uboot/board/gdsys/a38x/hre.c
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   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * (C) Copyright 2013
   4 * Reinhard Pfau, Guntermann & Drunck GmbH, reinhard.pfau@gdsys.cc
   5 */
   6
   7#include <common.h>
   8#include <log.h>
   9#include <malloc.h>
  10#include <fs.h>
  11#include <i2c.h>
  12#include <mmc.h>
  13#include <tpm-v1.h>
  14#include <u-boot/crc.h>
  15#include <u-boot/sha1.h>
  16#include <asm/byteorder.h>
  17#include <asm/unaligned.h>
  18#include <pca9698.h>
  19
  20#include "hre.h"
  21
  22/* other constants */
  23enum {
  24        ESDHC_BOOT_IMAGE_SIG_OFS        = 0x40,
  25        ESDHC_BOOT_IMAGE_SIZE_OFS       = 0x48,
  26        ESDHC_BOOT_IMAGE_ADDR_OFS       = 0x50,
  27        ESDHC_BOOT_IMAGE_TARGET_OFS     = 0x58,
  28        ESDHC_BOOT_IMAGE_ENTRY_OFS      = 0x60,
  29};
  30
  31enum {
  32        I2C_SOC_0 = 0,
  33        I2C_SOC_1 = 1,
  34};
  35
  36enum access_mode {
  37        HREG_NONE       = 0,
  38        HREG_RD         = 1,
  39        HREG_WR         = 2,
  40        HREG_RDWR       = 3,
  41};
  42
  43/* register constants */
  44enum {
  45        FIX_HREG_DEVICE_ID_HASH = 0,
  46        FIX_HREG_UNUSED1        = 1,
  47        FIX_HREG_UNUSED2        = 2,
  48        FIX_HREG_VENDOR         = 3,
  49        COUNT_FIX_HREGS
  50};
  51
  52static struct h_reg pcr_hregs[24];
  53static struct h_reg fix_hregs[COUNT_FIX_HREGS];
  54static struct h_reg var_hregs[8];
  55
  56/* hre opcodes */
  57enum {
  58        /* opcodes w/o data */
  59        HRE_NOP         = 0x00,
  60        HRE_SYNC        = HRE_NOP,
  61        HRE_CHECK0      = 0x01,
  62        /* opcodes w/o data, w/ sync dst */
  63        /* opcodes w/ data */
  64        HRE_LOAD        = 0x81,
  65        /* opcodes w/data, w/sync dst */
  66        HRE_XOR         = 0xC1,
  67        HRE_AND         = 0xC2,
  68        HRE_OR          = 0xC3,
  69        HRE_EXTEND      = 0xC4,
  70        HRE_LOADKEY     = 0xC5,
  71};
  72
  73/* hre errors */
  74enum {
  75        HRE_E_OK        = 0,
  76        HRE_E_TPM_FAILURE,
  77        HRE_E_INVALID_HREG,
  78};
  79
  80static uint64_t device_id;
  81static uint64_t device_cl;
  82static uint64_t device_type;
  83
  84static uint32_t platform_key_handle;
  85
  86static uint32_t hre_tpm_err;
  87static int hre_err = HRE_E_OK;
  88
  89#define IS_PCR_HREG(spec) ((spec) & 0x20)
  90#define IS_FIX_HREG(spec) (((spec) & 0x38) == 0x08)
  91#define IS_VAR_HREG(spec) (((spec) & 0x38) == 0x10)
  92#define HREG_IDX(spec) ((spec) & (IS_PCR_HREG(spec) ? 0x1f : 0x7))
  93
  94static const uint8_t vendor[] = "Guntermann & Drunck";
  95
  96/**
  97 * @brief get the size of a given (TPM) NV area
  98 * @param tpm           TPM device
  99 * @param index NV index of the area to get size for
 100 * @param size  pointer to the size
 101 * @return 0 on success, != 0 on error
 102 */
 103static int get_tpm_nv_size(struct udevice *tpm, uint32_t index, uint32_t *size)
 104{
 105        uint32_t err;
 106        uint8_t info[72];
 107        uint8_t *ptr;
 108        uint16_t v16;
 109
 110        err = tpm_get_capability(tpm, TPM_CAP_NV_INDEX, index,
 111                                 info, sizeof(info));
 112        if (err) {
 113                printf("tpm_get_capability(CAP_NV_INDEX, %08x) failed: %u\n",
 114                       index, err);
 115                return 1;
 116        }
 117
 118        /* skip tag and nvIndex */
 119        ptr = info + 6;
 120        /* skip 2 pcr info fields */
 121        v16 = get_unaligned_be16(ptr);
 122        ptr += 2 + v16 + 1 + 20;
 123        v16 = get_unaligned_be16(ptr);
 124        ptr += 2 + v16 + 1 + 20;
 125        /* skip permission and flags */
 126        ptr += 6 + 3;
 127
 128        *size = get_unaligned_be32(ptr);
 129        return 0;
 130}
 131
 132/**
 133 * @brief search for a key by usage auth and pub key hash.
 134 * @param tpm           TPM device
 135 * @param auth  usage auth of the key to search for
 136 * @param pubkey_digest (SHA1) hash of the pub key structure of the key
 137 * @param[out] handle   the handle of the key iff found
 138 * @return 0 if key was found in TPM; != 0 if not.
 139 */
 140static int find_key(struct udevice *tpm, const uint8_t auth[20],
 141                    const uint8_t pubkey_digest[20], uint32_t *handle)
 142{
 143        uint16_t key_count;
 144        uint32_t key_handles[10];
 145        uint8_t buf[288];
 146        uint8_t *ptr;
 147        uint32_t err;
 148        uint8_t digest[20];
 149        size_t buf_len;
 150        unsigned int i;
 151
 152        /* fetch list of already loaded keys in the TPM */
 153        err = tpm_get_capability(tpm, TPM_CAP_HANDLE, TPM_RT_KEY, buf,
 154                                 sizeof(buf));
 155        if (err)
 156                return -1;
 157        key_count = get_unaligned_be16(buf);
 158        ptr = buf + 2;
 159        for (i = 0; i < key_count; ++i, ptr += 4)
 160                key_handles[i] = get_unaligned_be32(ptr);
 161
 162        /* now search a(/ the) key which we can access with the given auth */
 163        for (i = 0; i < key_count; ++i) {
 164                buf_len = sizeof(buf);
 165                err = tpm_get_pub_key_oiap(tpm, key_handles[i], auth, buf,
 166                                           &buf_len);
 167                if (err && err != TPM_AUTHFAIL)
 168                        return -1;
 169                if (err)
 170                        continue;
 171                sha1_csum(buf, buf_len, digest);
 172                if (!memcmp(digest, pubkey_digest, 20)) {
 173                        *handle = key_handles[i];
 174                        return 0;
 175                }
 176        }
 177        return 1;
 178}
 179
 180/**
 181 * @brief read CCDM common data from TPM NV
 182 * @param tpm           TPM device
 183 * @return 0 if CCDM common data was found and read, !=0 if something failed.
 184 */
 185static int read_common_data(struct udevice *tpm)
 186{
 187        uint32_t size = 0;
 188        uint32_t err;
 189        uint8_t buf[256];
 190        sha1_context ctx;
 191
 192        if (get_tpm_nv_size(tpm, NV_COMMON_DATA_INDEX, &size) ||
 193            size < NV_COMMON_DATA_MIN_SIZE)
 194                return 1;
 195        err = tpm_nv_read_value(tpm, NV_COMMON_DATA_INDEX,
 196                                buf, min(sizeof(buf), size));
 197        if (err) {
 198                printf("tpm_nv_read_value() failed: %u\n", err);
 199                return 1;
 200        }
 201
 202        device_id = get_unaligned_be64(buf);
 203        device_cl = get_unaligned_be64(buf + 8);
 204        device_type = get_unaligned_be64(buf + 16);
 205
 206        sha1_starts(&ctx);
 207        sha1_update(&ctx, buf, 24);
 208        sha1_finish(&ctx, fix_hregs[FIX_HREG_DEVICE_ID_HASH].digest);
 209        fix_hregs[FIX_HREG_DEVICE_ID_HASH].valid = true;
 210
 211        platform_key_handle = get_unaligned_be32(buf + 24);
 212
 213        return 0;
 214}
 215
 216/**
 217 * @brief get pointer to  hash register by specification
 218 * @param spec  specification of a hash register
 219 * @return pointer to hash register or NULL if @a spec does not qualify a
 220 * valid hash register; NULL else.
 221 */
 222static struct h_reg *get_hreg(uint8_t spec)
 223{
 224        uint8_t idx;
 225
 226        idx = HREG_IDX(spec);
 227        if (IS_FIX_HREG(spec)) {
 228                if (idx < ARRAY_SIZE(fix_hregs))
 229                        return fix_hregs + idx;
 230                hre_err = HRE_E_INVALID_HREG;
 231        } else if (IS_PCR_HREG(spec)) {
 232                if (idx < ARRAY_SIZE(pcr_hregs))
 233                        return pcr_hregs + idx;
 234                hre_err = HRE_E_INVALID_HREG;
 235        } else if (IS_VAR_HREG(spec)) {
 236                if (idx < ARRAY_SIZE(var_hregs))
 237                        return var_hregs + idx;
 238                hre_err = HRE_E_INVALID_HREG;
 239        }
 240        return NULL;
 241}
 242
 243/**
 244 * @brief get pointer of a hash register by specification and usage.
 245 * @param tpm           TPM device
 246 * @param spec  specification of a hash register
 247 * @param mode  access mode (read or write or read/write)
 248 * @return pointer to hash register if found and valid; NULL else.
 249 *
 250 * This func uses @a get_reg() to determine the hash register for a given spec.
 251 * If a register is found it is validated according to the desired access mode.
 252 * The value of automatic registers (PCR register and fixed registers) is
 253 * loaded or computed on read access.
 254 */
 255static struct h_reg *access_hreg(struct udevice *tpm, uint8_t spec,
 256                                 enum access_mode mode)
 257{
 258        struct h_reg *result;
 259
 260        result = get_hreg(spec);
 261        if (!result)
 262                return NULL;
 263
 264        if (mode & HREG_WR) {
 265                if (IS_FIX_HREG(spec)) {
 266                        hre_err = HRE_E_INVALID_HREG;
 267                        return NULL;
 268                }
 269        }
 270        if (mode & HREG_RD) {
 271                if (!result->valid) {
 272                        if (IS_PCR_HREG(spec)) {
 273                                hre_tpm_err = tpm_pcr_read(tpm, HREG_IDX(spec),
 274                                        result->digest, 20);
 275                                result->valid = (hre_tpm_err == TPM_SUCCESS);
 276                        } else if (IS_FIX_HREG(spec)) {
 277                                switch (HREG_IDX(spec)) {
 278                                case FIX_HREG_DEVICE_ID_HASH:
 279                                        read_common_data(tpm);
 280                                        break;
 281                                case FIX_HREG_VENDOR:
 282                                        memcpy(result->digest, vendor, 20);
 283                                        result->valid = true;
 284                                        break;
 285                                }
 286                        } else {
 287                                result->valid = true;
 288                        }
 289                }
 290                if (!result->valid) {
 291                        hre_err = HRE_E_INVALID_HREG;
 292                        return NULL;
 293                }
 294        }
 295
 296        return result;
 297}
 298
 299static void *compute_and(void *_dst, const void *_src, size_t n)
 300{
 301        uint8_t *dst = _dst;
 302        const uint8_t *src = _src;
 303        size_t i;
 304
 305        for (i = n; i-- > 0; )
 306                *dst++ &= *src++;
 307
 308        return _dst;
 309}
 310
 311static void *compute_or(void *_dst, const void *_src, size_t n)
 312{
 313        uint8_t *dst = _dst;
 314        const uint8_t *src = _src;
 315        size_t i;
 316
 317        for (i = n; i-- > 0; )
 318                *dst++ |= *src++;
 319
 320        return _dst;
 321}
 322
 323static void *compute_xor(void *_dst, const void *_src, size_t n)
 324{
 325        uint8_t *dst = _dst;
 326        const uint8_t *src = _src;
 327        size_t i;
 328
 329        for (i = n; i-- > 0; )
 330                *dst++ ^= *src++;
 331
 332        return _dst;
 333}
 334
 335static void *compute_extend(void *_dst, const void *_src, size_t n)
 336{
 337        uint8_t digest[20];
 338        sha1_context ctx;
 339
 340        sha1_starts(&ctx);
 341        sha1_update(&ctx, _dst, n);
 342        sha1_update(&ctx, _src, n);
 343        sha1_finish(&ctx, digest);
 344        memcpy(_dst, digest, min(n, sizeof(digest)));
 345
 346        return _dst;
 347}
 348
 349static int hre_op_loadkey(struct udevice *tpm, struct h_reg *src_reg,
 350                          struct h_reg *dst_reg, const void *key,
 351                          size_t key_size)
 352{
 353        uint32_t parent_handle;
 354        uint32_t key_handle;
 355
 356        if (!src_reg || !dst_reg || !src_reg->valid || !dst_reg->valid)
 357                return -1;
 358        if (find_key(tpm, src_reg->digest, dst_reg->digest, &parent_handle))
 359                return -1;
 360        hre_tpm_err = tpm_load_key2_oiap(tpm, parent_handle, key, key_size,
 361                                         src_reg->digest, &key_handle);
 362        if (hre_tpm_err) {
 363                hre_err = HRE_E_TPM_FAILURE;
 364                return -1;
 365        }
 366
 367        return 0;
 368}
 369
 370/**
 371 * @brief executes the next opcode on the hash register engine.
 372 * @param tpm           TPM device
 373 * @param[in,out] ip    pointer to the opcode (instruction pointer)
 374 * @param[in,out] code_size     (remaining) size of the code
 375 * @return new instruction pointer on success, NULL on error.
 376 */
 377static const uint8_t *hre_execute_op(struct udevice *tpm, const uint8_t **ip,
 378                                     size_t *code_size)
 379{
 380        bool dst_modified = false;
 381        uint32_t ins;
 382        uint8_t opcode;
 383        uint8_t src_spec;
 384        uint8_t dst_spec;
 385        uint16_t data_size;
 386        struct h_reg *src_reg, *dst_reg;
 387        uint8_t buf[20];
 388        const uint8_t *src_buf, *data;
 389        uint8_t *ptr;
 390        int i;
 391        void * (*bin_func)(void *, const void *, size_t);
 392
 393        if (*code_size < 4)
 394                return NULL;
 395
 396        ins = get_unaligned_be32(*ip);
 397        opcode = **ip;
 398        data = *ip + 4;
 399        src_spec = (ins >> 18) & 0x3f;
 400        dst_spec = (ins >> 12) & 0x3f;
 401        data_size = (ins & 0x7ff);
 402
 403        debug("HRE: ins=%08x (op=%02x, s=%02x, d=%02x, L=%d)\n", ins,
 404              opcode, src_spec, dst_spec, data_size);
 405
 406        if ((opcode & 0x80) && (data_size + 4) > *code_size)
 407                return NULL;
 408
 409        src_reg = access_hreg(tpm, src_spec, HREG_RD);
 410        if (hre_err || hre_tpm_err)
 411                return NULL;
 412        dst_reg = access_hreg(tpm, dst_spec,
 413                              (opcode & 0x40) ? HREG_RDWR : HREG_WR);
 414        if (hre_err || hre_tpm_err)
 415                return NULL;
 416
 417        switch (opcode) {
 418        case HRE_NOP:
 419                goto end;
 420        case HRE_CHECK0:
 421                if (src_reg) {
 422                        for (i = 0; i < 20; ++i) {
 423                                if (src_reg->digest[i])
 424                                        return NULL;
 425                        }
 426                }
 427                break;
 428        case HRE_LOAD:
 429                bin_func = memcpy;
 430                goto do_bin_func;
 431        case HRE_XOR:
 432                bin_func = compute_xor;
 433                goto do_bin_func;
 434        case HRE_AND:
 435                bin_func = compute_and;
 436                goto do_bin_func;
 437        case HRE_OR:
 438                bin_func = compute_or;
 439                goto do_bin_func;
 440        case HRE_EXTEND:
 441                bin_func = compute_extend;
 442do_bin_func:
 443                if (!dst_reg)
 444                        return NULL;
 445                if (src_reg) {
 446                        src_buf = src_reg->digest;
 447                } else {
 448                        if (!data_size) {
 449                                memset(buf, 0, 20);
 450                                src_buf = buf;
 451                        } else if (data_size == 1) {
 452                                memset(buf, *data, 20);
 453                                src_buf = buf;
 454                        } else if (data_size >= 20) {
 455                                src_buf = data;
 456                        } else {
 457                                src_buf = buf;
 458                                for (ptr = (uint8_t *)src_buf, i = 20; i > 0;
 459                                        i -= data_size, ptr += data_size)
 460                                        memcpy(ptr, data,
 461                                               min_t(size_t, i, data_size));
 462                        }
 463                }
 464                bin_func(dst_reg->digest, src_buf, 20);
 465                dst_reg->valid = true;
 466                dst_modified = true;
 467                break;
 468        case HRE_LOADKEY:
 469                if (hre_op_loadkey(tpm, src_reg, dst_reg, data, data_size))
 470                        return NULL;
 471                break;
 472        default:
 473                return NULL;
 474        }
 475
 476        if (dst_reg && dst_modified && IS_PCR_HREG(dst_spec)) {
 477                hre_tpm_err = tpm_extend(tpm, HREG_IDX(dst_spec),
 478                                         dst_reg->digest, dst_reg->digest);
 479                if (hre_tpm_err) {
 480                        hre_err = HRE_E_TPM_FAILURE;
 481                        return NULL;
 482                }
 483        }
 484end:
 485        *ip += 4;
 486        *code_size -= 4;
 487        if (opcode & 0x80) {
 488                *ip += data_size;
 489                *code_size -= data_size;
 490        }
 491
 492        return *ip;
 493}
 494
 495/**
 496 * @brief runs a program on the hash register engine.
 497 * @param tpm           TPM device
 498 * @param code          pointer to the (HRE) code.
 499 * @param code_size     size of the code (in bytes).
 500 * @return 0 on success, != 0 on failure.
 501 */
 502int hre_run_program(struct udevice *tpm, const uint8_t *code, size_t code_size)
 503{
 504        size_t code_left;
 505        const uint8_t *ip = code;
 506
 507        code_left = code_size;
 508        hre_tpm_err = 0;
 509        hre_err = HRE_E_OK;
 510        while (code_left > 0)
 511                if (!hre_execute_op(tpm, &ip, &code_left))
 512                        return -1;
 513
 514        return hre_err;
 515}
 516
 517int hre_verify_program(struct key_program *prg)
 518{
 519        uint32_t crc;
 520
 521        crc = crc32(0, prg->code, prg->code_size);
 522
 523        if (crc != prg->code_crc) {
 524                printf("HRC crc mismatch: %08x != %08x\n",
 525                       crc, prg->code_crc);
 526                return 1;
 527        }
 528        return 0;
 529}
 530