diff options
Diffstat (limited to 'src/security/tpm/tcg-1.2/tss.c')
-rw-r--r-- | src/security/tpm/tcg-1.2/tss.c | 353 |
1 files changed, 353 insertions, 0 deletions
diff --git a/src/security/tpm/tcg-1.2/tss.c b/src/security/tpm/tcg-1.2/tss.c new file mode 100644 index 000000000000..e0ffdea4333f --- /dev/null +++ b/src/security/tpm/tcg-1.2/tss.c @@ -0,0 +1,353 @@ +/* Copyright (c) 2012 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. + */ + +/* A lightweight TPM command library. + * + * The general idea is that TPM commands are array of bytes whose + * fields are mostly compile-time constant. The goal is to build much + * of the commands at compile time (or build time) and change some of + * the fields at run time as needed. The code in + * utility/tlcl_generator.c builds structures containing the commands, + * as well as the offsets of the fields that need to be set at run + * time. + */ + +#include <arch/early_variables.h> +#include <assert.h> +#include <string.h> +#include <security/tpm/tis.h> +#include <vb2_api.h> +#include "tss_internal.h" +#include "tss_structures.h" +#include "../tss.h" + +#ifdef FOR_TEST +#include <stdio.h> +#define VBDEBUG(format, args...) printf(format, ## args) +#else +#include <console/console.h> +#define VBDEBUG(format, args...) printk(BIOS_DEBUG, format, ## args) +#endif + +static int tpm_send_receive(const uint8_t *request, + uint32_t request_length, + uint8_t *response, + uint32_t *response_length) +{ + size_t len = *response_length; + if (tis_sendrecv(request, request_length, response, &len)) + return VB2_ERROR_UNKNOWN; + /* check 64->32bit overflow and (re)check response buffer overflow */ + if (len > *response_length) + return VB2_ERROR_UNKNOWN; + *response_length = len; + return VB2_SUCCESS; +} + +/* Sets the size field of a TPM command. */ +static inline void set_tpm_command_size(uint8_t *buffer, uint32_t size) +{ + to_tpm_uint32(buffer + sizeof(uint16_t), size); +} + +/* Gets the size field of a TPM command. */ +__attribute__((unused)) +static inline int tpm_command_size(const uint8_t *buffer) +{ + uint32_t size; + from_tpm_uint32(buffer + sizeof(uint16_t), &size); + return (int) size; +} + +/* Gets the code field of a TPM command. */ +static inline int tpm_command_code(const uint8_t *buffer) +{ + uint32_t code; + from_tpm_uint32(buffer + sizeof(uint16_t) + sizeof(uint32_t), &code); + return code; +} + +/* Gets the return code field of a TPM result. */ +static inline int tpm_return_code(const uint8_t *buffer) +{ + return tpm_command_code(buffer); +} + +/* Like TlclSendReceive below, but do not retry if NEEDS_SELFTEST or + * DOING_SELFTEST errors are returned. + */ +static uint32_t tlcl_send_receive_no_retry(const uint8_t *request, + uint8_t *response, int max_length) +{ + uint32_t response_length = max_length; + uint32_t result; + + result = tpm_send_receive(request, tpm_command_size(request), + response, &response_length); + if (result != 0) { + /* Communication with TPM failed, so response is garbage */ + VBDEBUG("TPM: command 0x%x send/receive failed: 0x%x\n", + tpm_command_code(request), result); + return result; + } + /* Otherwise, use the result code from the response */ + result = tpm_return_code(response); + + /* TODO: add paranoia about returned response_length vs. max_length + * (and possibly expected length from the response header). See + * crosbug.com/17017 */ + + VBDEBUG("TPM: command 0x%x returned 0x%x\n", + tpm_command_code(request), result); + +return result; +} + + +/* Sends a TPM command and gets a response. Returns 0 if success or the TPM + * error code if error. Waits for the self test to complete if needed. */ +uint32_t tlcl_send_receive(const uint8_t *request, uint8_t *response, + int max_length) +{ + uint32_t result = tlcl_send_receive_no_retry(request, response, + max_length); + /* If the command fails because the self test has not completed, try it + * again after attempting to ensure that the self test has completed. */ + if (result == TPM_E_NEEDS_SELFTEST || result == TPM_E_DOING_SELFTEST) { + result = tlcl_continue_self_test(); + if (result != TPM_SUCCESS) + return result; +#if defined(TPM_BLOCKING_CONTINUESELFTEST) || defined(VB_RECOVERY_MODE) + /* Retry only once */ + result = tlcl_send_receive_no_retry(request, response, + max_length); +#else + /* This needs serious testing. The TPM specification says: "iii. + * The caller MUST wait for the actions of TPM_ContinueSelfTest + * to complete before reissuing the command C1." But, if + * ContinueSelfTest is non-blocking, how do we know that the + * actions have completed other than trying again? */ + do { + result = tlcl_send_receive_no_retry(request, response, + max_length); + } while (result == TPM_E_DOING_SELFTEST); +#endif + } + return result; +} + +/* Sends a command and returns the error code. */ +static uint32_t send(const uint8_t *command) +{ + uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE]; + return tlcl_send_receive(command, response, sizeof(response)); +} + +/* Exported functions. */ + +static uint8_t tlcl_init_done CAR_GLOBAL; + +uint32_t tlcl_lib_init(void) +{ + uint8_t done = car_get_var(tlcl_init_done); + if (done) + return VB2_SUCCESS; + + if (tis_init()) + return VB2_ERROR_UNKNOWN; + if (tis_open()) + return VB2_ERROR_UNKNOWN; + + car_set_var(tlcl_init_done, 1); + + return VB2_SUCCESS; +} + +uint32_t tlcl_startup(void) +{ + VBDEBUG("TPM: Startup\n"); + return send(tpm_startup_cmd.buffer); +} + +uint32_t tlcl_resume(void) +{ + VBDEBUG("TPM: Resume\n"); + return send(tpm_resume_cmd.buffer); +} + +uint32_t tlcl_self_test_full(void) +{ + VBDEBUG("TPM: Self test full\n"); + return send(tpm_selftestfull_cmd.buffer); +} + +uint32_t tlcl_continue_self_test(void) +{ + uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE]; + VBDEBUG("TPM: Continue self test\n"); + /* Call the No Retry version of SendReceive to avoid recursion. */ + return tlcl_send_receive_no_retry(tpm_continueselftest_cmd.buffer, + response, sizeof(response)); +} + +uint32_t tlcl_define_space(uint32_t index, uint32_t perm, uint32_t size) +{ + struct s_tpm_nv_definespace_cmd cmd; + VBDEBUG("TPM: TlclDefineSpace(0x%x, 0x%x, %d)\n", index, perm, size); + memcpy(&cmd, &tpm_nv_definespace_cmd, sizeof(cmd)); + to_tpm_uint32(cmd.buffer + tpm_nv_definespace_cmd.index, index); + to_tpm_uint32(cmd.buffer + tpm_nv_definespace_cmd.perm, perm); + to_tpm_uint32(cmd.buffer + tpm_nv_definespace_cmd.size, size); + return send(cmd.buffer); +} + +uint32_t tlcl_write(uint32_t index, const void *data, uint32_t length) +{ + struct s_tpm_nv_write_cmd cmd; + uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE]; + const int total_length = + kTpmRequestHeaderLength + kWriteInfoLength + length; + + VBDEBUG("TPM: tlcl_write(0x%x, %d)\n", index, length); + memcpy(&cmd, &tpm_nv_write_cmd, sizeof(cmd)); + assert(total_length <= TPM_LARGE_ENOUGH_COMMAND_SIZE); + set_tpm_command_size(cmd.buffer, total_length); + + to_tpm_uint32(cmd.buffer + tpm_nv_write_cmd.index, index); + to_tpm_uint32(cmd.buffer + tpm_nv_write_cmd.length, length); + memcpy(cmd.buffer + tpm_nv_write_cmd.data, data, length); + + return tlcl_send_receive(cmd.buffer, response, sizeof(response)); +} + +uint32_t tlcl_read(uint32_t index, void *data, uint32_t length) +{ + struct s_tpm_nv_read_cmd cmd; + uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE]; + uint32_t result_length; + uint32_t result; + + VBDEBUG("TPM: tlcl_read(0x%x, %d)\n", index, length); + memcpy(&cmd, &tpm_nv_read_cmd, sizeof(cmd)); + to_tpm_uint32(cmd.buffer + tpm_nv_read_cmd.index, index); + to_tpm_uint32(cmd.buffer + tpm_nv_read_cmd.length, length); + + result = tlcl_send_receive(cmd.buffer, response, sizeof(response)); + if (result == TPM_SUCCESS && length > 0) { + uint8_t *nv_read_cursor = response + kTpmResponseHeaderLength; + from_tpm_uint32(nv_read_cursor, &result_length); + nv_read_cursor += sizeof(uint32_t); + memcpy(data, nv_read_cursor, result_length); + } + + return result; +} + + +uint32_t tlcl_assert_physical_presence(void) +{ + VBDEBUG("TPM: Asserting physical presence\n"); + return send(tpm_ppassert_cmd.buffer); +} + +uint32_t tlcl_physical_presence_cmd_enable(void) +{ + VBDEBUG("TPM: Enable the physical presence command\n"); + return send(tpm_ppenable_cmd.buffer); +} + +uint32_t tlcl_finalize_physical_presence(void) +{ + VBDEBUG("TPM: Enable PP cmd, disable HW pp, and set lifetime lock\n"); + return send(tpm_finalizepp_cmd.buffer); +} + +uint32_t tlcl_set_nv_locked(void) +{ + VBDEBUG("TPM: Set NV locked\n"); + return tlcl_define_space(TPM_NV_INDEX_LOCK, 0, 0); +} + +uint32_t tlcl_force_clear(void) +{ + VBDEBUG("TPM: Force clear\n"); + return send(tpm_forceclear_cmd.buffer); +} + +uint32_t tlcl_set_enable(void) +{ + VBDEBUG("TPM: Enabling TPM\n"); + return send(tpm_physicalenable_cmd.buffer); +} + +uint32_t tlcl_set_deactivated(uint8_t flag) +{ + struct s_tpm_physicalsetdeactivated_cmd cmd; + VBDEBUG("TPM: SetDeactivated(%d)\n", flag); + memcpy(&cmd, &tpm_physicalsetdeactivated_cmd, sizeof(cmd)); + *(cmd.buffer + cmd.deactivated) = flag; + return send(cmd.buffer); +} + +uint32_t tlcl_get_permanent_flags(TPM_PERMANENT_FLAGS *pflags) +{ + uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE]; + uint32_t size; + uint32_t result = tlcl_send_receive(tpm_getflags_cmd.buffer, response, + sizeof(response)); + if (result != TPM_SUCCESS) + return result; + from_tpm_uint32(response + kTpmResponseHeaderLength, &size); + assert(size == sizeof(TPM_PERMANENT_FLAGS)); + memcpy(pflags, response + kTpmResponseHeaderLength + sizeof(size), + sizeof(TPM_PERMANENT_FLAGS)); + return result; +} + +uint32_t tlcl_get_flags(uint8_t *disable, uint8_t *deactivated, + uint8_t *nvlocked) +{ + TPM_PERMANENT_FLAGS pflags; + uint32_t result = tlcl_get_permanent_flags(&pflags); + if (result == TPM_SUCCESS) { + if (disable) + *disable = pflags.disable; + if (deactivated) + *deactivated = pflags.deactivated; + if (nvlocked) + *nvlocked = pflags.nvLocked; + VBDEBUG("TPM: flags disable=%d, deactivated=%d, nvlocked=%d\n", + pflags.disable, pflags.deactivated, pflags.nvLocked); + } + return result; +} + +uint32_t tlcl_set_global_lock(void) +{ + uint32_t x; + VBDEBUG("TPM: Set global lock\n"); + return tlcl_write(TPM_NV_INDEX0, (uint8_t *) &x, 0); +} + +uint32_t tlcl_extend(int pcr_num, const uint8_t *in_digest, + uint8_t *out_digest) +{ + struct s_tpm_extend_cmd cmd; + uint8_t response[kTpmResponseHeaderLength + kPcrDigestLength]; + uint32_t result; + + memcpy(&cmd, &tpm_extend_cmd, sizeof(cmd)); + to_tpm_uint32(cmd.buffer + tpm_extend_cmd.pcrNum, pcr_num); + memcpy(cmd.buffer + cmd.inDigest, in_digest, kPcrDigestLength); + + result = tlcl_send_receive(cmd.buffer, response, sizeof(response)); + if (result != TPM_SUCCESS) + return result; + + if (out_digest) + memcpy(out_digest, response + kTpmResponseHeaderLength, + kPcrDigestLength); + return result; +} |