Dirk Eibach | 6008326 | 2017-02-22 16:07:23 +0100 | [diff] [blame^] | 1 | /* |
| 2 | * (C) Copyright 2013 |
| 3 | * Reinhard Pfau, Guntermann & Drunck GmbH, reinhard.pfau@gdsys.cc |
| 4 | * |
| 5 | * SPDX-License-Identifier: GPL-2.0+ |
| 6 | */ |
| 7 | |
| 8 | #include <common.h> |
| 9 | #include <malloc.h> |
| 10 | #include <fs.h> |
| 11 | #include <i2c.h> |
| 12 | #include <mmc.h> |
| 13 | #include <tpm.h> |
| 14 | #include <u-boot/sha1.h> |
| 15 | #include <asm/byteorder.h> |
| 16 | #include <asm/unaligned.h> |
| 17 | #include <pca9698.h> |
| 18 | |
| 19 | #include "hre.h" |
| 20 | |
| 21 | /* other constants */ |
| 22 | enum { |
| 23 | ESDHC_BOOT_IMAGE_SIG_OFS = 0x40, |
| 24 | ESDHC_BOOT_IMAGE_SIZE_OFS = 0x48, |
| 25 | ESDHC_BOOT_IMAGE_ADDR_OFS = 0x50, |
| 26 | ESDHC_BOOT_IMAGE_TARGET_OFS = 0x58, |
| 27 | ESDHC_BOOT_IMAGE_ENTRY_OFS = 0x60, |
| 28 | }; |
| 29 | |
| 30 | enum { |
| 31 | I2C_SOC_0 = 0, |
| 32 | I2C_SOC_1 = 1, |
| 33 | }; |
| 34 | |
| 35 | enum access_mode { |
| 36 | HREG_NONE = 0, |
| 37 | HREG_RD = 1, |
| 38 | HREG_WR = 2, |
| 39 | HREG_RDWR = 3, |
| 40 | }; |
| 41 | |
| 42 | /* register constants */ |
| 43 | enum { |
| 44 | FIX_HREG_DEVICE_ID_HASH = 0, |
| 45 | FIX_HREG_UNUSED1 = 1, |
| 46 | FIX_HREG_UNUSED2 = 2, |
| 47 | FIX_HREG_VENDOR = 3, |
| 48 | COUNT_FIX_HREGS |
| 49 | }; |
| 50 | |
| 51 | static struct h_reg pcr_hregs[24]; |
| 52 | static struct h_reg fix_hregs[COUNT_FIX_HREGS]; |
| 53 | static struct h_reg var_hregs[8]; |
| 54 | |
| 55 | /* hre opcodes */ |
| 56 | enum { |
| 57 | /* opcodes w/o data */ |
| 58 | HRE_NOP = 0x00, |
| 59 | HRE_SYNC = HRE_NOP, |
| 60 | HRE_CHECK0 = 0x01, |
| 61 | /* opcodes w/o data, w/ sync dst */ |
| 62 | /* opcodes w/ data */ |
| 63 | HRE_LOAD = 0x81, |
| 64 | /* opcodes w/data, w/sync dst */ |
| 65 | HRE_XOR = 0xC1, |
| 66 | HRE_AND = 0xC2, |
| 67 | HRE_OR = 0xC3, |
| 68 | HRE_EXTEND = 0xC4, |
| 69 | HRE_LOADKEY = 0xC5, |
| 70 | }; |
| 71 | |
| 72 | /* hre errors */ |
| 73 | enum { |
| 74 | HRE_E_OK = 0, |
| 75 | HRE_E_TPM_FAILURE, |
| 76 | HRE_E_INVALID_HREG, |
| 77 | }; |
| 78 | |
| 79 | static uint64_t device_id; |
| 80 | static uint64_t device_cl; |
| 81 | static uint64_t device_type; |
| 82 | |
| 83 | static uint32_t platform_key_handle; |
| 84 | |
| 85 | static uint32_t hre_tpm_err; |
| 86 | static int hre_err = HRE_E_OK; |
| 87 | |
| 88 | #define IS_PCR_HREG(spec) ((spec) & 0x20) |
| 89 | #define IS_FIX_HREG(spec) (((spec) & 0x38) == 0x08) |
| 90 | #define IS_VAR_HREG(spec) (((spec) & 0x38) == 0x10) |
| 91 | #define HREG_IDX(spec) ((spec) & (IS_PCR_HREG(spec) ? 0x1f : 0x7)) |
| 92 | |
| 93 | static const uint8_t vendor[] = "Guntermann & Drunck"; |
| 94 | |
| 95 | /** |
| 96 | * @brief get the size of a given (TPM) NV area |
| 97 | * @param index NV index of the area to get size for |
| 98 | * @param size pointer to the size |
| 99 | * @return 0 on success, != 0 on error |
| 100 | */ |
| 101 | static int get_tpm_nv_size(uint32_t index, uint32_t *size) |
| 102 | { |
| 103 | uint32_t err; |
| 104 | uint8_t info[72]; |
| 105 | uint8_t *ptr; |
| 106 | uint16_t v16; |
| 107 | |
| 108 | err = tpm_get_capability(TPM_CAP_NV_INDEX, index, |
| 109 | info, sizeof(info)); |
| 110 | if (err) { |
| 111 | printf("tpm_get_capability(CAP_NV_INDEX, %08x) failed: %u\n", |
| 112 | index, err); |
| 113 | return 1; |
| 114 | } |
| 115 | |
| 116 | /* skip tag and nvIndex */ |
| 117 | ptr = info + 6; |
| 118 | /* skip 2 pcr info fields */ |
| 119 | v16 = get_unaligned_be16(ptr); |
| 120 | ptr += 2 + v16 + 1 + 20; |
| 121 | v16 = get_unaligned_be16(ptr); |
| 122 | ptr += 2 + v16 + 1 + 20; |
| 123 | /* skip permission and flags */ |
| 124 | ptr += 6 + 3; |
| 125 | |
| 126 | *size = get_unaligned_be32(ptr); |
| 127 | return 0; |
| 128 | } |
| 129 | |
| 130 | /** |
| 131 | * @brief search for a key by usage auth and pub key hash. |
| 132 | * @param auth usage auth of the key to search for |
| 133 | * @param pubkey_digest (SHA1) hash of the pub key structure of the key |
| 134 | * @param[out] handle the handle of the key iff found |
| 135 | * @return 0 if key was found in TPM; != 0 if not. |
| 136 | */ |
| 137 | static int find_key(const uint8_t auth[20], const uint8_t pubkey_digest[20], |
| 138 | uint32_t *handle) |
| 139 | { |
| 140 | uint16_t key_count; |
| 141 | uint32_t key_handles[10]; |
| 142 | uint8_t buf[288]; |
| 143 | uint8_t *ptr; |
| 144 | uint32_t err; |
| 145 | uint8_t digest[20]; |
| 146 | size_t buf_len; |
| 147 | unsigned int i; |
| 148 | |
| 149 | /* fetch list of already loaded keys in the TPM */ |
| 150 | err = tpm_get_capability(TPM_CAP_HANDLE, TPM_RT_KEY, buf, sizeof(buf)); |
| 151 | if (err) |
| 152 | return -1; |
| 153 | key_count = get_unaligned_be16(buf); |
| 154 | ptr = buf + 2; |
| 155 | for (i = 0; i < key_count; ++i, ptr += 4) |
| 156 | key_handles[i] = get_unaligned_be32(ptr); |
| 157 | |
| 158 | /* now search a(/ the) key which we can access with the given auth */ |
| 159 | for (i = 0; i < key_count; ++i) { |
| 160 | buf_len = sizeof(buf); |
| 161 | err = tpm_get_pub_key_oiap(key_handles[i], auth, buf, &buf_len); |
| 162 | if (err && err != TPM_AUTHFAIL) |
| 163 | return -1; |
| 164 | if (err) |
| 165 | continue; |
| 166 | sha1_csum(buf, buf_len, digest); |
| 167 | if (!memcmp(digest, pubkey_digest, 20)) { |
| 168 | *handle = key_handles[i]; |
| 169 | return 0; |
| 170 | } |
| 171 | } |
| 172 | return 1; |
| 173 | } |
| 174 | |
| 175 | /** |
| 176 | * @brief read CCDM common data from TPM NV |
| 177 | * @return 0 if CCDM common data was found and read, !=0 if something failed. |
| 178 | */ |
| 179 | static int read_common_data(void) |
| 180 | { |
| 181 | uint32_t size = 0; |
| 182 | uint32_t err; |
| 183 | uint8_t buf[256]; |
| 184 | sha1_context ctx; |
| 185 | |
| 186 | if (get_tpm_nv_size(NV_COMMON_DATA_INDEX, &size) || |
| 187 | size < NV_COMMON_DATA_MIN_SIZE) |
| 188 | return 1; |
| 189 | err = tpm_nv_read_value(NV_COMMON_DATA_INDEX, |
| 190 | buf, min(sizeof(buf), size)); |
| 191 | if (err) { |
| 192 | printf("tpm_nv_read_value() failed: %u\n", err); |
| 193 | return 1; |
| 194 | } |
| 195 | |
| 196 | device_id = get_unaligned_be64(buf); |
| 197 | device_cl = get_unaligned_be64(buf + 8); |
| 198 | device_type = get_unaligned_be64(buf + 16); |
| 199 | |
| 200 | sha1_starts(&ctx); |
| 201 | sha1_update(&ctx, buf, 24); |
| 202 | sha1_finish(&ctx, fix_hregs[FIX_HREG_DEVICE_ID_HASH].digest); |
| 203 | fix_hregs[FIX_HREG_DEVICE_ID_HASH].valid = true; |
| 204 | |
| 205 | platform_key_handle = get_unaligned_be32(buf + 24); |
| 206 | |
| 207 | return 0; |
| 208 | } |
| 209 | |
| 210 | /** |
| 211 | * @brief get pointer to hash register by specification |
| 212 | * @param spec specification of a hash register |
| 213 | * @return pointer to hash register or NULL if @a spec does not qualify a |
| 214 | * valid hash register; NULL else. |
| 215 | */ |
| 216 | static struct h_reg *get_hreg(uint8_t spec) |
| 217 | { |
| 218 | uint8_t idx; |
| 219 | |
| 220 | idx = HREG_IDX(spec); |
| 221 | if (IS_FIX_HREG(spec)) { |
| 222 | if (idx < ARRAY_SIZE(fix_hregs)) |
| 223 | return fix_hregs + idx; |
| 224 | hre_err = HRE_E_INVALID_HREG; |
| 225 | } else if (IS_PCR_HREG(spec)) { |
| 226 | if (idx < ARRAY_SIZE(pcr_hregs)) |
| 227 | return pcr_hregs + idx; |
| 228 | hre_err = HRE_E_INVALID_HREG; |
| 229 | } else if (IS_VAR_HREG(spec)) { |
| 230 | if (idx < ARRAY_SIZE(var_hregs)) |
| 231 | return var_hregs + idx; |
| 232 | hre_err = HRE_E_INVALID_HREG; |
| 233 | } |
| 234 | return NULL; |
| 235 | } |
| 236 | |
| 237 | /** |
| 238 | * @brief get pointer of a hash register by specification and usage. |
| 239 | * @param spec specification of a hash register |
| 240 | * @param mode access mode (read or write or read/write) |
| 241 | * @return pointer to hash register if found and valid; NULL else. |
| 242 | * |
| 243 | * This func uses @a get_reg() to determine the hash register for a given spec. |
| 244 | * If a register is found it is validated according to the desired access mode. |
| 245 | * The value of automatic registers (PCR register and fixed registers) is |
| 246 | * loaded or computed on read access. |
| 247 | */ |
| 248 | static struct h_reg *access_hreg(uint8_t spec, enum access_mode mode) |
| 249 | { |
| 250 | struct h_reg *result; |
| 251 | |
| 252 | result = get_hreg(spec); |
| 253 | if (!result) |
| 254 | return NULL; |
| 255 | |
| 256 | if (mode & HREG_WR) { |
| 257 | if (IS_FIX_HREG(spec)) { |
| 258 | hre_err = HRE_E_INVALID_HREG; |
| 259 | return NULL; |
| 260 | } |
| 261 | } |
| 262 | if (mode & HREG_RD) { |
| 263 | if (!result->valid) { |
| 264 | if (IS_PCR_HREG(spec)) { |
| 265 | hre_tpm_err = tpm_pcr_read(HREG_IDX(spec), |
| 266 | result->digest, 20); |
| 267 | result->valid = (hre_tpm_err == TPM_SUCCESS); |
| 268 | } else if (IS_FIX_HREG(spec)) { |
| 269 | switch (HREG_IDX(spec)) { |
| 270 | case FIX_HREG_DEVICE_ID_HASH: |
| 271 | read_common_data(); |
| 272 | break; |
| 273 | case FIX_HREG_VENDOR: |
| 274 | memcpy(result->digest, vendor, 20); |
| 275 | result->valid = true; |
| 276 | break; |
| 277 | } |
| 278 | } else { |
| 279 | result->valid = true; |
| 280 | } |
| 281 | } |
| 282 | if (!result->valid) { |
| 283 | hre_err = HRE_E_INVALID_HREG; |
| 284 | return NULL; |
| 285 | } |
| 286 | } |
| 287 | |
| 288 | return result; |
| 289 | } |
| 290 | |
| 291 | static void *compute_and(void *_dst, const void *_src, size_t n) |
| 292 | { |
| 293 | uint8_t *dst = _dst; |
| 294 | const uint8_t *src = _src; |
| 295 | size_t i; |
| 296 | |
| 297 | for (i = n; i-- > 0; ) |
| 298 | *dst++ &= *src++; |
| 299 | |
| 300 | return _dst; |
| 301 | } |
| 302 | |
| 303 | static void *compute_or(void *_dst, const void *_src, size_t n) |
| 304 | { |
| 305 | uint8_t *dst = _dst; |
| 306 | const uint8_t *src = _src; |
| 307 | size_t i; |
| 308 | |
| 309 | for (i = n; i-- > 0; ) |
| 310 | *dst++ |= *src++; |
| 311 | |
| 312 | return _dst; |
| 313 | } |
| 314 | |
| 315 | static void *compute_xor(void *_dst, const void *_src, size_t n) |
| 316 | { |
| 317 | uint8_t *dst = _dst; |
| 318 | const uint8_t *src = _src; |
| 319 | size_t i; |
| 320 | |
| 321 | for (i = n; i-- > 0; ) |
| 322 | *dst++ ^= *src++; |
| 323 | |
| 324 | return _dst; |
| 325 | } |
| 326 | |
| 327 | static void *compute_extend(void *_dst, const void *_src, size_t n) |
| 328 | { |
| 329 | uint8_t digest[20]; |
| 330 | sha1_context ctx; |
| 331 | |
| 332 | sha1_starts(&ctx); |
| 333 | sha1_update(&ctx, _dst, n); |
| 334 | sha1_update(&ctx, _src, n); |
| 335 | sha1_finish(&ctx, digest); |
| 336 | memcpy(_dst, digest, min(n, sizeof(digest))); |
| 337 | |
| 338 | return _dst; |
| 339 | } |
| 340 | |
| 341 | static int hre_op_loadkey(struct h_reg *src_reg, struct h_reg *dst_reg, |
| 342 | const void *key, size_t key_size) |
| 343 | { |
| 344 | uint32_t parent_handle; |
| 345 | uint32_t key_handle; |
| 346 | |
| 347 | if (!src_reg || !dst_reg || !src_reg->valid || !dst_reg->valid) |
| 348 | return -1; |
| 349 | if (find_key(src_reg->digest, dst_reg->digest, &parent_handle)) |
| 350 | return -1; |
| 351 | hre_tpm_err = tpm_load_key2_oiap(parent_handle, key, key_size, |
| 352 | src_reg->digest, &key_handle); |
| 353 | if (hre_tpm_err) { |
| 354 | hre_err = HRE_E_TPM_FAILURE; |
| 355 | return -1; |
| 356 | } |
| 357 | |
| 358 | return 0; |
| 359 | } |
| 360 | |
| 361 | /** |
| 362 | * @brief executes the next opcode on the hash register engine. |
| 363 | * @param[in,out] ip pointer to the opcode (instruction pointer) |
| 364 | * @param[in,out] code_size (remaining) size of the code |
| 365 | * @return new instruction pointer on success, NULL on error. |
| 366 | */ |
| 367 | static const uint8_t *hre_execute_op(const uint8_t **ip, size_t *code_size) |
| 368 | { |
| 369 | bool dst_modified = false; |
| 370 | uint32_t ins; |
| 371 | uint8_t opcode; |
| 372 | uint8_t src_spec; |
| 373 | uint8_t dst_spec; |
| 374 | uint16_t data_size; |
| 375 | struct h_reg *src_reg, *dst_reg; |
| 376 | uint8_t buf[20]; |
| 377 | const uint8_t *src_buf, *data; |
| 378 | uint8_t *ptr; |
| 379 | int i; |
| 380 | void * (*bin_func)(void *, const void *, size_t); |
| 381 | |
| 382 | if (*code_size < 4) |
| 383 | return NULL; |
| 384 | |
| 385 | ins = get_unaligned_be32(*ip); |
| 386 | opcode = **ip; |
| 387 | data = *ip + 4; |
| 388 | src_spec = (ins >> 18) & 0x3f; |
| 389 | dst_spec = (ins >> 12) & 0x3f; |
| 390 | data_size = (ins & 0x7ff); |
| 391 | |
| 392 | debug("HRE: ins=%08x (op=%02x, s=%02x, d=%02x, L=%d)\n", ins, |
| 393 | opcode, src_spec, dst_spec, data_size); |
| 394 | |
| 395 | if ((opcode & 0x80) && (data_size + 4) > *code_size) |
| 396 | return NULL; |
| 397 | |
| 398 | src_reg = access_hreg(src_spec, HREG_RD); |
| 399 | if (hre_err || hre_tpm_err) |
| 400 | return NULL; |
| 401 | dst_reg = access_hreg(dst_spec, (opcode & 0x40) ? HREG_RDWR : HREG_WR); |
| 402 | if (hre_err || hre_tpm_err) |
| 403 | return NULL; |
| 404 | |
| 405 | switch (opcode) { |
| 406 | case HRE_NOP: |
| 407 | goto end; |
| 408 | case HRE_CHECK0: |
| 409 | if (src_reg) { |
| 410 | for (i = 0; i < 20; ++i) { |
| 411 | if (src_reg->digest[i]) |
| 412 | return NULL; |
| 413 | } |
| 414 | } |
| 415 | break; |
| 416 | case HRE_LOAD: |
| 417 | bin_func = memcpy; |
| 418 | goto do_bin_func; |
| 419 | case HRE_XOR: |
| 420 | bin_func = compute_xor; |
| 421 | goto do_bin_func; |
| 422 | case HRE_AND: |
| 423 | bin_func = compute_and; |
| 424 | goto do_bin_func; |
| 425 | case HRE_OR: |
| 426 | bin_func = compute_or; |
| 427 | goto do_bin_func; |
| 428 | case HRE_EXTEND: |
| 429 | bin_func = compute_extend; |
| 430 | do_bin_func: |
| 431 | if (!dst_reg) |
| 432 | return NULL; |
| 433 | if (src_reg) { |
| 434 | src_buf = src_reg->digest; |
| 435 | } else { |
| 436 | if (!data_size) { |
| 437 | memset(buf, 0, 20); |
| 438 | src_buf = buf; |
| 439 | } else if (data_size == 1) { |
| 440 | memset(buf, *data, 20); |
| 441 | src_buf = buf; |
| 442 | } else if (data_size >= 20) { |
| 443 | src_buf = data; |
| 444 | } else { |
| 445 | src_buf = buf; |
| 446 | for (ptr = (uint8_t *)src_buf, i = 20; i > 0; |
| 447 | i -= data_size, ptr += data_size) |
| 448 | memcpy(ptr, data, |
| 449 | min_t(size_t, i, data_size)); |
| 450 | } |
| 451 | } |
| 452 | bin_func(dst_reg->digest, src_buf, 20); |
| 453 | dst_reg->valid = true; |
| 454 | dst_modified = true; |
| 455 | break; |
| 456 | case HRE_LOADKEY: |
| 457 | if (hre_op_loadkey(src_reg, dst_reg, data, data_size)) |
| 458 | return NULL; |
| 459 | break; |
| 460 | default: |
| 461 | return NULL; |
| 462 | } |
| 463 | |
| 464 | if (dst_reg && dst_modified && IS_PCR_HREG(dst_spec)) { |
| 465 | hre_tpm_err = tpm_extend(HREG_IDX(dst_spec), dst_reg->digest, |
| 466 | dst_reg->digest); |
| 467 | if (hre_tpm_err) { |
| 468 | hre_err = HRE_E_TPM_FAILURE; |
| 469 | return NULL; |
| 470 | } |
| 471 | } |
| 472 | end: |
| 473 | *ip += 4; |
| 474 | *code_size -= 4; |
| 475 | if (opcode & 0x80) { |
| 476 | *ip += data_size; |
| 477 | *code_size -= data_size; |
| 478 | } |
| 479 | |
| 480 | return *ip; |
| 481 | } |
| 482 | |
| 483 | /** |
| 484 | * @brief runs a program on the hash register engine. |
| 485 | * @param code pointer to the (HRE) code. |
| 486 | * @param code_size size of the code (in bytes). |
| 487 | * @return 0 on success, != 0 on failure. |
| 488 | */ |
| 489 | int hre_run_program(const uint8_t *code, size_t code_size) |
| 490 | { |
| 491 | size_t code_left; |
| 492 | const uint8_t *ip = code; |
| 493 | |
| 494 | code_left = code_size; |
| 495 | hre_tpm_err = 0; |
| 496 | hre_err = HRE_E_OK; |
| 497 | while (code_left > 0) |
| 498 | if (!hre_execute_op(&ip, &code_left)) |
| 499 | return -1; |
| 500 | |
| 501 | return hre_err; |
| 502 | } |
| 503 | |
| 504 | int hre_verify_program(struct key_program *prg) |
| 505 | { |
| 506 | uint32_t crc; |
| 507 | |
| 508 | crc = crc32(0, prg->code, prg->code_size); |
| 509 | |
| 510 | if (crc != prg->code_crc) { |
| 511 | printf("HRC crc mismatch: %08x != %08x\n", |
| 512 | crc, prg->code_crc); |
| 513 | return 1; |
| 514 | } |
| 515 | return 0; |
| 516 | } |