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u-boot/lib/tpm.c
Tom Rini 667d685697 tpm: Fix comparison of unsigned expression warning 
The function tpm_xfer returns int so make 'err' be int rather than
uint32_t so that we can catch an error condition.  Reported by
clang-3.8.

Signed-off-by: Tom Rini <trini@konsulko.com>
2017-05-12 08:37:40 -04:00

1038 lines
28 KiB
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/*
* Copyright (c) 2013 The Chromium OS Authors.
* Coypright (c) 2013 Guntermann & Drunck GmbH
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <dm.h>
#include <tpm.h>
#include <asm/unaligned.h>
#include <u-boot/sha1.h>
/* Internal error of TPM command library */
#define TPM_LIB_ERROR ((uint32_t)~0u)
/* Useful constants */
enum {
COMMAND_BUFFER_SIZE = 256,
TPM_REQUEST_HEADER_LENGTH = 10,
TPM_RESPONSE_HEADER_LENGTH = 10,
PCR_DIGEST_LENGTH = 20,
DIGEST_LENGTH = 20,
TPM_REQUEST_AUTH_LENGTH = 45,
TPM_RESPONSE_AUTH_LENGTH = 41,
/* some max lengths, valid for RSA keys <= 2048 bits */
TPM_KEY12_MAX_LENGTH = 618,
TPM_PUBKEY_MAX_LENGTH = 288,
};
#ifdef CONFIG_TPM_AUTH_SESSIONS
#ifndef CONFIG_SHA1
#error "TPM_AUTH_SESSIONS require SHA1 to be configured, too"
#endif /* !CONFIG_SHA1 */
struct session_data {
int valid;
uint32_t handle;
uint8_t nonce_even[DIGEST_LENGTH];
uint8_t nonce_odd[DIGEST_LENGTH];
};
static struct session_data oiap_session = {0, };
#endif /* CONFIG_TPM_AUTH_SESSIONS */
/**
* 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)
{
struct udevice *dev;
int err, ret;
uint8_t response_buffer[COMMAND_BUFFER_SIZE];
size_t response_length;
if (response) {
response_length = *size_ptr;
} else {
response = response_buffer;
response_length = sizeof(response_buffer);
}
ret = uclass_first_device_err(UCLASS_TPM, &dev);
if (ret)
return ret;
err = tpm_xfer(dev, command, tpm_command_size(command),
response, &response_length);
if (err < 0)
return TPM_LIB_ERROR;
if (size_ptr)
*size_ptr = response_length;
return tpm_return_code(response);
}
int tpm_init(void)
{
int err;
struct udevice *dev;
err = uclass_first_device_err(UCLASS_TPM, &dev);
if (err)
return err;
return tpm_open(dev);
}
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;
}
uint32_t tpm_get_permanent_flags(struct tpm_permanent_flags *pflags)
{
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, 0x4, /* TPM_CAP_FLAG_PERM */
0x0, 0x0, 0x0, 0x4, /* subcap size */
0x0, 0x0, 0x1, 0x8, /* subcap value */
};
uint8_t response[COMMAND_BUFFER_SIZE];
size_t response_length = sizeof(response);
uint32_t err;
err = tpm_sendrecv_command(command, response, &response_length);
if (err)
return err;
memcpy(pflags, response + TPM_HEADER_SIZE, sizeof(*pflags));
return 0;
}
uint32_t tpm_get_permissions(uint32_t index, uint32_t *perm)
{
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, 0x11,
0x0, 0x0, 0x0, 0x4,
};
const size_t index_offset = 18;
const size_t perm_offset = 60;
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), "d", 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, "d",
perm_offset, perm))
return TPM_LIB_ERROR;
return 0;
}
#ifdef CONFIG_TPM_FLUSH_RESOURCES
uint32_t tpm_flush_specific(uint32_t key_handle, uint32_t resource_type)
{
const uint8_t command[18] = {
0x00, 0xc1, /* TPM_TAG */
0x00, 0x00, 0x00, 0x12, /* parameter size */
0x00, 0x00, 0x00, 0xba, /* TPM_COMMAND_CODE */
0x00, 0x00, 0x00, 0x00, /* key handle */
0x00, 0x00, 0x00, 0x00, /* resource type */
};
const size_t key_handle_offset = 10;
const size_t resource_type_offset = 14;
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), "sdd",
0, command, sizeof(command),
key_handle_offset, key_handle,
resource_type_offset, resource_type))
return TPM_LIB_ERROR;
err = tpm_sendrecv_command(buf, response, &response_length);
if (err)
return err;
return 0;
}
#endif /* CONFIG_TPM_FLUSH_RESOURCES */
#ifdef CONFIG_TPM_AUTH_SESSIONS
/**
* Fill an authentication block in a request.
* This func can create the first as well as the second auth block (for
* double authorized commands).
*
* @param request pointer to the request (w/ uninitialised auth data)
* @param request_len0 length of the request without auth data
* @param handles_len length of the handles area in request
* @param auth_session pointer to the (valid) auth session to be used
* @param request_auth pointer to the auth block of the request to be filled
* @param auth authentication data (HMAC key)
*/
static uint32_t create_request_auth(const void *request, size_t request_len0,
size_t handles_len,
struct session_data *auth_session,
void *request_auth, const void *auth)
{
uint8_t hmac_data[DIGEST_LENGTH * 3 + 1];
sha1_context hash_ctx;
const size_t command_code_offset = 6;
const size_t auth_nonce_odd_offset = 4;
const size_t auth_continue_offset = 24;
const size_t auth_auth_offset = 25;
if (!auth_session || !auth_session->valid)
return TPM_LIB_ERROR;
sha1_starts(&hash_ctx);
sha1_update(&hash_ctx, request + command_code_offset, 4);
if (request_len0 > TPM_REQUEST_HEADER_LENGTH + handles_len)
sha1_update(&hash_ctx,
request + TPM_REQUEST_HEADER_LENGTH + handles_len,
request_len0 - TPM_REQUEST_HEADER_LENGTH
- handles_len);
sha1_finish(&hash_ctx, hmac_data);
sha1_starts(&hash_ctx);
sha1_update(&hash_ctx, auth_session->nonce_odd, DIGEST_LENGTH);
sha1_update(&hash_ctx, hmac_data, sizeof(hmac_data));
sha1_finish(&hash_ctx, auth_session->nonce_odd);
if (pack_byte_string(request_auth, TPM_REQUEST_AUTH_LENGTH, "dsb",
0, auth_session->handle,
auth_nonce_odd_offset, auth_session->nonce_odd,
DIGEST_LENGTH,
auth_continue_offset, 1))
return TPM_LIB_ERROR;
if (pack_byte_string(hmac_data, sizeof(hmac_data), "ss",
DIGEST_LENGTH,
auth_session->nonce_even,
DIGEST_LENGTH,
2 * DIGEST_LENGTH,
request_auth + auth_nonce_odd_offset,
DIGEST_LENGTH + 1))
return TPM_LIB_ERROR;
sha1_hmac(auth, DIGEST_LENGTH, hmac_data, sizeof(hmac_data),
request_auth + auth_auth_offset);
return TPM_SUCCESS;
}
/**
* Verify an authentication block in a response.
* Since this func updates the nonce_even in the session data it has to be
* called when receiving a succesfull AUTH response.
* This func can verify the first as well as the second auth block (for
* double authorized commands).
*
* @param command_code command code of the request
* @param response pointer to the request (w/ uninitialised auth data)
* @param handles_len length of the handles area in response
* @param auth_session pointer to the (valid) auth session to be used
* @param response_auth pointer to the auth block of the response to be verified
* @param auth authentication data (HMAC key)
*/
static uint32_t verify_response_auth(uint32_t command_code,
const void *response, size_t response_len0,
size_t handles_len,
struct session_data *auth_session,
const void *response_auth, const void *auth)
{
uint8_t hmac_data[DIGEST_LENGTH * 3 + 1];
uint8_t computed_auth[DIGEST_LENGTH];
sha1_context hash_ctx;
const size_t return_code_offset = 6;
const size_t auth_continue_offset = 20;
const size_t auth_auth_offset = 21;
uint8_t auth_continue;
if (!auth_session || !auth_session->valid)
return TPM_AUTHFAIL;
if (pack_byte_string(hmac_data, sizeof(hmac_data), "d",
0, command_code))
return TPM_LIB_ERROR;
if (response_len0 < TPM_RESPONSE_HEADER_LENGTH)
return TPM_LIB_ERROR;
sha1_starts(&hash_ctx);
sha1_update(&hash_ctx, response + return_code_offset, 4);
sha1_update(&hash_ctx, hmac_data, 4);
if (response_len0 > TPM_RESPONSE_HEADER_LENGTH + handles_len)
sha1_update(&hash_ctx,
response + TPM_RESPONSE_HEADER_LENGTH + handles_len,
response_len0 - TPM_RESPONSE_HEADER_LENGTH
- handles_len);
sha1_finish(&hash_ctx, hmac_data);
memcpy(auth_session->nonce_even, response_auth, DIGEST_LENGTH);
auth_continue = ((uint8_t *)response_auth)[auth_continue_offset];
if (pack_byte_string(hmac_data, sizeof(hmac_data), "ssb",
DIGEST_LENGTH,
response_auth,
DIGEST_LENGTH,
2 * DIGEST_LENGTH,
auth_session->nonce_odd,
DIGEST_LENGTH,
3 * DIGEST_LENGTH,
auth_continue))
return TPM_LIB_ERROR;
sha1_hmac(auth, DIGEST_LENGTH, hmac_data, sizeof(hmac_data),
computed_auth);
if (memcmp(computed_auth, response_auth + auth_auth_offset,
DIGEST_LENGTH))
return TPM_AUTHFAIL;
return TPM_SUCCESS;
}
uint32_t tpm_terminate_auth_session(uint32_t auth_handle)
{
const uint8_t command[18] = {
0x00, 0xc1, /* TPM_TAG */
0x00, 0x00, 0x00, 0x00, /* parameter size */
0x00, 0x00, 0x00, 0xba, /* TPM_COMMAND_CODE */
0x00, 0x00, 0x00, 0x00, /* TPM_HANDLE */
0x00, 0x00, 0x00, 0x02, /* TPM_RESSOURCE_TYPE */
};
const size_t req_handle_offset = TPM_REQUEST_HEADER_LENGTH;
uint8_t request[COMMAND_BUFFER_SIZE];
if (pack_byte_string(request, sizeof(request), "sd",
0, command, sizeof(command),
req_handle_offset, auth_handle))
return TPM_LIB_ERROR;
if (oiap_session.valid && oiap_session.handle == auth_handle)
oiap_session.valid = 0;
return tpm_sendrecv_command(request, NULL, NULL);
}
uint32_t tpm_end_oiap(void)
{
uint32_t err = TPM_SUCCESS;
if (oiap_session.valid)
err = tpm_terminate_auth_session(oiap_session.handle);
return err;
}
uint32_t tpm_oiap(uint32_t *auth_handle)
{
const uint8_t command[10] = {
0x00, 0xc1, /* TPM_TAG */
0x00, 0x00, 0x00, 0x0a, /* parameter size */
0x00, 0x00, 0x00, 0x0a, /* TPM_COMMAND_CODE */
};
const size_t res_auth_handle_offset = TPM_RESPONSE_HEADER_LENGTH;
const size_t res_nonce_even_offset = TPM_RESPONSE_HEADER_LENGTH + 4;
uint8_t response[COMMAND_BUFFER_SIZE];
size_t response_length = sizeof(response);
uint32_t err;
if (oiap_session.valid)
tpm_terminate_auth_session(oiap_session.handle);
err = tpm_sendrecv_command(command, response, &response_length);
if (err)
return err;
if (unpack_byte_string(response, response_length, "ds",
res_auth_handle_offset, &oiap_session.handle,
res_nonce_even_offset, &oiap_session.nonce_even,
(uint32_t)DIGEST_LENGTH))
return TPM_LIB_ERROR;
oiap_session.valid = 1;
if (auth_handle)
*auth_handle = oiap_session.handle;
return 0;
}
uint32_t tpm_load_key2_oiap(uint32_t parent_handle,
const void *key, size_t key_length,
const void *parent_key_usage_auth,
uint32_t *key_handle)
{
const uint8_t command[14] = {
0x00, 0xc2, /* TPM_TAG */
0x00, 0x00, 0x00, 0x00, /* parameter size */
0x00, 0x00, 0x00, 0x41, /* TPM_COMMAND_CODE */
0x00, 0x00, 0x00, 0x00, /* parent handle */
};
const size_t req_size_offset = 2;
const size_t req_parent_handle_offset = TPM_REQUEST_HEADER_LENGTH;
const size_t req_key_offset = TPM_REQUEST_HEADER_LENGTH + 4;
const size_t res_handle_offset = TPM_RESPONSE_HEADER_LENGTH;
uint8_t request[sizeof(command) + TPM_KEY12_MAX_LENGTH
+ TPM_REQUEST_AUTH_LENGTH];
uint8_t response[COMMAND_BUFFER_SIZE];
size_t response_length = sizeof(response);
uint32_t err;
if (!oiap_session.valid) {
err = tpm_oiap(NULL);
if (err)
return err;
}
if (pack_byte_string(request, sizeof(request), "sdds",
0, command, sizeof(command),
req_size_offset,
sizeof(command) + key_length
+ TPM_REQUEST_AUTH_LENGTH,
req_parent_handle_offset, parent_handle,
req_key_offset, key, key_length
))
return TPM_LIB_ERROR;
err = create_request_auth(request, sizeof(command) + key_length, 4,
&oiap_session,
request + sizeof(command) + key_length,
parent_key_usage_auth);
if (err)
return err;
err = tpm_sendrecv_command(request, response, &response_length);
if (err) {
if (err == TPM_AUTHFAIL)
oiap_session.valid = 0;
return err;
}
err = verify_response_auth(0x00000041, response,
response_length - TPM_RESPONSE_AUTH_LENGTH,
4, &oiap_session,
response + response_length - TPM_RESPONSE_AUTH_LENGTH,
parent_key_usage_auth);
if (err)
return err;
if (key_handle) {
if (unpack_byte_string(response, response_length, "d",
res_handle_offset, key_handle))
return TPM_LIB_ERROR;
}
return 0;
}
uint32_t tpm_get_pub_key_oiap(uint32_t key_handle, const void *usage_auth,
void *pubkey, size_t *pubkey_len)
{
const uint8_t command[14] = {
0x00, 0xc2, /* TPM_TAG */
0x00, 0x00, 0x00, 0x00, /* parameter size */
0x00, 0x00, 0x00, 0x21, /* TPM_COMMAND_CODE */
0x00, 0x00, 0x00, 0x00, /* key handle */
};
const size_t req_size_offset = 2;
const size_t req_key_handle_offset = TPM_REQUEST_HEADER_LENGTH;
const size_t res_pubkey_offset = TPM_RESPONSE_HEADER_LENGTH;
uint8_t request[sizeof(command) + TPM_REQUEST_AUTH_LENGTH];
uint8_t response[TPM_RESPONSE_HEADER_LENGTH + TPM_PUBKEY_MAX_LENGTH
+ TPM_RESPONSE_AUTH_LENGTH];
size_t response_length = sizeof(response);
uint32_t err;
if (!oiap_session.valid) {
err = tpm_oiap(NULL);
if (err)
return err;
}
if (pack_byte_string(request, sizeof(request), "sdd",
0, command, sizeof(command),
req_size_offset,
(uint32_t)(sizeof(command)
+ TPM_REQUEST_AUTH_LENGTH),
req_key_handle_offset, key_handle
))
return TPM_LIB_ERROR;
err = create_request_auth(request, sizeof(command), 4, &oiap_session,
request + sizeof(command), usage_auth);
if (err)
return err;
err = tpm_sendrecv_command(request, response, &response_length);
if (err) {
if (err == TPM_AUTHFAIL)
oiap_session.valid = 0;
return err;
}
err = verify_response_auth(0x00000021, response,
response_length - TPM_RESPONSE_AUTH_LENGTH,
0, &oiap_session,
response + response_length - TPM_RESPONSE_AUTH_LENGTH,
usage_auth);
if (err)
return err;
if (pubkey) {
if ((response_length - TPM_RESPONSE_HEADER_LENGTH
- TPM_RESPONSE_AUTH_LENGTH) > *pubkey_len)
return TPM_LIB_ERROR;
*pubkey_len = response_length - TPM_RESPONSE_HEADER_LENGTH
- TPM_RESPONSE_AUTH_LENGTH;
memcpy(pubkey, response + res_pubkey_offset,
response_length - TPM_RESPONSE_HEADER_LENGTH
- TPM_RESPONSE_AUTH_LENGTH);
}
return 0;
}
#ifdef CONFIG_TPM_LOAD_KEY_BY_SHA1
uint32_t tpm_find_key_sha1(const uint8_t auth[20], const uint8_t
pubkey_digest[20], uint32_t *handle)
{
uint16_t key_count;
uint32_t key_handles[10];
uint8_t buf[288];
uint8_t *ptr;
uint32_t err;
uint8_t digest[20];
size_t buf_len;
unsigned int i;
/* fetch list of already loaded keys in the TPM */
err = tpm_get_capability(TPM_CAP_HANDLE, TPM_RT_KEY, buf, sizeof(buf));
if (err)
return -1;
key_count = get_unaligned_be16(buf);
ptr = buf + 2;
for (i = 0; i < key_count; ++i, ptr += 4)
key_handles[i] = get_unaligned_be32(ptr);
/* now search a(/ the) key which we can access with the given auth */
for (i = 0; i < key_count; ++i) {
buf_len = sizeof(buf);
err = tpm_get_pub_key_oiap(key_handles[i], auth, buf, &buf_len);
if (err && err != TPM_AUTHFAIL)
return -1;
if (err)
continue;
sha1_csum(buf, buf_len, digest);
if (!memcmp(digest, pubkey_digest, 20)) {
*handle = key_handles[i];
return 0;
}
}
return 1;
}
#endif /* CONFIG_TPM_LOAD_KEY_BY_SHA1 */
#endif /* CONFIG_TPM_AUTH_SESSIONS */
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