1/* Copyright (c) 2012 The Chromium OS Authors. All rights reserved. 2 * Use of this source code is governed by a BSD-style license that can be 3 * found in the LICENSE file. 4 */ 5 6/* A lightweight TPM command library. 7 * 8 * The general idea is that TPM commands are array of bytes whose 9 * fields are mostly compile-time constant. The goal is to build much 10 * of the commands at compile time (or build time) and change some of 11 * the fields at run time as needed. The code in 12 * utility/tlcl_generator.c builds structures containing the commands, 13 * as well as the offsets of the fields that need to be set at run 14 * time. 15 */ 16 17#include "sysincludes.h" 18 19#include "tlcl.h" 20#include "tlcl_internal.h" 21#include "tlcl_structures.h" 22#include "utility.h" 23#include "vboot_api.h" 24 25#ifdef FOR_TEST 26/* Allow unit testing implementation of TlclSendReceive() */ 27#undef CHROMEOS_ENVIRONMENT 28#endif 29 30/* Sets the size field of a TPM command. */ 31static inline void SetTpmCommandSize(uint8_t* buffer, uint32_t size) { 32 ToTpmUint32(buffer + sizeof(uint16_t), size); 33} 34 35/* Gets the size field of a TPM command. */ 36__attribute__((unused)) 37static inline int TpmCommandSize(const uint8_t* buffer) { 38 uint32_t size; 39 FromTpmUint32(buffer + sizeof(uint16_t), &size); 40 return (int) size; 41} 42 43/* Gets the size field of a TPM request or response. */ 44int TlclPacketSize(const uint8_t* packet) { 45 return TpmCommandSize(packet); 46} 47 48/* Gets the code field of a TPM command. */ 49static inline int TpmCommandCode(const uint8_t* buffer) { 50 uint32_t code; 51 FromTpmUint32(buffer + sizeof(uint16_t) + sizeof(uint32_t), &code); 52 return code; 53} 54 55/* Gets the return code field of a TPM result. */ 56static inline int TpmReturnCode(const uint8_t* buffer) { 57 return TpmCommandCode(buffer); 58} 59 60/* Like TlclSendReceive below, but do not retry if NEEDS_SELFTEST or 61 * DOING_SELFTEST errors are returned. 62 */ 63static uint32_t TlclSendReceiveNoRetry(const uint8_t* request, 64 uint8_t* response, int max_length) { 65 66 uint32_t response_length = max_length; 67 uint32_t result; 68 69#ifdef EXTRA_LOGGING 70 VBDEBUG(("TPM: command: %x%x %x%x%x%x %x%x%x%x\n", 71 request[0], request[1], 72 request[2], request[3], request[4], request[5], 73 request[6], request[7], request[8], request[9])); 74#endif 75 76 result = VbExTpmSendReceive(request, TpmCommandSize(request), 77 response, &response_length); 78 if (0 != result) { 79 /* Communication with TPM failed, so response is garbage */ 80 VBDEBUG(("TPM: command 0x%x send/receive failed: 0x%x\n", 81 TpmCommandCode(request), result)); 82 return result; 83 } 84 /* Otherwise, use the result code from the response */ 85 result = TpmReturnCode(response); 86 87 /* TODO: add paranoia about returned response_length vs. max_length 88 * (and possibly expected length from the response header). See 89 * crosbug.com/17017 */ 90 91#ifdef EXTRA_LOGGING 92 VBDEBUG(("TPM: response: %x%x %x%x%x%x %x%x%x%x\n", 93 response[0], response[1], 94 response[2], response[3], response[4], response[5], 95 response[6], response[7], response[8], response[9])); 96#endif 97 98 VBDEBUG(("TPM: command 0x%x returned 0x%x\n", 99 TpmCommandCode(request), result)); 100 101 return result; 102} 103 104 105/* Sends a TPM command and gets a response. Returns 0 if success or the TPM 106 * error code if error. In the firmware, waits for the self test to complete 107 * if needed. In the host, reports the first error without retries. */ 108uint32_t TlclSendReceive(const uint8_t* request, uint8_t* response, 109 int max_length) { 110 uint32_t result = TlclSendReceiveNoRetry(request, response, max_length); 111 /* When compiling for the firmware, hide command failures due to the self 112 * test not having run or completed. */ 113#ifndef CHROMEOS_ENVIRONMENT 114 /* If the command fails because the self test has not completed, try it 115 * again after attempting to ensure that the self test has completed. */ 116 if (result == TPM_E_NEEDS_SELFTEST || result == TPM_E_DOING_SELFTEST) { 117 result = TlclContinueSelfTest(); 118 if (result != TPM_SUCCESS) { 119 return result; 120 } 121#if defined(TPM_BLOCKING_CONTINUESELFTEST) || defined(VB_RECOVERY_MODE) 122 /* Retry only once */ 123 result = TlclSendReceiveNoRetry(request, response, max_length); 124#else 125 /* This needs serious testing. The TPM specification says: "iii. The 126 * caller MUST wait for the actions of TPM_ContinueSelfTest to complete 127 * before reissuing the command C1." But, if ContinueSelfTest is 128 * non-blocking, how do we know that the actions have completed other than 129 * trying again? */ 130 do { 131 result = TlclSendReceiveNoRetry(request, response, max_length); 132 } while (result == TPM_E_DOING_SELFTEST); 133#endif 134 } 135#endif /* ! defined(CHROMEOS_ENVIRONMENT) */ 136 return result; 137} 138 139/* Sends a command and returns the error code. */ 140static uint32_t Send(const uint8_t* command) { 141 uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE]; 142 return TlclSendReceive(command, response, sizeof(response)); 143} 144 145/* Exported functions. */ 146 147uint32_t TlclLibInit(void) { 148 return VbExTpmInit(); 149} 150 151uint32_t TlclLibClose(void) { 152 return VbExTpmClose(); 153} 154 155uint32_t TlclStartup(void) { 156 VBDEBUG(("TPM: Startup\n")); 157 return Send(tpm_startup_cmd.buffer); 158} 159 160uint32_t TlclSaveState(void) { 161 VBDEBUG(("TPM: SaveState\n")); 162 return Send(tpm_savestate_cmd.buffer); 163} 164 165uint32_t TlclResume(void) { 166 VBDEBUG(("TPM: Resume\n")); 167 return Send(tpm_resume_cmd.buffer); 168} 169 170uint32_t TlclSelfTestFull(void) { 171 VBDEBUG(("TPM: Self test full\n")); 172 return Send(tpm_selftestfull_cmd.buffer); 173} 174 175uint32_t TlclContinueSelfTest(void) { 176 uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE]; 177 VBDEBUG(("TPM: Continue self test\n")); 178 /* Call the No Retry version of SendReceive to avoid recursion. */ 179 return TlclSendReceiveNoRetry(tpm_continueselftest_cmd.buffer, 180 response, sizeof(response)); 181} 182 183uint32_t TlclDefineSpace(uint32_t index, uint32_t perm, uint32_t size) { 184 struct s_tpm_nv_definespace_cmd cmd; 185 VBDEBUG(("TPM: TlclDefineSpace(0x%x, 0x%x, %d)\n", index, perm, size)); 186 Memcpy(&cmd, &tpm_nv_definespace_cmd, sizeof(cmd)); 187 ToTpmUint32(cmd.buffer + tpm_nv_definespace_cmd.index, index); 188 ToTpmUint32(cmd.buffer + tpm_nv_definespace_cmd.perm, perm); 189 ToTpmUint32(cmd.buffer + tpm_nv_definespace_cmd.size, size); 190 return Send(cmd.buffer); 191} 192 193uint32_t TlclWrite(uint32_t index, const void* data, uint32_t length) { 194 struct s_tpm_nv_write_cmd cmd; 195 uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE]; 196 const int total_length = 197 kTpmRequestHeaderLength + kWriteInfoLength + length; 198 199 VBDEBUG(("TPM: TlclWrite(0x%x, %d)\n", index, length)); 200 Memcpy(&cmd, &tpm_nv_write_cmd, sizeof(cmd)); 201 VbAssert(total_length <= TPM_LARGE_ENOUGH_COMMAND_SIZE); 202 SetTpmCommandSize(cmd.buffer, total_length); 203 204 ToTpmUint32(cmd.buffer + tpm_nv_write_cmd.index, index); 205 ToTpmUint32(cmd.buffer + tpm_nv_write_cmd.length, length); 206 Memcpy(cmd.buffer + tpm_nv_write_cmd.data, data, length); 207 208 return TlclSendReceive(cmd.buffer, response, sizeof(response)); 209} 210 211uint32_t TlclRead(uint32_t index, void* data, uint32_t length) { 212 struct s_tpm_nv_read_cmd cmd; 213 uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE]; 214 uint32_t result_length; 215 uint32_t result; 216 217 VBDEBUG(("TPM: TlclRead(0x%x, %d)\n", index, length)); 218 Memcpy(&cmd, &tpm_nv_read_cmd, sizeof(cmd)); 219 ToTpmUint32(cmd.buffer + tpm_nv_read_cmd.index, index); 220 ToTpmUint32(cmd.buffer + tpm_nv_read_cmd.length, length); 221 222 result = TlclSendReceive(cmd.buffer, response, sizeof(response)); 223 if (result == TPM_SUCCESS && length > 0) { 224 uint8_t* nv_read_cursor = response + kTpmResponseHeaderLength; 225 FromTpmUint32(nv_read_cursor, &result_length); 226 nv_read_cursor += sizeof(uint32_t); 227 Memcpy(data, nv_read_cursor, result_length); 228 } 229 230 return result; 231} 232 233uint32_t TlclPCRRead(uint32_t index, void* data, uint32_t length) { 234 struct s_tpm_pcr_read_cmd cmd; 235 uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE]; 236 uint32_t result; 237 238 VBDEBUG(("TPM: TlclPCRRead(0x%x, %d)\n", index, length)); 239 if (length < kPcrDigestLength) { 240 return TPM_E_IOERROR; 241 } 242 Memcpy(&cmd, &tpm_pcr_read_cmd, sizeof(cmd)); 243 ToTpmUint32(cmd.buffer + tpm_pcr_read_cmd.pcrNum, index); 244 245 result = TlclSendReceive(cmd.buffer, response, sizeof(response)); 246 if (result == TPM_SUCCESS) { 247 uint8_t* pcr_read_cursor = response + kTpmResponseHeaderLength; 248 Memcpy(data, pcr_read_cursor, kPcrDigestLength); 249 } 250 251 return result; 252} 253 254uint32_t TlclWriteLock(uint32_t index) { 255 VBDEBUG(("TPM: Write lock 0x%x\n", index)); 256 return TlclWrite(index, NULL, 0); 257} 258 259uint32_t TlclReadLock(uint32_t index) { 260 VBDEBUG(("TPM: Read lock 0x%x\n", index)); 261 return TlclRead(index, NULL, 0); 262} 263 264uint32_t TlclAssertPhysicalPresence(void) { 265 VBDEBUG(("TPM: Asserting physical presence\n")); 266 return Send(tpm_ppassert_cmd.buffer); 267} 268 269uint32_t TlclPhysicalPresenceCMDEnable(void) { 270 VBDEBUG(("TPM: Enable the physical presence command\n")); 271 return Send(tpm_ppenable_cmd.buffer); 272} 273 274uint32_t TlclFinalizePhysicalPresence(void) { 275 VBDEBUG(("TPM: Enable PP cmd, disable HW pp, and set lifetime lock\n")); 276 return Send(tpm_finalizepp_cmd.buffer); 277} 278 279uint32_t TlclAssertPhysicalPresenceResult(void) { 280 uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE]; 281 return TlclSendReceive(tpm_ppassert_cmd.buffer, response, sizeof(response)); 282} 283 284uint32_t TlclLockPhysicalPresence(void) { 285 VBDEBUG(("TPM: Lock physical presence\n")); 286 return Send(tpm_pplock_cmd.buffer); 287} 288 289uint32_t TlclSetNvLocked(void) { 290 VBDEBUG(("TPM: Set NV locked\n")); 291 return TlclDefineSpace(TPM_NV_INDEX_LOCK, 0, 0); 292} 293 294int TlclIsOwned(void) { 295 uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE + TPM_PUBEK_SIZE]; 296 uint32_t result; 297 result = TlclSendReceive(tpm_readpubek_cmd.buffer, 298 response, sizeof(response)); 299 return (result != TPM_SUCCESS); 300} 301 302uint32_t TlclForceClear(void) { 303 VBDEBUG(("TPM: Force clear\n")); 304 return Send(tpm_forceclear_cmd.buffer); 305} 306 307uint32_t TlclSetEnable(void) { 308 VBDEBUG(("TPM: Enabling TPM\n")); 309 return Send(tpm_physicalenable_cmd.buffer); 310} 311 312uint32_t TlclClearEnable(void) { 313 VBDEBUG(("TPM: Disabling TPM\n")); 314 return Send(tpm_physicaldisable_cmd.buffer); 315} 316 317uint32_t TlclSetDeactivated(uint8_t flag) { 318 struct s_tpm_physicalsetdeactivated_cmd cmd; 319 VBDEBUG(("TPM: SetDeactivated(%d)\n", flag)); 320 Memcpy(&cmd, &tpm_physicalsetdeactivated_cmd, sizeof(cmd)); 321 *(cmd.buffer + cmd.deactivated) = flag; 322 return Send(cmd.buffer); 323} 324 325uint32_t TlclGetPermanentFlags(TPM_PERMANENT_FLAGS* pflags) { 326 uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE]; 327 uint32_t size; 328 uint32_t result = 329 TlclSendReceive(tpm_getflags_cmd.buffer, response, sizeof(response)); 330 if (result != TPM_SUCCESS) 331 return result; 332 FromTpmUint32(response + kTpmResponseHeaderLength, &size); 333 /* TODO(crbug.com/379255): This fails. Find out why. 334 * VbAssert(size == sizeof(TPM_PERMANENT_FLAGS)); 335 */ 336 Memcpy(pflags, 337 response + kTpmResponseHeaderLength + sizeof(size), 338 sizeof(TPM_PERMANENT_FLAGS)); 339 return result; 340} 341 342uint32_t TlclGetSTClearFlags(TPM_STCLEAR_FLAGS* vflags) { 343 uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE]; 344 uint32_t size; 345 uint32_t result = 346 TlclSendReceive(tpm_getstclearflags_cmd.buffer, response, sizeof(response)); 347 if (result != TPM_SUCCESS) 348 return result; 349 FromTpmUint32(response + kTpmResponseHeaderLength, &size); 350 /* Ugly assertion, but the struct is padded up by one byte. */ 351 /* TODO(crbug.com/379255): This fails. Find out why. 352 * VbAssert(size == 7 && sizeof(TPM_STCLEAR_FLAGS) - 1 == 7); 353 */ 354 Memcpy(vflags, 355 response + kTpmResponseHeaderLength + sizeof(size), 356 sizeof(TPM_STCLEAR_FLAGS)); 357 return result; 358} 359 360uint32_t TlclGetFlags(uint8_t* disable, 361 uint8_t* deactivated, 362 uint8_t *nvlocked) { 363 TPM_PERMANENT_FLAGS pflags; 364 uint32_t result = TlclGetPermanentFlags(&pflags); 365 if (result == TPM_SUCCESS) { 366 if (disable) 367 *disable = pflags.disable; 368 if (deactivated) 369 *deactivated = pflags.deactivated; 370 if (nvlocked) 371 *nvlocked = pflags.nvLocked; 372 VBDEBUG(("TPM: Got flags disable=%d, deactivated=%d, nvlocked=%d\n", 373 pflags.disable, pflags.deactivated, pflags.nvLocked)); 374 } 375 return result; 376} 377 378uint32_t TlclSetGlobalLock(void) { 379 uint32_t x; 380 VBDEBUG(("TPM: Set global lock\n")); 381 return TlclWrite(TPM_NV_INDEX0, (uint8_t*) &x, 0); 382} 383 384uint32_t TlclExtend(int pcr_num, const uint8_t* in_digest, 385 uint8_t* out_digest) { 386 struct s_tpm_extend_cmd cmd; 387 uint8_t response[kTpmResponseHeaderLength + kPcrDigestLength]; 388 uint32_t result; 389 390 Memcpy(&cmd, &tpm_extend_cmd, sizeof(cmd)); 391 ToTpmUint32(cmd.buffer + tpm_extend_cmd.pcrNum, pcr_num); 392 Memcpy(cmd.buffer + cmd.inDigest, in_digest, kPcrDigestLength); 393 394 result = TlclSendReceive(cmd.buffer, response, sizeof(response)); 395 if (result != TPM_SUCCESS) 396 return result; 397 398 Memcpy(out_digest, response + kTpmResponseHeaderLength, kPcrDigestLength); 399 return result; 400} 401 402uint32_t TlclGetPermissions(uint32_t index, uint32_t* permissions) { 403 struct s_tpm_getpermissions_cmd cmd; 404 uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE]; 405 uint8_t* nvdata; 406 uint32_t result; 407 uint32_t size; 408 409 Memcpy(&cmd, &tpm_getpermissions_cmd, sizeof(cmd)); 410 ToTpmUint32(cmd.buffer + tpm_getpermissions_cmd.index, index); 411 result = TlclSendReceive(cmd.buffer, response, sizeof(response)); 412 if (result != TPM_SUCCESS) 413 return result; 414 415 nvdata = response + kTpmResponseHeaderLength + sizeof(size); 416 FromTpmUint32(nvdata + kNvDataPublicPermissionsOffset, permissions); 417 return result; 418} 419 420uint32_t TlclGetOwnership(uint8_t* owned) { 421 uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE]; 422 uint32_t size; 423 uint32_t result = 424 TlclSendReceive(tpm_getownership_cmd.buffer, response, sizeof(response)); 425 if (result != TPM_SUCCESS) 426 return result; 427 FromTpmUint32(response + kTpmResponseHeaderLength, &size); 428 /* TODO(crbug.com/379255): This fails. Find out why. 429 * VbAssert(size == sizeof(*owned)); 430 */ 431 Memcpy(owned, 432 response + kTpmResponseHeaderLength + sizeof(size), 433 sizeof(*owned)); 434 return result; 435} 436 437uint32_t TlclGetRandom(uint8_t* data, uint32_t length, uint32_t *size) { 438 struct s_tpm_get_random_cmd cmd; 439 uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE]; 440 uint32_t result; 441 442 VBDEBUG(("TPM: TlclGetRandom(%d)\n", length)); 443 Memcpy(&cmd, &tpm_get_random_cmd, sizeof(cmd)); 444 ToTpmUint32(cmd.buffer + tpm_get_random_cmd.bytesRequested, length); 445 /* There must be room in the response buffer for the bytes. */ 446 if (length > TPM_LARGE_ENOUGH_COMMAND_SIZE - kTpmResponseHeaderLength 447 - sizeof(uint32_t)) { 448 return TPM_E_IOERROR; 449 } 450 451 result = TlclSendReceive(cmd.buffer, response, sizeof(response)); 452 if (result == TPM_SUCCESS) { 453 uint8_t* get_random_cursor; 454 FromTpmUint32(response + kTpmResponseHeaderLength, size); 455 456 /* There must be room in the target buffer for the bytes. */ 457 if (*size > length) { 458 return TPM_E_RESPONSE_TOO_LARGE; 459 } 460 get_random_cursor = response + kTpmResponseHeaderLength 461 + sizeof(uint32_t); 462 Memcpy(data, get_random_cursor, *size); 463 } 464 465 return result; 466} 467