common/hash.c

   1 /*
   2  * Copyright (c) 2012 The Chromium OS Authors.
   3  *
   4  * (C) Copyright 2011
   5  * Joe Hershberger, National Instruments, joe.hershberger@ni.com
   6  *
   7  * (C) Copyright 2000
   8  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   9  *
  10  * SPDX-License-Identifier:     GPL-2.0+
  11  */
  12
  13 #include <common.h>
  14 #include <command.h>
  15 #include <malloc.h>
  16 #include <hw_sha.h>
  17 #include <hash.h>
  18 #include <u-boot/sha1.h>
  19 #include <u-boot/sha256.h>
  20 #include <asm/io.h>
  21 #include <asm/errno.h>
  22
  23 #ifdef CONFIG_CMD_SHA1SUM
  24 static int hash_init_sha1(struct hash_algo *algo, void **ctxp)
  25 {
  26         sha1_context *ctx = malloc(sizeof(sha1_context));
  27         sha1_starts(ctx);
  28         *ctxp = ctx;
  29         return 0;
  30 }
  31
  32 static int hash_update_sha1(struct hash_algo *algo, void *ctx, const void *buf,
  33                             unsigned int size, int is_last)
  34 {
  35         sha1_update((sha1_context *)ctx, buf, size);
  36         return 0;
  37 }
  38
  39 static int hash_finish_sha1(struct hash_algo *algo, void *ctx, void *dest_buf,
  40                             int size)
  41 {
  42         if (size < algo->digest_size)
  43                 return -1;
  44
  45         sha1_finish((sha1_context *)ctx, dest_buf);
  46         free(ctx);
  47         return 0;
  48 }
  49 #endif
  50
  51 #ifdef CONFIG_SHA256
  52 static int hash_init_sha256(struct hash_algo *algo, void **ctxp)
  53 {
  54         sha256_context *ctx = malloc(sizeof(sha256_context));
  55         sha256_starts(ctx);
  56         *ctxp = ctx;
  57         return 0;
  58 }
  59
  60 static int hash_update_sha256(struct hash_algo *algo, void *ctx,
  61                               const void *buf, unsigned int size, int is_last)
  62 {
  63         sha256_update((sha256_context *)ctx, buf, size);
  64         return 0;
  65 }
  66
  67 static int hash_finish_sha256(struct hash_algo *algo, void *ctx, void
  68                               *dest_buf, int size)
  69 {
  70         if (size < algo->digest_size)
  71                 return -1;
  72
  73         sha256_finish((sha256_context *)ctx, dest_buf);
  74         free(ctx);
  75         return 0;
  76 }
  77 #endif
  78
  79 static int hash_init_crc32(struct hash_algo *algo, void **ctxp)
  80 {
  81         uint32_t *ctx = malloc(sizeof(uint32_t));
  82         *ctx = 0;
  83         *ctxp = ctx;
  84         return 0;
  85 }
  86
  87 static int hash_update_crc32(struct hash_algo *algo, void *ctx,
  88                              const void *buf, unsigned int size, int is_last)
  89 {
  90         *((uint32_t *)ctx) = crc32(*((uint32_t *)ctx), buf, size);
  91         return 0;
  92 }
  93
  94 static int hash_finish_crc32(struct hash_algo *algo, void *ctx, void *dest_buf,
  95                              int size)
  96 {
  97         if (size < algo->digest_size)
  98                 return -1;
  99
 100         *((uint32_t *)dest_buf) = *((uint32_t *)ctx);
 101         free(ctx);
 102         return 0;
 103 }
 104
 105 /*
 106  * These are the hash algorithms we support. Chips which support accelerated
 107  * crypto could perhaps add named version of these algorithms here. Note that
 108  * algorithm names must be in lower case.
 109  */
 110 static struct hash_algo hash_algo[] = {
 111         /*
 112          * CONFIG_SHA_HW_ACCEL is defined if hardware acceleration is
 113          * available.
 114          */
 115 #ifdef CONFIG_SHA_HW_ACCEL
 116         {
 117                 "sha1",
 118                 SHA1_SUM_LEN,
 119                 hw_sha1,
 120                 CHUNKSZ_SHA1,
 121         }, {
 122                 "sha256",
 123                 SHA256_SUM_LEN,
 124                 hw_sha256,
 125                 CHUNKSZ_SHA256,
 126         },
 127 #endif
 128         /*
 129          * This is CONFIG_CMD_SHA1SUM instead of CONFIG_SHA1 since otherwise
 130          * it bloats the code for boards which use SHA1 but not the 'hash'
 131          * or 'sha1sum' commands.
 132          */
 133 #ifdef CONFIG_CMD_SHA1SUM
 134         {
 135                 "sha1",
 136                 SHA1_SUM_LEN,
 137                 sha1_csum_wd,
 138                 CHUNKSZ_SHA1,
 139                 hash_init_sha1,
 140                 hash_update_sha1,
 141                 hash_finish_sha1,
 142         },
 143 #define MULTI_HASH
 144 #endif
 145 #ifdef CONFIG_SHA256
 146         {
 147                 "sha256",
 148                 SHA256_SUM_LEN,
 149                 sha256_csum_wd,
 150                 CHUNKSZ_SHA256,
 151                 hash_init_sha256,
 152                 hash_update_sha256,
 153                 hash_finish_sha256,
 154         },
 155 #define MULTI_HASH
 156 #endif
 157         {
 158                 "crc32",
 159                 4,
 160                 crc32_wd_buf,
 161                 CHUNKSZ_CRC32,
 162                 hash_init_crc32,
 163                 hash_update_crc32,
 164                 hash_finish_crc32,
 165         },
 166 };
 167
 168 #if defined(CONFIG_HASH_VERIFY) || defined(CONFIG_CMD_HASH)
 169 #define MULTI_HASH
 170 #endif
 171
 172 /* Try to minimize code size for boards that don't want much hashing */
 173 #ifdef MULTI_HASH
 174 #define multi_hash()    1
 175 #else
 176 #define multi_hash()    0
 177 #endif
 178
 179 /**
 180  * store_result: Store the resulting sum to an address or variable
 181  *
 182  * @algo:               Hash algorithm being used
 183  * @sum:                Hash digest (algo->digest_size bytes)
 184  * @dest:               Destination, interpreted as a hex address if it starts
 185  *                      with * (or allow_env_vars is 0) or otherwise as an
 186  *                      environment variable.
 187  * @allow_env_vars:     non-zero to permit storing the result to an
 188  *                      variable environment
 189  */
 190 static void store_result(struct hash_algo *algo, const uint8_t *sum,
 191                          const char *dest, int allow_env_vars)
 192 {
 193         unsigned int i;
 194         int env_var = 0;
 195
 196         /*
 197          * If environment variables are allowed, then we assume that 'dest'
 198          * is an environment variable, unless it starts with *, in which
 199          * case we assume it is an address. If not allowed, it is always an
 200          * address. This is to support the crc32 command.
 201          */
 202         if (allow_env_vars) {
 203                 if (*dest == '*')
 204                         dest++;
 205                 else
 206                         env_var = 1;
 207         }
 208
 209         if (env_var) {
 210                 char str_output[HASH_MAX_DIGEST_SIZE * 2 + 1];
 211                 char *str_ptr = str_output;
 212
 213                 for (i = 0; i < algo->digest_size; i++) {
 214                         sprintf(str_ptr, "%02x", sum[i]);
 215                         str_ptr += 2;
 216                 }
 217                 *str_ptr = '\0';
 218                 setenv(dest, str_output);
 219         } else {
 220                 ulong addr;
 221                 void *buf;
 222
 223                 addr = simple_strtoul(dest, NULL, 16);
 224                 buf = map_sysmem(addr, algo->digest_size);
 225                 memcpy(buf, sum, algo->digest_size);
 226                 unmap_sysmem(buf);
 227         }
 228 }
 229
 230 /**
 231  * parse_verify_sum: Parse a hash verification parameter
 232  *
 233  * @algo:               Hash algorithm being used
 234  * @verify_str:         Argument to parse. If it starts with * then it is
 235  *                      interpreted as a hex address containing the hash.
 236  *                      If the length is exactly the right number of hex digits
 237  *                      for the digest size, then we assume it is a hex digest.
 238  *                      Otherwise we assume it is an environment variable, and
 239  *                      look up its value (it must contain a hex digest).
 240  * @vsum:               Returns binary digest value (algo->digest_size bytes)
 241  * @allow_env_vars:     non-zero to permit storing the result to an environment
 242  *                      variable. If 0 then verify_str is assumed to be an
 243  *                      address, and the * prefix is not expected.
 244  * @return 0 if ok, non-zero on error
 245  */
 246 static int parse_verify_sum(struct hash_algo *algo, char *verify_str,
 247                             uint8_t *vsum, int allow_env_vars)
 248 {
 249         int env_var = 0;
 250
 251         /* See comment above in store_result() */
 252         if (allow_env_vars) {
 253                 if (*verify_str == '*')
 254                         verify_str++;
 255                 else
 256                         env_var = 1;
 257         }
 258
 259         if (env_var) {
 260                 ulong addr;
 261                 void *buf;
 262
 263                 addr = simple_strtoul(verify_str, NULL, 16);
 264                 buf = map_sysmem(addr, algo->digest_size);
 265                 memcpy(vsum, buf, algo->digest_size);
 266         } else {
 267                 unsigned int i;
 268                 char *vsum_str;
 269                 int digits = algo->digest_size * 2;
 270
 271                 /*
 272                  * As with the original code from sha1sum.c, we assume that a
 273                  * string which matches the digest size exactly is a hex
 274                  * string and not an environment variable.
 275                  */
 276                 if (strlen(verify_str) == digits)
 277                         vsum_str = verify_str;
 278                 else {
 279                         vsum_str = getenv(verify_str);
 280                         if (vsum_str == NULL || strlen(vsum_str) != digits) {
 281                                 printf("Expected %d hex digits in env var\n",
 282                                        digits);
 283                                 return 1;
 284                         }
 285                 }
 286
 287                 for (i = 0; i < algo->digest_size; i++) {
 288                         char *nullp = vsum_str + (i + 1) * 2;
 289                         char end = *nullp;
 290
 291                         *nullp = '\0';
 292                         vsum[i] = simple_strtoul(vsum_str + (i * 2), NULL, 16);
 293                         *nullp = end;
 294                 }
 295         }
 296         return 0;
 297 }
 298
 299 int hash_lookup_algo(const char *algo_name, struct hash_algo **algop)
 300 {
 301         int i;
 302
 303         for (i = 0; i < ARRAY_SIZE(hash_algo); i++) {
 304                 if (!strcmp(algo_name, hash_algo[i].name)) {
 305                         *algop = &hash_algo[i];
 306                         return 0;
 307                 }
 308         }
 309
 310         debug("Unknown hash algorithm '%s'\n", algo_name);
 311         return -EPROTONOSUPPORT;
 312 }
 313
 314 void hash_show(struct hash_algo *algo, ulong addr, ulong len, uint8_t *output)
 315 {
 316         int i;
 317
 318         printf("%s for %08lx ... %08lx ==> ", algo->name, addr, addr + len - 1);
 319         for (i = 0; i < algo->digest_size; i++)
 320                 printf("%02x", output[i]);
 321 }
 322
 323 int hash_block(const char *algo_name, const void *data, unsigned int len,
 324                uint8_t *output, int *output_size)
 325 {
 326         struct hash_algo *algo;
 327         int ret;
 328
 329         ret = hash_lookup_algo(algo_name, &algo);
 330         if (ret)
 331                 return ret;
 332
 333         if (output_size && *output_size < algo->digest_size) {
 334                 debug("Output buffer size %d too small (need %d bytes)",
 335                       *output_size, algo->digest_size);
 336                 return -ENOSPC;
 337         }
 338         if (output_size)
 339                 *output_size = algo->digest_size;
 340         algo->hash_func_ws(data, len, output, algo->chunk_size);
 341
 342         return 0;
 343 }
 344
 345 int hash_command(const char *algo_name, int flags, cmd_tbl_t *cmdtp, int flag,
 346                  int argc, char * const argv[])
 347 {
 348         ulong addr, len;
 349
 350         if (argc < 2)
 351                 return CMD_RET_USAGE;
 352
 353         addr = simple_strtoul(*argv++, NULL, 16);
 354         len = simple_strtoul(*argv++, NULL, 16);
 355
 356         if (multi_hash()) {
 357                 struct hash_algo *algo;
 358                 uint8_t output[HASH_MAX_DIGEST_SIZE];
 359                 uint8_t vsum[HASH_MAX_DIGEST_SIZE];
 360                 void *buf;
 361
 362                 if (hash_lookup_algo(algo_name, &algo)) {
 363                         printf("Unknown hash algorithm '%s'\n", algo_name);
 364                         return CMD_RET_USAGE;
 365                 }
 366                 argc -= 2;
 367
 368                 if (algo->digest_size > HASH_MAX_DIGEST_SIZE) {
 369                         puts("HASH_MAX_DIGEST_SIZE exceeded\n");
 370                         return 1;
 371                 }
 372
 373                 buf = map_sysmem(addr, len);
 374                 algo->hash_func_ws(buf, len, output, algo->chunk_size);
 375                 unmap_sysmem(buf);
 376
 377                 /* Try to avoid code bloat when verify is not needed */
 378 #ifdef CONFIG_HASH_VERIFY
 379                 if (flags & HASH_FLAG_VERIFY) {
 380 #else
 381                 if (0) {
 382 #endif
 383                         if (!argc)
 384                                 return CMD_RET_USAGE;
 385                         if (parse_verify_sum(algo, *argv, vsum,
 386                                         flags & HASH_FLAG_ENV)) {
 387                                 printf("ERROR: %s does not contain a valid "
 388                                         "%s sum\n", *argv, algo->name);
 389                                 return 1;
 390                         }
 391                         if (memcmp(output, vsum, algo->digest_size) != 0) {
 392                                 int i;
 393
 394                                 hash_show(algo, addr, len, output);
 395                                 printf(" != ");
 396                                 for (i = 0; i < algo->digest_size; i++)
 397                                         printf("%02x", vsum[i]);
 398                                 puts(" ** ERROR **\n");
 399                                 return 1;
 400                         }
 401                 } else {
 402                         hash_show(algo, addr, len, output);
 403                         printf("\n");
 404
 405                         if (argc) {
 406                                 store_result(algo, output, *argv,
 407                                         flags & HASH_FLAG_ENV);
 408                         }
 409                 }
 410
 411         /* Horrible code size hack for boards that just want crc32 */
 412         } else {
 413                 ulong crc;
 414                 ulong *ptr;
 415
 416                 crc = crc32_wd(0, (const uchar *)addr, len, CHUNKSZ_CRC32);
 417
 418                 printf("CRC32 for %08lx ... %08lx ==> %08lx\n",
 419                                 addr, addr + len - 1, crc);
 420
 421                 if (argc >= 3) {
 422                         ptr = (ulong *)simple_strtoul(argv[0], NULL, 16);
 423                         *ptr = crc;
 424                 }
 425         }
 426
 427         return 0;
 428 }