tools/firmware-utils: add buffalo specific fw tools
[openwrt/openwrt.git] / tools / firmware-utils / src / buffalo-lib.c
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
19 static 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
87 int 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
119 int 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
148 void bcrypt_finish(struct bcrypt_ctx *ctx)
149 {
150 if (ctx->state)
151 free(ctx->state);
152 }
153
154 int 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
180 uint32_t buffalo_csum(uint32_t csum, void *buf, unsigned long len)
181 {
182 unsigned 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
195 uint32_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
212 unsigned 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
218 unsigned 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
230 static 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
240 static 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
250 static 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
261 int 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
319 out:
320 return ret;
321 }
322
323 int 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;
414 out:
415 return ret;
416
417 #undef CHECKLEN
418 #undef INCP
419 }
420
421 ssize_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
433 int 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
450 close:
451 fclose(f);
452 out:
453 return ret;
454 }
455
456 int 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
473 close:
474 fflush(f);
475 fclose(f);
476 if (ret)
477 unlink(name);
478 out:
479 return ret;
480 }