1 /*
2 * SPDX-License-Identifier: Apache-2.0
3 *
4 * Copyright (c) 2017-2020 Linaro LTD
5 * Copyright (c) 2017-2019 JUUL Labs
6 * Copyright (c) 2019-2021 Arm Limited
7 *
8 * Original license:
9 *
10 * Licensed to the Apache Software Foundation (ASF) under one
11 * or more contributor license agreements. See the NOTICE file
12 * distributed with this work for additional information
13 * regarding copyright ownership. The ASF licenses this file
14 * to you under the Apache License, Version 2.0 (the
15 * "License"); you may not use this file except in compliance
16 * with the License. You may obtain a copy of the License at
17 *
18 * http://www.apache.org/licenses/LICENSE-2.0
19 *
20 * Unless required by applicable law or agreed to in writing,
21 * software distributed under the License is distributed on an
22 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
23 * KIND, either express or implied. See the License for the
24 * specific language governing permissions and limitations
25 * under the License.
26 */
27
28 #ifndef H_BOOTUTIL_PRIV_
29 #define H_BOOTUTIL_PRIV_
30
31 #include <string.h>
32
33 #include "sysflash/sysflash.h"
34
35 #include <flash_map_backend/flash_map_backend.h>
36
37 #include "bootutil/bootutil.h"
38 #include "bootutil/image.h"
39 #include "bootutil/fault_injection_hardening.h"
40 #include "mcuboot_config/mcuboot_config.h"
41
42 #ifdef MCUBOOT_ENC_IMAGES
43 #include "bootutil/enc_key.h"
44 #endif
45
46 #ifdef __cplusplus
47 extern "C" {
48 #endif
49
50 struct flash_area;
51
52 #define BOOT_TMPBUF_SZ 256
53
54 /** Number of image slots in flash; currently limited to two. */
55 #define BOOT_NUM_SLOTS 2
56
57 #if (defined(MCUBOOT_OVERWRITE_ONLY) + \
58 defined(MCUBOOT_SWAP_USING_MOVE) + \
59 defined(MCUBOOT_DIRECT_XIP) + \
60 defined(MCUBOOT_RAM_LOAD) + \
61 defined(MCUBOOT_FIRMWARE_LOADER) + \
62 defined(MCUBOOT_SWAP_USING_SCRATCH)) > 1
63 #error "Please enable only one of MCUBOOT_OVERWRITE_ONLY, MCUBOOT_SWAP_USING_MOVE, MCUBOOT_DIRECT_XIP, MCUBOOT_RAM_LOAD or MCUBOOT_FIRMWARE_LOADER"
64 #endif
65
66 #if !defined(MCUBOOT_DIRECT_XIP) && \
67 defined(MCUBOOT_DIRECT_XIP_REVERT)
68 #error "MCUBOOT_DIRECT_XIP_REVERT cannot be enabled unless MCUBOOT_DIRECT_XIP is used"
69 #endif
70
71 #if !defined(MCUBOOT_OVERWRITE_ONLY) && \
72 !defined(MCUBOOT_SWAP_USING_MOVE) && \
73 !defined(MCUBOOT_DIRECT_XIP) && \
74 !defined(MCUBOOT_RAM_LOAD) && \
75 !defined(MCUBOOT_SINGLE_APPLICATION_SLOT) && \
76 !defined(MCUBOOT_FIRMWARE_LOADER)
77 #define MCUBOOT_SWAP_USING_SCRATCH 1
78 #endif
79
80 #define BOOT_STATUS_OP_MOVE 1
81 #define BOOT_STATUS_OP_SWAP 2
82
83 /*
84 * Maintain state of copy progress.
85 */
86 struct boot_status {
87 uint32_t idx; /* Which area we're operating on */
88 uint8_t state; /* Which part of the swapping process are we at */
89 uint8_t op; /* What operation are we performing? */
90 uint8_t use_scratch; /* Are status bytes ever written to scratch? */
91 uint8_t swap_type; /* The type of swap in effect */
92 uint32_t swap_size; /* Total size of swapped image */
93 #ifdef MCUBOOT_ENC_IMAGES
94 uint8_t enckey[BOOT_NUM_SLOTS][BOOT_ENC_KEY_ALIGN_SIZE];
95 #if MCUBOOT_SWAP_SAVE_ENCTLV
96 uint8_t enctlv[BOOT_NUM_SLOTS][BOOT_ENC_TLV_ALIGN_SIZE];
97 #endif
98 #endif
99 int source; /* Which slot contains swap status metadata */
100 };
101
102 #define BOOT_STATUS_IDX_0 1
103
104 #define BOOT_STATUS_STATE_0 1
105 #define BOOT_STATUS_STATE_1 2
106 #define BOOT_STATUS_STATE_2 3
107
108 /**
109 * End-of-image slot structure.
110 *
111 * 0 1 2 3
112 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
113 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
114 * ~ ~
115 * ~ Swap status (BOOT_MAX_IMG_SECTORS * min-write-size * 3) ~
116 * ~ ~
117 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
118 * | Encryption key 0 (16 octets) [*] |
119 * | |
120 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
121 * | 0xff padding as needed |
122 * | (BOOT_MAX_ALIGN minus 16 octets from Encryption key 0) [*] |
123 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
124 * | Encryption key 1 (16 octets) [*] |
125 * | |
126 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
127 * | 0xff padding as needed |
128 * | (BOOT_MAX_ALIGN minus 16 octets from Encryption key 1) [*] |
129 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
130 * | Swap size (4 octets) |
131 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
132 * | 0xff padding as needed |
133 * | (BOOT_MAX_ALIGN minus 4 octets from Swap size) |
134 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
135 * | Swap info | 0xff padding (BOOT_MAX_ALIGN minus 1 octet) |
136 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
137 * | Copy done | 0xff padding (BOOT_MAX_ALIGN minus 1 octet) |
138 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
139 * | Image OK | 0xff padding (BOOT_MAX_ALIGN minus 1 octet) |
140 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
141 * | 0xff padding as needed |
142 * | (BOOT_MAX_ALIGN minus 16 octets from MAGIC) |
143 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
144 * | MAGIC (16 octets) |
145 * | |
146 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
147 *
148 * [*]: Only present if the encryption option is enabled
149 * (`MCUBOOT_ENC_IMAGES`).
150 */
151
152 union boot_img_magic_t
153 {
154 struct {
155 uint16_t align;
156 uint8_t magic[14];
157 };
158 uint8_t val[16];
159 };
160
161 extern const union boot_img_magic_t boot_img_magic;
162
163 #define BOOT_IMG_MAGIC (boot_img_magic.val)
164
165 #if BOOT_MAX_ALIGN == 8
166 #define BOOT_IMG_ALIGN (BOOT_MAX_ALIGN)
167 #else
168 #define BOOT_IMG_ALIGN (boot_img_magic.align)
169 #endif
170
171 _Static_assert(sizeof(boot_img_magic) == BOOT_MAGIC_SZ, "Invalid size for image magic");
172
173 #if !defined(MCUBOOT_DIRECT_XIP) && !defined(MCUBOOT_RAM_LOAD)
174 #define ARE_SLOTS_EQUIVALENT() 0
175 #else
176 #define ARE_SLOTS_EQUIVALENT() 1
177
178 #if defined(MCUBOOT_DIRECT_XIP) && defined(MCUBOOT_ENC_IMAGES)
179 #error "Image encryption (MCUBOOT_ENC_IMAGES) is not supported when MCUBOOT_DIRECT_XIP is selected."
180 #endif /* MCUBOOT_DIRECT_XIP && MCUBOOT_ENC_IMAGES */
181 #endif /* MCUBOOT_DIRECT_XIP || MCUBOOT_RAM_LOAD */
182
183 #define BOOT_MAX_IMG_SECTORS MCUBOOT_MAX_IMG_SECTORS
184
185 #define BOOT_LOG_IMAGE_INFO(slot, hdr) \
186 BOOT_LOG_INF("%-9s slot: version=%u.%u.%u+%u", \
187 ((slot) == BOOT_PRIMARY_SLOT) ? "Primary" : "Secondary", \
188 (hdr)->ih_ver.iv_major, \
189 (hdr)->ih_ver.iv_minor, \
190 (hdr)->ih_ver.iv_revision, \
191 (hdr)->ih_ver.iv_build_num)
192
193 #if MCUBOOT_SWAP_USING_MOVE
194 #define BOOT_STATUS_MOVE_STATE_COUNT 1
195 #define BOOT_STATUS_SWAP_STATE_COUNT 2
196 #define BOOT_STATUS_STATE_COUNT (BOOT_STATUS_MOVE_STATE_COUNT + BOOT_STATUS_SWAP_STATE_COUNT)
197 #else
198 #define BOOT_STATUS_STATE_COUNT 3
199 #endif
200
201 /** Maximum number of image sectors supported by the bootloader. */
202 #define BOOT_STATUS_MAX_ENTRIES BOOT_MAX_IMG_SECTORS
203
204 #define BOOT_PRIMARY_SLOT 0
205 #define BOOT_SECONDARY_SLOT 1
206
207 #define BOOT_STATUS_SOURCE_NONE 0
208 #define BOOT_STATUS_SOURCE_SCRATCH 1
209 #define BOOT_STATUS_SOURCE_PRIMARY_SLOT 2
210
211 /**
212 * Compatibility shim for flash sector type.
213 *
214 * This can be deleted when flash_area_to_sectors() is removed.
215 */
216 #ifdef MCUBOOT_USE_FLASH_AREA_GET_SECTORS
217 typedef struct flash_sector boot_sector_t;
218 #else
219 typedef struct flash_area boot_sector_t;
220 #endif
221
222 /** Private state maintained during boot. */
223 struct boot_loader_state {
224 struct {
225 struct image_header hdr;
226 const struct flash_area *area;
227 boot_sector_t *sectors;
228 uint32_t num_sectors;
229 } imgs[BOOT_IMAGE_NUMBER][BOOT_NUM_SLOTS];
230
231 #if MCUBOOT_SWAP_USING_SCRATCH
232 struct {
233 const struct flash_area *area;
234 boot_sector_t *sectors;
235 uint32_t num_sectors;
236 } scratch;
237 #endif
238
239 uint8_t swap_type[BOOT_IMAGE_NUMBER];
240 uint32_t write_sz;
241
242 #if defined(MCUBOOT_ENC_IMAGES)
243 struct enc_key_data enc[BOOT_IMAGE_NUMBER][BOOT_NUM_SLOTS];
244 #endif
245
246 #if (BOOT_IMAGE_NUMBER > 1)
247 uint8_t curr_img_idx;
248 bool img_mask[BOOT_IMAGE_NUMBER];
249 #endif
250
251 #if defined(MCUBOOT_DIRECT_XIP) || defined(MCUBOOT_RAM_LOAD)
252 struct slot_usage_t {
253 /* Index of the slot chosen to be loaded */
254 uint32_t active_slot;
255 bool slot_available[BOOT_NUM_SLOTS];
256 #if defined(MCUBOOT_RAM_LOAD)
257 /* Image destination and size for the active slot */
258 uint32_t img_dst;
259 uint32_t img_sz;
260 #elif defined(MCUBOOT_DIRECT_XIP_REVERT)
261 /* Swap status for the active slot */
262 struct boot_swap_state swap_state;
263 #endif
264 } slot_usage[BOOT_IMAGE_NUMBER];
265 #endif /* MCUBOOT_DIRECT_XIP || MCUBOOT_RAM_LOAD */
266 };
267
268 fih_ret bootutil_verify_sig(uint8_t *hash, uint32_t hlen, uint8_t *sig,
269 size_t slen, uint8_t key_id);
270
271 fih_ret boot_fih_memequal(const void *s1, const void *s2, size_t n);
272
273 int boot_find_status(int image_index, const struct flash_area **fap);
274 int boot_magic_compatible_check(uint8_t tbl_val, uint8_t val);
275 uint32_t boot_status_sz(uint32_t min_write_sz);
276 uint32_t boot_trailer_sz(uint32_t min_write_sz);
277 int boot_status_entries(int image_index, const struct flash_area *fap);
278 uint32_t boot_status_off(const struct flash_area *fap);
279 int boot_read_swap_state(const struct flash_area *fap,
280 struct boot_swap_state *state);
281 int boot_read_swap_state_by_id(int flash_area_id,
282 struct boot_swap_state *state);
283 int boot_write_magic(const struct flash_area *fap);
284 int boot_write_status(const struct boot_loader_state *state, struct boot_status *bs);
285 int boot_write_copy_done(const struct flash_area *fap);
286 int boot_write_image_ok(const struct flash_area *fap);
287 int boot_write_swap_info(const struct flash_area *fap, uint8_t swap_type,
288 uint8_t image_num);
289 int boot_write_swap_size(const struct flash_area *fap, uint32_t swap_size);
290 int boot_write_trailer(const struct flash_area *fap, uint32_t off,
291 const uint8_t *inbuf, uint8_t inlen);
292 int boot_write_trailer_flag(const struct flash_area *fap, uint32_t off,
293 uint8_t flag_val);
294 int boot_read_swap_size(const struct flash_area *fap, uint32_t *swap_size);
295 int boot_slots_compatible(struct boot_loader_state *state);
296 uint32_t boot_status_internal_off(const struct boot_status *bs, int elem_sz);
297 int boot_read_image_header(struct boot_loader_state *state, int slot,
298 struct image_header *out_hdr, struct boot_status *bs);
299 int boot_copy_region(struct boot_loader_state *state,
300 const struct flash_area *fap_src,
301 const struct flash_area *fap_dst,
302 uint32_t off_src, uint32_t off_dst, uint32_t sz);
303 int boot_erase_region(const struct flash_area *fap, uint32_t off, uint32_t sz);
304 bool boot_status_is_reset(const struct boot_status *bs);
305
306 #ifdef MCUBOOT_ENC_IMAGES
307 int boot_write_enc_key(const struct flash_area *fap, uint8_t slot,
308 const struct boot_status *bs);
309 int boot_read_enc_key(const struct flash_area *fap, uint8_t slot,
310 struct boot_status *bs);
311 #endif
312
313 /**
314 * Checks that a buffer is erased according to what the erase value for the
315 * flash device provided in `flash_area` is.
316 *
317 * @returns true if the buffer is erased; false if any of the bytes is not
318 * erased, or when buffer is NULL, or when len == 0.
319 */
320 bool bootutil_buffer_is_erased(const struct flash_area *area,
321 const void *buffer, size_t len);
322
323 /**
324 * Safe (non-overflowing) uint32_t addition. Returns true, and stores
325 * the result in *dest if it can be done without overflow. Otherwise,
326 * returns false.
327 */
boot_u32_safe_add(uint32_t * dest,uint32_t a,uint32_t b)328 static inline bool boot_u32_safe_add(uint32_t *dest, uint32_t a, uint32_t b)
329 {
330 /*
331 * "a + b <= UINT32_MAX", subtract 'b' from both sides to avoid
332 * the overflow.
333 */
334 if (a > UINT32_MAX - b) {
335 return false;
336 } else {
337 *dest = a + b;
338 return true;
339 }
340 }
341
342 /**
343 * Safe (non-overflowing) uint16_t addition. Returns true, and stores
344 * the result in *dest if it can be done without overflow. Otherwise,
345 * returns false.
346 */
boot_u16_safe_add(uint16_t * dest,uint16_t a,uint16_t b)347 static inline bool boot_u16_safe_add(uint16_t *dest, uint16_t a, uint16_t b)
348 {
349 uint32_t tmp = a + b;
350 if (tmp > UINT16_MAX) {
351 return false;
352 } else {
353 *dest = tmp;
354 return true;
355 }
356 }
357
358 /*
359 * Accessors for the contents of struct boot_loader_state.
360 */
361
362 /* These are macros so they can be used as lvalues. */
363 #if (BOOT_IMAGE_NUMBER > 1)
364 #define BOOT_CURR_IMG(state) ((state)->curr_img_idx)
365 #else
366 #define BOOT_CURR_IMG(state) 0
367 #endif
368 #ifdef MCUBOOT_ENC_IMAGES
369 #define BOOT_CURR_ENC(state) ((state)->enc[BOOT_CURR_IMG(state)])
370 #else
371 #define BOOT_CURR_ENC(state) NULL
372 #endif
373 #define BOOT_IMG(state, slot) ((state)->imgs[BOOT_CURR_IMG(state)][(slot)])
374 #define BOOT_IMG_AREA(state, slot) (BOOT_IMG(state, slot).area)
375 #define BOOT_WRITE_SZ(state) ((state)->write_sz)
376 #define BOOT_SWAP_TYPE(state) ((state)->swap_type[BOOT_CURR_IMG(state)])
377 #define BOOT_TLV_OFF(hdr) ((hdr)->ih_hdr_size + (hdr)->ih_img_size)
378
379 #define BOOT_IS_UPGRADE(swap_type) \
380 (((swap_type) == BOOT_SWAP_TYPE_TEST) || \
381 ((swap_type) == BOOT_SWAP_TYPE_REVERT) || \
382 ((swap_type) == BOOT_SWAP_TYPE_PERM))
383
384 static inline struct image_header*
boot_img_hdr(struct boot_loader_state * state,size_t slot)385 boot_img_hdr(struct boot_loader_state *state, size_t slot)
386 {
387 return &BOOT_IMG(state, slot).hdr;
388 }
389
390 static inline size_t
boot_img_num_sectors(const struct boot_loader_state * state,size_t slot)391 boot_img_num_sectors(const struct boot_loader_state *state, size_t slot)
392 {
393 return BOOT_IMG(state, slot).num_sectors;
394 }
395
396 /*
397 * Offset of the slot from the beginning of the flash device.
398 */
399 static inline uint32_t
boot_img_slot_off(struct boot_loader_state * state,size_t slot)400 boot_img_slot_off(struct boot_loader_state *state, size_t slot)
401 {
402 return flash_area_get_off(BOOT_IMG(state, slot).area);
403 }
404
405 #ifndef MCUBOOT_USE_FLASH_AREA_GET_SECTORS
406
407 static inline size_t
boot_img_sector_size(const struct boot_loader_state * state,size_t slot,size_t sector)408 boot_img_sector_size(const struct boot_loader_state *state,
409 size_t slot, size_t sector)
410 {
411 return flash_area_get_size(&BOOT_IMG(state, slot).sectors[sector]);
412 }
413
414 /*
415 * Offset of the sector from the beginning of the image, NOT the flash
416 * device.
417 */
418 static inline uint32_t
boot_img_sector_off(const struct boot_loader_state * state,size_t slot,size_t sector)419 boot_img_sector_off(const struct boot_loader_state *state, size_t slot,
420 size_t sector)
421 {
422 return flash_area_get_off(&BOOT_IMG(state, slot).sectors[sector]) -
423 flash_area_get_off(&BOOT_IMG(state, slot).sectors[0]);
424 }
425
426 #else /* defined(MCUBOOT_USE_FLASH_AREA_GET_SECTORS) */
427
428 static inline size_t
boot_img_sector_size(const struct boot_loader_state * state,size_t slot,size_t sector)429 boot_img_sector_size(const struct boot_loader_state *state,
430 size_t slot, size_t sector)
431 {
432 return flash_sector_get_size(&BOOT_IMG(state, slot).sectors[sector]);
433 }
434
435 static inline uint32_t
boot_img_sector_off(const struct boot_loader_state * state,size_t slot,size_t sector)436 boot_img_sector_off(const struct boot_loader_state *state, size_t slot,
437 size_t sector)
438 {
439 return flash_sector_get_off(&BOOT_IMG(state, slot).sectors[sector]) -
440 flash_sector_get_off(&BOOT_IMG(state, slot).sectors[0]);
441 }
442
443 #endif /* !defined(MCUBOOT_USE_FLASH_AREA_GET_SECTORS) */
444
445 #ifdef MCUBOOT_RAM_LOAD
446 # ifdef __BOOTSIM__
447
448 /* Query for the layout of a RAM buffer appropriate for holding the
449 * image. This will be per-test-thread, and therefore must be queried
450 * through this call. */
451 struct bootsim_ram_info {
452 uint32_t start;
453 uint32_t size;
454 uintptr_t base;
455 };
456 struct bootsim_ram_info *bootsim_get_ram_info(void);
457
458 #define IMAGE_GET_FIELD(field) (bootsim_get_ram_info()->field)
459 #define IMAGE_RAM_BASE IMAGE_GET_FIELD(base)
460 #define IMAGE_EXECUTABLE_RAM_START IMAGE_GET_FIELD(start)
461 #define IMAGE_EXECUTABLE_RAM_SIZE IMAGE_GET_FIELD(size)
462
463 # else
464 # define IMAGE_RAM_BASE ((uintptr_t)0)
465 # endif
466
467 #define LOAD_IMAGE_DATA(hdr, fap, start, output, size) \
468 (memcpy((output),(void*)(IMAGE_RAM_BASE + (hdr)->ih_load_addr + (start)), \
469 (size)), 0)
470 #else
471 #define IMAGE_RAM_BASE ((uintptr_t)0)
472
473 #define LOAD_IMAGE_DATA(hdr, fap, start, output, size) \
474 (flash_area_read((fap), (start), (output), (size)))
475 #endif /* MCUBOOT_RAM_LOAD */
476
477 uint32_t bootutil_max_image_size(const struct flash_area *fap);
478
479 #ifdef __cplusplus
480 }
481 #endif
482
483 #endif
484
