diff options
Diffstat (limited to 'src/lib/tlcl.c')
-rw-r--r-- | src/lib/tlcl.c | 466 |
1 files changed, 466 insertions, 0 deletions
diff --git a/src/lib/tlcl.c b/src/lib/tlcl.c new file mode 100644 index 0000000000..bf2d27f99c --- /dev/null +++ b/src/lib/tlcl.c @@ -0,0 +1,466 @@ +/* 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 "sysincludes.h" + +#include "tlcl.h" +#include "tlcl_internal.h" +#include "tlcl_structures.h" +#include "utility.h" +#include "vboot_api.h" + +#ifdef FOR_TEST +/* Allow unit testing implementation of TlclSendReceive() */ +#undef CHROMEOS_ENVIRONMENT +#endif + +/* Sets the size field of a TPM command. */ +static inline void SetTpmCommandSize(uint8_t* buffer, uint32_t size) { + ToTpmUint32(buffer + sizeof(uint16_t), size); +} + +/* Gets the size field of a TPM command. */ +__attribute__((unused)) +static inline int TpmCommandSize(const uint8_t* buffer) { + uint32_t size; + FromTpmUint32(buffer + sizeof(uint16_t), &size); + return (int) size; +} + +/* Gets the size field of a TPM request or response. */ +int TlclPacketSize(const uint8_t* packet) { + return TpmCommandSize(packet); +} + +/* Gets the code field of a TPM command. */ +static inline int TpmCommandCode(const uint8_t* buffer) { + uint32_t code; + FromTpmUint32(buffer + sizeof(uint16_t) + sizeof(uint32_t), &code); + return code; +} + +/* Gets the return code field of a TPM result. */ +static inline int TpmReturnCode(const uint8_t* buffer) { + return TpmCommandCode(buffer); +} + +/* Like TlclSendReceive below, but do not retry if NEEDS_SELFTEST or + * DOING_SELFTEST errors are returned. + */ +static uint32_t TlclSendReceiveNoRetry(const uint8_t* request, + uint8_t* response, int max_length) { + + uint32_t response_length = max_length; + uint32_t result; + +#ifdef EXTRA_LOGGING + VBDEBUG(("TPM: command: %x%x %x%x%x%x %x%x%x%x\n", + request[0], request[1], + request[2], request[3], request[4], request[5], + request[6], request[7], request[8], request[9])); +#endif + + result = VbExTpmSendReceive(request, TpmCommandSize(request), + response, &response_length); + if (0 != result) { + /* Communication with TPM failed, so response is garbage */ + VBDEBUG(("TPM: command 0x%x send/receive failed: 0x%x\n", + TpmCommandCode(request), result)); + return result; + } + /* Otherwise, use the result code from the response */ + result = TpmReturnCode(response); + + /* TODO: add paranoia about returned response_length vs. max_length + * (and possibly expected length from the response header). See + * crosbug.com/17017 */ + +#ifdef EXTRA_LOGGING + VBDEBUG(("TPM: response: %x%x %x%x%x%x %x%x%x%x\n", + response[0], response[1], + response[2], response[3], response[4], response[5], + response[6], response[7], response[8], response[9])); +#endif + + VBDEBUG(("TPM: command 0x%x returned 0x%x\n", + TpmCommandCode(request), result)); + + return result; +} + + +/* Sends a TPM command and gets a response. Returns 0 if success or the TPM + * error code if error. In the firmware, waits for the self test to complete + * if needed. In the host, reports the first error without retries. */ +uint32_t TlclSendReceive(const uint8_t* request, uint8_t* response, + int max_length) { + uint32_t result = TlclSendReceiveNoRetry(request, response, max_length); + /* When compiling for the firmware, hide command failures due to the self + * test not having run or completed. */ +#ifndef CHROMEOS_ENVIRONMENT + /* 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 = TlclContinueSelfTest(); + if (result != TPM_SUCCESS) { + return result; + } +#if defined(TPM_BLOCKING_CONTINUESELFTEST) || defined(VB_RECOVERY_MODE) + /* Retry only once */ + result = TlclSendReceiveNoRetry(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 = TlclSendReceiveNoRetry(request, response, max_length); + } while (result == TPM_E_DOING_SELFTEST); +#endif + } +#endif /* ! defined(CHROMEOS_ENVIRONMENT) */ + 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 TlclSendReceive(command, response, sizeof(response)); +} + +/* Exported functions. */ + +uint32_t TlclLibInit(void) { + return VbExTpmInit(); +} + +uint32_t TlclLibClose(void) { + return VbExTpmClose(); +} + +uint32_t TlclStartup(void) { + VBDEBUG(("TPM: Startup\n")); + return Send(tpm_startup_cmd.buffer); +} + +uint32_t TlclSaveState(void) { + VBDEBUG(("TPM: SaveState\n")); + return Send(tpm_savestate_cmd.buffer); +} + +uint32_t TlclResume(void) { + VBDEBUG(("TPM: Resume\n")); + return Send(tpm_resume_cmd.buffer); +} + +uint32_t TlclSelfTestFull(void) { + VBDEBUG(("TPM: Self test full\n")); + return Send(tpm_selftestfull_cmd.buffer); +} + +uint32_t TlclContinueSelfTest(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 TlclSendReceiveNoRetry(tpm_continueselftest_cmd.buffer, + response, sizeof(response)); +} + +uint32_t TlclDefineSpace(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)); + ToTpmUint32(cmd.buffer + tpm_nv_definespace_cmd.index, index); + ToTpmUint32(cmd.buffer + tpm_nv_definespace_cmd.perm, perm); + ToTpmUint32(cmd.buffer + tpm_nv_definespace_cmd.size, size); + return Send(cmd.buffer); +} + +uint32_t TlclWrite(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: TlclWrite(0x%x, %d)\n", index, length)); + Memcpy(&cmd, &tpm_nv_write_cmd, sizeof(cmd)); + VbAssert(total_length <= TPM_LARGE_ENOUGH_COMMAND_SIZE); + SetTpmCommandSize(cmd.buffer, total_length); + + ToTpmUint32(cmd.buffer + tpm_nv_write_cmd.index, index); + ToTpmUint32(cmd.buffer + tpm_nv_write_cmd.length, length); + Memcpy(cmd.buffer + tpm_nv_write_cmd.data, data, length); + + return TlclSendReceive(cmd.buffer, response, sizeof(response)); +} + +uint32_t TlclRead(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: TlclRead(0x%x, %d)\n", index, length)); + Memcpy(&cmd, &tpm_nv_read_cmd, sizeof(cmd)); + ToTpmUint32(cmd.buffer + tpm_nv_read_cmd.index, index); + ToTpmUint32(cmd.buffer + tpm_nv_read_cmd.length, length); + + result = TlclSendReceive(cmd.buffer, response, sizeof(response)); + if (result == TPM_SUCCESS && length > 0) { + uint8_t* nv_read_cursor = response + kTpmResponseHeaderLength; + FromTpmUint32(nv_read_cursor, &result_length); + nv_read_cursor += sizeof(uint32_t); + Memcpy(data, nv_read_cursor, result_length); + } + + return result; +} + +uint32_t TlclPCRRead(uint32_t index, void* data, uint32_t length) { + struct s_tpm_pcr_read_cmd cmd; + uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE]; + uint32_t result; + + VBDEBUG(("TPM: TlclPCRRead(0x%x, %d)\n", index, length)); + if (length < kPcrDigestLength) { + return TPM_E_IOERROR; + } + Memcpy(&cmd, &tpm_pcr_read_cmd, sizeof(cmd)); + ToTpmUint32(cmd.buffer + tpm_pcr_read_cmd.pcrNum, index); + + result = TlclSendReceive(cmd.buffer, response, sizeof(response)); + if (result == TPM_SUCCESS) { + uint8_t* pcr_read_cursor = response + kTpmResponseHeaderLength; + Memcpy(data, pcr_read_cursor, kPcrDigestLength); + } + + return result; +} + +uint32_t TlclWriteLock(uint32_t index) { + VBDEBUG(("TPM: Write lock 0x%x\n", index)); + return TlclWrite(index, NULL, 0); +} + +uint32_t TlclReadLock(uint32_t index) { + VBDEBUG(("TPM: Read lock 0x%x\n", index)); + return TlclRead(index, NULL, 0); +} + +uint32_t TlclAssertPhysicalPresence(void) { + VBDEBUG(("TPM: Asserting physical presence\n")); + return Send(tpm_ppassert_cmd.buffer); +} + +uint32_t TlclPhysicalPresenceCMDEnable(void) { + VBDEBUG(("TPM: Enable the physical presence command\n")); + return Send(tpm_ppenable_cmd.buffer); +} + +uint32_t TlclFinalizePhysicalPresence(void) { + VBDEBUG(("TPM: Enable PP cmd, disable HW pp, and set lifetime lock\n")); + return Send(tpm_finalizepp_cmd.buffer); +} + +uint32_t TlclAssertPhysicalPresenceResult(void) { + uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE]; + return TlclSendReceive(tpm_ppassert_cmd.buffer, response, sizeof(response)); +} + +uint32_t TlclLockPhysicalPresence(void) { + VBDEBUG(("TPM: Lock physical presence\n")); + return Send(tpm_pplock_cmd.buffer); +} + +uint32_t TlclSetNvLocked(void) { + VBDEBUG(("TPM: Set NV locked\n")); + return TlclDefineSpace(TPM_NV_INDEX_LOCK, 0, 0); +} + +int TlclIsOwned(void) { + uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE + TPM_PUBEK_SIZE]; + uint32_t result; + result = TlclSendReceive(tpm_readpubek_cmd.buffer, + response, sizeof(response)); + return (result != TPM_SUCCESS); +} + +uint32_t TlclForceClear(void) { + VBDEBUG(("TPM: Force clear\n")); + return Send(tpm_forceclear_cmd.buffer); +} + +uint32_t TlclSetEnable(void) { + VBDEBUG(("TPM: Enabling TPM\n")); + return Send(tpm_physicalenable_cmd.buffer); +} + +uint32_t TlclClearEnable(void) { + VBDEBUG(("TPM: Disabling TPM\n")); + return Send(tpm_physicaldisable_cmd.buffer); +} + +uint32_t TlclSetDeactivated(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 TlclGetPermanentFlags(TPM_PERMANENT_FLAGS* pflags) { + uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE]; + uint32_t size; + uint32_t result = + TlclSendReceive(tpm_getflags_cmd.buffer, response, sizeof(response)); + if (result != TPM_SUCCESS) + return result; + FromTpmUint32(response + kTpmResponseHeaderLength, &size); + /* TODO(crbug.com/379255): This fails. Find out why. + * VbAssert(size == sizeof(TPM_PERMANENT_FLAGS)); + */ + Memcpy(pflags, + response + kTpmResponseHeaderLength + sizeof(size), + sizeof(TPM_PERMANENT_FLAGS)); + return result; +} + +uint32_t TlclGetSTClearFlags(TPM_STCLEAR_FLAGS* vflags) { + uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE]; + uint32_t size; + uint32_t result = + TlclSendReceive(tpm_getstclearflags_cmd.buffer, response, sizeof(response)); + if (result != TPM_SUCCESS) + return result; + FromTpmUint32(response + kTpmResponseHeaderLength, &size); + /* Ugly assertion, but the struct is padded up by one byte. */ + /* TODO(crbug.com/379255): This fails. Find out why. + * VbAssert(size == 7 && sizeof(TPM_STCLEAR_FLAGS) - 1 == 7); + */ + Memcpy(vflags, + response + kTpmResponseHeaderLength + sizeof(size), + sizeof(TPM_STCLEAR_FLAGS)); + return result; +} + +uint32_t TlclGetFlags(uint8_t* disable, + uint8_t* deactivated, + uint8_t *nvlocked) { + TPM_PERMANENT_FLAGS pflags; + uint32_t result = TlclGetPermanentFlags(&pflags); + if (result == TPM_SUCCESS) { + if (disable) + *disable = pflags.disable; + if (deactivated) + *deactivated = pflags.deactivated; + if (nvlocked) + *nvlocked = pflags.nvLocked; + VBDEBUG(("TPM: Got flags disable=%d, deactivated=%d, nvlocked=%d\n", + pflags.disable, pflags.deactivated, pflags.nvLocked)); + } + return result; +} + +uint32_t TlclSetGlobalLock(void) { + uint32_t x; + VBDEBUG(("TPM: Set global lock\n")); + return TlclWrite(TPM_NV_INDEX0, (uint8_t*) &x, 0); +} + +uint32_t TlclExtend(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)); + ToTpmUint32(cmd.buffer + tpm_extend_cmd.pcrNum, pcr_num); + Memcpy(cmd.buffer + cmd.inDigest, in_digest, kPcrDigestLength); + + result = TlclSendReceive(cmd.buffer, response, sizeof(response)); + if (result != TPM_SUCCESS) + return result; + + Memcpy(out_digest, response + kTpmResponseHeaderLength, kPcrDigestLength); + return result; +} + +uint32_t TlclGetPermissions(uint32_t index, uint32_t* permissions) { + struct s_tpm_getpermissions_cmd cmd; + uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE]; + uint8_t* nvdata; + uint32_t result; + uint32_t size; + + Memcpy(&cmd, &tpm_getpermissions_cmd, sizeof(cmd)); + ToTpmUint32(cmd.buffer + tpm_getpermissions_cmd.index, index); + result = TlclSendReceive(cmd.buffer, response, sizeof(response)); + if (result != TPM_SUCCESS) + return result; + + nvdata = response + kTpmResponseHeaderLength + sizeof(size); + FromTpmUint32(nvdata + kNvDataPublicPermissionsOffset, permissions); + return result; +} + +uint32_t TlclGetOwnership(uint8_t* owned) { + uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE]; + uint32_t size; + uint32_t result = + TlclSendReceive(tpm_getownership_cmd.buffer, response, sizeof(response)); + if (result != TPM_SUCCESS) + return result; + FromTpmUint32(response + kTpmResponseHeaderLength, &size); + /* TODO(crbug.com/379255): This fails. Find out why. + * VbAssert(size == sizeof(*owned)); + */ + Memcpy(owned, + response + kTpmResponseHeaderLength + sizeof(size), + sizeof(*owned)); + return result; +} + +uint32_t TlclGetRandom(uint8_t* data, uint32_t length, uint32_t *size) { + struct s_tpm_get_random_cmd cmd; + uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE]; + uint32_t result; + + VBDEBUG(("TPM: TlclGetRandom(%d)\n", length)); + Memcpy(&cmd, &tpm_get_random_cmd, sizeof(cmd)); + ToTpmUint32(cmd.buffer + tpm_get_random_cmd.bytesRequested, length); + /* There must be room in the response buffer for the bytes. */ + if (length > TPM_LARGE_ENOUGH_COMMAND_SIZE - kTpmResponseHeaderLength + - sizeof(uint32_t)) { + return TPM_E_IOERROR; + } + + result = TlclSendReceive(cmd.buffer, response, sizeof(response)); + if (result == TPM_SUCCESS) { + uint8_t* get_random_cursor; + FromTpmUint32(response + kTpmResponseHeaderLength, size); + + /* There must be room in the target buffer for the bytes. */ + if (*size > length) { + return TPM_E_RESPONSE_TOO_LARGE; + } + get_random_cursor = response + kTpmResponseHeaderLength + + sizeof(uint32_t); + Memcpy(data, get_random_cursor, *size); + } + + return result; +} |