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 <log.h>
12 #include <malloc.h>
13 #include <asm/global_data.h>
14 DECLARE_GLOBAL_DATA_PTR;
15 #endif /* !USE_HOSTCC*/
16 #include <fdt_region.h>
17 #include <image.h>
18 #include <u-boot/rsa.h>
19 #include <u-boot/rsa-checksum.h>
20
21 #define IMAGE_MAX_HASHED_NODES 100
22
23 /**
24 * fit_region_make_list() - Make a list of image regions
25 *
26 * Given a list of fdt_regions, create a list of image_regions. This is a
27 * simple conversion routine since the FDT and image code use different
28 * structures.
29 *
30 * @fit: FIT image
31 * @fdt_regions: Pointer to FDT regions
32 * @count: Number of FDT regions
33 * @region: Pointer to image regions, which must hold @count records. If
34 * region is NULL, then (except for an SPL build) the array will be
35 * allocated.
36 * @return: Pointer to image regions
37 */
fit_region_make_list(const void * fit,struct fdt_region * fdt_regions,int count,struct image_region * region)38 struct image_region *fit_region_make_list(const void *fit,
39 struct fdt_region *fdt_regions,
40 int count,
41 struct image_region *region)
42 {
43 int i;
44
45 debug("Hash regions:\n");
46 debug("%10s %10s\n", "Offset", "Size");
47
48 /*
49 * Use malloc() except in SPL (to save code size). In SPL the caller
50 * must allocate the array.
51 */
52 #ifndef CONFIG_SPL_BUILD
53 if (!region)
54 region = calloc(sizeof(*region), count);
55 #endif
56 if (!region)
57 return NULL;
58 for (i = 0; i < count; i++) {
59 debug("%10x %10x\n", fdt_regions[i].offset,
60 fdt_regions[i].size);
61 region[i].data = fit + fdt_regions[i].offset;
62 region[i].size = fdt_regions[i].size;
63 }
64
65 return region;
66 }
67
fit_image_setup_verify(struct image_sign_info * info,const void * fit,int noffset,int required_keynode,char ** err_msgp)68 static int fit_image_setup_verify(struct image_sign_info *info,
69 const void *fit, int noffset,
70 int required_keynode, char **err_msgp)
71 {
72 char *algo_name;
73 const char *padding_name;
74
75 if (fdt_totalsize(fit) > CONFIG_FIT_SIGNATURE_MAX_SIZE) {
76 *err_msgp = "Total size too large";
77 return 1;
78 }
79
80 if (fit_image_hash_get_algo(fit, noffset, &algo_name)) {
81 *err_msgp = "Can't get hash algo property";
82 return -1;
83 }
84
85 padding_name = fdt_getprop(fit, noffset, "padding", NULL);
86 if (!padding_name)
87 padding_name = RSA_DEFAULT_PADDING_NAME;
88
89 memset(info, '\0', sizeof(*info));
90 info->keyname = fdt_getprop(fit, noffset, FIT_KEY_HINT, NULL);
91 info->fit = (void *)fit;
92 info->node_offset = noffset;
93 info->name = algo_name;
94 info->checksum = image_get_checksum_algo(algo_name);
95 info->crypto = image_get_crypto_algo(algo_name);
96 info->padding = image_get_padding_algo(padding_name);
97 info->fdt_blob = gd_fdt_blob();
98 info->required_keynode = required_keynode;
99 printf("%s:%s", algo_name, info->keyname);
100
101 if (!info->checksum || !info->crypto || !info->padding) {
102 *err_msgp = "Unknown signature algorithm";
103 return -1;
104 }
105
106 return 0;
107 }
108
fit_image_check_sig(const void * fit,int noffset,const void * data,size_t size,int required_keynode,char ** err_msgp)109 int fit_image_check_sig(const void *fit, int noffset, const void *data,
110 size_t size, int required_keynode, char **err_msgp)
111 {
112 struct image_sign_info info;
113 struct image_region region;
114 uint8_t *fit_value;
115 int fit_value_len;
116
117 *err_msgp = NULL;
118 if (fit_image_setup_verify(&info, fit, noffset, required_keynode,
119 err_msgp))
120 return -1;
121
122 if (fit_image_hash_get_value(fit, noffset, &fit_value,
123 &fit_value_len)) {
124 *err_msgp = "Can't get hash value property";
125 return -1;
126 }
127
128 region.data = data;
129 region.size = size;
130
131 if (info.crypto->verify(&info, ®ion, 1, fit_value, fit_value_len)) {
132 *err_msgp = "Verification failed";
133 return -1;
134 }
135
136 return 0;
137 }
138
fit_image_verify_sig(const void * fit,int image_noffset,const char * data,size_t size,const void * sig_blob,int sig_offset)139 static int fit_image_verify_sig(const void *fit, int image_noffset,
140 const char *data, size_t size,
141 const void *sig_blob, int sig_offset)
142 {
143 int noffset;
144 char *err_msg = "";
145 int verified = 0;
146 int ret;
147
148 /* Process all hash subnodes of the component image node */
149 fdt_for_each_subnode(noffset, fit, image_noffset) {
150 const char *name = fit_get_name(fit, noffset, NULL);
151
152 /*
153 * We don't support this since libfdt considers names with the
154 * name root but different @ suffix to be equal
155 */
156 if (strchr(name, '@')) {
157 err_msg = "Node name contains @";
158 goto error;
159 }
160 if (!strncmp(name, FIT_SIG_NODENAME,
161 strlen(FIT_SIG_NODENAME))) {
162 ret = fit_image_check_sig(fit, noffset, data,
163 size, -1, &err_msg);
164 if (ret) {
165 puts("- ");
166 } else {
167 puts("+ ");
168 verified = 1;
169 break;
170 }
171 }
172 }
173
174 if (noffset == -FDT_ERR_TRUNCATED || noffset == -FDT_ERR_BADSTRUCTURE) {
175 err_msg = "Corrupted or truncated tree";
176 goto error;
177 }
178
179 return verified ? 0 : -EPERM;
180
181 error:
182 printf(" error!\n%s for '%s' hash node in '%s' image node\n",
183 err_msg, fit_get_name(fit, noffset, NULL),
184 fit_get_name(fit, image_noffset, NULL));
185 return -1;
186 }
187
fit_image_verify_required_sigs(const void * fit,int image_noffset,const char * data,size_t size,const void * sig_blob,int * no_sigsp)188 int fit_image_verify_required_sigs(const void *fit, int image_noffset,
189 const char *data, size_t size,
190 const void *sig_blob, int *no_sigsp)
191 {
192 int verify_count = 0;
193 int noffset;
194 int sig_node;
195
196 /* Work out what we need to verify */
197 *no_sigsp = 1;
198 sig_node = fdt_subnode_offset(sig_blob, 0, FIT_SIG_NODENAME);
199 if (sig_node < 0) {
200 debug("%s: No signature node found: %s\n", __func__,
201 fdt_strerror(sig_node));
202 return 0;
203 }
204
205 fdt_for_each_subnode(noffset, sig_blob, sig_node) {
206 const char *required;
207 int ret;
208
209 required = fdt_getprop(sig_blob, noffset, FIT_KEY_REQUIRED,
210 NULL);
211 if (!required || strcmp(required, "image"))
212 continue;
213 ret = fit_image_verify_sig(fit, image_noffset, data, size,
214 sig_blob, noffset);
215 if (ret) {
216 printf("Failed to verify required signature '%s'\n",
217 fit_get_name(sig_blob, noffset, NULL));
218 return ret;
219 }
220 verify_count++;
221 }
222
223 if (verify_count)
224 *no_sigsp = 0;
225
226 return 0;
227 }
228
229 /**
230 * fit_config_check_sig() - Check the signature of a config
231 *
232 * @fit: FIT to check
233 * @noffset: Offset of configuration node (e.g. /configurations/conf-1)
234 * @required_keynode: Offset in the control FDT of the required key node,
235 * if any. If this is given, then the configuration wil not
236 * pass verification unless that key is used. If this is
237 * -1 then any signature will do.
238 * @conf_noffset: Offset of the configuration subnode being checked (e.g.
239 * /configurations/conf-1/kernel)
240 * @err_msgp: In the event of an error, this will be pointed to a
241 * help error string to display to the user.
242 * @return 0 if all verified ok, <0 on error
243 */
fit_config_check_sig(const void * fit,int noffset,int required_keynode,int conf_noffset,char ** err_msgp)244 static int fit_config_check_sig(const void *fit, int noffset,
245 int required_keynode, int conf_noffset,
246 char **err_msgp)
247 {
248 char * const exc_prop[] = {"data", "data-size", "data-position"};
249 const char *prop, *end, *name;
250 struct image_sign_info info;
251 const uint32_t *strings;
252 const char *config_name;
253 uint8_t *fit_value;
254 int fit_value_len;
255 bool found_config;
256 int max_regions;
257 int i, prop_len;
258 char path[200];
259 int count;
260
261 config_name = fit_get_name(fit, conf_noffset, NULL);
262 debug("%s: fdt=%p, conf='%s', sig='%s'\n", __func__, gd_fdt_blob(),
263 fit_get_name(fit, noffset, NULL),
264 fit_get_name(gd_fdt_blob(), required_keynode, NULL));
265 *err_msgp = NULL;
266 if (fit_image_setup_verify(&info, fit, noffset, required_keynode,
267 err_msgp))
268 return -1;
269
270 if (fit_image_hash_get_value(fit, noffset, &fit_value,
271 &fit_value_len)) {
272 *err_msgp = "Can't get hash value property";
273 return -1;
274 }
275
276 /* Count the number of strings in the property */
277 prop = fdt_getprop(fit, noffset, "hashed-nodes", &prop_len);
278 end = prop ? prop + prop_len : prop;
279 for (name = prop, count = 0; name < end; name++)
280 if (!*name)
281 count++;
282 if (!count) {
283 *err_msgp = "Can't get hashed-nodes property";
284 return -1;
285 }
286
287 if (prop && prop_len > 0 && prop[prop_len - 1] != '\0') {
288 *err_msgp = "hashed-nodes property must be null-terminated";
289 return -1;
290 }
291
292 /* Add a sanity check here since we are using the stack */
293 if (count > IMAGE_MAX_HASHED_NODES) {
294 *err_msgp = "Number of hashed nodes exceeds maximum";
295 return -1;
296 }
297
298 /* Create a list of node names from those strings */
299 char *node_inc[count];
300
301 debug("Hash nodes (%d):\n", count);
302 found_config = false;
303 for (name = prop, i = 0; name < end; name += strlen(name) + 1, i++) {
304 debug(" '%s'\n", name);
305 node_inc[i] = (char *)name;
306 if (!strncmp(FIT_CONFS_PATH, name, strlen(FIT_CONFS_PATH)) &&
307 name[sizeof(FIT_CONFS_PATH) - 1] == '/' &&
308 !strcmp(name + sizeof(FIT_CONFS_PATH), config_name)) {
309 debug(" (found config node %s)", config_name);
310 found_config = true;
311 }
312 }
313 if (!found_config) {
314 *err_msgp = "Selected config not in hashed nodes";
315 return -1;
316 }
317
318 /*
319 * Each node can generate one region for each sub-node. Allow for
320 * 7 sub-nodes (hash-1, signature-1, etc.) and some extra.
321 */
322 max_regions = 20 + count * 7;
323 struct fdt_region fdt_regions[max_regions];
324
325 /* Get a list of regions to hash */
326 count = fdt_find_regions(fit, node_inc, count,
327 exc_prop, ARRAY_SIZE(exc_prop),
328 fdt_regions, max_regions - 1,
329 path, sizeof(path), 0);
330 if (count < 0) {
331 *err_msgp = "Failed to hash configuration";
332 return -1;
333 }
334 if (count == 0) {
335 *err_msgp = "No data to hash";
336 return -1;
337 }
338 if (count >= max_regions - 1) {
339 *err_msgp = "Too many hash regions";
340 return -1;
341 }
342
343 /* Add the strings */
344 strings = fdt_getprop(fit, noffset, "hashed-strings", NULL);
345 if (strings) {
346 /*
347 * The strings region offset must be a static 0x0.
348 * This is set in tool/image-host.c
349 */
350 fdt_regions[count].offset = fdt_off_dt_strings(fit);
351 fdt_regions[count].size = fdt32_to_cpu(strings[1]);
352 count++;
353 }
354
355 /* Allocate the region list on the stack */
356 struct image_region region[count];
357
358 fit_region_make_list(fit, fdt_regions, count, region);
359 if (info.crypto->verify(&info, region, count, fit_value,
360 fit_value_len)) {
361 *err_msgp = "Verification failed";
362 return -1;
363 }
364
365 return 0;
366 }
367
fit_config_verify_sig(const void * fit,int conf_noffset,const void * sig_blob,int sig_offset)368 static int fit_config_verify_sig(const void *fit, int conf_noffset,
369 const void *sig_blob, int sig_offset)
370 {
371 int noffset;
372 char *err_msg = "No 'signature' subnode found";
373 int verified = 0;
374 int ret;
375
376 /* Process all hash subnodes of the component conf node */
377 fdt_for_each_subnode(noffset, fit, conf_noffset) {
378 const char *name = fit_get_name(fit, noffset, NULL);
379
380 if (!strncmp(name, FIT_SIG_NODENAME,
381 strlen(FIT_SIG_NODENAME))) {
382 ret = fit_config_check_sig(fit, noffset, sig_offset,
383 conf_noffset, &err_msg);
384 if (ret) {
385 puts("- ");
386 } else {
387 puts("+ ");
388 verified = 1;
389 break;
390 }
391 }
392 }
393
394 if (noffset == -FDT_ERR_TRUNCATED || noffset == -FDT_ERR_BADSTRUCTURE) {
395 err_msg = "Corrupted or truncated tree";
396 goto error;
397 }
398
399 if (verified)
400 return 0;
401
402 error:
403 printf(" error!\n%s for '%s' hash node in '%s' config node\n",
404 err_msg, fit_get_name(fit, noffset, NULL),
405 fit_get_name(fit, conf_noffset, NULL));
406 return -EPERM;
407 }
408
fit_config_verify_required_sigs(const void * fit,int conf_noffset,const void * sig_blob)409 static int fit_config_verify_required_sigs(const void *fit, int conf_noffset,
410 const void *sig_blob)
411 {
412 const char *name = fit_get_name(fit, conf_noffset, NULL);
413 int noffset;
414 int sig_node;
415 int verified = 0;
416 int reqd_sigs = 0;
417 bool reqd_policy_all = true;
418 const char *reqd_mode;
419
420 /*
421 * We don't support this since libfdt considers names with the
422 * name root but different @ suffix to be equal
423 */
424 if (strchr(name, '@')) {
425 printf("Configuration node '%s' contains '@'\n", name);
426 return -EPERM;
427 }
428
429 /* Work out what we need to verify */
430 sig_node = fdt_subnode_offset(sig_blob, 0, FIT_SIG_NODENAME);
431 if (sig_node < 0) {
432 debug("%s: No signature node found: %s\n", __func__,
433 fdt_strerror(sig_node));
434 return 0;
435 }
436
437 /* Get required-mode policy property from DTB */
438 reqd_mode = fdt_getprop(sig_blob, sig_node, "required-mode", NULL);
439 if (reqd_mode && !strcmp(reqd_mode, "any"))
440 reqd_policy_all = false;
441
442 debug("%s: required-mode policy set to '%s'\n", __func__,
443 reqd_policy_all ? "all" : "any");
444
445 fdt_for_each_subnode(noffset, sig_blob, sig_node) {
446 const char *required;
447 int ret;
448
449 required = fdt_getprop(sig_blob, noffset, FIT_KEY_REQUIRED,
450 NULL);
451 if (!required || strcmp(required, "conf"))
452 continue;
453
454 reqd_sigs++;
455
456 ret = fit_config_verify_sig(fit, conf_noffset, sig_blob,
457 noffset);
458 if (ret) {
459 if (reqd_policy_all) {
460 printf("Failed to verify required signature '%s'\n",
461 fit_get_name(sig_blob, noffset, NULL));
462 return ret;
463 }
464 } else {
465 verified++;
466 if (!reqd_policy_all)
467 break;
468 }
469 }
470
471 if (reqd_sigs && !verified) {
472 printf("Failed to verify 'any' of the required signature(s)\n");
473 return -EPERM;
474 }
475
476 return 0;
477 }
478
fit_config_verify(const void * fit,int conf_noffset)479 int fit_config_verify(const void *fit, int conf_noffset)
480 {
481 return fit_config_verify_required_sigs(fit, conf_noffset,
482 gd_fdt_blob());
483 }
484