1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * EFI image loader
4 *
5 * based partly on wine code
6 *
7 * Copyright (c) 2016 Alexander Graf
8 */
9
10 #define LOG_CATEGORY LOGC_EFI
11
12 #include <common.h>
13 #include <cpu_func.h>
14 #include <efi_loader.h>
15 #include <log.h>
16 #include <malloc.h>
17 #include <pe.h>
18 #include <sort.h>
19 #include <crypto/pkcs7_parser.h>
20 #include <linux/err.h>
21
22 const efi_guid_t efi_global_variable_guid = EFI_GLOBAL_VARIABLE_GUID;
23 const efi_guid_t efi_guid_device_path = EFI_DEVICE_PATH_PROTOCOL_GUID;
24 const efi_guid_t efi_guid_loaded_image = EFI_LOADED_IMAGE_PROTOCOL_GUID;
25 const efi_guid_t efi_guid_loaded_image_device_path =
26 EFI_LOADED_IMAGE_DEVICE_PATH_PROTOCOL_GUID;
27 const efi_guid_t efi_simple_file_system_protocol_guid =
28 EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_GUID;
29 const efi_guid_t efi_file_info_guid = EFI_FILE_INFO_GUID;
30
31 static int machines[] = {
32 #if defined(__aarch64__)
33 IMAGE_FILE_MACHINE_ARM64,
34 #elif defined(__arm__)
35 IMAGE_FILE_MACHINE_ARM,
36 IMAGE_FILE_MACHINE_THUMB,
37 IMAGE_FILE_MACHINE_ARMNT,
38 #endif
39
40 #if defined(__x86_64__)
41 IMAGE_FILE_MACHINE_AMD64,
42 #elif defined(__i386__)
43 IMAGE_FILE_MACHINE_I386,
44 #endif
45
46 #if defined(__riscv) && (__riscv_xlen == 32)
47 IMAGE_FILE_MACHINE_RISCV32,
48 #endif
49
50 #if defined(__riscv) && (__riscv_xlen == 64)
51 IMAGE_FILE_MACHINE_RISCV64,
52 #endif
53 0 };
54
55 /**
56 * efi_print_image_info() - print information about a loaded image
57 *
58 * If the program counter is located within the image the offset to the base
59 * address is shown.
60 *
61 * @obj: EFI object
62 * @image: loaded image
63 * @pc: program counter (use NULL to suppress offset output)
64 * Return: status code
65 */
efi_print_image_info(struct efi_loaded_image_obj * obj,struct efi_loaded_image * image,void * pc)66 static efi_status_t efi_print_image_info(struct efi_loaded_image_obj *obj,
67 struct efi_loaded_image *image,
68 void *pc)
69 {
70 printf("UEFI image");
71 printf(" [0x%p:0x%p]",
72 image->image_base, image->image_base + image->image_size - 1);
73 if (pc && pc >= image->image_base &&
74 pc < image->image_base + image->image_size)
75 printf(" pc=0x%zx", pc - image->image_base);
76 if (image->file_path)
77 printf(" '%pD'", image->file_path);
78 printf("\n");
79 return EFI_SUCCESS;
80 }
81
82 /**
83 * efi_print_image_infos() - print information about all loaded images
84 *
85 * @pc: program counter (use NULL to suppress offset output)
86 */
efi_print_image_infos(void * pc)87 void efi_print_image_infos(void *pc)
88 {
89 struct efi_object *efiobj;
90 struct efi_handler *handler;
91
92 list_for_each_entry(efiobj, &efi_obj_list, link) {
93 list_for_each_entry(handler, &efiobj->protocols, link) {
94 if (!guidcmp(handler->guid, &efi_guid_loaded_image)) {
95 efi_print_image_info(
96 (struct efi_loaded_image_obj *)efiobj,
97 handler->protocol_interface, pc);
98 }
99 }
100 }
101 }
102
103 /**
104 * efi_loader_relocate() - relocate UEFI binary
105 *
106 * @rel: pointer to the relocation table
107 * @rel_size: size of the relocation table in bytes
108 * @efi_reloc: actual load address of the image
109 * @pref_address: preferred load address of the image
110 * Return: status code
111 */
efi_loader_relocate(const IMAGE_BASE_RELOCATION * rel,unsigned long rel_size,void * efi_reloc,unsigned long pref_address)112 static efi_status_t efi_loader_relocate(const IMAGE_BASE_RELOCATION *rel,
113 unsigned long rel_size, void *efi_reloc,
114 unsigned long pref_address)
115 {
116 unsigned long delta = (unsigned long)efi_reloc - pref_address;
117 const IMAGE_BASE_RELOCATION *end;
118 int i;
119
120 if (delta == 0)
121 return EFI_SUCCESS;
122
123 end = (const IMAGE_BASE_RELOCATION *)((const char *)rel + rel_size);
124 while (rel < end && rel->SizeOfBlock) {
125 const uint16_t *relocs = (const uint16_t *)(rel + 1);
126 i = (rel->SizeOfBlock - sizeof(*rel)) / sizeof(uint16_t);
127 while (i--) {
128 uint32_t offset = (uint32_t)(*relocs & 0xfff) +
129 rel->VirtualAddress;
130 int type = *relocs >> EFI_PAGE_SHIFT;
131 uint64_t *x64 = efi_reloc + offset;
132 uint32_t *x32 = efi_reloc + offset;
133 uint16_t *x16 = efi_reloc + offset;
134
135 switch (type) {
136 case IMAGE_REL_BASED_ABSOLUTE:
137 break;
138 case IMAGE_REL_BASED_HIGH:
139 *x16 += ((uint32_t)delta) >> 16;
140 break;
141 case IMAGE_REL_BASED_LOW:
142 *x16 += (uint16_t)delta;
143 break;
144 case IMAGE_REL_BASED_HIGHLOW:
145 *x32 += (uint32_t)delta;
146 break;
147 case IMAGE_REL_BASED_DIR64:
148 *x64 += (uint64_t)delta;
149 break;
150 #ifdef __riscv
151 case IMAGE_REL_BASED_RISCV_HI20:
152 *x32 = ((*x32 & 0xfffff000) + (uint32_t)delta) |
153 (*x32 & 0x00000fff);
154 break;
155 case IMAGE_REL_BASED_RISCV_LOW12I:
156 case IMAGE_REL_BASED_RISCV_LOW12S:
157 /* We know that we're 4k aligned */
158 if (delta & 0xfff) {
159 log_err("Unsupported reloc offset\n");
160 return EFI_LOAD_ERROR;
161 }
162 break;
163 #endif
164 default:
165 log_err("Unknown Relocation off %x type %x\n",
166 offset, type);
167 return EFI_LOAD_ERROR;
168 }
169 relocs++;
170 }
171 rel = (const IMAGE_BASE_RELOCATION *)relocs;
172 }
173 return EFI_SUCCESS;
174 }
175
invalidate_icache_all(void)176 void __weak invalidate_icache_all(void)
177 {
178 /* If the system doesn't support icache_all flush, cross our fingers */
179 }
180
181 /**
182 * efi_set_code_and_data_type() - determine the memory types to be used for code
183 * and data.
184 *
185 * @loaded_image_info: image descriptor
186 * @image_type: field Subsystem of the optional header for
187 * Windows specific field
188 */
efi_set_code_and_data_type(struct efi_loaded_image * loaded_image_info,uint16_t image_type)189 static void efi_set_code_and_data_type(
190 struct efi_loaded_image *loaded_image_info,
191 uint16_t image_type)
192 {
193 switch (image_type) {
194 case IMAGE_SUBSYSTEM_EFI_APPLICATION:
195 loaded_image_info->image_code_type = EFI_LOADER_CODE;
196 loaded_image_info->image_data_type = EFI_LOADER_DATA;
197 break;
198 case IMAGE_SUBSYSTEM_EFI_BOOT_SERVICE_DRIVER:
199 loaded_image_info->image_code_type = EFI_BOOT_SERVICES_CODE;
200 loaded_image_info->image_data_type = EFI_BOOT_SERVICES_DATA;
201 break;
202 case IMAGE_SUBSYSTEM_EFI_RUNTIME_DRIVER:
203 case IMAGE_SUBSYSTEM_EFI_ROM:
204 loaded_image_info->image_code_type = EFI_RUNTIME_SERVICES_CODE;
205 loaded_image_info->image_data_type = EFI_RUNTIME_SERVICES_DATA;
206 break;
207 default:
208 log_err("invalid image type: %u\n", image_type);
209 /* Let's assume it is an application */
210 loaded_image_info->image_code_type = EFI_LOADER_CODE;
211 loaded_image_info->image_data_type = EFI_LOADER_DATA;
212 break;
213 }
214 }
215
216 /**
217 * efi_image_region_add() - add an entry of region
218 * @regs: Pointer to array of regions
219 * @start: Start address of region (included)
220 * @end: End address of region (excluded)
221 * @nocheck: flag against overlapped regions
222 *
223 * Take one entry of region \[@start, @end\[ and insert it into the list.
224 *
225 * * If @nocheck is false, the list will be sorted ascending by address.
226 * Overlapping entries will not be allowed.
227 *
228 * * If @nocheck is true, the list will be sorted ascending by sequence
229 * of adding the entries. Overlapping is allowed.
230 *
231 * Return: status code
232 */
efi_image_region_add(struct efi_image_regions * regs,const void * start,const void * end,int nocheck)233 efi_status_t efi_image_region_add(struct efi_image_regions *regs,
234 const void *start, const void *end,
235 int nocheck)
236 {
237 struct image_region *reg;
238 int i, j;
239
240 if (regs->num >= regs->max) {
241 EFI_PRINT("%s: no more room for regions\n", __func__);
242 return EFI_OUT_OF_RESOURCES;
243 }
244
245 if (end < start)
246 return EFI_INVALID_PARAMETER;
247
248 for (i = 0; i < regs->num; i++) {
249 reg = ®s->reg[i];
250 if (nocheck)
251 continue;
252
253 /* new data after registered region */
254 if (start >= reg->data + reg->size)
255 continue;
256
257 /* new data preceding registered region */
258 if (end <= reg->data) {
259 for (j = regs->num - 1; j >= i; j--)
260 memcpy(®s->reg[j + 1], ®s->reg[j],
261 sizeof(*reg));
262 break;
263 }
264
265 /* new data overlapping registered region */
266 EFI_PRINT("%s: new region already part of another\n", __func__);
267 return EFI_INVALID_PARAMETER;
268 }
269
270 reg = ®s->reg[i];
271 reg->data = start;
272 reg->size = end - start;
273 regs->num++;
274
275 return EFI_SUCCESS;
276 }
277
278 /**
279 * cmp_pe_section() - compare virtual addresses of two PE image sections
280 * @arg1: pointer to pointer to first section header
281 * @arg2: pointer to pointer to second section header
282 *
283 * Compare the virtual addresses of two sections of an portable executable.
284 * The arguments are defined as const void * to allow usage with qsort().
285 *
286 * Return: -1 if the virtual address of arg1 is less than that of arg2,
287 * 0 if the virtual addresses are equal, 1 if the virtual address
288 * of arg1 is greater than that of arg2.
289 */
cmp_pe_section(const void * arg1,const void * arg2)290 static int cmp_pe_section(const void *arg1, const void *arg2)
291 {
292 const IMAGE_SECTION_HEADER *section1, *section2;
293
294 section1 = *((const IMAGE_SECTION_HEADER **)arg1);
295 section2 = *((const IMAGE_SECTION_HEADER **)arg2);
296
297 if (section1->VirtualAddress < section2->VirtualAddress)
298 return -1;
299 else if (section1->VirtualAddress == section2->VirtualAddress)
300 return 0;
301 else
302 return 1;
303 }
304
305 /**
306 * efi_prepare_aligned_image() - prepare 8-byte aligned image
307 * @efi: pointer to the EFI binary
308 * @efi_size: size of @efi binary
309 *
310 * If @efi is not 8-byte aligned, this function newly allocates
311 * the image buffer.
312 *
313 * Return: valid pointer to a image, return NULL if allocation fails.
314 */
efi_prepare_aligned_image(void * efi,u64 * efi_size)315 void *efi_prepare_aligned_image(void *efi, u64 *efi_size)
316 {
317 size_t new_efi_size;
318 void *new_efi;
319
320 /*
321 * Size must be 8-byte aligned and the trailing bytes must be
322 * zero'ed. Otherwise hash value may be incorrect.
323 */
324 if (!IS_ALIGNED(*efi_size, 8)) {
325 new_efi_size = ALIGN(*efi_size, 8);
326 new_efi = calloc(new_efi_size, 1);
327 if (!new_efi)
328 return NULL;
329 memcpy(new_efi, efi, *efi_size);
330 *efi_size = new_efi_size;
331 return new_efi;
332 } else {
333 return efi;
334 }
335 }
336
337 /**
338 * efi_image_parse() - parse a PE image
339 * @efi: Pointer to image
340 * @len: Size of @efi
341 * @regp: Pointer to a list of regions
342 * @auth: Pointer to a pointer to authentication data in PE
343 * @auth_len: Size of @auth
344 *
345 * Parse image binary in PE32(+) format, assuming that sanity of PE image
346 * has been checked by a caller.
347 * On success, an address of authentication data in @efi and its size will
348 * be returned in @auth and @auth_len, respectively.
349 *
350 * Return: true on success, false on error
351 */
efi_image_parse(void * efi,size_t len,struct efi_image_regions ** regp,WIN_CERTIFICATE ** auth,size_t * auth_len)352 bool efi_image_parse(void *efi, size_t len, struct efi_image_regions **regp,
353 WIN_CERTIFICATE **auth, size_t *auth_len)
354 {
355 struct efi_image_regions *regs;
356 IMAGE_DOS_HEADER *dos;
357 IMAGE_NT_HEADERS32 *nt;
358 IMAGE_SECTION_HEADER *sections, **sorted;
359 int num_regions, num_sections, i;
360 int ctidx = IMAGE_DIRECTORY_ENTRY_SECURITY;
361 u32 align, size, authsz, authoff;
362 size_t bytes_hashed;
363
364 dos = (void *)efi;
365 nt = (void *)(efi + dos->e_lfanew);
366 authoff = 0;
367 authsz = 0;
368
369 /*
370 * Count maximum number of regions to be digested.
371 * We don't have to have an exact number here.
372 * See efi_image_region_add()'s in parsing below.
373 */
374 num_regions = 3; /* for header */
375 num_regions += nt->FileHeader.NumberOfSections;
376 num_regions++; /* for extra */
377
378 regs = calloc(sizeof(*regs) + sizeof(struct image_region) * num_regions,
379 1);
380 if (!regs)
381 goto err;
382 regs->max = num_regions;
383
384 /*
385 * Collect data regions for hash calculation
386 * 1. File headers
387 */
388 if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR64_MAGIC) {
389 IMAGE_NT_HEADERS64 *nt64 = (void *)nt;
390 IMAGE_OPTIONAL_HEADER64 *opt = &nt64->OptionalHeader;
391
392 /* Skip CheckSum */
393 efi_image_region_add(regs, efi, &opt->CheckSum, 0);
394 if (nt64->OptionalHeader.NumberOfRvaAndSizes <= ctidx) {
395 efi_image_region_add(regs,
396 &opt->Subsystem,
397 efi + opt->SizeOfHeaders, 0);
398 } else {
399 /* Skip Certificates Table */
400 efi_image_region_add(regs,
401 &opt->Subsystem,
402 &opt->DataDirectory[ctidx], 0);
403 efi_image_region_add(regs,
404 &opt->DataDirectory[ctidx] + 1,
405 efi + opt->SizeOfHeaders, 0);
406
407 authoff = opt->DataDirectory[ctidx].VirtualAddress;
408 authsz = opt->DataDirectory[ctidx].Size;
409 }
410
411 bytes_hashed = opt->SizeOfHeaders;
412 align = opt->FileAlignment;
413 } else if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
414 IMAGE_OPTIONAL_HEADER32 *opt = &nt->OptionalHeader;
415
416 /* Skip CheckSum */
417 efi_image_region_add(regs, efi, &opt->CheckSum, 0);
418 if (nt->OptionalHeader.NumberOfRvaAndSizes <= ctidx) {
419 efi_image_region_add(regs,
420 &opt->Subsystem,
421 efi + opt->SizeOfHeaders, 0);
422 } else {
423 /* Skip Certificates Table */
424 efi_image_region_add(regs, &opt->Subsystem,
425 &opt->DataDirectory[ctidx], 0);
426 efi_image_region_add(regs,
427 &opt->DataDirectory[ctidx] + 1,
428 efi + opt->SizeOfHeaders, 0);
429
430 authoff = opt->DataDirectory[ctidx].VirtualAddress;
431 authsz = opt->DataDirectory[ctidx].Size;
432 }
433
434 bytes_hashed = opt->SizeOfHeaders;
435 align = opt->FileAlignment;
436 } else {
437 EFI_PRINT("%s: Invalid optional header magic %x\n", __func__,
438 nt->OptionalHeader.Magic);
439 goto err;
440 }
441
442 /* 2. Sections */
443 num_sections = nt->FileHeader.NumberOfSections;
444 sections = (void *)((uint8_t *)&nt->OptionalHeader +
445 nt->FileHeader.SizeOfOptionalHeader);
446 sorted = calloc(sizeof(IMAGE_SECTION_HEADER *), num_sections);
447 if (!sorted) {
448 EFI_PRINT("%s: Out of memory\n", __func__);
449 goto err;
450 }
451
452 /*
453 * Make sure the section list is in ascending order.
454 */
455 for (i = 0; i < num_sections; i++)
456 sorted[i] = §ions[i];
457 qsort(sorted, num_sections, sizeof(sorted[0]), cmp_pe_section);
458
459 for (i = 0; i < num_sections; i++) {
460 if (!sorted[i]->SizeOfRawData)
461 continue;
462
463 size = (sorted[i]->SizeOfRawData + align - 1) & ~(align - 1);
464 efi_image_region_add(regs, efi + sorted[i]->PointerToRawData,
465 efi + sorted[i]->PointerToRawData + size,
466 0);
467 EFI_PRINT("section[%d](%s): raw: 0x%x-0x%x, virt: %x-%x\n",
468 i, sorted[i]->Name,
469 sorted[i]->PointerToRawData,
470 sorted[i]->PointerToRawData + size,
471 sorted[i]->VirtualAddress,
472 sorted[i]->VirtualAddress
473 + sorted[i]->Misc.VirtualSize);
474
475 bytes_hashed += size;
476 }
477 free(sorted);
478
479 /* 3. Extra data excluding Certificates Table */
480 if (bytes_hashed + authsz < len) {
481 EFI_PRINT("extra data for hash: %zu\n",
482 len - (bytes_hashed + authsz));
483 efi_image_region_add(regs, efi + bytes_hashed,
484 efi + len - authsz, 0);
485 }
486
487 /* Return Certificates Table */
488 if (authsz) {
489 if (len < authoff + authsz) {
490 EFI_PRINT("%s: Size for auth too large: %u >= %zu\n",
491 __func__, authsz, len - authoff);
492 goto err;
493 }
494 if (authsz < sizeof(*auth)) {
495 EFI_PRINT("%s: Size for auth too small: %u < %zu\n",
496 __func__, authsz, sizeof(*auth));
497 goto err;
498 }
499 *auth = efi + authoff;
500 *auth_len = authsz;
501 EFI_PRINT("WIN_CERTIFICATE: 0x%x, size: 0x%x\n", authoff,
502 authsz);
503 } else {
504 *auth = NULL;
505 *auth_len = 0;
506 }
507
508 *regp = regs;
509
510 return true;
511
512 err:
513 free(regs);
514
515 return false;
516 }
517
518 #ifdef CONFIG_EFI_SECURE_BOOT
519 /**
520 * efi_image_unsigned_authenticate() - authenticate unsigned image with
521 * SHA256 hash
522 * @regs: List of regions to be verified
523 *
524 * If an image is not signed, it doesn't have a signature. In this case,
525 * its message digest is calculated and it will be compared with one of
526 * hash values stored in signature databases.
527 *
528 * Return: true if authenticated, false if not
529 */
efi_image_unsigned_authenticate(struct efi_image_regions * regs)530 static bool efi_image_unsigned_authenticate(struct efi_image_regions *regs)
531 {
532 struct efi_signature_store *db = NULL, *dbx = NULL;
533 bool ret = false;
534
535 dbx = efi_sigstore_parse_sigdb(L"dbx");
536 if (!dbx) {
537 EFI_PRINT("Getting signature database(dbx) failed\n");
538 goto out;
539 }
540
541 db = efi_sigstore_parse_sigdb(L"db");
542 if (!db) {
543 EFI_PRINT("Getting signature database(db) failed\n");
544 goto out;
545 }
546
547 /* try black-list first */
548 if (efi_signature_lookup_digest(regs, dbx)) {
549 EFI_PRINT("Image is not signed and its digest found in \"dbx\"\n");
550 goto out;
551 }
552
553 /* try white-list */
554 if (efi_signature_lookup_digest(regs, db))
555 ret = true;
556 else
557 EFI_PRINT("Image is not signed and its digest not found in \"db\" or \"dbx\"\n");
558
559 out:
560 efi_sigstore_free(db);
561 efi_sigstore_free(dbx);
562
563 return ret;
564 }
565
566 /**
567 * efi_image_authenticate() - verify a signature of signed image
568 * @efi: Pointer to image
569 * @efi_size: Size of @efi
570 *
571 * A signed image should have its signature stored in a table of its PE header.
572 * So if an image is signed and only if if its signature is verified using
573 * signature databases, an image is authenticated.
574 * If an image is not signed, its validity is checked by using
575 * efi_image_unsigned_authenticated().
576 * TODO:
577 * When AuditMode==0, if the image's signature is not found in
578 * the authorized database, or is found in the forbidden database,
579 * the image will not be started and instead, information about it
580 * will be placed in this table.
581 * When AuditMode==1, an EFI_IMAGE_EXECUTION_INFO element is created
582 * in the EFI_IMAGE_EXECUTION_INFO_TABLE for every certificate found
583 * in the certificate table of every image that is validated.
584 *
585 * Return: true if authenticated, false if not
586 */
efi_image_authenticate(void * efi,size_t efi_size)587 static bool efi_image_authenticate(void *efi, size_t efi_size)
588 {
589 struct efi_image_regions *regs = NULL;
590 WIN_CERTIFICATE *wincerts = NULL, *wincert;
591 size_t wincerts_len;
592 struct pkcs7_message *msg = NULL;
593 struct efi_signature_store *db = NULL, *dbx = NULL;
594 void *new_efi = NULL;
595 u8 *auth, *wincerts_end;
596 size_t auth_size;
597 bool ret = false;
598
599 EFI_PRINT("%s: Enter, %d\n", __func__, ret);
600
601 if (!efi_secure_boot_enabled())
602 return true;
603
604 new_efi = efi_prepare_aligned_image(efi, (u64 *)&efi_size);
605 if (!new_efi)
606 return false;
607
608 if (!efi_image_parse(new_efi, efi_size, ®s, &wincerts,
609 &wincerts_len)) {
610 EFI_PRINT("Parsing PE executable image failed\n");
611 goto err;
612 }
613
614 if (!wincerts) {
615 /* The image is not signed */
616 ret = efi_image_unsigned_authenticate(regs);
617
618 goto err;
619 }
620
621 /*
622 * verify signature using db and dbx
623 */
624 db = efi_sigstore_parse_sigdb(L"db");
625 if (!db) {
626 EFI_PRINT("Getting signature database(db) failed\n");
627 goto err;
628 }
629
630 dbx = efi_sigstore_parse_sigdb(L"dbx");
631 if (!dbx) {
632 EFI_PRINT("Getting signature database(dbx) failed\n");
633 goto err;
634 }
635
636 if (efi_signature_lookup_digest(regs, dbx)) {
637 EFI_PRINT("Image's digest was found in \"dbx\"\n");
638 goto err;
639 }
640
641 /*
642 * go through WIN_CERTIFICATE list
643 * NOTE:
644 * We may have multiple signatures either as WIN_CERTIFICATE's
645 * in PE header, or as pkcs7 SignerInfo's in SignedData.
646 * So the verification policy here is:
647 * - Success if, at least, one of signatures is verified
648 * - unless signature is rejected explicitly with its digest.
649 */
650
651 for (wincert = wincerts, wincerts_end = (u8 *)wincerts + wincerts_len;
652 (u8 *)wincert < wincerts_end;
653 wincert = (WIN_CERTIFICATE *)
654 ((u8 *)wincert + ALIGN(wincert->dwLength, 8))) {
655 if ((u8 *)wincert + sizeof(*wincert) >= wincerts_end)
656 break;
657
658 if (wincert->dwLength <= sizeof(*wincert)) {
659 EFI_PRINT("dwLength too small: %u < %zu\n",
660 wincert->dwLength, sizeof(*wincert));
661 continue;
662 }
663
664 EFI_PRINT("WIN_CERTIFICATE_TYPE: 0x%x\n",
665 wincert->wCertificateType);
666
667 auth = (u8 *)wincert + sizeof(*wincert);
668 auth_size = wincert->dwLength - sizeof(*wincert);
669 if (wincert->wCertificateType == WIN_CERT_TYPE_EFI_GUID) {
670 if (auth + sizeof(efi_guid_t) >= wincerts_end)
671 break;
672
673 if (auth_size <= sizeof(efi_guid_t)) {
674 EFI_PRINT("dwLength too small: %u < %zu\n",
675 wincert->dwLength, sizeof(*wincert));
676 continue;
677 }
678 if (guidcmp(auth, &efi_guid_cert_type_pkcs7)) {
679 EFI_PRINT("Certificate type not supported: %pUl\n",
680 auth);
681 continue;
682 }
683
684 auth += sizeof(efi_guid_t);
685 auth_size -= sizeof(efi_guid_t);
686 } else if (wincert->wCertificateType
687 != WIN_CERT_TYPE_PKCS_SIGNED_DATA) {
688 EFI_PRINT("Certificate type not supported\n");
689 continue;
690 }
691
692 msg = pkcs7_parse_message(auth, auth_size);
693 if (IS_ERR(msg)) {
694 EFI_PRINT("Parsing image's signature failed\n");
695 msg = NULL;
696 continue;
697 }
698
699 /*
700 * NOTE:
701 * UEFI specification defines two signature types possible
702 * in signature database:
703 * a. x509 certificate, where a signature in image is
704 * a message digest encrypted by RSA public key
705 * (EFI_CERT_X509_GUID)
706 * b. bare hash value of message digest
707 * (EFI_CERT_SHAxxx_GUID)
708 *
709 * efi_signature_verify() handles case (a), while
710 * efi_signature_lookup_digest() handles case (b).
711 *
712 * There is a third type:
713 * c. message digest of a certificate
714 * (EFI_CERT_X509_SHAAxxx_GUID)
715 * This type of signature is used only in revocation list
716 * (dbx) and handled as part of efi_signatgure_verify().
717 */
718 /* try black-list first */
719 if (efi_signature_verify_one(regs, msg, dbx)) {
720 EFI_PRINT("Signature was rejected by \"dbx\"\n");
721 continue;
722 }
723
724 if (!efi_signature_check_signers(msg, dbx)) {
725 EFI_PRINT("Signer(s) in \"dbx\"\n");
726 continue;
727 }
728
729 /* try white-list */
730 if (efi_signature_verify(regs, msg, db, dbx)) {
731 ret = true;
732 break;
733 }
734
735 EFI_PRINT("Signature was not verified by \"db\"\n");
736
737 if (efi_signature_lookup_digest(regs, db)) {
738 ret = true;
739 break;
740 }
741
742 EFI_PRINT("Image's digest was not found in \"db\" or \"dbx\"\n");
743 }
744
745 err:
746 efi_sigstore_free(db);
747 efi_sigstore_free(dbx);
748 pkcs7_free_message(msg);
749 free(regs);
750 if (new_efi != efi)
751 free(new_efi);
752
753 EFI_PRINT("%s: Exit, %d\n", __func__, ret);
754 return ret;
755 }
756 #else
efi_image_authenticate(void * efi,size_t efi_size)757 static bool efi_image_authenticate(void *efi, size_t efi_size)
758 {
759 return true;
760 }
761 #endif /* CONFIG_EFI_SECURE_BOOT */
762
763
764 /**
765 * efi_check_pe() - check if a memory buffer contains a PE-COFF image
766 *
767 * @buffer: buffer to check
768 * @size: size of buffer
769 * @nt_header: on return pointer to NT header of PE-COFF image
770 * Return: EFI_SUCCESS if the buffer contains a PE-COFF image
771 */
efi_check_pe(void * buffer,size_t size,void ** nt_header)772 efi_status_t efi_check_pe(void *buffer, size_t size, void **nt_header)
773 {
774 IMAGE_DOS_HEADER *dos = buffer;
775 IMAGE_NT_HEADERS32 *nt;
776
777 if (size < sizeof(*dos))
778 return EFI_INVALID_PARAMETER;
779
780 /* Check for DOS magix */
781 if (dos->e_magic != IMAGE_DOS_SIGNATURE)
782 return EFI_INVALID_PARAMETER;
783
784 /*
785 * Check if the image section header fits into the file. Knowing that at
786 * least one section header follows we only need to check for the length
787 * of the 64bit header which is longer than the 32bit header.
788 */
789 if (size < dos->e_lfanew + sizeof(IMAGE_NT_HEADERS32))
790 return EFI_INVALID_PARAMETER;
791 nt = (IMAGE_NT_HEADERS32 *)((u8 *)buffer + dos->e_lfanew);
792
793 /* Check for PE-COFF magic */
794 if (nt->Signature != IMAGE_NT_SIGNATURE)
795 return EFI_INVALID_PARAMETER;
796
797 if (nt_header)
798 *nt_header = nt;
799
800 return EFI_SUCCESS;
801 }
802
803 /**
804 * efi_load_pe() - relocate EFI binary
805 *
806 * This function loads all sections from a PE binary into a newly reserved
807 * piece of memory. On success the entry point is returned as handle->entry.
808 *
809 * @handle: loaded image handle
810 * @efi: pointer to the EFI binary
811 * @efi_size: size of @efi binary
812 * @loaded_image_info: loaded image protocol
813 * Return: status code
814 */
efi_load_pe(struct efi_loaded_image_obj * handle,void * efi,size_t efi_size,struct efi_loaded_image * loaded_image_info)815 efi_status_t efi_load_pe(struct efi_loaded_image_obj *handle,
816 void *efi, size_t efi_size,
817 struct efi_loaded_image *loaded_image_info)
818 {
819 IMAGE_NT_HEADERS32 *nt;
820 IMAGE_DOS_HEADER *dos;
821 IMAGE_SECTION_HEADER *sections;
822 int num_sections;
823 void *efi_reloc;
824 int i;
825 const IMAGE_BASE_RELOCATION *rel;
826 unsigned long rel_size;
827 int rel_idx = IMAGE_DIRECTORY_ENTRY_BASERELOC;
828 uint64_t image_base;
829 unsigned long virt_size = 0;
830 int supported = 0;
831 efi_status_t ret;
832
833 ret = efi_check_pe(efi, efi_size, (void **)&nt);
834 if (ret != EFI_SUCCESS) {
835 log_err("Not a PE-COFF file\n");
836 return EFI_LOAD_ERROR;
837 }
838
839 for (i = 0; machines[i]; i++)
840 if (machines[i] == nt->FileHeader.Machine) {
841 supported = 1;
842 break;
843 }
844
845 if (!supported) {
846 log_err("Machine type 0x%04x is not supported\n",
847 nt->FileHeader.Machine);
848 return EFI_LOAD_ERROR;
849 }
850
851 num_sections = nt->FileHeader.NumberOfSections;
852 sections = (void *)&nt->OptionalHeader +
853 nt->FileHeader.SizeOfOptionalHeader;
854
855 if (efi_size < ((void *)sections + sizeof(sections[0]) * num_sections
856 - efi)) {
857 log_err("Invalid number of sections: %d\n", num_sections);
858 return EFI_LOAD_ERROR;
859 }
860
861 /* Authenticate an image */
862 if (efi_image_authenticate(efi, efi_size)) {
863 handle->auth_status = EFI_IMAGE_AUTH_PASSED;
864 } else {
865 handle->auth_status = EFI_IMAGE_AUTH_FAILED;
866 log_err("Image not authenticated\n");
867 }
868
869 /* Calculate upper virtual address boundary */
870 for (i = num_sections - 1; i >= 0; i--) {
871 IMAGE_SECTION_HEADER *sec = §ions[i];
872 virt_size = max_t(unsigned long, virt_size,
873 sec->VirtualAddress + sec->Misc.VirtualSize);
874 }
875
876 /* Read 32/64bit specific header bits */
877 if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR64_MAGIC) {
878 IMAGE_NT_HEADERS64 *nt64 = (void *)nt;
879 IMAGE_OPTIONAL_HEADER64 *opt = &nt64->OptionalHeader;
880 image_base = opt->ImageBase;
881 efi_set_code_and_data_type(loaded_image_info, opt->Subsystem);
882 handle->image_type = opt->Subsystem;
883 efi_reloc = efi_alloc(virt_size,
884 loaded_image_info->image_code_type);
885 if (!efi_reloc) {
886 log_err("Out of memory\n");
887 ret = EFI_OUT_OF_RESOURCES;
888 goto err;
889 }
890 handle->entry = efi_reloc + opt->AddressOfEntryPoint;
891 rel_size = opt->DataDirectory[rel_idx].Size;
892 rel = efi_reloc + opt->DataDirectory[rel_idx].VirtualAddress;
893 virt_size = ALIGN(virt_size, opt->SectionAlignment);
894 } else if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
895 IMAGE_OPTIONAL_HEADER32 *opt = &nt->OptionalHeader;
896 image_base = opt->ImageBase;
897 efi_set_code_and_data_type(loaded_image_info, opt->Subsystem);
898 handle->image_type = opt->Subsystem;
899 efi_reloc = efi_alloc(virt_size,
900 loaded_image_info->image_code_type);
901 if (!efi_reloc) {
902 log_err("Out of memory\n");
903 ret = EFI_OUT_OF_RESOURCES;
904 goto err;
905 }
906 handle->entry = efi_reloc + opt->AddressOfEntryPoint;
907 rel_size = opt->DataDirectory[rel_idx].Size;
908 rel = efi_reloc + opt->DataDirectory[rel_idx].VirtualAddress;
909 virt_size = ALIGN(virt_size, opt->SectionAlignment);
910 } else {
911 log_err("Invalid optional header magic %x\n",
912 nt->OptionalHeader.Magic);
913 ret = EFI_LOAD_ERROR;
914 goto err;
915 }
916
917 #if CONFIG_IS_ENABLED(EFI_TCG2_PROTOCOL)
918 /* Measure an PE/COFF image */
919 if (tcg2_measure_pe_image(efi, efi_size, handle,
920 loaded_image_info))
921 log_err("PE image measurement failed\n");
922 #endif
923
924 /* Copy PE headers */
925 memcpy(efi_reloc, efi,
926 sizeof(*dos)
927 + sizeof(*nt)
928 + nt->FileHeader.SizeOfOptionalHeader
929 + num_sections * sizeof(IMAGE_SECTION_HEADER));
930
931 /* Load sections into RAM */
932 for (i = num_sections - 1; i >= 0; i--) {
933 IMAGE_SECTION_HEADER *sec = §ions[i];
934 memset(efi_reloc + sec->VirtualAddress, 0,
935 sec->Misc.VirtualSize);
936 memcpy(efi_reloc + sec->VirtualAddress,
937 efi + sec->PointerToRawData,
938 min(sec->Misc.VirtualSize, sec->SizeOfRawData));
939 }
940
941 /* Run through relocations */
942 if (efi_loader_relocate(rel, rel_size, efi_reloc,
943 (unsigned long)image_base) != EFI_SUCCESS) {
944 efi_free_pages((uintptr_t) efi_reloc,
945 (virt_size + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT);
946 ret = EFI_LOAD_ERROR;
947 goto err;
948 }
949
950 /* Flush cache */
951 flush_cache((ulong)efi_reloc,
952 ALIGN(virt_size, EFI_CACHELINE_SIZE));
953 invalidate_icache_all();
954
955 /* Populate the loaded image interface bits */
956 loaded_image_info->image_base = efi_reloc;
957 loaded_image_info->image_size = virt_size;
958
959 if (handle->auth_status == EFI_IMAGE_AUTH_PASSED)
960 return EFI_SUCCESS;
961 else
962 return EFI_SECURITY_VIOLATION;
963
964 err:
965 return ret;
966 }
967