1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2009-2011 Gabor Juhos <juhosg@openwrt.org> 4 */ 5 6 #include <stdio.h> 7 #include <stdlib.h> 8 #include <string.h> 9 #include <errno.h> 10 #include <unistd.h> 11 #include <sys/stat.h> 12 13 #include "buffalo-lib.h" 14 15 static uint32_t crc32_table[256] = 16 { 17 0x00000000, 0x04c11db7, 0x09823b6e, 0x0d4326d9, 18 0x130476dc, 0x17c56b6b, 0x1a864db2, 0x1e475005, 19 0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61, 20 0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd, 21 0x4c11db70, 0x48d0c6c7, 0x4593e01e, 0x4152fda9, 22 0x5f15adac, 0x5bd4b01b, 0x569796c2, 0x52568b75, 23 0x6a1936c8, 0x6ed82b7f, 0x639b0da6, 0x675a1011, 24 0x791d4014, 0x7ddc5da3, 0x709f7b7a, 0x745e66cd, 25 0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039, 26 0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5, 27 0xbe2b5b58, 0xbaea46ef, 0xb7a96036, 0xb3687d81, 28 0xad2f2d84, 0xa9ee3033, 0xa4ad16ea, 0xa06c0b5d, 29 0xd4326d90, 0xd0f37027, 0xddb056fe, 0xd9714b49, 30 0xc7361b4c, 0xc3f706fb, 0xceb42022, 0xca753d95, 31 0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1, 32 0xe13ef6f4, 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d, 33 0x34867077, 0x30476dc0, 0x3d044b19, 0x39c556ae, 34 0x278206ab, 0x23431b1c, 0x2e003dc5, 0x2ac12072, 35 0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16, 36 0x018aeb13, 0x054bf6a4, 0x0808d07d, 0x0cc9cdca, 37 0x7897ab07, 0x7c56b6b0, 0x71159069, 0x75d48dde, 38 0x6b93dddb, 0x6f52c06c, 0x6211e6b5, 0x66d0fb02, 39 0x5e9f46bf, 0x5a5e5b08, 0x571d7dd1, 0x53dc6066, 40 0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba, 41 0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e, 42 0xbfa1b04b, 0xbb60adfc, 0xb6238b25, 0xb2e29692, 43 0x8aad2b2f, 0x8e6c3698, 0x832f1041, 0x87ee0df6, 44 0x99a95df3, 0x9d684044, 0x902b669d, 0x94ea7b2a, 45 0xe0b41de7, 0xe4750050, 0xe9362689, 0xedf73b3e, 46 0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2, 47 0xc6bcf05f, 0xc27dede8, 0xcf3ecb31, 0xcbffd686, 48 0xd5b88683, 0xd1799b34, 0xdc3abded, 0xd8fba05a, 49 0x690ce0ee, 0x6dcdfd59, 0x608edb80, 0x644fc637, 50 0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb, 51 0x4f040d56, 0x4bc510e1, 0x46863638, 0x42472b8f, 52 0x5c007b8a, 0x58c1663d, 0x558240e4, 0x51435d53, 53 0x251d3b9e, 0x21dc2629, 0x2c9f00f0, 0x285e1d47, 54 0x36194d42, 0x32d850f5, 0x3f9b762c, 0x3b5a6b9b, 55 0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff, 56 0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623, 57 0xf12f560e, 0xf5ee4bb9, 0xf8ad6d60, 0xfc6c70d7, 58 0xe22b20d2, 0xe6ea3d65, 0xeba91bbc, 0xef68060b, 59 0xd727bbb6, 0xd3e6a601, 0xdea580d8, 0xda649d6f, 60 0xc423cd6a, 0xc0e2d0dd, 0xcda1f604, 0xc960ebb3, 61 0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7, 62 0xae3afba2, 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b, 63 0x9b3660c6, 0x9ff77d71, 0x92b45ba8, 0x9675461f, 64 0x8832161a, 0x8cf30bad, 0x81b02d74, 0x857130c3, 65 0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640, 66 0x4e8ee645, 0x4a4ffbf2, 0x470cdd2b, 0x43cdc09c, 67 0x7b827d21, 0x7f436096, 0x7200464f, 0x76c15bf8, 68 0x68860bfd, 0x6c47164a, 0x61043093, 0x65c52d24, 69 0x119b4be9, 0x155a565e, 0x18197087, 0x1cd86d30, 70 0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec, 71 0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088, 72 0x2497d08d, 0x2056cd3a, 0x2d15ebe3, 0x29d4f654, 73 0xc5a92679, 0xc1683bce, 0xcc2b1d17, 0xc8ea00a0, 74 0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb, 0xdbee767c, 75 0xe3a1cbc1, 0xe760d676, 0xea23f0af, 0xeee2ed18, 76 0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4, 77 0x89b8fd09, 0x8d79e0be, 0x803ac667, 0x84fbdbd0, 78 0x9abc8bd5, 0x9e7d9662, 0x933eb0bb, 0x97ffad0c, 79 0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668, 80 0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4 81 }; 82 83 int bcrypt_init(struct bcrypt_ctx *ctx, void *key, int keylen, 84 unsigned long state_len) 85 { 86 unsigned char *state; 87 unsigned char *p = key; 88 unsigned long i, j; 89 unsigned long k = 0; 90 91 state = malloc(state_len); 92 if (state == NULL) 93 return -1; 94 95 ctx->i = 0; 96 ctx->j = 0; 97 ctx->state = state; 98 ctx->state_len = state_len; 99 100 for (i = 0; i < state_len; i++) 101 state[i] = i; 102 103 for(i = 0, j = 0; i < state_len; i++, j = (j + 1) % keylen) { 104 unsigned char t; 105 106 t = state[i]; 107 k = (k + p[j] + t) % state_len; 108 state[i] = state[k]; 109 state[k] = t; 110 } 111 112 return 0; 113 } 114 115 int bcrypt_process(struct bcrypt_ctx *ctx, unsigned char *src, 116 unsigned char *dst, unsigned long len) 117 { 118 unsigned char *state = ctx->state; 119 unsigned long state_len = ctx->state_len; 120 unsigned char i, j; 121 unsigned long k; 122 123 i = ctx->i; 124 j = ctx->j; 125 126 for (k = 0; k < len; k++) { 127 unsigned char t; 128 129 i = (i + 1) % state_len; 130 j = (j + state[i]) % state_len; 131 t = state[j]; 132 state[j] = state[i]; 133 state[i] = t; 134 135 dst[k] = src[k] ^ state[(state[i] + state[j]) % state_len]; 136 } 137 138 ctx->i = i; 139 ctx->j = j; 140 141 return len; 142 } 143 144 void bcrypt_finish(struct bcrypt_ctx *ctx) 145 { 146 if (ctx->state) 147 free(ctx->state); 148 } 149 150 int bcrypt_buf(unsigned char seed, unsigned char *key, unsigned char *src, 151 unsigned char *dst, unsigned long len, int longstate) 152 { 153 unsigned char bckey[BCRYPT_MAX_KEYLEN + 1]; 154 unsigned int keylen; 155 struct bcrypt_ctx ctx; 156 int ret; 157 158 /* setup decryption key */ 159 keylen = strlen((char *) key); 160 bckey[0] = seed; 161 memcpy(&bckey[1], key, keylen); 162 163 keylen++; 164 165 ret = bcrypt_init(&ctx, bckey, keylen, 166 (longstate) ? len : BCRYPT_DEFAULT_STATE_LEN); 167 if (ret) 168 return ret; 169 170 bcrypt_process(&ctx, src, dst, len); 171 bcrypt_finish(&ctx); 172 173 return 0; 174 } 175 176 uint32_t buffalo_csum(uint32_t csum, void *buf, unsigned long len) 177 { 178 signed char *p = buf; 179 180 while (len--) { 181 int i; 182 183 csum ^= *p++; 184 for (i = 0; i < 8; i++) 185 csum = (csum >> 1) ^ ((csum & 1) ? 0xedb88320ul : 0); 186 } 187 188 return csum; 189 } 190 191 uint32_t buffalo_crc(void *buf, unsigned long len) 192 { 193 unsigned char *p = buf; 194 unsigned long t = len; 195 uint32_t crc = 0; 196 197 while (len--) 198 crc = (crc << 8) ^ crc32_table[((crc >> 24) ^ *p++) & 0xFF]; 199 200 while (t) { 201 crc = (crc << 8) ^ crc32_table[((crc >> 24) ^ t) & 0xFF]; 202 t >>= 8; 203 } 204 205 return ~crc; 206 } 207 208 unsigned long enc_compute_header_len(char *product, char *version) 209 { 210 return ENC_MAGIC_LEN + 1 + strlen(product) + 1 + 211 strlen(version) + 1 + 3 * sizeof(uint32_t); 212 } 213 214 unsigned long enc_compute_buf_len(char *product, char *version, 215 unsigned long datalen) 216 { 217 unsigned long ret; 218 219 ret = enc_compute_header_len(product, version); 220 ret += datalen + sizeof(uint32_t); 221 ret += (4 - ret % 4); 222 223 return ret; 224 } 225 226 static void put_be32(void *data, uint32_t val) 227 { 228 unsigned char *p = data; 229 230 p[0] = (val >> 24) & 0xff; 231 p[1] = (val >> 16) & 0xff; 232 p[2] = (val >> 8) & 0xff; 233 p[3] = val & 0xff; 234 } 235 236 static uint32_t get_be32(void *data) 237 { 238 unsigned char *p = data; 239 240 return (((uint32_t)p[0]) << 24) | 241 (((uint32_t)p[1]) << 16) | 242 (((uint32_t)p[2]) << 8) | 243 ((uint32_t)p[3]); 244 } 245 246 static int check_magic(void *magic) 247 { 248 if (!memcmp("start", magic, ENC_MAGIC_LEN)) 249 return 0; 250 251 if (!memcmp("asar1", magic, ENC_MAGIC_LEN)) 252 return 0; 253 254 return -1; 255 } 256 257 int encrypt_buf(struct enc_param *ep, unsigned char *hdr, 258 unsigned char *data) 259 { 260 unsigned char *p; 261 uint32_t len; 262 int err; 263 int ret = -1; 264 unsigned char s; 265 266 p = (unsigned char *) hdr; 267 268 /* setup magic */ 269 len = strlen((char *) ep->magic) + 1; 270 memcpy(p, ep->magic, len); 271 p += len; 272 273 /* setup seed */ 274 *p++ = ep->seed; 275 276 /* put product len */ 277 len = strlen((char *) ep->product) + 1; 278 put_be32(p, len); 279 p += sizeof(uint32_t); 280 281 /* copy and crypt product name */ 282 memcpy(p, ep->product, len); 283 err = bcrypt_buf(ep->seed, ep->key, p, p, len, ep->longstate); 284 if (err) 285 goto out; 286 s = *p; 287 p += len; 288 289 /* put version length */ 290 len = strlen((char *) ep->version) + 1; 291 put_be32(p, len); 292 p += sizeof(uint32_t); 293 294 /* copy and crypt version */ 295 memcpy(p, ep->version, len); 296 err = bcrypt_buf(s, ep->key, p, p, len, ep->longstate); 297 if (err) 298 goto out; 299 s = *p; 300 p += len; 301 302 /* put data length */ 303 put_be32(p, ep->datalen); 304 305 /* encrypt data */ 306 err = bcrypt_buf(s, ep->key, data, data, ep->datalen, ep->longstate); 307 if (err) 308 goto out; 309 310 /* put checksum */ 311 put_be32(&data[ep->datalen], ep->csum); 312 313 ret = 0; 314 315 out: 316 return ret; 317 } 318 319 int decrypt_buf(struct enc_param *ep, unsigned char *data, 320 unsigned long datalen) 321 { 322 unsigned char *p; 323 uint32_t prod_len; 324 uint32_t ver_len; 325 uint32_t len; 326 uint32_t csum; 327 ssize_t remain; 328 int err; 329 int ret = -1; 330 331 #define CHECKLEN(_l) do { \ 332 len = (_l); \ 333 if (remain < len) { \ 334 goto out; \ 335 } \ 336 } while (0) 337 338 #define INCP() do { \ 339 p += len; \ 340 remain -= len; \ 341 } while (0) 342 343 remain = datalen; 344 p = data; 345 346 CHECKLEN(ENC_MAGIC_LEN); 347 err = check_magic(p); 348 if (err) 349 goto out; 350 memcpy(ep->magic, p, ENC_MAGIC_LEN); 351 INCP(); 352 353 CHECKLEN(1); 354 ep->seed = *p; 355 INCP(); 356 357 CHECKLEN(sizeof(uint32_t)); 358 prod_len = get_be32(p); 359 if (prod_len > ENC_PRODUCT_LEN) 360 goto out; 361 INCP(); 362 363 CHECKLEN(prod_len); 364 memcpy(ep->product, p, prod_len); 365 INCP(); 366 367 CHECKLEN(sizeof(uint32_t)); 368 ver_len = get_be32(p); 369 if (ver_len > ENC_VERSION_LEN) 370 goto out; 371 INCP(); 372 373 CHECKLEN(ver_len); 374 memcpy(ep->version, p, ver_len); 375 INCP(); 376 377 CHECKLEN(sizeof(uint32_t)); 378 ep->datalen = get_be32(p); 379 INCP(); 380 381 /* decrypt data */ 382 CHECKLEN(ep->datalen); 383 err = bcrypt_buf(ep->version[0], ep->key, p, data, ep->datalen, 384 ep->longstate); 385 if (err) 386 goto out; 387 INCP(); 388 389 CHECKLEN(sizeof(uint32_t)); 390 ep->csum = get_be32(p); 391 INCP(); 392 393 csum = buffalo_csum(ep->datalen, data, ep->datalen); 394 if (csum != ep->csum) 395 goto out; 396 397 /* decrypt product name */ 398 err = bcrypt_buf(ep->product[0], ep->key, ep->version, ep->version, 399 ver_len, ep->longstate); 400 if (err) 401 goto out; 402 403 /* decrypt version */ 404 err = bcrypt_buf(ep->seed, ep->key, ep->product, ep->product, prod_len, 405 ep->longstate); 406 if (err) 407 goto out; 408 409 ret = 0; 410 out: 411 return ret; 412 413 #undef CHECKLEN 414 #undef INCP 415 } 416 417 ssize_t get_file_size(char *name) 418 { 419 struct stat st; 420 int err; 421 422 err = stat(name, &st); 423 if (err) 424 return -1; 425 426 return st.st_size; 427 } 428 429 int read_file_to_buf(char *name, void *buf, ssize_t buflen) 430 { 431 FILE *f; 432 size_t done; 433 int ret = -1; 434 435 f = fopen(name, "r"); 436 if (f == NULL) 437 goto out; 438 439 errno = 0; 440 done = fread(buf, buflen, 1, f); 441 if (done != 1) 442 goto close; 443 444 ret = 0; 445 446 close: 447 fclose(f); 448 out: 449 return ret; 450 } 451 452 int write_buf_to_file(char *name, void *buf, ssize_t buflen) 453 { 454 FILE *f; 455 size_t done; 456 int ret = -1; 457 458 f = fopen(name, "w"); 459 if (f == NULL) 460 goto out; 461 462 errno = 0; 463 done = fwrite(buf, buflen, 1, f); 464 if (done != 1) 465 goto close; 466 467 ret = 0; 468 469 close: 470 fflush(f); 471 fclose(f); 472 if (ret) 473 unlink(name); 474 out: 475 return ret; 476 } 477
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