 0x17, /* ...->TPM_STRUCTURE_TAG */
0, 0, 0, 0, /* ...->attributes */
/* End of TPM_NV_ATTRIBUTES */
0, /* bReadSTClear */
0, /* bWriteSTClear */
0, /* bWriteDefine */
0, 0, 0, 0, /* size */
};
const size_t index_offset = 12;
const size_t perm_offset = 70;
const size_t size_offset = 77;
uint8_t buf[COMMAND_BUFFER_SIZE];
if (pack_byte_string(buf, sizeof(buf), "sddd",
0, command, sizeof(command),
index_offset, index,
perm_offset, perm,
size_offset, size))
return TPM_LIB_ERROR;
return tpm_sendrecv_command(buf, NULL, NULL);
}
uint32_t tpm_nv_read_value(uint32_t index, void *data, uint32_t count)
{
const uint8_t command[22] = {
0x0, 0xc1, 0x0, 0x0, 0x0, 0x16, 0x0, 0x0, 0x0, 0xcf,
};
const size_t index_offset = 10;
const size_t length_offset = 18;
const size_t data_size_offset = 10;
const size_t data_offset = 14;
uint8_t buf[COMMAND_BUFFER_SIZE], response[COMMAND_BUFFER_SIZE];
size_t response_length = sizeof(response);
uint32_t data_size;
uint32_t err;
if (pack_byte_string(buf, sizeof(buf), "sdd",
0, command, sizeof(command),
index_offset, index,
length_offset, count))
return TPM_LIB_ERROR;
err = tpm_sendrecv_command(buf, response, &response_length);
if (err)
return err;
if (unpack_byte_string(response, response_length, "d",
data_size_offset, &data_size))
return TPM_LIB_ERROR;
if (data_size > count)
return TPM_LIB_ERROR;
if (unpack_byte_string(response, response_length, "s",
data_offset, data, data_size))
return TPM_LIB_ERROR;
return 0;
}
uint32_t tpm_nv_write_value(uint32_t index, const void *data, uint32_t length)
{
const uint8_t command[256] = {
0x0, 0xc1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xcd,
};
const size_t command_size_offset = 2;
const size_t index_offset = 10;
const size_t length_offset = 18;
const size_t data_offset = 22;
const size_t write_info_size = 12;
const uint32_t total_length =
TPM_REQUEST_HEADER_LENGTH + write_info_size + length;
uint8_t buf[COMMAND_BUFFER_SIZE], response[COMMAND_BUFFER_SIZE];
size_t response_length = sizeof(response);
uint32_t err;
if (pack_byte_string(buf, sizeof(buf), "sddds",
0, command, sizeof(command),
command_size_offset, total_length,
index_offset, index,
length_offset, length,
data_offset, data, length))
return TPM_LIB_ERROR;
err = tpm_sendrecv_command(buf, response, &response_length);
if (err)
return err;
return 0;
}
uint32_t tpm_extend(uint32_t index, const void *in_digest, void *out_digest)
{
const uint8_t command[34] = {
0x0, 0xc1, 0x0, 0x0, 0x0, 0x22, 0x0, 0x0, 0x0, 0x14,
};
const size_t index_offset = 10;
const size_t in_digest_offset = 14;
const size_t out_digest_offset = 10;
uint8_t buf[COMMAND_BUFFER_SIZE];
uint8_t response[TPM_RESPONSE_HEADER_LENGTH + PCR_DIGEST_LENGTH];
size_t response_length = sizeof(response);
uint32_t err;
if (pack_byte_string(buf, sizeof(buf), "sds",
0, command, sizeof(command),
index_offset, index,
in_digest_offset, in_digest,
PCR_DIGEST_LENGTH))
return TPM_LIB_ERROR;
err = tpm_sendrecv_command(buf, response, &response_length);
if (err)
return err;
if (unpack_byte_string(response, response_length, "s",
out_digest_offset, out_digest,
PCR_DIGEST_LENGTH))
return TPM_LIB_ERROR;
return 0;
}
uint32_t tpm_pcr_read(uint32_t index, void *data, size_t count)
{
const uint8_t command[14] = {
0x0, 0xc1, 0x0, 0x0, 0x0, 0xe, 0x0, 0x0, 0x0, 0x15,
};
const size_t index_offset = 10;
const size_t out_digest_offset = 10;
uint8_t buf[COMMAND_BUFFER_SIZE], response[COMMAND_BUFFER_SIZE];
size_t response_length = sizeof(response);
uint32_t err;
if (count < PCR_DIGEST_LENGTH)
return TPM_LIB_ERROR;
if (pack_byte_string(buf, sizeof(buf), "sd",
0, command, sizeof(command),
index_offset, index))
return TPM_LIB_ERROR;
err = tpm_sendrecv_command(buf, response, &response_length);
if (err)
return err;
if (unpack_byte_string(response, response_length, "s",
out_digest_offset, data, PCR_DIGEST_LENGTH))
return TPM_LIB_ERROR;
return 0;
}
uint32_t tpm_tsc_physical_presence(uint16_t presence)
{
const uint8_t command[12] = {
0x0, 0xc1, 0x0, 0x0, 0x0, 0xc, 0x40, 0x0, 0x0, 0xa, 0x0, 0x0,
};
const size_t presence_offset = 10;
uint8_t buf[COMMAND_BUFFER_SIZE];
if (pack_byte_string(buf, sizeof(buf), "sw",
0, command, sizeof(command),
presence_offset, presence))
return TPM_LIB_ERROR;
return tpm_sendrecv_command(buf, NULL, NULL);
}
uint32_t tpm_read_pubek(void *data, size_t count)
{
const uint8_t command[30] = {
0x0, 0xc1, 0x0, 0x0, 0x0, 0x1e, 0x0, 0x0, 0x0, 0x7c,
};
const size_t response_size_offset = 2;
const size_t data_offset = 10;
const size_t header_and_checksum_size = TPM_RESPONSE_HEADER_LENGTH + 20;
uint8_t response[COMMAND_BUFFER_SIZE + TPM_PUBEK_SIZE];
size_t response_length = sizeof(response);
uint32_t data_size;
uint32_t err;
err = tpm_sendrecv_command(command, response, &response_length);
if (err)
return err;
if (unpack_byte_string(response, response_length, "d",
response_size_offset, &data_size))
return TPM_LIB_ERROR;
if (data_size < header_and_checksum_size)
return TPM_LIB_ERROR;
data_size -= header_and_checksum_size;
if (data_size > count)
return TPM_LIB_ERROR;
if (unpack_byte_string(response, response_length, "s",
data_offset, data, data_size))
return TPM_LIB_ERROR;
return 0;
}
uint32_t tpm_force_clear(void)
{
const uint8_t command[10] = {
0x0, 0xc1, 0x0, 0x0, 0x0, 0xa, 0x0, 0x0, 0x0, 0x5d,
};
return tpm_sendrecv_command(command, NULL, NULL);
}
uint32_t tpm_physical_enable(void)
{
const uint8_t command[10] = {
0x0, 0xc1, 0x0, 0x0, 0x0, 0xa, 0x0, 0x0, 0x0, 0x6f,
};
return tpm_sendrecv_command(command, NULL, NULL);
}
uint32_t tpm_physical_disable(void)
{
const uint8_t command[10] = {
0x0, 0xc1, 0x0, 0x0, 0x0, 0xa, 0x0, 0x0, 0x0, 0x70,
};
return tpm_sendrecv_command(command, NULL, NULL);
}
uint32_t tpm_physical_set_deactivated(uint8_t state)
{
const uint8_t command[11] = {
0x0, 0xc1, 0x0, 0x0, 0x0, 0xb, 0x0, 0x0, 0x0, 0x72,
};
const size_t state_offset = 10;
uint8_t buf[COMMAND_BUFFER_SIZE];
if (pack_byte_string(buf, sizeof(buf), "sb",
0, command, sizeof(command),
state_offset, state))
return TPM_LIB_ERROR;
return tpm_sendrecv_command(buf, NULL, NULL);
}
uint32_t tpm_get_capability(uint32_t cap_area, uint32_t sub_cap,
void *cap, size_t count)
{
const uint8_t command[22] = {
0x0, 0xc1, /* TPM_TAG */
0x0, 0x0, 0x0, 0x16, /* parameter size */
0x0, 0x0, 0x0, 0x65, /* TPM_COMMAND_CODE */
0x0, 0x0, 0x0, 0x0, /* TPM_CAPABILITY_AREA */
0x0, 0x0, 0x0, 0x4, /* subcap size */
0x0, 0x0, 0x0, 0x0, /* subcap value */
};
const size_t cap_area_offset = 10;
const size_t sub_cap_offset = 18;
const size_t cap_offset = 14;
const size_t cap_size_offset = 10;
uint8_t buf[COMMAND_BUFFER_SIZE], response[COMMAND_BUFFER_SIZE];
size_t response_length = sizeof(response);
uint32_t cap_size;
uint32_t err;
if (pack_byte_string(buf, sizeof(buf), "sdd",
0, command, sizeof(command),
cap_area_offset, cap_area,
sub_cap_offset, sub_cap))
return TPM_LIB_ERROR;
err = tpm_sendrecv_command(buf, response, &response_length);
if (err)
return err;
if (unpack_byte_string(response, response_length, "d",
cap_size_offset, &cap_size))
return TPM_LIB_ERROR;
if (cap_size > response_length || cap_size > count)
return TPM_LIB_ERROR;
if (unpack_byte_string(response, response_length, "s",
cap_offset, cap, cap_size))
return TPM_LIB_ERROR;
return 0;
}