1/* 2 * Copyright (C) 2009-2011 Gabor Juhos <juhosg@openwrt.org> 3 * 4 * This program is free software; you can redistribute it and/or modify it 5 * under the terms of the GNU General Public License version 2 as published 6 * by the Free Software Foundation. 7 * 8 */ 9 10#include <stdio.h> 11#include <stdlib.h> 12#include <string.h> 13#include <errno.h> 14#include <unistd.h> 15#include <sys/stat.h> 16 17#include "buffalo-lib.h" 18 19static uint32_t crc32_table[256] = 20{ 21 0x00000000, 0x04c11db7, 0x09823b6e, 0x0d4326d9, 22 0x130476dc, 0x17c56b6b, 0x1a864db2, 0x1e475005, 23 0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61, 24 0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd, 25 0x4c11db70, 0x48d0c6c7, 0x4593e01e, 0x4152fda9, 26 0x5f15adac, 0x5bd4b01b, 0x569796c2, 0x52568b75, 27 0x6a1936c8, 0x6ed82b7f, 0x639b0da6, 0x675a1011, 28 0x791d4014, 0x7ddc5da3, 0x709f7b7a, 0x745e66cd, 29 0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039, 30 0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5, 31 0xbe2b5b58, 0xbaea46ef, 0xb7a96036, 0xb3687d81, 32 0xad2f2d84, 0xa9ee3033, 0xa4ad16ea, 0xa06c0b5d, 33 0xd4326d90, 0xd0f37027, 0xddb056fe, 0xd9714b49, 34 0xc7361b4c, 0xc3f706fb, 0xceb42022, 0xca753d95, 35 0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1, 36 0xe13ef6f4, 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d, 37 0x34867077, 0x30476dc0, 0x3d044b19, 0x39c556ae, 38 0x278206ab, 0x23431b1c, 0x2e003dc5, 0x2ac12072, 39 0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16, 40 0x018aeb13, 0x054bf6a4, 0x0808d07d, 0x0cc9cdca, 41 0x7897ab07, 0x7c56b6b0, 0x71159069, 0x75d48dde, 42 0x6b93dddb, 0x6f52c06c, 0x6211e6b5, 0x66d0fb02, 43 0x5e9f46bf, 0x5a5e5b08, 0x571d7dd1, 0x53dc6066, 44 0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba, 45 0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e, 46 0xbfa1b04b, 0xbb60adfc, 0xb6238b25, 0xb2e29692, 47 0x8aad2b2f, 0x8e6c3698, 0x832f1041, 0x87ee0df6, 48 0x99a95df3, 0x9d684044, 0x902b669d, 0x94ea7b2a, 49 0xe0b41de7, 0xe4750050, 0xe9362689, 0xedf73b3e, 50 0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2, 51 0xc6bcf05f, 0xc27dede8, 0xcf3ecb31, 0xcbffd686, 52 0xd5b88683, 0xd1799b34, 0xdc3abded, 0xd8fba05a, 53 0x690ce0ee, 0x6dcdfd59, 0x608edb80, 0x644fc637, 54 0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb, 55 0x4f040d56, 0x4bc510e1, 0x46863638, 0x42472b8f, 56 0x5c007b8a, 0x58c1663d, 0x558240e4, 0x51435d53, 57 0x251d3b9e, 0x21dc2629, 0x2c9f00f0, 0x285e1d47, 58 0x36194d42, 0x32d850f5, 0x3f9b762c, 0x3b5a6b9b, 59 0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff, 60 0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623, 61 0xf12f560e, 0xf5ee4bb9, 0xf8ad6d60, 0xfc6c70d7, 62 0xe22b20d2, 0xe6ea3d65, 0xeba91bbc, 0xef68060b, 63 0xd727bbb6, 0xd3e6a601, 0xdea580d8, 0xda649d6f, 64 0xc423cd6a, 0xc0e2d0dd, 0xcda1f604, 0xc960ebb3, 65 0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7, 66 0xae3afba2, 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b, 67 0x9b3660c6, 0x9ff77d71, 0x92b45ba8, 0x9675461f, 68 0x8832161a, 0x8cf30bad, 0x81b02d74, 0x857130c3, 69 0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640, 70 0x4e8ee645, 0x4a4ffbf2, 0x470cdd2b, 0x43cdc09c, 71 0x7b827d21, 0x7f436096, 0x7200464f, 0x76c15bf8, 72 0x68860bfd, 0x6c47164a, 0x61043093, 0x65c52d24, 73 0x119b4be9, 0x155a565e, 0x18197087, 0x1cd86d30, 74 0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec, 75 0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088, 76 0x2497d08d, 0x2056cd3a, 0x2d15ebe3, 0x29d4f654, 77 0xc5a92679, 0xc1683bce, 0xcc2b1d17, 0xc8ea00a0, 78 0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb, 0xdbee767c, 79 0xe3a1cbc1, 0xe760d676, 0xea23f0af, 0xeee2ed18, 80 0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4, 81 0x89b8fd09, 0x8d79e0be, 0x803ac667, 0x84fbdbd0, 82 0x9abc8bd5, 0x9e7d9662, 0x933eb0bb, 0x97ffad0c, 83 0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668, 84 0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4 85}; 86 87int bcrypt_init(struct bcrypt_ctx *ctx, void *key, int keylen, 88 unsigned long state_len) 89{ 90 unsigned char *state; 91 unsigned char *p = key; 92 unsigned long i, j; 93 unsigned long k = 0; 94 95 state = malloc(state_len); 96 if (state == NULL) 97 return -1; 98 99 ctx->i = 0; 100 ctx->j = 0; 101 ctx->state = state; 102 ctx->state_len = state_len; 103 104 for (i = 0; i < state_len; i++) 105 state[i] = i; 106 107 for(i = 0, j = 0; i < state_len; i++, j = (j + 1) % keylen) { 108 unsigned char t; 109 110 t = state[i]; 111 k = (k + p[j] + t) % state_len; 112 state[i] = state[k]; 113 state[k] = t; 114 } 115 116 return 0; 117} 118 119int bcrypt_process(struct bcrypt_ctx *ctx, unsigned char *src, 120 unsigned char *dst, unsigned long len) 121{ 122 unsigned char *state = ctx->state; 123 unsigned long state_len = ctx->state_len; 124 unsigned char i, j; 125 unsigned long k; 126 127 i = ctx->i; 128 j = ctx->j; 129 130 for (k = 0; k < len; k++) { 131 unsigned char t; 132 133 i = (i + 1) % state_len; 134 j = (j + state[i]) % state_len; 135 t = state[j]; 136 state[j] = state[i]; 137 state[i] = t; 138 139 dst[k] = src[k] ^ state[(state[i] + state[j]) % state_len]; 140 } 141 142 ctx->i = i; 143 ctx->j = j; 144 145 return len; 146} 147 148void bcrypt_finish(struct bcrypt_ctx *ctx) 149{ 150 if (ctx->state) 151 free(ctx->state); 152} 153 154int bcrypt_buf(unsigned char seed, unsigned char *key, unsigned char *src, 155 unsigned char *dst, unsigned long len, int longstate) 156{ 157 unsigned char bckey[BCRYPT_MAX_KEYLEN + 1]; 158 unsigned int keylen; 159 struct bcrypt_ctx ctx; 160 int ret; 161 162 /* setup decryption key */ 163 keylen = strlen((char *) key); 164 bckey[0] = seed; 165 memcpy(&bckey[1], key, keylen); 166 167 keylen++; 168 169 ret = bcrypt_init(&ctx, bckey, keylen, 170 (longstate) ? len : BCRYPT_DEFAULT_STATE_LEN); 171 if (ret) 172 return ret; 173 174 bcrypt_process(&ctx, src, dst, len); 175 bcrypt_finish(&ctx); 176 177 return 0; 178} 179 180uint32_t buffalo_csum(uint32_t csum, void *buf, unsigned long len) 181{ 182 char *p = buf; 183 184 while (len--) { 185 int i; 186 187 csum ^= *p++; 188 for (i = 0; i < 8; i++) 189 csum = (csum >> 1) ^ ((csum & 1) ? 0xedb88320ul : 0); 190 } 191 192 return csum; 193} 194 195uint32_t buffalo_crc(void *buf, unsigned long len) 196{ 197 unsigned char *p = buf; 198 unsigned long t = len; 199 uint32_t crc = 0; 200 201 while (len--) 202 crc = (crc << 8) ^ crc32_table[((crc >> 24) ^ *p++) & 0xFF]; 203 204 while (t) { 205 crc = (crc << 8) ^ crc32_table[((crc >> 24) ^ t) & 0xFF]; 206 t >>= 8; 207 } 208 209 return ~crc; 210} 211 212unsigned long enc_compute_header_len(char *product, char *version) 213{ 214 return ENC_MAGIC_LEN + 1 + strlen(product) + 1 + 215 strlen(version) + 1 + 3 * sizeof(uint32_t); 216} 217 218unsigned long enc_compute_buf_len(char *product, char *version, 219 unsigned long datalen) 220{ 221 unsigned long ret; 222 223 ret = enc_compute_header_len(product, version); 224 ret += datalen + sizeof(uint32_t); 225 ret += (4 - ret % 4); 226 227 return ret; 228} 229 230static void put_be32(void *data, uint32_t val) 231{ 232 unsigned char *p = data; 233 234 p[0] = (val >> 24) & 0xff; 235 p[1] = (val >> 16) & 0xff; 236 p[2] = (val >> 8) & 0xff; 237 p[3] = val & 0xff; 238} 239 240static uint32_t get_be32(void *data) 241{ 242 unsigned char *p = data; 243 244 return (((uint32_t)p[0]) << 24) | 245 (((uint32_t)p[1]) << 16) | 246 (((uint32_t)p[2]) << 8) | 247 ((uint32_t)p[3]); 248} 249 250static int check_magic(void *magic) 251{ 252 if (!memcmp("start", magic, ENC_MAGIC_LEN)); 253 return 0; 254 255 if (!memcmp("asar1", magic, ENC_MAGIC_LEN)); 256 return 0; 257 258 return -1; 259} 260 261int encrypt_buf(struct enc_param *ep, unsigned char *hdr, 262 unsigned char *data) 263{ 264 unsigned char *p; 265 uint32_t len; 266 int err; 267 int ret = -1; 268 unsigned char s; 269 270 p = (unsigned char *) hdr; 271 272 /* setup magic */ 273 len = strlen((char *) ep->magic) + 1; 274 memcpy(p, ep->magic, len); 275 p += len; 276 277 /* setup seed */ 278 *p++ = ep->seed; 279 280 /* put product len */ 281 len = strlen((char *) ep->product) + 1; 282 put_be32(p, len); 283 p += sizeof(uint32_t); 284 285 /* copy and crypt product name */ 286 memcpy(p, ep->product, len); 287 err = bcrypt_buf(ep->seed, ep->key, p, p, len, ep->longstate); 288 if (err) 289 goto out; 290 s = *p; 291 p += len; 292 293 /* put version length */ 294 len = strlen((char *) ep->version) + 1; 295 put_be32(p, len); 296 p += sizeof(uint32_t); 297 298 /* copy and crypt version */ 299 memcpy(p, ep->version, len); 300 err = bcrypt_buf(s, ep->key, p, p, len, ep->longstate); 301 if (err) 302 goto out; 303 s = *p; 304 p += len; 305 306 /* put data length */ 307 put_be32(p, ep->datalen); 308 309 /* encrypt data */ 310 err = bcrypt_buf(s, ep->key, data, data, ep->datalen, ep->longstate); 311 if (err) 312 goto out; 313 314 /* put checksum */ 315 put_be32(&data[ep->datalen], ep->csum); 316 317 ret = 0; 318 319out: 320 return ret; 321} 322 323int decrypt_buf(struct enc_param *ep, unsigned char *data, 324 unsigned long datalen) 325{ 326 unsigned char *p; 327 uint32_t prod_len; 328 uint32_t ver_len; 329 uint32_t len; 330 uint32_t csum; 331 ssize_t remain; 332 int err; 333 int ret = -1; 334 335#define CHECKLEN(_l) do { \ 336 len = (_l); \ 337 if (remain < len) { \ 338 goto out; \ 339 } \ 340} while (0) 341 342#define INCP() do { \ 343 p += len; \ 344 remain -= len; \ 345} while (0) 346 347 remain = datalen; 348 p = data; 349 350 CHECKLEN(ENC_MAGIC_LEN); 351 err = check_magic(p); 352 if (err) 353 goto out; 354 memcpy(ep->magic, p, ENC_MAGIC_LEN); 355 INCP(); 356 357 CHECKLEN(1); 358 ep->seed = *p; 359 INCP(); 360 361 CHECKLEN(sizeof(uint32_t)); 362 prod_len = get_be32(p); 363 if (prod_len > ENC_PRODUCT_LEN) 364 goto out; 365 INCP(); 366 367 CHECKLEN(prod_len); 368 memcpy(ep->product, p, prod_len); 369 INCP(); 370 371 CHECKLEN(sizeof(uint32_t)); 372 ver_len = get_be32(p); 373 if (ver_len > ENC_VERSION_LEN) 374 goto out; 375 INCP(); 376 377 CHECKLEN(ver_len); 378 memcpy(ep->version, p, ver_len); 379 INCP(); 380 381 CHECKLEN(sizeof(uint32_t)); 382 ep->datalen = get_be32(p); 383 INCP(); 384 385 /* decrypt data */ 386 CHECKLEN(ep->datalen); 387 err = bcrypt_buf(ep->version[0], ep->key, p, data, ep->datalen, 388 ep->longstate); 389 if (err) 390 goto out; 391 INCP(); 392 393 CHECKLEN(sizeof(uint32_t)); 394 ep->csum = get_be32(p); 395 INCP(); 396 397 csum = buffalo_csum(ep->datalen, data, ep->datalen); 398 if (csum != ep->csum) 399 goto out; 400 401 /* decrypt product name */ 402 err = bcrypt_buf(ep->product[0], ep->key, ep->version, ep->version, 403 ver_len, ep->longstate); 404 if (err) 405 goto out; 406 407 /* decrypt version */ 408 err = bcrypt_buf(ep->seed, ep->key, ep->product, ep->product, prod_len, 409 ep->longstate); 410 if (err) 411 goto out; 412 413 ret = 0; 414out: 415 return ret; 416 417#undef CHECKLEN 418#undef INCP 419} 420 421ssize_t get_file_size(char *name) 422{ 423 struct stat st; 424 int err; 425 426 err = stat(name, &st); 427 if (err) 428 return -1; 429 430 return st.st_size; 431} 432 433int read_file_to_buf(char *name, void *buf, ssize_t buflen) 434{ 435 FILE *f; 436 size_t done; 437 int ret = -1; 438 439 f = fopen(name, "r"); 440 if (f == NULL) 441 goto out; 442 443 errno = 0; 444 done = fread(buf, buflen, 1, f); 445 if (done != 1) 446 goto close; 447 448 ret = 0; 449 450close: 451 fclose(f); 452out: 453 return ret; 454} 455 456int write_buf_to_file(char *name, void *buf, ssize_t buflen) 457{ 458 FILE *f; 459 size_t done; 460 int ret = -1; 461 462 f = fopen(name, "w"); 463 if (f == NULL) 464 goto out; 465 466 errno = 0; 467 done = fwrite(buf, buflen, 1, f); 468 if (done != 1) 469 goto close; 470 471 ret = 0; 472 473close: 474 fflush(f); 475 fclose(f); 476 if (ret) 477 unlink(name); 478out: 479 return ret; 480} 481