diff options
Diffstat (limited to 'lib/tpm.c')
| -rw-r--r-- | lib/tpm.c | 581 |
1 files changed, 581 insertions, 0 deletions
diff --git a/lib/tpm.c b/lib/tpm.c new file mode 100644 index 0000000000..42c9bea0f9 --- /dev/null +++ b/lib/tpm.c @@ -0,0 +1,581 @@ +/* + * 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; +} |
