1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright (c) 2013, Google Inc.
4 */
5
6 #ifdef USE_HOSTCC
7 #include "mkimage.h"
8 #include <time.h>
9 #else
10 #include <common.h>
11 #include <malloc.h>
12 DECLARE_GLOBAL_DATA_PTR;
13 #endif /* !USE_HOSTCC*/
14 #include <image.h>
15 #include <u-boot/rsa.h>
16 #include <u-boot/rsa-checksum.h>
17
18 #define IMAGE_MAX_HASHED_NODES 100
19
20 #ifdef USE_HOSTCC
21 void *host_blob;
image_set_host_blob(void * blob)22 void image_set_host_blob(void *blob)
23 {
24 host_blob = blob;
25 }
image_get_host_blob(void)26 void *image_get_host_blob(void)
27 {
28 return host_blob;
29 }
30 #endif
31
32 struct checksum_algo checksum_algos[] = {
33 {
34 .name = "sha1",
35 .checksum_len = SHA1_SUM_LEN,
36 .der_len = SHA1_DER_LEN,
37 .der_prefix = sha1_der_prefix,
38 #if IMAGE_ENABLE_SIGN
39 .calculate_sign = EVP_sha1,
40 #endif
41 .calculate = hash_calculate,
42 },
43 {
44 .name = "sha256",
45 .checksum_len = SHA256_SUM_LEN,
46 .der_len = SHA256_DER_LEN,
47 .der_prefix = sha256_der_prefix,
48 #if IMAGE_ENABLE_SIGN
49 .calculate_sign = EVP_sha256,
50 #endif
51 .calculate = hash_calculate,
52 }
53
54 };
55
56 struct crypto_algo crypto_algos[] = {
57 {
58 .name = "rsa2048",
59 .key_len = RSA2048_BYTES,
60 .sign = rsa_sign,
61 .add_verify_data = rsa_add_verify_data,
62 .verify = rsa_verify,
63 },
64 {
65 .name = "rsa4096",
66 .key_len = RSA4096_BYTES,
67 .sign = rsa_sign,
68 .add_verify_data = rsa_add_verify_data,
69 .verify = rsa_verify,
70 }
71
72 };
73
74 struct padding_algo padding_algos[] = {
75 {
76 .name = "pkcs-1.5",
77 .verify = padding_pkcs_15_verify,
78 },
79 #ifdef CONFIG_FIT_ENABLE_RSASSA_PSS_SUPPORT
80 {
81 .name = "pss",
82 .verify = padding_pss_verify,
83 }
84 #endif /* CONFIG_FIT_ENABLE_RSASSA_PSS_SUPPORT */
85 };
86
image_get_checksum_algo(const char * full_name)87 struct checksum_algo *image_get_checksum_algo(const char *full_name)
88 {
89 int i;
90 const char *name;
91
92 #if !defined(USE_HOSTCC) && defined(CONFIG_NEEDS_MANUAL_RELOC)
93 static bool done;
94
95 if (!done) {
96 done = true;
97 for (i = 0; i < ARRAY_SIZE(checksum_algos); i++) {
98 checksum_algos[i].name += gd->reloc_off;
99 #if IMAGE_ENABLE_SIGN
100 checksum_algos[i].calculate_sign += gd->reloc_off;
101 #endif
102 checksum_algos[i].calculate += gd->reloc_off;
103 }
104 }
105 #endif
106
107 for (i = 0; i < ARRAY_SIZE(checksum_algos); i++) {
108 name = checksum_algos[i].name;
109 /* Make sure names match and next char is a comma */
110 if (!strncmp(name, full_name, strlen(name)) &&
111 full_name[strlen(name)] == ',')
112 return &checksum_algos[i];
113 }
114
115 return NULL;
116 }
117
image_get_crypto_algo(const char * full_name)118 struct crypto_algo *image_get_crypto_algo(const char *full_name)
119 {
120 int i;
121 const char *name;
122
123 #if !defined(USE_HOSTCC) && defined(CONFIG_NEEDS_MANUAL_RELOC)
124 static bool done;
125
126 if (!done) {
127 done = true;
128 for (i = 0; i < ARRAY_SIZE(crypto_algos); i++) {
129 crypto_algos[i].name += gd->reloc_off;
130 crypto_algos[i].sign += gd->reloc_off;
131 crypto_algos[i].add_verify_data += gd->reloc_off;
132 crypto_algos[i].verify += gd->reloc_off;
133 }
134 }
135 #endif
136
137 /* Move name to after the comma */
138 name = strchr(full_name, ',');
139 if (!name)
140 return NULL;
141 name += 1;
142
143 for (i = 0; i < ARRAY_SIZE(crypto_algos); i++) {
144 if (!strcmp(crypto_algos[i].name, name))
145 return &crypto_algos[i];
146 }
147
148 return NULL;
149 }
150
image_get_padding_algo(const char * name)151 struct padding_algo *image_get_padding_algo(const char *name)
152 {
153 int i;
154
155 if (!name)
156 return NULL;
157
158 for (i = 0; i < ARRAY_SIZE(padding_algos); i++) {
159 if (!strcmp(padding_algos[i].name, name))
160 return &padding_algos[i];
161 }
162
163 return NULL;
164 }
165
166 /**
167 * fit_region_make_list() - Make a list of image regions
168 *
169 * Given a list of fdt_regions, create a list of image_regions. This is a
170 * simple conversion routine since the FDT and image code use different
171 * structures.
172 *
173 * @fit: FIT image
174 * @fdt_regions: Pointer to FDT regions
175 * @count: Number of FDT regions
176 * @region: Pointer to image regions, which must hold @count records. If
177 * region is NULL, then (except for an SPL build) the array will be
178 * allocated.
179 * @return: Pointer to image regions
180 */
fit_region_make_list(const void * fit,struct fdt_region * fdt_regions,int count,struct image_region * region)181 struct image_region *fit_region_make_list(const void *fit,
182 struct fdt_region *fdt_regions, int count,
183 struct image_region *region)
184 {
185 int i;
186
187 debug("Hash regions:\n");
188 debug("%10s %10s\n", "Offset", "Size");
189
190 /*
191 * Use malloc() except in SPL (to save code size). In SPL the caller
192 * must allocate the array.
193 */
194 #ifndef CONFIG_SPL_BUILD
195 if (!region)
196 region = calloc(sizeof(*region), count);
197 #endif
198 if (!region)
199 return NULL;
200 for (i = 0; i < count; i++) {
201 debug("%10x %10x\n", fdt_regions[i].offset,
202 fdt_regions[i].size);
203 region[i].data = fit + fdt_regions[i].offset;
204 region[i].size = fdt_regions[i].size;
205 }
206
207 return region;
208 }
209
fit_image_setup_verify(struct image_sign_info * info,const void * fit,int noffset,int required_keynode,char ** err_msgp)210 static int fit_image_setup_verify(struct image_sign_info *info,
211 const void *fit, int noffset, int required_keynode,
212 char **err_msgp)
213 {
214 char *algo_name;
215 const char *padding_name;
216
217 if (fdt_totalsize(fit) > CONFIG_FIT_SIGNATURE_MAX_SIZE) {
218 *err_msgp = "Total size too large";
219 return 1;
220 }
221
222 if (fit_image_hash_get_algo(fit, noffset, &algo_name)) {
223 *err_msgp = "Can't get hash algo property";
224 return -1;
225 }
226
227 padding_name = fdt_getprop(fit, noffset, "padding", NULL);
228 if (!padding_name)
229 padding_name = RSA_DEFAULT_PADDING_NAME;
230
231 memset(info, '\0', sizeof(*info));
232 info->keyname = fdt_getprop(fit, noffset, FIT_KEY_HINT, NULL);
233 info->fit = (void *)fit;
234 info->node_offset = noffset;
235 info->name = algo_name;
236 info->checksum = image_get_checksum_algo(algo_name);
237 info->crypto = image_get_crypto_algo(algo_name);
238 info->padding = image_get_padding_algo(padding_name);
239 info->fdt_blob = gd_fdt_blob();
240 info->required_keynode = required_keynode;
241 printf("%s:%s", algo_name, info->keyname);
242
243 if (!info->checksum || !info->crypto || !info->padding) {
244 *err_msgp = "Unknown signature algorithm";
245 return -1;
246 }
247
248 return 0;
249 }
250
fit_image_check_sig(const void * fit,int noffset,const void * data,size_t size,int required_keynode,char ** err_msgp)251 int fit_image_check_sig(const void *fit, int noffset, const void *data,
252 size_t size, int required_keynode, char **err_msgp)
253 {
254 struct image_sign_info info;
255 struct image_region region;
256 uint8_t *fit_value;
257 int fit_value_len;
258
259 *err_msgp = NULL;
260 if (fit_image_setup_verify(&info, fit, noffset, required_keynode,
261 err_msgp))
262 return -1;
263
264 if (fit_image_hash_get_value(fit, noffset, &fit_value,
265 &fit_value_len)) {
266 *err_msgp = "Can't get hash value property";
267 return -1;
268 }
269
270 region.data = data;
271 region.size = size;
272
273 if (info.crypto->verify(&info, ®ion, 1, fit_value, fit_value_len)) {
274 *err_msgp = "Verification failed";
275 return -1;
276 }
277
278 return 0;
279 }
280
fit_image_verify_sig(const void * fit,int image_noffset,const char * data,size_t size,const void * sig_blob,int sig_offset)281 static int fit_image_verify_sig(const void *fit, int image_noffset,
282 const char *data, size_t size, const void *sig_blob,
283 int sig_offset)
284 {
285 int noffset;
286 char *err_msg = "";
287 int verified = 0;
288 int ret;
289
290 /* Process all hash subnodes of the component image node */
291 fdt_for_each_subnode(noffset, fit, image_noffset) {
292 const char *name = fit_get_name(fit, noffset, NULL);
293
294 /*
295 * We don't support this since libfdt considers names with the
296 * name root but different @ suffix to be equal
297 */
298 if (strchr(name, '@')) {
299 err_msg = "Node name contains @";
300 goto error;
301 }
302 if (!strncmp(name, FIT_SIG_NODENAME,
303 strlen(FIT_SIG_NODENAME))) {
304 ret = fit_image_check_sig(fit, noffset, data,
305 size, -1, &err_msg);
306 if (ret) {
307 puts("- ");
308 } else {
309 puts("+ ");
310 verified = 1;
311 break;
312 }
313 }
314 }
315
316 if (noffset == -FDT_ERR_TRUNCATED || noffset == -FDT_ERR_BADSTRUCTURE) {
317 err_msg = "Corrupted or truncated tree";
318 goto error;
319 }
320
321 return verified ? 0 : -EPERM;
322
323 error:
324 printf(" error!\n%s for '%s' hash node in '%s' image node\n",
325 err_msg, fit_get_name(fit, noffset, NULL),
326 fit_get_name(fit, image_noffset, NULL));
327 return -1;
328 }
329
fit_image_verify_required_sigs(const void * fit,int image_noffset,const char * data,size_t size,const void * sig_blob,int * no_sigsp)330 int fit_image_verify_required_sigs(const void *fit, int image_noffset,
331 const char *data, size_t size, const void *sig_blob,
332 int *no_sigsp)
333 {
334 int verify_count = 0;
335 int noffset;
336 int sig_node;
337
338 /* Work out what we need to verify */
339 *no_sigsp = 1;
340 sig_node = fdt_subnode_offset(sig_blob, 0, FIT_SIG_NODENAME);
341 if (sig_node < 0) {
342 debug("%s: No signature node found: %s\n", __func__,
343 fdt_strerror(sig_node));
344 return 0;
345 }
346
347 fdt_for_each_subnode(noffset, sig_blob, sig_node) {
348 const char *required;
349 int ret;
350
351 required = fdt_getprop(sig_blob, noffset, FIT_KEY_REQUIRED,
352 NULL);
353 if (!required || strcmp(required, "image"))
354 continue;
355 ret = fit_image_verify_sig(fit, image_noffset, data, size,
356 sig_blob, noffset);
357 if (ret) {
358 printf("Failed to verify required signature '%s'\n",
359 fit_get_name(sig_blob, noffset, NULL));
360 return ret;
361 }
362 verify_count++;
363 }
364
365 if (verify_count)
366 *no_sigsp = 0;
367
368 return 0;
369 }
370
371 /**
372 * fit_config_check_sig() - Check the signature of a config
373 *
374 * @fit: FIT to check
375 * @noffset: Offset of configuration node (e.g. /configurations/conf-1)
376 * @required_keynode: Offset in the control FDT of the required key node,
377 * if any. If this is given, then the configuration wil not
378 * pass verification unless that key is used. If this is
379 * -1 then any signature will do.
380 * @conf_noffset: Offset of the configuration subnode being checked (e.g.
381 * /configurations/conf-1/kernel)
382 * @err_msgp: In the event of an error, this will be pointed to a
383 * help error string to display to the user.
384 * @return 0 if all verified ok, <0 on error
385 */
fit_config_check_sig(const void * fit,int noffset,int required_keynode,int conf_noffset,char ** err_msgp)386 static int fit_config_check_sig(const void *fit, int noffset,
387 int required_keynode, int conf_noffset,
388 char **err_msgp)
389 {
390 char * const exc_prop[] = {"data"};
391 const char *prop, *end, *name;
392 struct image_sign_info info;
393 const uint32_t *strings;
394 const char *config_name;
395 uint8_t *fit_value;
396 int fit_value_len;
397 bool found_config;
398 int max_regions;
399 int i, prop_len;
400 char path[200];
401 int count;
402
403 config_name = fit_get_name(fit, conf_noffset, NULL);
404 debug("%s: fdt=%p, conf='%s', sig='%s'\n", __func__, gd_fdt_blob(),
405 fit_get_name(fit, noffset, NULL),
406 fit_get_name(gd_fdt_blob(), required_keynode, NULL));
407 *err_msgp = NULL;
408 if (fit_image_setup_verify(&info, fit, noffset, required_keynode,
409 err_msgp))
410 return -1;
411
412 if (fit_image_hash_get_value(fit, noffset, &fit_value,
413 &fit_value_len)) {
414 *err_msgp = "Can't get hash value property";
415 return -1;
416 }
417
418 /* Count the number of strings in the property */
419 prop = fdt_getprop(fit, noffset, "hashed-nodes", &prop_len);
420 end = prop ? prop + prop_len : prop;
421 for (name = prop, count = 0; name < end; name++)
422 if (!*name)
423 count++;
424 if (!count) {
425 *err_msgp = "Can't get hashed-nodes property";
426 return -1;
427 }
428
429 if (prop && prop_len > 0 && prop[prop_len - 1] != '\0') {
430 *err_msgp = "hashed-nodes property must be null-terminated";
431 return -1;
432 }
433
434 /* Add a sanity check here since we are using the stack */
435 if (count > IMAGE_MAX_HASHED_NODES) {
436 *err_msgp = "Number of hashed nodes exceeds maximum";
437 return -1;
438 }
439
440 /* Create a list of node names from those strings */
441 char *node_inc[count];
442
443 debug("Hash nodes (%d):\n", count);
444 found_config = false;
445 for (name = prop, i = 0; name < end; name += strlen(name) + 1, i++) {
446 debug(" '%s'\n", name);
447 node_inc[i] = (char *)name;
448 if (!strncmp(FIT_CONFS_PATH, name, strlen(FIT_CONFS_PATH)) &&
449 name[sizeof(FIT_CONFS_PATH) - 1] == '/' &&
450 !strcmp(name + sizeof(FIT_CONFS_PATH), config_name)) {
451 debug(" (found config node %s)", config_name);
452 found_config = true;
453 }
454 }
455 if (!found_config) {
456 *err_msgp = "Selected config not in hashed nodes";
457 return -1;
458 }
459
460 /*
461 * Each node can generate one region for each sub-node. Allow for
462 * 7 sub-nodes (hash-1, signature-1, etc.) and some extra.
463 */
464 max_regions = 20 + count * 7;
465 struct fdt_region fdt_regions[max_regions];
466
467 /* Get a list of regions to hash */
468 count = fdt_find_regions(fit, node_inc, count,
469 exc_prop, ARRAY_SIZE(exc_prop),
470 fdt_regions, max_regions - 1,
471 path, sizeof(path), 0);
472 if (count < 0) {
473 *err_msgp = "Failed to hash configuration";
474 return -1;
475 }
476 if (count == 0) {
477 *err_msgp = "No data to hash";
478 return -1;
479 }
480 if (count >= max_regions - 1) {
481 *err_msgp = "Too many hash regions";
482 return -1;
483 }
484
485 /* Add the strings */
486 strings = fdt_getprop(fit, noffset, "hashed-strings", NULL);
487 if (strings) {
488 /*
489 * The strings region offset must be a static 0x0.
490 * This is set in tool/image-host.c
491 */
492 fdt_regions[count].offset = fdt_off_dt_strings(fit);
493 fdt_regions[count].size = fdt32_to_cpu(strings[1]);
494 count++;
495 }
496
497 /* Allocate the region list on the stack */
498 struct image_region region[count];
499
500 fit_region_make_list(fit, fdt_regions, count, region);
501 if (info.crypto->verify(&info, region, count, fit_value,
502 fit_value_len)) {
503 *err_msgp = "Verification failed";
504 return -1;
505 }
506
507 return 0;
508 }
509
fit_config_verify_sig(const void * fit,int conf_noffset,const void * sig_blob,int sig_offset)510 static int fit_config_verify_sig(const void *fit, int conf_noffset,
511 const void *sig_blob, int sig_offset)
512 {
513 int noffset;
514 char *err_msg = "";
515 int verified = 0;
516 int ret;
517
518 /* Process all hash subnodes of the component conf node */
519 fdt_for_each_subnode(noffset, fit, conf_noffset) {
520 const char *name = fit_get_name(fit, noffset, NULL);
521
522 if (!strncmp(name, FIT_SIG_NODENAME,
523 strlen(FIT_SIG_NODENAME))) {
524 ret = fit_config_check_sig(fit, noffset, sig_offset,
525 conf_noffset, &err_msg);
526 if (ret) {
527 puts("- ");
528 } else {
529 puts("+ ");
530 verified = 1;
531 break;
532 }
533 }
534 }
535
536 if (noffset == -FDT_ERR_TRUNCATED || noffset == -FDT_ERR_BADSTRUCTURE) {
537 err_msg = "Corrupted or truncated tree";
538 goto error;
539 }
540
541 if (verified)
542 return 0;
543
544 error:
545 printf(" error!\n%s for '%s' hash node in '%s' config node\n",
546 err_msg, fit_get_name(fit, noffset, NULL),
547 fit_get_name(fit, conf_noffset, NULL));
548 return -EPERM;
549 }
550
fit_config_verify_required_sigs(const void * fit,int conf_noffset,const void * sig_blob)551 static int fit_config_verify_required_sigs(const void *fit, int conf_noffset,
552 const void *sig_blob)
553 {
554 const char *name = fit_get_name(fit, conf_noffset, NULL);
555 int noffset;
556 int sig_node;
557
558 /*
559 * We don't support this since libfdt considers names with the
560 * name root but different @ suffix to be equal
561 */
562 if (strchr(name, '@')) {
563 printf("Configuration node '%s' contains '@'\n", name);
564 return -EPERM;
565 }
566
567 /* Work out what we need to verify */
568 sig_node = fdt_subnode_offset(sig_blob, 0, FIT_SIG_NODENAME);
569 if (sig_node < 0) {
570 debug("%s: No signature node found: %s\n", __func__,
571 fdt_strerror(sig_node));
572 return 0;
573 }
574
575 fdt_for_each_subnode(noffset, sig_blob, sig_node) {
576 const char *required;
577 int ret;
578
579 required = fdt_getprop(sig_blob, noffset, FIT_KEY_REQUIRED,
580 NULL);
581 if (!required || strcmp(required, "conf"))
582 continue;
583 ret = fit_config_verify_sig(fit, conf_noffset, sig_blob,
584 noffset);
585 if (ret) {
586 printf("Failed to verify required signature '%s'\n",
587 fit_get_name(sig_blob, noffset, NULL));
588 return ret;
589 }
590 }
591
592 return 0;
593 }
594
fit_config_verify(const void * fit,int conf_noffset)595 int fit_config_verify(const void *fit, int conf_noffset)
596 {
597 return fit_config_verify_required_sigs(fit, conf_noffset,
598 gd_fdt_blob());
599 }
600