]> git.proxmox.com Git - mirror_edk2.git/blob - SecurityPkg/Library/DxeImageVerificationLib/DxeImageVerificationLib.c
projects / mirror_edk2.git / blob
? search:


8cedb1bfb0a3e04ac3944ec4d837a4c9d1abfcc5
[mirror_edk2.git] / SecurityPkg / Library / DxeImageVerificationLib / DxeImageVerificationLib.c
1 /** @file
2 Implement image verification services for secure boot service
3
4 Caution: This file requires additional review when modified.
5 This library will have external input - PE/COFF image.
6 This external input must be validated carefully to avoid security issue like
7 buffer overflow, integer overflow.
8
9 DxeImageVerificationLibImageRead() function will make sure the PE/COFF image content
10 read is within the image buffer.
11
12 DxeImageVerificationHandler(), HashPeImageByType(), HashPeImage() function will accept
13 untrusted PE/COFF image and validate its data structure within this image buffer before use.
14
15 Copyright (c) 2009 - 2016, Intel Corporation. All rights reserved.<BR>
16 This program and the accompanying materials
17 are licensed and made available under the terms and conditions of the BSD License
18 which accompanies this distribution. The full text of the license may be found at
19 http://opensource.org/licenses/bsd-license.php
20
21 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
22 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
23
24 **/
25
26 #include "DxeImageVerificationLib.h"
27
28 //
29 // Caution: This is used by a function which may receive untrusted input.
30 // These global variables hold PE/COFF image data, and they should be validated before use.
31 //
32 EFI_IMAGE_OPTIONAL_HEADER_PTR_UNION mNtHeader;
33 UINT32 mPeCoffHeaderOffset;
34 EFI_GUID mCertType;
35
36 //
37 // Information on current PE/COFF image
38 //
39 UINTN mImageSize;
40 UINT8 *mImageBase = NULL;
41 UINT8 mImageDigest[MAX_DIGEST_SIZE];
42 UINTN mImageDigestSize;
43
44 //
45 // Notify string for authorization UI.
46 //
47 CHAR16 mNotifyString1[MAX_NOTIFY_STRING_LEN] = L"Image verification pass but not found in authorized database!";
48 CHAR16 mNotifyString2[MAX_NOTIFY_STRING_LEN] = L"Launch this image anyway? (Yes/Defer/No)";
49 //
50 // Public Exponent of RSA Key.
51 //
52 CONST UINT8 mRsaE[] = { 0x01, 0x00, 0x01 };
53
54
55 //
56 // OID ASN.1 Value for Hash Algorithms
57 //
58 UINT8 mHashOidValue[] = {
59 0x2B, 0x0E, 0x03, 0x02, 0x1A, // OBJ_sha1
60 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04, // OBJ_sha224
61 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, // OBJ_sha256
62 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02, // OBJ_sha384
63 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03, // OBJ_sha512
64 };
65
66 HASH_TABLE mHash[] = {
67 { L"SHA1", 20, &mHashOidValue[0], 5, Sha1GetContextSize, Sha1Init, Sha1Update, Sha1Final },
68 { L"SHA224", 28, &mHashOidValue[5], 9, NULL, NULL, NULL, NULL },
69 { L"SHA256", 32, &mHashOidValue[14], 9, Sha256GetContextSize, Sha256Init, Sha256Update, Sha256Final},
70 { L"SHA384", 48, &mHashOidValue[23], 9, Sha384GetContextSize, Sha384Init, Sha384Update, Sha384Final},
71 { L"SHA512", 64, &mHashOidValue[32], 9, Sha512GetContextSize, Sha512Init, Sha512Update, Sha512Final}
72 };
73
74 /**
75 SecureBoot Hook for processing image verification.
76
77 @param[in] VariableName Name of Variable to be found.
78 @param[in] VendorGuid Variable vendor GUID.
79 @param[in] DataSize Size of Data found. If size is less than the
80 data, this value contains the required size.
81 @param[in] Data Data pointer.
82
83 **/
84 VOID
85 EFIAPI
86 SecureBootHook (
87 IN CHAR16 *VariableName,
88 IN EFI_GUID *VendorGuid,
89 IN UINTN DataSize,
90 IN VOID *Data
91 );
92
93 /**
94 Reads contents of a PE/COFF image in memory buffer.
95
96 Caution: This function may receive untrusted input.
97 PE/COFF image is external input, so this function will make sure the PE/COFF image content
98 read is within the image buffer.
99
100 @param FileHandle Pointer to the file handle to read the PE/COFF image.
101 @param FileOffset Offset into the PE/COFF image to begin the read operation.
102 @param ReadSize On input, the size in bytes of the requested read operation.
103 On output, the number of bytes actually read.
104 @param Buffer Output buffer that contains the data read from the PE/COFF image.
105
106 @retval EFI_SUCCESS The specified portion of the PE/COFF image was read and the size
107 **/
108 EFI_STATUS
109 EFIAPI
110 DxeImageVerificationLibImageRead (
111 IN VOID *FileHandle,
112 IN UINTN FileOffset,
113 IN OUT UINTN *ReadSize,
114 OUT VOID *Buffer
115 )
116 {
117 UINTN EndPosition;
118
119 if (FileHandle == NULL || ReadSize == NULL || Buffer == NULL) {
120 return EFI_INVALID_PARAMETER;
121 }
122
123 if (MAX_ADDRESS - FileOffset < *ReadSize) {
124 return EFI_INVALID_PARAMETER;
125 }
126
127 EndPosition = FileOffset + *ReadSize;
128 if (EndPosition > mImageSize) {
129 *ReadSize = (UINT32)(mImageSize - FileOffset);
130 }
131
132 if (FileOffset >= mImageSize) {
133 *ReadSize = 0;
134 }
135
136 CopyMem (Buffer, (UINT8 *)((UINTN) FileHandle + FileOffset), *ReadSize);
137
138 return EFI_SUCCESS;
139 }
140
141
142 /**
143 Get the image type.
144
145 @param[in] File This is a pointer to the device path of the file that is
146 being dispatched.
147
148 @return UINT32 Image Type
149
150 **/
151 UINT32
152 GetImageType (
153 IN CONST EFI_DEVICE_PATH_PROTOCOL *File
154 )
155 {
156 EFI_STATUS Status;
157 EFI_HANDLE DeviceHandle;
158 EFI_DEVICE_PATH_PROTOCOL *TempDevicePath;
159 EFI_BLOCK_IO_PROTOCOL *BlockIo;
160
161 if (File == NULL) {
162 return IMAGE_UNKNOWN;
163 }
164
165 //
166 // First check to see if File is from a Firmware Volume
167 //
168 DeviceHandle = NULL;
169 TempDevicePath = (EFI_DEVICE_PATH_PROTOCOL *) File;
170 Status = gBS->LocateDevicePath (
171 &gEfiFirmwareVolume2ProtocolGuid,
172 &TempDevicePath,
173 &DeviceHandle
174 );
175 if (!EFI_ERROR (Status)) {
176 Status = gBS->OpenProtocol (
177 DeviceHandle,
178 &gEfiFirmwareVolume2ProtocolGuid,
179 NULL,
180 NULL,
181 NULL,
182 EFI_OPEN_PROTOCOL_TEST_PROTOCOL
183 );
184 if (!EFI_ERROR (Status)) {
185 return IMAGE_FROM_FV;
186 }
187 }
188
189 //
190 // Next check to see if File is from a Block I/O device
191 //
192 DeviceHandle = NULL;
193 TempDevicePath = (EFI_DEVICE_PATH_PROTOCOL *) File;
194 Status = gBS->LocateDevicePath (
195 &gEfiBlockIoProtocolGuid,
196 &TempDevicePath,
197 &DeviceHandle
198 );
199 if (!EFI_ERROR (Status)) {
200 BlockIo = NULL;
201 Status = gBS->OpenProtocol (
202 DeviceHandle,
203 &gEfiBlockIoProtocolGuid,
204 (VOID **) &BlockIo,
205 NULL,
206 NULL,
207 EFI_OPEN_PROTOCOL_GET_PROTOCOL
208 );
209 if (!EFI_ERROR (Status) && BlockIo != NULL) {
210 if (BlockIo->Media != NULL) {
211 if (BlockIo->Media->RemovableMedia) {
212 //
213 // Block I/O is present and specifies the media is removable
214 //
215 return IMAGE_FROM_REMOVABLE_MEDIA;
216 } else {
217 //
218 // Block I/O is present and specifies the media is not removable
219 //
220 return IMAGE_FROM_FIXED_MEDIA;
221 }
222 }
223 }
224 }
225
226 //
227 // File is not in a Firmware Volume or on a Block I/O device, so check to see if
228 // the device path supports the Simple File System Protocol.
229 //
230 DeviceHandle = NULL;
231 TempDevicePath = (EFI_DEVICE_PATH_PROTOCOL *) File;
232 Status = gBS->LocateDevicePath (
233 &gEfiSimpleFileSystemProtocolGuid,
234 &TempDevicePath,
235 &DeviceHandle
236 );
237 if (!EFI_ERROR (Status)) {
238 //
239 // Simple File System is present without Block I/O, so assume media is fixed.
240 //
241 return IMAGE_FROM_FIXED_MEDIA;
242 }
243
244 //
245 // File is not from an FV, Block I/O or Simple File System, so the only options
246 // left are a PCI Option ROM and a Load File Protocol such as a PXE Boot from a NIC.
247 //
248 TempDevicePath = (EFI_DEVICE_PATH_PROTOCOL *) File;
249 while (!IsDevicePathEndType (TempDevicePath)) {
250 switch (DevicePathType (TempDevicePath)) {
251
252 case MEDIA_DEVICE_PATH:
253 if (DevicePathSubType (TempDevicePath) == MEDIA_RELATIVE_OFFSET_RANGE_DP) {
254 return IMAGE_FROM_OPTION_ROM;
255 }
256 break;
257
258 case MESSAGING_DEVICE_PATH:
259 if (DevicePathSubType(TempDevicePath) == MSG_MAC_ADDR_DP) {
260 return IMAGE_FROM_REMOVABLE_MEDIA;
261 }
262 break;
263
264 default:
265 break;
266 }
267 TempDevicePath = NextDevicePathNode (TempDevicePath);
268 }
269 return IMAGE_UNKNOWN;
270 }
271
272 /**
273 Calculate hash of Pe/Coff image based on the authenticode image hashing in
274 PE/COFF Specification 8.0 Appendix A
275
276 Caution: This function may receive untrusted input.
277 PE/COFF image is external input, so this function will validate its data structure
278 within this image buffer before use.
279
280 @param[in] HashAlg Hash algorithm type.
281
282 @retval TRUE Successfully hash image.
283 @retval FALSE Fail in hash image.
284
285 **/
286 BOOLEAN
287 HashPeImage (
288 IN UINT32 HashAlg
289 )
290 {
291 BOOLEAN Status;
292 UINT16 Magic;
293 EFI_IMAGE_SECTION_HEADER *Section;
294 VOID *HashCtx;
295 UINTN CtxSize;
296 UINT8 *HashBase;
297 UINTN HashSize;
298 UINTN SumOfBytesHashed;
299 EFI_IMAGE_SECTION_HEADER *SectionHeader;
300 UINTN Index;
301 UINTN Pos;
302 UINT32 CertSize;
303 UINT32 NumberOfRvaAndSizes;
304
305 HashCtx = NULL;
306 SectionHeader = NULL;
307 Status = FALSE;
308
309 if ((HashAlg >= HASHALG_MAX)) {
310 return FALSE;
311 }
312
313 //
314 // Initialize context of hash.
315 //
316 ZeroMem (mImageDigest, MAX_DIGEST_SIZE);
317
318 switch (HashAlg) {
319 case HASHALG_SHA1:
320 mImageDigestSize = SHA1_DIGEST_SIZE;
321 mCertType = gEfiCertSha1Guid;
322 break;
323
324 case HASHALG_SHA256:
325 mImageDigestSize = SHA256_DIGEST_SIZE;
326 mCertType = gEfiCertSha256Guid;
327 break;
328
329 case HASHALG_SHA384:
330 mImageDigestSize = SHA384_DIGEST_SIZE;
331 mCertType = gEfiCertSha384Guid;
332 break;
333
334 case HASHALG_SHA512:
335 mImageDigestSize = SHA512_DIGEST_SIZE;
336 mCertType = gEfiCertSha512Guid;
337 break;
338
339 default:
340 return FALSE;
341 }
342
343 CtxSize = mHash[HashAlg].GetContextSize();
344
345 HashCtx = AllocatePool (CtxSize);
346 if (HashCtx == NULL) {
347 return FALSE;
348 }
349
350 // 1. Load the image header into memory.
351
352 // 2. Initialize a SHA hash context.
353 Status = mHash[HashAlg].HashInit(HashCtx);
354
355 if (!Status) {
356 goto Done;
357 }
358
359 //
360 // Measuring PE/COFF Image Header;
361 // But CheckSum field and SECURITY data directory (certificate) are excluded
362 //
363 if (mNtHeader.Pe32->FileHeader.Machine == IMAGE_FILE_MACHINE_IA64 && mNtHeader.Pe32->OptionalHeader.Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
364 //
365 // NOTE: Some versions of Linux ELILO for Itanium have an incorrect magic value
366 // in the PE/COFF Header. If the MachineType is Itanium(IA64) and the
367 // Magic value in the OptionalHeader is EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC
368 // then override the magic value to EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC
369 //
370 Magic = EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC;
371 } else {
372 //
373 // Get the magic value from the PE/COFF Optional Header
374 //
375 Magic = mNtHeader.Pe32->OptionalHeader.Magic;
376 }
377
378 //
379 // 3. Calculate the distance from the base of the image header to the image checksum address.
380 // 4. Hash the image header from its base to beginning of the image checksum.
381 //
382 HashBase = mImageBase;
383 if (Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
384 //
385 // Use PE32 offset.
386 //
387 HashSize = (UINTN) ((UINT8 *) (&mNtHeader.Pe32->OptionalHeader.CheckSum) - HashBase);
388 NumberOfRvaAndSizes = mNtHeader.Pe32->OptionalHeader.NumberOfRvaAndSizes;
389 } else if (Magic == EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC) {
390 //
391 // Use PE32+ offset.
392 //
393 HashSize = (UINTN) ((UINT8 *) (&mNtHeader.Pe32Plus->OptionalHeader.CheckSum) - HashBase);
394 NumberOfRvaAndSizes = mNtHeader.Pe32Plus->OptionalHeader.NumberOfRvaAndSizes;
395 } else {
396 //
397 // Invalid header magic number.
398 //
399 Status = FALSE;
400 goto Done;
401 }
402
403 Status = mHash[HashAlg].HashUpdate(HashCtx, HashBase, HashSize);
404 if (!Status) {
405 goto Done;
406 }
407
408 //
409 // 5. Skip over the image checksum (it occupies a single ULONG).
410 //
411 if (NumberOfRvaAndSizes <= EFI_IMAGE_DIRECTORY_ENTRY_SECURITY) {
412 //
413 // 6. Since there is no Cert Directory in optional header, hash everything
414 // from the end of the checksum to the end of image header.
415 //
416 if (Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
417 //
418 // Use PE32 offset.
419 //
420 HashBase = (UINT8 *) &mNtHeader.Pe32->OptionalHeader.CheckSum + sizeof (UINT32);
421 HashSize = mNtHeader.Pe32->OptionalHeader.SizeOfHeaders - (UINTN) (HashBase - mImageBase);
422 } else {
423 //
424 // Use PE32+ offset.
425 //
426 HashBase = (UINT8 *) &mNtHeader.Pe32Plus->OptionalHeader.CheckSum + sizeof (UINT32);
427 HashSize = mNtHeader.Pe32Plus->OptionalHeader.SizeOfHeaders - (UINTN) (HashBase - mImageBase);
428 }
429
430 if (HashSize != 0) {
431 Status = mHash[HashAlg].HashUpdate(HashCtx, HashBase, HashSize);
432 if (!Status) {
433 goto Done;
434 }
435 }
436 } else {
437 //
438 // 7. Hash everything from the end of the checksum to the start of the Cert Directory.
439 //
440 if (Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
441 //
442 // Use PE32 offset.
443 //
444 HashBase = (UINT8 *) &mNtHeader.Pe32->OptionalHeader.CheckSum + sizeof (UINT32);
445 HashSize = (UINTN) ((UINT8 *) (&mNtHeader.Pe32->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY]) - HashBase);
446 } else {
447 //
448 // Use PE32+ offset.
449 //
450 HashBase = (UINT8 *) &mNtHeader.Pe32Plus->OptionalHeader.CheckSum + sizeof (UINT32);
451 HashSize = (UINTN) ((UINT8 *) (&mNtHeader.Pe32Plus->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY]) - HashBase);
452 }
453
454 if (HashSize != 0) {
455 Status = mHash[HashAlg].HashUpdate(HashCtx, HashBase, HashSize);
456 if (!Status) {
457 goto Done;
458 }
459 }
460
461 //
462 // 8. Skip over the Cert Directory. (It is sizeof(IMAGE_DATA_DIRECTORY) bytes.)
463 // 9. Hash everything from the end of the Cert Directory to the end of image header.
464 //
465 if (Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
466 //
467 // Use PE32 offset
468 //
469 HashBase = (UINT8 *) &mNtHeader.Pe32->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY + 1];
470 HashSize = mNtHeader.Pe32->OptionalHeader.SizeOfHeaders - (UINTN) (HashBase - mImageBase);
471 } else {
472 //
473 // Use PE32+ offset.
474 //
475 HashBase = (UINT8 *) &mNtHeader.Pe32Plus->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY + 1];
476 HashSize = mNtHeader.Pe32Plus->OptionalHeader.SizeOfHeaders - (UINTN) (HashBase - mImageBase);
477 }
478
479 if (HashSize != 0) {
480 Status = mHash[HashAlg].HashUpdate(HashCtx, HashBase, HashSize);
481 if (!Status) {
482 goto Done;
483 }
484 }
485 }
486
487 //
488 // 10. Set the SUM_OF_BYTES_HASHED to the size of the header.
489 //
490 if (Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
491 //
492 // Use PE32 offset.
493 //
494 SumOfBytesHashed = mNtHeader.Pe32->OptionalHeader.SizeOfHeaders;
495 } else {
496 //
497 // Use PE32+ offset
498 //
499 SumOfBytesHashed = mNtHeader.Pe32Plus->OptionalHeader.SizeOfHeaders;
500 }
501
502
503 Section = (EFI_IMAGE_SECTION_HEADER *) (
504 mImageBase +
505 mPeCoffHeaderOffset +
506 sizeof (UINT32) +
507 sizeof (EFI_IMAGE_FILE_HEADER) +
508 mNtHeader.Pe32->FileHeader.SizeOfOptionalHeader
509 );
510
511 //
512 // 11. Build a temporary table of pointers to all the IMAGE_SECTION_HEADER
513 // structures in the image. The 'NumberOfSections' field of the image
514 // header indicates how big the table should be. Do not include any
515 // IMAGE_SECTION_HEADERs in the table whose 'SizeOfRawData' field is zero.
516 //
517 SectionHeader = (EFI_IMAGE_SECTION_HEADER *) AllocateZeroPool (sizeof (EFI_IMAGE_SECTION_HEADER) * mNtHeader.Pe32->FileHeader.NumberOfSections);
518 if (SectionHeader == NULL) {
519 Status = FALSE;
520 goto Done;
521 }
522 //
523 // 12. Using the 'PointerToRawData' in the referenced section headers as
524 // a key, arrange the elements in the table in ascending order. In other
525 // words, sort the section headers according to the disk-file offset of
526 // the section.
527 //
528 for (Index = 0; Index < mNtHeader.Pe32->FileHeader.NumberOfSections; Index++) {
529 Pos = Index;
530 while ((Pos > 0) && (Section->PointerToRawData < SectionHeader[Pos - 1].PointerToRawData)) {
531 CopyMem (&SectionHeader[Pos], &SectionHeader[Pos - 1], sizeof (EFI_IMAGE_SECTION_HEADER));
532 Pos--;
533 }
534 CopyMem (&SectionHeader[Pos], Section, sizeof (EFI_IMAGE_SECTION_HEADER));
535 Section += 1;
536 }
537
538 //
539 // 13. Walk through the sorted table, bring the corresponding section
540 // into memory, and hash the entire section (using the 'SizeOfRawData'
541 // field in the section header to determine the amount of data to hash).
542 // 14. Add the section's 'SizeOfRawData' to SUM_OF_BYTES_HASHED .
543 // 15. Repeat steps 13 and 14 for all the sections in the sorted table.
544 //
545 for (Index = 0; Index < mNtHeader.Pe32->FileHeader.NumberOfSections; Index++) {
546 Section = &SectionHeader[Index];
547 if (Section->SizeOfRawData == 0) {
548 continue;
549 }
550 HashBase = mImageBase + Section->PointerToRawData;
551 HashSize = (UINTN) Section->SizeOfRawData;
552
553 Status = mHash[HashAlg].HashUpdate(HashCtx, HashBase, HashSize);
554 if (!Status) {
555 goto Done;
556 }
557
558 SumOfBytesHashed += HashSize;
559 }
560
561 //
562 // 16. If the file size is greater than SUM_OF_BYTES_HASHED, there is extra
563 // data in the file that needs to be added to the hash. This data begins
564 // at file offset SUM_OF_BYTES_HASHED and its length is:
565 // FileSize - (CertDirectory->Size)
566 //
567 if (mImageSize > SumOfBytesHashed) {
568 HashBase = mImageBase + SumOfBytesHashed;
569
570 if (NumberOfRvaAndSizes <= EFI_IMAGE_DIRECTORY_ENTRY_SECURITY) {
571 CertSize = 0;
572 } else {
573 if (Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
574 //
575 // Use PE32 offset.
576 //
577 CertSize = mNtHeader.Pe32->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY].Size;
578 } else {
579 //
580 // Use PE32+ offset.
581 //
582 CertSize = mNtHeader.Pe32Plus->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY].Size;
583 }
584 }
585
586 if (mImageSize > CertSize + SumOfBytesHashed) {
587 HashSize = (UINTN) (mImageSize - CertSize - SumOfBytesHashed);
588
589 Status = mHash[HashAlg].HashUpdate(HashCtx, HashBase, HashSize);
590 if (!Status) {
591 goto Done;
592 }
593 } else if (mImageSize < CertSize + SumOfBytesHashed) {
594 Status = FALSE;
595 goto Done;
596 }
597 }
598
599 Status = mHash[HashAlg].HashFinal(HashCtx, mImageDigest);
600
601 Done:
602 if (HashCtx != NULL) {
603 FreePool (HashCtx);
604 }
605 if (SectionHeader != NULL) {
606 FreePool (SectionHeader);
607 }
608 return Status;
609 }
610
611 /**
612 Recognize the Hash algorithm in PE/COFF Authenticode and calculate hash of
613 Pe/Coff image based on the authenticode image hashing in PE/COFF Specification
614 8.0 Appendix A
615
616 Caution: This function may receive untrusted input.
617 PE/COFF image is external input, so this function will validate its data structure
618 within this image buffer before use.
619
620 @param[in] AuthData Pointer to the Authenticode Signature retrieved from signed image.
621 @param[in] AuthDataSize Size of the Authenticode Signature in bytes.
622
623 @retval EFI_UNSUPPORTED Hash algorithm is not supported.
624 @retval EFI_SUCCESS Hash successfully.
625
626 **/
627 EFI_STATUS
628 HashPeImageByType (
629 IN UINT8 *AuthData,
630 IN UINTN AuthDataSize
631 )
632 {
633 UINT8 Index;
634
635 for (Index = 0; Index < HASHALG_MAX; Index++) {
636 //
637 // Check the Hash algorithm in PE/COFF Authenticode.
638 // According to PKCS#7 Definition:
639 // SignedData ::= SEQUENCE {
640 // version Version,
641 // digestAlgorithms DigestAlgorithmIdentifiers,
642 // contentInfo ContentInfo,
643 // .... }
644 // The DigestAlgorithmIdentifiers can be used to determine the hash algorithm in PE/COFF hashing
645 // This field has the fixed offset (+32) in final Authenticode ASN.1 data.
646 // Fixed offset (+32) is calculated based on two bytes of length encoding.
647 //
648 if ((*(AuthData + 1) & TWO_BYTE_ENCODE) != TWO_BYTE_ENCODE) {
649 //
650 // Only support two bytes of Long Form of Length Encoding.
651 //
652 continue;
653 }
654
655 if (AuthDataSize < 32 + mHash[Index].OidLength) {
656 return EFI_UNSUPPORTED;
657 }
658
659 if (CompareMem (AuthData + 32, mHash[Index].OidValue, mHash[Index].OidLength) == 0) {
660 break;
661 }
662 }
663
664 if (Index == HASHALG_MAX) {
665 return EFI_UNSUPPORTED;
666 }
667
668 //
669 // HASH PE Image based on Hash algorithm in PE/COFF Authenticode.
670 //
671 if (!HashPeImage(Index)) {
672 return EFI_UNSUPPORTED;
673 }
674
675 return EFI_SUCCESS;
676 }
677
678
679 /**
680 Returns the size of a given image execution info table in bytes.
681
682 This function returns the size, in bytes, of the image execution info table specified by
683 ImageExeInfoTable. If ImageExeInfoTable is NULL, then 0 is returned.
684
685 @param ImageExeInfoTable A pointer to a image execution info table structure.
686
687 @retval 0 If ImageExeInfoTable is NULL.
688 @retval Others The size of a image execution info table in bytes.
689
690 **/
691 UINTN
692 GetImageExeInfoTableSize (
693 EFI_IMAGE_EXECUTION_INFO_TABLE *ImageExeInfoTable
694 )
695 {
696 UINTN Index;
697 EFI_IMAGE_EXECUTION_INFO *ImageExeInfoItem;
698 UINTN TotalSize;
699
700 if (ImageExeInfoTable == NULL) {
701 return 0;
702 }
703
704 ImageExeInfoItem = (EFI_IMAGE_EXECUTION_INFO *) ((UINT8 *) ImageExeInfoTable + sizeof (EFI_IMAGE_EXECUTION_INFO_TABLE));
705 TotalSize = sizeof (EFI_IMAGE_EXECUTION_INFO_TABLE);
706 for (Index = 0; Index < ImageExeInfoTable->NumberOfImages; Index++) {
707 TotalSize += ReadUnaligned32 ((UINT32 *) &ImageExeInfoItem->InfoSize);
708 ImageExeInfoItem = (EFI_IMAGE_EXECUTION_INFO *) ((UINT8 *) ImageExeInfoItem + ReadUnaligned32 ((UINT32 *) &ImageExeInfoItem->InfoSize));
709 }
710
711 return TotalSize;
712 }
713
714 /**
715 Create signature list based on input signature data and certificate type GUID. Caller is reposible
716 to free new created SignatureList.
717
718 @param[in] SignatureData Signature data in SignatureList.
719 @param[in] SignatureDataSize Signature data size.
720 @param[in] CertType Certificate Type.
721 @param[out] SignatureList Created SignatureList.
722 @param[out] SignatureListSize Created SignatureListSize.
723
724 @return EFI_OUT_OF_RESOURCES The operation is failed due to lack of resources.
725 @retval EFI_SUCCESS Successfully create signature list.
726
727 **/
728 EFI_STATUS
729 CreateSignatureList(
730 IN UINT8 *SignatureData,
731 IN UINTN SignatureDataSize,
732 IN EFI_GUID *CertType,
733 OUT EFI_SIGNATURE_LIST **SignatureList,
734 OUT UINTN *SignatureListSize
735 )
736 {
737 EFI_SIGNATURE_LIST *SignList;
738 UINTN SignListSize;
739 EFI_SIGNATURE_DATA *Signature;
740
741 SignList = NULL;
742 *SignatureList = NULL;
743
744 SignListSize = sizeof (EFI_SIGNATURE_LIST) + sizeof (EFI_SIGNATURE_DATA) - 1 + SignatureDataSize;
745 SignList = (EFI_SIGNATURE_LIST *) AllocateZeroPool (SignListSize);
746 if (SignList == NULL) {
747 return EFI_OUT_OF_RESOURCES;
748 }
749
750 SignList->SignatureHeaderSize = 0;
751 SignList->SignatureListSize = (UINT32) SignListSize;
752 SignList->SignatureSize = (UINT32) SignatureDataSize + sizeof (EFI_SIGNATURE_DATA) - 1;
753 CopyMem (&SignList->SignatureType, CertType, sizeof (EFI_GUID));
754
755 DEBUG((EFI_D_INFO, "SignatureDataSize %x\n", SignatureDataSize));
756 Signature = (EFI_SIGNATURE_DATA *) ((UINT8 *) SignList + sizeof (EFI_SIGNATURE_LIST));
757 CopyMem (Signature->SignatureData, SignatureData, SignatureDataSize);
758
759 *SignatureList = SignList;
760 *SignatureListSize = SignListSize;
761
762 return EFI_SUCCESS;
763
764 }
765
766 /**
767 Create an Image Execution Information Table entry and add it to system configuration table.
768
769 @param[in] Action Describes the action taken by the firmware regarding this image.
770 @param[in] Name Input a null-terminated, user-friendly name.
771 @param[in] DevicePath Input device path pointer.
772 @param[in] Signature Input signature info in EFI_SIGNATURE_LIST data structure.
773 @param[in] SignatureSize Size of signature.
774
775 **/
776 VOID
777 AddImageExeInfo (
778 IN EFI_IMAGE_EXECUTION_ACTION Action,
779 IN CHAR16 *Name OPTIONAL,
780 IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath,
781 IN EFI_SIGNATURE_LIST *Signature OPTIONAL,
782 IN UINTN SignatureSize
783 )
784 {
785 EFI_IMAGE_EXECUTION_INFO_TABLE *ImageExeInfoTable;
786 EFI_IMAGE_EXECUTION_INFO_TABLE *NewImageExeInfoTable;
787 EFI_IMAGE_EXECUTION_INFO *ImageExeInfoEntry;
788 UINTN ImageExeInfoTableSize;
789 UINTN NewImageExeInfoEntrySize;
790 UINTN NameStringLen;
791 UINTN DevicePathSize;
792 CHAR16 *NameStr;
793
794 ImageExeInfoTable = NULL;
795 NewImageExeInfoTable = NULL;
796 ImageExeInfoEntry = NULL;
797 NameStringLen = 0;
798 NameStr = NULL;
799
800 if (DevicePath == NULL) {
801 return ;
802 }
803
804 if (Name != NULL) {
805 NameStringLen = StrSize (Name);
806 } else {
807 NameStringLen = sizeof (CHAR16);
808 }
809
810 EfiGetSystemConfigurationTable (&gEfiImageSecurityDatabaseGuid, (VOID **) &ImageExeInfoTable);
811 if (ImageExeInfoTable != NULL) {
812 //
813 // The table has been found!
814 // We must enlarge the table to accomodate the new exe info entry.
815 //
816 ImageExeInfoTableSize = GetImageExeInfoTableSize (ImageExeInfoTable);
817 } else {
818 //
819 // Not Found!
820 // We should create a new table to append to the configuration table.
821 //
822 ImageExeInfoTableSize = sizeof (EFI_IMAGE_EXECUTION_INFO_TABLE);
823 }
824
825 DevicePathSize = GetDevicePathSize (DevicePath);
826
827 //
828 // Signature size can be odd. Pad after signature to ensure next EXECUTION_INFO entry align
829 //
830 NewImageExeInfoEntrySize = sizeof (EFI_IMAGE_EXECUTION_INFO) + NameStringLen + DevicePathSize + SignatureSize;
831
832 NewImageExeInfoTable = (EFI_IMAGE_EXECUTION_INFO_TABLE *) AllocateRuntimePool (ImageExeInfoTableSize + NewImageExeInfoEntrySize);
833 if (NewImageExeInfoTable == NULL) {
834 return ;
835 }
836
837 if (ImageExeInfoTable != NULL) {
838 CopyMem (NewImageExeInfoTable, ImageExeInfoTable, ImageExeInfoTableSize);
839 } else {
840 NewImageExeInfoTable->NumberOfImages = 0;
841 }
842 NewImageExeInfoTable->NumberOfImages++;
843 ImageExeInfoEntry = (EFI_IMAGE_EXECUTION_INFO *) ((UINT8 *) NewImageExeInfoTable + ImageExeInfoTableSize);
844 //
845 // Update new item's information.
846 //
847 WriteUnaligned32 ((UINT32 *) ImageExeInfoEntry, Action);
848 WriteUnaligned32 ((UINT32 *) ((UINT8 *) ImageExeInfoEntry + sizeof (EFI_IMAGE_EXECUTION_ACTION)), (UINT32) NewImageExeInfoEntrySize);
849
850 NameStr = (CHAR16 *)(ImageExeInfoEntry + 1);
851 if (Name != NULL) {
852 CopyMem ((UINT8 *) NameStr, Name, NameStringLen);
853 } else {
854 ZeroMem ((UINT8 *) NameStr, sizeof (CHAR16));
855 }
856
857 CopyMem (
858 (UINT8 *) NameStr + NameStringLen,
859 DevicePath,
860 DevicePathSize
861 );
862 if (Signature != NULL) {
863 CopyMem (
864 (UINT8 *) NameStr + NameStringLen + DevicePathSize,
865 Signature,
866 SignatureSize
867 );
868 }
869 //
870 // Update/replace the image execution table.
871 //
872 gBS->InstallConfigurationTable (&gEfiImageSecurityDatabaseGuid, (VOID *) NewImageExeInfoTable);
873
874 //
875 // Free Old table data!
876 //
877 if (ImageExeInfoTable != NULL) {
878 FreePool (ImageExeInfoTable);
879 }
880 }
881
882 /**
883 Check whether the hash of an given X.509 certificate is in forbidden database (DBX).
884
885 @param[in] Certificate Pointer to X.509 Certificate that is searched for.
886 @param[in] CertSize Size of X.509 Certificate.
887 @param[in] SignatureList Pointer to the Signature List in forbidden database.
888 @param[in] SignatureListSize Size of Signature List.
889 @param[out] RevocationTime Return the time that the certificate was revoked.
890
891 @return TRUE The certificate hash is found in the forbidden database.
892 @return FALSE The certificate hash is not found in the forbidden database.
893
894 **/
895 BOOLEAN
896 IsCertHashFoundInDatabase (
897 IN UINT8 *Certificate,
898 IN UINTN CertSize,
899 IN EFI_SIGNATURE_LIST *SignatureList,
900 IN UINTN SignatureListSize,
901 OUT EFI_TIME *RevocationTime
902 )
903 {
904 BOOLEAN IsFound;
905 BOOLEAN Status;
906 EFI_SIGNATURE_LIST *DbxList;
907 UINTN DbxSize;
908 EFI_SIGNATURE_DATA *CertHash;
909 UINTN CertHashCount;
910 UINTN Index;
911 UINT32 HashAlg;
912 VOID *HashCtx;
913 UINT8 CertDigest[MAX_DIGEST_SIZE];
914 UINT8 *DbxCertHash;
915 UINTN SiglistHeaderSize;
916 UINT8 *TBSCert;
917 UINTN TBSCertSize;
918
919 IsFound = FALSE;
920 DbxList = SignatureList;
921 DbxSize = SignatureListSize;
922 HashCtx = NULL;
923 HashAlg = HASHALG_MAX;
924
925 if ((RevocationTime == NULL) || (DbxList == NULL)) {
926 return FALSE;
927 }
928
929 //
930 // Retrieve the TBSCertificate from the X.509 Certificate.
931 //
932 if (!X509GetTBSCert (Certificate, CertSize, &TBSCert, &TBSCertSize)) {
933 return FALSE;
934 }
935
936 while ((DbxSize > 0) && (SignatureListSize >= DbxList->SignatureListSize)) {
937 //
938 // Determine Hash Algorithm of Certificate in the forbidden database.
939 //
940 if (CompareGuid (&DbxList->SignatureType, &gEfiCertX509Sha256Guid)) {
941 HashAlg = HASHALG_SHA256;
942 } else if (CompareGuid (&DbxList->SignatureType, &gEfiCertX509Sha384Guid)) {
943 HashAlg = HASHALG_SHA384;
944 } else if (CompareGuid (&DbxList->SignatureType, &gEfiCertX509Sha512Guid)) {
945 HashAlg = HASHALG_SHA512;
946 } else {
947 DbxSize -= DbxList->SignatureListSize;
948 DbxList = (EFI_SIGNATURE_LIST *) ((UINT8 *) DbxList + DbxList->SignatureListSize);
949 continue;
950 }
951
952 //
953 // Calculate the hash value of current TBSCertificate for comparision.
954 //
955 if (mHash[HashAlg].GetContextSize == NULL) {
956 goto Done;
957 }
958 ZeroMem (CertDigest, MAX_DIGEST_SIZE);
959 HashCtx = AllocatePool (mHash[HashAlg].GetContextSize ());
960 if (HashCtx == NULL) {
961 goto Done;
962 }
963 Status = mHash[HashAlg].HashInit (HashCtx);
964 if (!Status) {
965 goto Done;
966 }
967 Status = mHash[HashAlg].HashUpdate (HashCtx, TBSCert, TBSCertSize);
968 if (!Status) {
969 goto Done;
970 }
971 Status = mHash[HashAlg].HashFinal (HashCtx, CertDigest);
972 if (!Status) {
973 goto Done;
974 }
975
976 SiglistHeaderSize = sizeof (EFI_SIGNATURE_LIST) + DbxList->SignatureHeaderSize;
977 CertHash = (EFI_SIGNATURE_DATA *) ((UINT8 *) DbxList + SiglistHeaderSize);
978 CertHashCount = (DbxList->SignatureListSize - SiglistHeaderSize) / DbxList->SignatureSize;
979 for (Index = 0; Index < CertHashCount; Index++) {
980 //
981 // Iterate each Signature Data Node within this CertList for verify.
982 //
983 DbxCertHash = CertHash->SignatureData;
984 if (CompareMem (DbxCertHash, CertDigest, mHash[HashAlg].DigestLength) == 0) {
985 //
986 // Hash of Certificate is found in forbidden database.
987 //
988 IsFound = TRUE;
989
990 //
991 // Return the revocation time.
992 //
993 CopyMem (RevocationTime, (EFI_TIME *)(DbxCertHash + mHash[HashAlg].DigestLength), sizeof (EFI_TIME));
994 goto Done;
995 }
996 CertHash = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertHash + DbxList->SignatureSize);
997 }
998
999 DbxSize -= DbxList->SignatureListSize;
1000 DbxList = (EFI_SIGNATURE_LIST *) ((UINT8 *) DbxList + DbxList->SignatureListSize);
1001 }
1002
1003 Done:
1004 if (HashCtx != NULL) {
1005 FreePool (HashCtx);
1006 }
1007
1008 return IsFound;
1009 }
1010
1011 /**
1012 Check whether signature is in specified database.
1013
1014 @param[in] VariableName Name of database variable that is searched in.
1015 @param[in] Signature Pointer to signature that is searched for.
1016 @param[in] CertType Pointer to hash algrithom.
1017 @param[in] SignatureSize Size of Signature.
1018
1019 @return TRUE Found the signature in the variable database.
1020 @return FALSE Not found the signature in the variable database.
1021
1022 **/
1023 BOOLEAN
1024 IsSignatureFoundInDatabase (
1025 IN CHAR16 *VariableName,
1026 IN UINT8 *Signature,
1027 IN EFI_GUID *CertType,
1028 IN UINTN SignatureSize
1029 )
1030 {
1031 EFI_STATUS Status;
1032 EFI_SIGNATURE_LIST *CertList;
1033 EFI_SIGNATURE_DATA *Cert;
1034 UINTN DataSize;
1035 UINT8 *Data;
1036 UINTN Index;
1037 UINTN CertCount;
1038 BOOLEAN IsFound;
1039
1040 //
1041 // Read signature database variable.
1042 //
1043 IsFound = FALSE;
1044 Data = NULL;
1045 DataSize = 0;
1046 Status = gRT->GetVariable (VariableName, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, NULL);
1047 if (Status != EFI_BUFFER_TOO_SMALL) {
1048 return FALSE;
1049 }
1050
1051 Data = (UINT8 *) AllocateZeroPool (DataSize);
1052 if (Data == NULL) {
1053 return FALSE;
1054 }
1055
1056 Status = gRT->GetVariable (VariableName, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, Data);
1057 if (EFI_ERROR (Status)) {
1058 goto Done;
1059 }
1060 //
1061 // Enumerate all signature data in SigDB to check if executable's signature exists.
1062 //
1063 CertList = (EFI_SIGNATURE_LIST *) Data;
1064 while ((DataSize > 0) && (DataSize >= CertList->SignatureListSize)) {
1065 CertCount = (CertList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - CertList->SignatureHeaderSize) / CertList->SignatureSize;
1066 Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertList + sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize);
1067 if ((CertList->SignatureSize == sizeof(EFI_SIGNATURE_DATA) - 1 + SignatureSize) && (CompareGuid(&CertList->SignatureType, CertType))) {
1068 for (Index = 0; Index < CertCount; Index++) {
1069 if (CompareMem (Cert->SignatureData, Signature, SignatureSize) == 0) {
1070 //
1071 // Find the signature in database.
1072 //
1073 IsFound = TRUE;
1074 SecureBootHook (VariableName, &gEfiImageSecurityDatabaseGuid, CertList->SignatureSize, Cert);
1075 break;
1076 }
1077
1078 Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) Cert + CertList->SignatureSize);
1079 }
1080
1081 if (IsFound) {
1082 break;
1083 }
1084 }
1085
1086 DataSize -= CertList->SignatureListSize;
1087 CertList = (EFI_SIGNATURE_LIST *) ((UINT8 *) CertList + CertList->SignatureListSize);
1088 }
1089
1090 Done:
1091 if (Data != NULL) {
1092 FreePool (Data);
1093 }
1094
1095 return IsFound;
1096 }
1097
1098 /**
1099 Check whether the timestamp is valid by comparing the signing time and the revocation time.
1100
1101 @param SigningTime A pointer to the signing time.
1102 @param RevocationTime A pointer to the revocation time.
1103
1104 @retval TRUE The SigningTime is not later than the RevocationTime.
1105 @retval FALSE The SigningTime is later than the RevocationTime.
1106
1107 **/
1108 BOOLEAN
1109 IsValidSignatureByTimestamp (
1110 IN EFI_TIME *SigningTime,
1111 IN EFI_TIME *RevocationTime
1112 )
1113 {
1114 if (SigningTime->Year != RevocationTime->Year) {
1115 return (BOOLEAN) (SigningTime->Year < RevocationTime->Year);
1116 } else if (SigningTime->Month != RevocationTime->Month) {
1117 return (BOOLEAN) (SigningTime->Month < RevocationTime->Month);
1118 } else if (SigningTime->Day != RevocationTime->Day) {
1119 return (BOOLEAN) (SigningTime->Day < RevocationTime->Day);
1120 } else if (SigningTime->Hour != RevocationTime->Hour) {
1121 return (BOOLEAN) (SigningTime->Hour < RevocationTime->Hour);
1122 } else if (SigningTime->Minute != RevocationTime->Minute) {
1123 return (BOOLEAN) (SigningTime->Minute < RevocationTime->Minute);
1124 }
1125
1126 return (BOOLEAN) (SigningTime->Second <= RevocationTime->Second);
1127 }
1128
1129 /**
1130 Check if the given time value is zero.
1131
1132 @param[in] Time Pointer of a time value.
1133
1134 @retval TRUE The Time is Zero.
1135 @retval FALSE The Time is not Zero.
1136
1137 **/
1138 BOOLEAN
1139 IsTimeZero (
1140 IN EFI_TIME *Time
1141 )
1142 {
1143 if ((Time->Year == 0) && (Time->Month == 0) && (Time->Day == 0) &&
1144 (Time->Hour == 0) && (Time->Minute == 0) && (Time->Second == 0)) {
1145 return TRUE;
1146 }
1147
1148 return FALSE;
1149 }
1150
1151 /**
1152 Record multiple certificate list & verification state of a verified image to
1153 IMAGE_EXECUTION_TABLE.
1154
1155 @param[in] CertBuf Certificate list buffer.
1156 @param[in] CertBufLength Certificate list buffer.
1157 @param[in] Action Certificate list action to be record.
1158 @param[in] ImageName Image name.
1159 @param[in] ImageDevicePath Image device path.
1160
1161 **/
1162 VOID
1163 RecordCertListToImageExeuctionTable(
1164 IN UINT8 *CertBuf,
1165 IN UINTN CertBufLength,
1166 IN EFI_IMAGE_EXECUTION_ACTION Action,
1167 IN CHAR16 *ImageName OPTIONAL,
1168 IN CONST EFI_DEVICE_PATH_PROTOCOL *ImageDevicePath OPTIONAL
1169 )
1170 {
1171 UINT8 CertNumber;
1172 UINT8 *CertPtr;
1173 UINTN Index;
1174 UINT8 *Cert;
1175 UINTN CertSize;
1176 EFI_STATUS Status;
1177 EFI_SIGNATURE_LIST *SignatureList;
1178 UINTN SignatureListSize;
1179
1180 CertNumber = (UINT8) (*CertBuf);
1181 CertPtr = CertBuf + 1;
1182 for (Index = 0; Index < CertNumber; Index++) {
1183 CertSize = (UINTN) ReadUnaligned32 ((UINT32 *)CertPtr);
1184 Cert = (UINT8 *)CertPtr + sizeof (UINT32);
1185
1186 //
1187 // Record all cert in cert chain to be passed
1188 //
1189 Status = CreateSignatureList(Cert, CertSize, &gEfiCertX509Guid, &SignatureList, &SignatureListSize);
1190 if (!EFI_ERROR(Status)) {
1191 AddImageExeInfo (Action, ImageName, ImageDevicePath, SignatureList, SignatureListSize);
1192 FreePool (SignatureList);
1193 }
1194 }
1195 }
1196
1197
1198 /**
1199 Check whether the timestamp signature is valid and the signing time is also earlier than
1200 the revocation time.
1201
1202 @param[in] AuthData Pointer to the Authenticode signature retrieved from signed image.
1203 @param[in] AuthDataSize Size of the Authenticode signature in bytes.
1204 @param[in] RevocationTime The time that the certificate was revoked.
1205
1206 @retval TRUE Timestamp signature is valid and signing time is no later than the
1207 revocation time.
1208 @retval FALSE Timestamp signature is not valid or the signing time is later than the
1209 revocation time.
1210
1211 **/
1212 BOOLEAN
1213 PassTimestampCheck (
1214 IN UINT8 *AuthData,
1215 IN UINTN AuthDataSize,
1216 IN EFI_TIME *RevocationTime
1217 )
1218 {
1219 EFI_STATUS Status;
1220 BOOLEAN VerifyStatus;
1221 EFI_SIGNATURE_LIST *CertList;
1222 EFI_SIGNATURE_DATA *Cert;
1223 UINT8 *DbtData;
1224 UINTN DbtDataSize;
1225 UINT8 *RootCert;
1226 UINTN RootCertSize;
1227 UINTN Index;
1228 UINTN CertCount;
1229 EFI_TIME SigningTime;
1230
1231 //
1232 // Variable Initialization
1233 //
1234 VerifyStatus = FALSE;
1235 DbtData = NULL;
1236 CertList = NULL;
1237 Cert = NULL;
1238 RootCert = NULL;
1239 RootCertSize = 0;
1240
1241 //
1242 // If RevocationTime is zero, the certificate shall be considered to always be revoked.
1243 //
1244 if (IsTimeZero (RevocationTime)) {
1245 return FALSE;
1246 }
1247
1248 //
1249 // RevocationTime is non-zero, the certificate should be considered to be revoked from that time and onwards.
1250 // Using the dbt to get the trusted TSA certificates.
1251 //
1252 DbtDataSize = 0;
1253 Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE2, &gEfiImageSecurityDatabaseGuid, NULL, &DbtDataSize, NULL);
1254 if (Status != EFI_BUFFER_TOO_SMALL) {
1255 goto Done;
1256 }
1257 DbtData = (UINT8 *) AllocateZeroPool (DbtDataSize);
1258 if (DbtData == NULL) {
1259 goto Done;
1260 }
1261 Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE2, &gEfiImageSecurityDatabaseGuid, NULL, &DbtDataSize, (VOID *) DbtData);
1262 if (EFI_ERROR (Status)) {
1263 goto Done;
1264 }
1265
1266 CertList = (EFI_SIGNATURE_LIST *) DbtData;
1267 while ((DbtDataSize > 0) && (DbtDataSize >= CertList->SignatureListSize)) {
1268 if (CompareGuid (&CertList->SignatureType, &gEfiCertX509Guid)) {
1269 Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertList + sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize);
1270 CertCount = (CertList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - CertList->SignatureHeaderSize) / CertList->SignatureSize;
1271 for (Index = 0; Index < CertCount; Index++) {
1272 //
1273 // Iterate each Signature Data Node within this CertList for verify.
1274 //
1275 RootCert = Cert->SignatureData;
1276 RootCertSize = CertList->SignatureSize - sizeof (EFI_GUID);
1277 //
1278 // Get the signing time if the timestamp signature is valid.
1279 //
1280 if (ImageTimestampVerify (AuthData, AuthDataSize, RootCert, RootCertSize, &SigningTime)) {
1281 //
1282 // The signer signature is valid only when the signing time is earlier than revocation time.
1283 //
1284 if (IsValidSignatureByTimestamp (&SigningTime, RevocationTime)) {
1285 VerifyStatus = TRUE;
1286 goto Done;
1287 }
1288 }
1289 Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) Cert + CertList->SignatureSize);
1290 }
1291 }
1292 DbtDataSize -= CertList->SignatureListSize;
1293 CertList = (EFI_SIGNATURE_LIST *) ((UINT8 *) CertList + CertList->SignatureListSize);
1294 }
1295
1296 Done:
1297 if (DbtData != NULL) {
1298 FreePool (DbtData);
1299 }
1300
1301 return VerifyStatus;
1302 }
1303
1304 /**
1305 Check whether the image signature is forbidden by the forbidden database (dbx).
1306 The image is forbidden to load if any certificates for signing are revoked before signing time.
1307
1308 @param[in] AuthData Pointer to the Authenticode signature retrieved from the signed image.
1309 @param[in] AuthDataSize Size of the Authenticode signature in bytes.
1310 @param[in] IsAuditMode Whether system Secure Boot Mode is in AuditMode.
1311 @param[in] ImageName Name of the image to verify.
1312 @param[in] ImageDevicePath DevicePath of the image to verify.
1313
1314 @retval TRUE Image is forbidden by dbx.
1315 @retval FALSE Image is not forbidden by dbx.
1316
1317 **/
1318 BOOLEAN
1319 IsForbiddenByDbx (
1320 IN UINT8 *AuthData,
1321 IN UINTN AuthDataSize,
1322 IN BOOLEAN IsAuditMode,
1323 IN CHAR16 *ImageName OPTIONAL,
1324 IN CONST EFI_DEVICE_PATH_PROTOCOL *ImageDevicePath OPTIONAL
1325 )
1326 {
1327 EFI_STATUS Status;
1328 BOOLEAN IsForbidden;
1329 UINT8 *Data;
1330 UINTN DataSize;
1331 EFI_SIGNATURE_LIST *CertList;
1332 UINTN CertListSize;
1333 EFI_SIGNATURE_DATA *CertData;
1334 UINT8 *RootCert;
1335 UINTN RootCertSize;
1336 UINTN CertCount;
1337 UINTN Index;
1338 UINT8 *CertBuffer;
1339 UINTN BufferLength;
1340 UINT8 *TrustedCert;
1341 UINTN TrustedCertLength;
1342 UINT8 CertNumber;
1343 UINT8 *CertPtr;
1344 UINT8 *Cert;
1345 UINTN CertSize;
1346 EFI_TIME RevocationTime;
1347 UINT8 *SignerCert;
1348 UINTN SignerCertLength;
1349 UINT8 *UnchainCert;
1350 UINTN UnchainCertLength;
1351 //
1352 // Variable Initialization
1353 //
1354 IsForbidden = FALSE;
1355 Data = NULL;
1356 CertList = NULL;
1357 CertData = NULL;
1358 RootCert = NULL;
1359 RootCertSize = 0;
1360 Cert = NULL;
1361 CertBuffer = NULL;
1362 BufferLength = 0;
1363 TrustedCert = NULL;
1364 TrustedCertLength = 0;
1365 SignerCert = NULL;
1366 SignerCertLength = 0;
1367 UnchainCert = NULL;
1368 UnchainCertLength = 0;
1369
1370 //
1371 // The image will not be forbidden if dbx can't be got.
1372 //
1373 DataSize = 0;
1374 Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE1, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, NULL);
1375 if (Status != EFI_BUFFER_TOO_SMALL) {
1376 return IsForbidden;
1377 }
1378 Data = (UINT8 *) AllocateZeroPool (DataSize);
1379 if (Data == NULL) {
1380 return IsForbidden;
1381 }
1382
1383 Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE1, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, (VOID *) Data);
1384 if (EFI_ERROR (Status)) {
1385 return IsForbidden;
1386 }
1387
1388 //
1389 // Verify image signature with RAW X509 certificates in DBX database.
1390 // If passed, the image will be forbidden.
1391 //
1392 CertList = (EFI_SIGNATURE_LIST *) Data;
1393 CertListSize = DataSize;
1394 while ((CertListSize > 0) && (CertListSize >= CertList->SignatureListSize)) {
1395 if (CompareGuid (&CertList->SignatureType, &gEfiCertX509Guid)) {
1396 CertData = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertList + sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize);
1397 CertCount = (CertList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - CertList->SignatureHeaderSize) / CertList->SignatureSize;
1398
1399 for (Index = 0; Index < CertCount; Index++) {
1400 //
1401 // Iterate each Signature Data Node within this CertList for verify.
1402 //
1403 RootCert = CertData->SignatureData;
1404 RootCertSize = CertList->SignatureSize - sizeof (EFI_GUID);
1405
1406 //
1407 // Call AuthenticodeVerify library to Verify Authenticode struct.
1408 //
1409 IsForbidden = AuthenticodeVerify (
1410 AuthData,
1411 AuthDataSize,
1412 RootCert,
1413 RootCertSize,
1414 mImageDigest,
1415 mImageDigestSize
1416 );
1417 if (IsForbidden) {
1418 SecureBootHook (EFI_IMAGE_SECURITY_DATABASE1, &gEfiImageSecurityDatabaseGuid, CertList->SignatureSize, CertData);
1419 goto Done;
1420 }
1421
1422 CertData = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertData + CertList->SignatureSize);
1423 }
1424 }
1425
1426 CertListSize -= CertList->SignatureListSize;
1427 CertList = (EFI_SIGNATURE_LIST *) ((UINT8 *) CertList + CertList->SignatureListSize);
1428 }
1429
1430 //
1431 // Check X.509 Certificate Hash & Possible Timestamp.
1432 //
1433
1434 //
1435 // Retrieve the certificate stack from AuthData
1436 // The output CertStack format will be:
1437 // UINT8 CertNumber;
1438 // UINT32 Cert1Length;
1439 // UINT8 Cert1[];
1440 // UINT32 Cert2Length;
1441 // UINT8 Cert2[];
1442 // ...
1443 // UINT32 CertnLength;
1444 // UINT8 Certn[];
1445 //
1446 Pkcs7GetSigners (AuthData, AuthDataSize, &CertBuffer, &BufferLength, &TrustedCert, &TrustedCertLength);
1447 if ((BufferLength == 0) || (CertBuffer == NULL)) {
1448 IsForbidden = TRUE;
1449 goto Done;
1450 }
1451
1452 //
1453 // Check if any hash of certificates embedded in AuthData is in the forbidden database.
1454 //
1455 CertNumber = (UINT8) (*CertBuffer);
1456 CertPtr = CertBuffer + 1;
1457 for (Index = 0; Index < CertNumber; Index++) {
1458 CertSize = (UINTN) ReadUnaligned32 ((UINT32 *)CertPtr);
1459 Cert = (UINT8 *)CertPtr + sizeof (UINT32);
1460 //
1461 // Advance CertPtr to the next cert in image signer's cert list
1462 //
1463 CertPtr = CertPtr + sizeof (UINT32) + CertSize;
1464
1465 if (IsCertHashFoundInDatabase (Cert, CertSize, (EFI_SIGNATURE_LIST *)Data, DataSize, &RevocationTime)) {
1466 //
1467 // Check the timestamp signature and signing time to determine if the image can be trusted.
1468 //
1469 IsForbidden = TRUE;
1470 if (PassTimestampCheck (AuthData, AuthDataSize, &RevocationTime)) {
1471 IsForbidden = FALSE;
1472 //
1473 // Pass DBT check. Continue to check other certs in image signer's cert list against DBX, DBT
1474 //
1475 continue;
1476 }
1477 goto Done;
1478 }
1479
1480 }
1481
1482 Done:
1483 if (IsForbidden && IsAuditMode) {
1484 Pkcs7GetCertificatesList(AuthData, AuthDataSize, &SignerCert, &SignerCertLength, &UnchainCert, &UnchainCertLength);
1485
1486 //
1487 // Record all certs in image to be failed
1488 //
1489 if ((SignerCertLength != 0) && (SignerCert != NULL)) {
1490 RecordCertListToImageExeuctionTable(
1491 SignerCert,
1492 SignerCertLength,
1493 EFI_IMAGE_EXECUTION_AUTH_SIG_FAILED | EFI_IMAGE_EXECUTION_INITIALIZED,
1494 ImageName,
1495 ImageDevicePath
1496 );
1497 }
1498
1499 if ((UnchainCertLength != 0) && (UnchainCert != NULL)) {
1500 RecordCertListToImageExeuctionTable(
1501 UnchainCert,
1502 UnchainCertLength,
1503 EFI_IMAGE_EXECUTION_AUTH_SIG_FAILED | EFI_IMAGE_EXECUTION_INITIALIZED,
1504 ImageName,
1505 ImageDevicePath
1506 );
1507 }
1508 }
1509
1510 if (Data != NULL) {
1511 FreePool (Data);
1512 }
1513
1514 Pkcs7FreeSigners (CertBuffer);
1515 Pkcs7FreeSigners (TrustedCert);
1516 Pkcs7FreeSigners (SignerCert);
1517 Pkcs7FreeSigners (UnchainCert);
1518
1519 return IsForbidden;
1520 }
1521
1522
1523 /**
1524 Check whether the image signature can be verified by the trusted certificates in DB database.
1525
1526 @param[in] AuthData Pointer to the Authenticode signature retrieved from signed image.
1527 @param[in] AuthDataSize Size of the Authenticode signature in bytes.
1528 @param[in] IsAuditMode Whether system Secure Boot Mode is in AuditMode.
1529 @param[in] ImageName Name of the image to verify.
1530 @param[in] ImageDevicePath DevicePath of the image to verify.
1531
1532 @retval TRUE Image passed verification using certificate in db.
1533 @retval FALSE Image didn't pass verification using certificate in db.
1534
1535 **/
1536 BOOLEAN
1537 IsAllowedByDb (
1538 IN UINT8 *AuthData,
1539 IN UINTN AuthDataSize,
1540 IN BOOLEAN IsAuditMode,
1541 IN CHAR16 *ImageName OPTIONAL,
1542 IN CONST EFI_DEVICE_PATH_PROTOCOL *ImageDevicePath OPTIONAL
1543 )
1544 {
1545 EFI_STATUS Status;
1546 BOOLEAN VerifyStatus;
1547 EFI_SIGNATURE_LIST *CertList;
1548 EFI_SIGNATURE_DATA *CertData;
1549 UINTN DataSize;
1550 UINT8 *Data;
1551 UINT8 *RootCert;
1552 UINTN RootCertSize;
1553 UINTN Index;
1554 UINTN CertCount;
1555 UINTN DbxDataSize;
1556 UINT8 *DbxData;
1557 EFI_TIME RevocationTime;
1558 UINT8 *SignerCert;
1559 UINTN SignerCertLength;
1560 UINT8 *UnchainCert;
1561 UINTN UnchainCertLength;
1562
1563 Data = NULL;
1564 CertList = NULL;
1565 CertData = NULL;
1566 RootCert = NULL;
1567 DbxData = NULL;
1568 RootCertSize = 0;
1569 VerifyStatus = FALSE;
1570 SignerCert = NULL;
1571 SignerCertLength = 0;
1572 UnchainCert = NULL;
1573 UnchainCertLength = 0;
1574
1575 DataSize = 0;
1576 Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, NULL);
1577 if (Status == EFI_BUFFER_TOO_SMALL) {
1578 Data = (UINT8 *) AllocateZeroPool (DataSize);
1579 if (Data == NULL) {
1580 return VerifyStatus;
1581 }
1582
1583 Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, (VOID *) Data);
1584 if (EFI_ERROR (Status)) {
1585 goto Done;
1586 }
1587
1588 //
1589 // Find X509 certificate in Signature List to verify the signature in pkcs7 signed data.
1590 //
1591 CertList = (EFI_SIGNATURE_LIST *) Data;
1592 while ((DataSize > 0) && (DataSize >= CertList->SignatureListSize)) {
1593 if (CompareGuid (&CertList->SignatureType, &gEfiCertX509Guid)) {
1594 CertData = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertList + sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize);
1595 CertCount = (CertList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - CertList->SignatureHeaderSize) / CertList->SignatureSize;
1596
1597 for (Index = 0; Index < CertCount; Index++) {
1598 //
1599 // Iterate each Signature Data Node within this CertList for verify.
1600 //
1601 RootCert = CertData->SignatureData;
1602 RootCertSize = CertList->SignatureSize - sizeof (EFI_GUID);
1603
1604 //
1605 // Call AuthenticodeVerify library to Verify Authenticode struct.
1606 //
1607 VerifyStatus = AuthenticodeVerify (
1608 AuthData,
1609 AuthDataSize,
1610 RootCert,
1611 RootCertSize,
1612 mImageDigest,
1613 mImageDigestSize
1614 );
1615 if (VerifyStatus) {
1616 //
1617 // Here We still need to check if this RootCert's Hash is revoked
1618 //
1619 Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE1, &gEfiImageSecurityDatabaseGuid, NULL, &DbxDataSize, NULL);
1620 if (Status == EFI_BUFFER_TOO_SMALL) {
1621 goto Done;
1622 }
1623 DbxData = (UINT8 *) AllocateZeroPool (DbxDataSize);
1624 if (DbxData == NULL) {
1625 goto Done;
1626 }
1627
1628 Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE1, &gEfiImageSecurityDatabaseGuid, NULL, &DbxDataSize, (VOID *) DbxData);
1629 if (EFI_ERROR (Status)) {
1630 goto Done;
1631 }
1632
1633 if (IsCertHashFoundInDatabase (RootCert, RootCertSize, (EFI_SIGNATURE_LIST *)DbxData, DbxDataSize, &RevocationTime)) {
1634 //
1635 // Check the timestamp signature and signing time to determine if the image can be trusted.
1636 //
1637 VerifyStatus = PassTimestampCheck (AuthData, AuthDataSize, &RevocationTime);
1638 }
1639
1640 goto Done;
1641 }
1642
1643 CertData = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertData + CertList->SignatureSize);
1644 }
1645 }
1646
1647 DataSize -= CertList->SignatureListSize;
1648 CertList = (EFI_SIGNATURE_LIST *) ((UINT8 *) CertList + CertList->SignatureListSize);
1649 }
1650 }
1651
1652 Done:
1653
1654 if (VerifyStatus) {
1655 SecureBootHook (EFI_IMAGE_SECURITY_DATABASE, &gEfiImageSecurityDatabaseGuid, CertList->SignatureSize, CertData);
1656 }
1657
1658 if (IsAuditMode) {
1659
1660 Pkcs7GetCertificatesList(AuthData, AuthDataSize, &SignerCert, &SignerCertLength, &UnchainCert, &UnchainCertLength);
1661 if (VerifyStatus) {
1662 if ((SignerCertLength != 0) && (SignerCert != NULL)) {
1663 //
1664 // Record all cert in signer's cert chain to be passed
1665 //
1666 RecordCertListToImageExeuctionTable(
1667 SignerCert,
1668 SignerCertLength,
1669 EFI_IMAGE_EXECUTION_AUTH_SIG_PASSED | EFI_IMAGE_EXECUTION_INITIALIZED,
1670 ImageName,
1671 ImageDevicePath
1672 );
1673 }
1674
1675 if ((UnchainCertLength != 0) && (UnchainCert != NULL)) {
1676 //
1677 // Record all certs in unchained certificates lists to be failed
1678 //
1679 RecordCertListToImageExeuctionTable(
1680 UnchainCert,
1681 UnchainCertLength,
1682 EFI_IMAGE_EXECUTION_AUTH_SIG_FAILED | EFI_IMAGE_EXECUTION_INITIALIZED,
1683 ImageName,
1684 ImageDevicePath
1685 );
1686 }
1687 } else {
1688 //
1689 // Record all certs in image to be failed
1690 //
1691 if ((SignerCertLength != 0) && (SignerCert != NULL)) {
1692 RecordCertListToImageExeuctionTable(
1693 SignerCert,
1694 SignerCertLength,
1695 EFI_IMAGE_EXECUTION_AUTH_SIG_FAILED | EFI_IMAGE_EXECUTION_INITIALIZED,
1696 ImageName,
1697 ImageDevicePath
1698 );
1699 }
1700
1701 if ((UnchainCertLength != 0) && (UnchainCert != NULL)) {
1702 RecordCertListToImageExeuctionTable(
1703 UnchainCert,
1704 UnchainCertLength,
1705 EFI_IMAGE_EXECUTION_AUTH_SIG_FAILED | EFI_IMAGE_EXECUTION_INITIALIZED,
1706 ImageName,
1707 ImageDevicePath
1708 );
1709 }
1710 }
1711 }
1712
1713
1714 if (Data != NULL) {
1715 FreePool (Data);
1716 }
1717 if (DbxData != NULL) {
1718 FreePool (DbxData);
1719 }
1720
1721 Pkcs7FreeSigners (SignerCert);
1722 Pkcs7FreeSigners (UnchainCert);
1723
1724 return VerifyStatus;
1725 }
1726
1727 /**
1728 Provide verification service for signed images in AuditMode, which include both signature validation
1729 and platform policy control. For signature types, both UEFI WIN_CERTIFICATE_UEFI_GUID and
1730 MSFT Authenticode type signatures are supported.
1731
1732 In this implementation, only verify external executables when in AuditMode.
1733 Executables from FV is bypass, so pass in AuthenticationStatus is ignored. Other authentication status
1734 are record into IMAGE_EXECUTION_TABLE.
1735
1736 The image verification policy is:
1737 If the image is signed,
1738 At least one valid signature or at least one hash value of the image must match a record
1739 in the security database "db", and no valid signature nor any hash value of the image may
1740 be reflected in the security database "dbx".
1741 Otherwise, the image is not signed,
1742 The SHA256 hash value of the image must match a record in the security database "db", and
1743 not be reflected in the security data base "dbx".
1744
1745 Caution: This function may receive untrusted input.
1746 PE/COFF image is external input, so this function will validate its data structure
1747 within this image buffer before use.
1748
1749 @param[in] AuthenticationStatus
1750 This is the authentication status returned from the security
1751 measurement services for the input file.
1752 @param[in] File This is a pointer to the device path of the file that is
1753 being dispatched. This will optionally be used for logging.
1754 @param[in] FileBuffer File buffer matches the input file device path.
1755 @param[in] FileSize Size of File buffer matches the input file device path.
1756 @param[in] BootPolicy A boot policy that was used to call LoadImage() UEFI service.
1757
1758 @retval EFI_SUCCESS The authenticate info is sucessfully stored for the file
1759 specified by DevicePath and non-NULL FileBuffer
1760 @retval EFI_ACCESS_DENIED The file specified by File and FileBuffer did not
1761 authenticate, and the platform policy dictates that the DXE
1762 Foundation many not use File.
1763
1764 **/
1765 EFI_STATUS
1766 EFIAPI
1767 ImageVerificationInAuditMode (
1768 IN UINT32 AuthenticationStatus,
1769 IN CONST EFI_DEVICE_PATH_PROTOCOL *File,
1770 IN VOID *FileBuffer,
1771 IN UINTN FileSize,
1772 IN BOOLEAN BootPolicy
1773 )
1774 {
1775 EFI_STATUS Status;
1776 UINT16 Magic;
1777 EFI_IMAGE_DOS_HEADER *DosHdr;
1778 EFI_SIGNATURE_LIST *SignatureList;
1779 EFI_IMAGE_EXECUTION_ACTION Action;
1780 WIN_CERTIFICATE *WinCertificate;
1781 UINT32 Policy;
1782 PE_COFF_LOADER_IMAGE_CONTEXT ImageContext;
1783 UINT32 NumberOfRvaAndSizes;
1784 WIN_CERTIFICATE_EFI_PKCS *PkcsCertData;
1785 WIN_CERTIFICATE_UEFI_GUID *WinCertUefiGuid;
1786 UINT8 *AuthData;
1787 UINTN AuthDataSize;
1788 EFI_IMAGE_DATA_DIRECTORY *SecDataDir;
1789 UINT32 OffSet;
1790 CHAR16 *FilePathStr;
1791 UINTN SignatureListSize;
1792
1793 SignatureList = NULL;
1794 WinCertificate = NULL;
1795 SecDataDir = NULL;
1796 PkcsCertData = NULL;
1797 FilePathStr = NULL;
1798 Action = EFI_IMAGE_EXECUTION_AUTH_SIG_FAILED | EFI_IMAGE_EXECUTION_INITIALIZED;
1799 Status = EFI_ACCESS_DENIED;
1800
1801
1802 //
1803 // Check the image type and get policy setting.
1804 //
1805 switch (GetImageType (File)) {
1806
1807 case IMAGE_FROM_FV:
1808 Policy = ALWAYS_EXECUTE;
1809 break;
1810
1811 case IMAGE_FROM_OPTION_ROM:
1812 Policy = PcdGet32 (PcdOptionRomImageVerificationPolicy);
1813 break;
1814
1815 case IMAGE_FROM_REMOVABLE_MEDIA:
1816 Policy = PcdGet32 (PcdRemovableMediaImageVerificationPolicy);
1817 break;
1818
1819 case IMAGE_FROM_FIXED_MEDIA:
1820 Policy = PcdGet32 (PcdFixedMediaImageVerificationPolicy);
1821 break;
1822
1823 default:
1824 Policy = DENY_EXECUTE_ON_SECURITY_VIOLATION;
1825 break;
1826 }
1827
1828 //
1829 // If policy is always/never execute, return directly.
1830 //
1831 if (Policy == ALWAYS_EXECUTE) {
1832 return EFI_SUCCESS;
1833 }
1834
1835 //
1836 // Get Image Device Path Str
1837 //
1838 FilePathStr = ConvertDevicePathToText (File, FALSE, TRUE);
1839
1840 //
1841 // Authentication failed because of (unspecified) firmware security policy
1842 //
1843 if (Policy == NEVER_EXECUTE) {
1844 //
1845 // No signature, record FilePath/FilePathStr only
1846 //
1847 AddImageExeInfo (EFI_IMAGE_EXECUTION_POLICY_FAILED | EFI_IMAGE_EXECUTION_INITIALIZED, FilePathStr, File, NULL, 0);
1848 goto END;
1849 }
1850
1851 //
1852 // The policy QUERY_USER_ON_SECURITY_VIOLATION and ALLOW_EXECUTE_ON_SECURITY_VIOLATION
1853 // violates the UEFI spec and has been removed.
1854 //
1855 ASSERT (Policy != QUERY_USER_ON_SECURITY_VIOLATION && Policy != ALLOW_EXECUTE_ON_SECURITY_VIOLATION);
1856 if (Policy == QUERY_USER_ON_SECURITY_VIOLATION || Policy == ALLOW_EXECUTE_ON_SECURITY_VIOLATION) {
1857 CpuDeadLoop ();
1858 }
1859
1860 //
1861 // Read the Dos header.
1862 //
1863 if (FileBuffer == NULL) {
1864 Status = EFI_INVALID_PARAMETER;
1865 goto END;
1866 }
1867
1868 mImageBase = (UINT8 *) FileBuffer;
1869 mImageSize = FileSize;
1870
1871 ZeroMem (&ImageContext, sizeof (ImageContext));
1872 ImageContext.Handle = (VOID *) FileBuffer;
1873 ImageContext.ImageRead = (PE_COFF_LOADER_READ_FILE) DxeImageVerificationLibImageRead;
1874
1875 //
1876 // Get information about the image being loaded
1877 //
1878 Status = PeCoffLoaderGetImageInfo (&ImageContext);
1879 if (EFI_ERROR (Status)) {
1880 //
1881 // The information can't be got from the invalid PeImage
1882 //
1883 goto END;
1884 }
1885
1886
1887 DosHdr = (EFI_IMAGE_DOS_HEADER *) mImageBase;
1888 if (DosHdr->e_magic == EFI_IMAGE_DOS_SIGNATURE) {
1889 //
1890 // DOS image header is present,
1891 // so read the PE header after the DOS image header.
1892 //
1893 mPeCoffHeaderOffset = DosHdr->e_lfanew;
1894 } else {
1895 mPeCoffHeaderOffset = 0;
1896 }
1897
1898 //
1899 // Check PE/COFF image.
1900 //
1901 mNtHeader.Pe32 = (EFI_IMAGE_NT_HEADERS32 *) (mImageBase + mPeCoffHeaderOffset);
1902 if (mNtHeader.Pe32->Signature != EFI_IMAGE_NT_SIGNATURE) {
1903 //
1904 // It is not a valid Pe/Coff file.
1905 //
1906 Status = EFI_ACCESS_DENIED;
1907 goto END;
1908 }
1909
1910 if (mNtHeader.Pe32->FileHeader.Machine == IMAGE_FILE_MACHINE_IA64 && mNtHeader.Pe32->OptionalHeader.Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
1911 //
1912 // NOTE: Some versions of Linux ELILO for Itanium have an incorrect magic value
1913 // in the PE/COFF Header. If the MachineType is Itanium(IA64) and the
1914 // Magic value in the OptionalHeader is EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC
1915 // then override the magic value to EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC
1916 //
1917 Magic = EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC;
1918 } else {
1919 //
1920 // Get the magic value from the PE/COFF Optional Header
1921 //
1922 Magic = mNtHeader.Pe32->OptionalHeader.Magic;
1923 }
1924
1925 if (Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
1926 //
1927 // Use PE32 offset.
1928 //
1929 NumberOfRvaAndSizes = mNtHeader.Pe32->OptionalHeader.NumberOfRvaAndSizes;
1930 if (NumberOfRvaAndSizes > EFI_IMAGE_DIRECTORY_ENTRY_SECURITY) {
1931 SecDataDir = (EFI_IMAGE_DATA_DIRECTORY *) &mNtHeader.Pe32->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY];
1932 }
1933 } else {
1934 //
1935 // Use PE32+ offset.
1936 //
1937 NumberOfRvaAndSizes = mNtHeader.Pe32Plus->OptionalHeader.NumberOfRvaAndSizes;
1938 if (NumberOfRvaAndSizes > EFI_IMAGE_DIRECTORY_ENTRY_SECURITY) {
1939 SecDataDir = (EFI_IMAGE_DATA_DIRECTORY *) &mNtHeader.Pe32Plus->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY];
1940 }
1941 }
1942
1943 //
1944 // Start Image Validation.
1945 //
1946 if (SecDataDir == NULL || SecDataDir->Size == 0) {
1947 //
1948 // This image is not signed. The SHA256 hash value of the image must match a record in the security database "db",
1949 // and not be reflected in the security data base "dbx".
1950 //
1951 if (!HashPeImage (HASHALG_SHA256)) {
1952 Status = EFI_ACCESS_DENIED;
1953 goto END;
1954 }
1955
1956 //
1957 // Image Hash is in forbidden database (DBX).
1958 //
1959 if (!IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE1, mImageDigest, &mCertType, mImageDigestSize)) {
1960 //
1961 // Image Hash is in allowed database (DB).
1962 //
1963 if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE, mImageDigest, &mCertType, mImageDigestSize)) {
1964 Action = EFI_IMAGE_EXECUTION_AUTH_SIG_PASSED | EFI_IMAGE_EXECUTION_INITIALIZED;
1965 }
1966 }
1967
1968 //
1969 // Add HASH digest for image without signature
1970 //
1971 Status = CreateSignatureList(mImageDigest, mImageDigestSize, &mCertType, &SignatureList, &SignatureListSize);
1972 if (!EFI_ERROR(Status)) {
1973 AddImageExeInfo (Action, FilePathStr, File, SignatureList, SignatureListSize);
1974 FreePool (SignatureList);
1975 }
1976 goto END;
1977 }
1978
1979 //
1980 // Verify the signature of the image, multiple signatures are allowed as per PE/COFF Section 4.7
1981 // "Attribute Certificate Table".
1982 // The first certificate starts at offset (SecDataDir->VirtualAddress) from the start of the file.
1983 //
1984 for (OffSet = SecDataDir->VirtualAddress;
1985 OffSet < (SecDataDir->VirtualAddress + SecDataDir->Size);
1986 OffSet += (WinCertificate->dwLength + ALIGN_SIZE (WinCertificate->dwLength))) {
1987 WinCertificate = (WIN_CERTIFICATE *) (mImageBase + OffSet);
1988 if ((SecDataDir->VirtualAddress + SecDataDir->Size - OffSet) <= sizeof (WIN_CERTIFICATE) ||
1989 (SecDataDir->VirtualAddress + SecDataDir->Size - OffSet) < WinCertificate->dwLength) {
1990 break;
1991 }
1992
1993 //
1994 // Verify the image's Authenticode signature, only DER-encoded PKCS#7 signed data is supported.
1995 //
1996 if (WinCertificate->wCertificateType == WIN_CERT_TYPE_PKCS_SIGNED_DATA) {
1997 //
1998 // The certificate is formatted as WIN_CERTIFICATE_EFI_PKCS which is described in the
1999 // Authenticode specification.
2000 //
2001 PkcsCertData = (WIN_CERTIFICATE_EFI_PKCS *) WinCertificate;
2002 if (PkcsCertData->Hdr.dwLength <= sizeof (PkcsCertData->Hdr)) {
2003 break;
2004 }
2005 AuthData = PkcsCertData->CertData;
2006 AuthDataSize = PkcsCertData->Hdr.dwLength - sizeof(PkcsCertData->Hdr);
2007 } else if (WinCertificate->wCertificateType == WIN_CERT_TYPE_EFI_GUID) {
2008 //
2009 // The certificate is formatted as WIN_CERTIFICATE_UEFI_GUID which is described in UEFI Spec.
2010 //
2011 WinCertUefiGuid = (WIN_CERTIFICATE_UEFI_GUID *) WinCertificate;
2012 if (WinCertUefiGuid->Hdr.dwLength <= OFFSET_OF(WIN_CERTIFICATE_UEFI_GUID, CertData)) {
2013 break;
2014 }
2015 if (!CompareGuid (&WinCertUefiGuid->CertType, &gEfiCertPkcs7Guid)) {
2016 continue;
2017 }
2018 AuthData = WinCertUefiGuid->CertData;
2019 AuthDataSize = WinCertUefiGuid->Hdr.dwLength - OFFSET_OF(WIN_CERTIFICATE_UEFI_GUID, CertData);
2020 } else {
2021 if (WinCertificate->dwLength < sizeof (WIN_CERTIFICATE)) {
2022 break;
2023 }
2024 continue;
2025 }
2026
2027 Status = HashPeImageByType (AuthData, AuthDataSize);
2028 if (EFI_ERROR (Status)) {
2029 continue;
2030 }
2031
2032 Action = EFI_IMAGE_EXECUTION_AUTH_SIG_FAILED | EFI_IMAGE_EXECUTION_INITIALIZED;
2033
2034 //
2035 // Check the digital signature against the revoked certificate in forbidden database (dbx).
2036 // Check the digital signature against the valid certificate in allowed database (db).
2037 //
2038 if (!IsForbiddenByDbx (AuthData, AuthDataSize, TRUE, FilePathStr, File)) {
2039 IsAllowedByDb (AuthData, AuthDataSize, TRUE, FilePathStr, File);
2040 }
2041
2042 //
2043 // Check the image's hash value.
2044 //
2045 if (!IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE1, mImageDigest, &mCertType, mImageDigestSize)) {
2046 if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE, mImageDigest, &mCertType, mImageDigestSize)) {
2047 Action = EFI_IMAGE_EXECUTION_AUTH_SIG_PASSED | EFI_IMAGE_EXECUTION_INITIALIZED;
2048 }
2049 }
2050
2051 //
2052 // Add HASH digest for image with signature
2053 //
2054 Status = CreateSignatureList(mImageDigest, mImageDigestSize, &mCertType, &SignatureList, &SignatureListSize);
2055
2056 if (!EFI_ERROR(Status)) {
2057 AddImageExeInfo (Action, FilePathStr, File, SignatureList, SignatureListSize);
2058 FreePool (SignatureList);
2059 } else {
2060 goto END;
2061 }
2062 }
2063
2064
2065 if (OffSet != (SecDataDir->VirtualAddress + SecDataDir->Size)) {
2066 //
2067 // The Size in Certificate Table or the attribute certicate table is corrupted.
2068 //
2069 Status = EFI_ACCESS_DENIED;
2070 } else {
2071 Status = EFI_SUCCESS;
2072 }
2073
2074 END:
2075
2076 if (FilePathStr != NULL) {
2077 FreePool(FilePathStr);
2078 FilePathStr = NULL;
2079 }
2080
2081 return Status;
2082 }
2083
2084 /**
2085 Provide verification service for signed images, which include both signature validation
2086 and platform policy control. For signature types, both UEFI WIN_CERTIFICATE_UEFI_GUID and
2087 MSFT Authenticode type signatures are supported.
2088
2089 In this implementation, only verify external executables when in USER MODE.
2090 Executables from FV is bypass, so pass in AuthenticationStatus is ignored.
2091
2092 The image verification policy is:
2093 If the image is signed,
2094 At least one valid signature or at least one hash value of the image must match a record
2095 in the security database "db", and no valid signature nor any hash value of the image may
2096 be reflected in the security database "dbx".
2097 Otherwise, the image is not signed,
2098 The SHA256 hash value of the image must match a record in the security database "db", and
2099 not be reflected in the security data base "dbx".
2100
2101 Caution: This function may receive untrusted input.
2102 PE/COFF image is external input, so this function will validate its data structure
2103 within this image buffer before use.
2104
2105 @param[in] AuthenticationStatus
2106 This is the authentication status returned from the security
2107 measurement services for the input file.
2108 @param[in] File This is a pointer to the device path of the file that is
2109 being dispatched. This will optionally be used for logging.
2110 @param[in] FileBuffer File buffer matches the input file device path.
2111 @param[in] FileSize Size of File buffer matches the input file device path.
2112 @param[in] BootPolicy A boot policy that was used to call LoadImage() UEFI service.
2113
2114 @retval EFI_SUCCESS The file specified by DevicePath and non-NULL
2115 FileBuffer did authenticate, and the platform policy dictates
2116 that the DXE Foundation may use the file.
2117 @retval EFI_SUCCESS The device path specified by NULL device path DevicePath
2118 and non-NULL FileBuffer did authenticate, and the platform
2119 policy dictates that the DXE Foundation may execute the image in
2120 FileBuffer.
2121 @retval EFI_OUT_RESOURCE Fail to allocate memory.
2122 @retval EFI_SECURITY_VIOLATION The file specified by File did not authenticate, and
2123 the platform policy dictates that File should be placed
2124 in the untrusted state. The image has been added to the file
2125 execution table.
2126 @retval EFI_ACCESS_DENIED The file specified by File and FileBuffer did not
2127 authenticate, and the platform policy dictates that the DXE
2128 Foundation many not use File.
2129
2130 **/
2131 EFI_STATUS
2132 EFIAPI
2133 DxeImageVerificationHandler (
2134 IN UINT32 AuthenticationStatus,
2135 IN CONST EFI_DEVICE_PATH_PROTOCOL *File,
2136 IN VOID *FileBuffer,
2137 IN UINTN FileSize,
2138 IN BOOLEAN BootPolicy
2139 )
2140 {
2141 EFI_STATUS Status;
2142 UINT16 Magic;
2143 EFI_IMAGE_DOS_HEADER *DosHdr;
2144 EFI_STATUS VerifyStatus;
2145 EFI_SIGNATURE_LIST *SignatureList;
2146 UINTN SignatureListSize;
2147 EFI_SIGNATURE_DATA *Signature;
2148 EFI_IMAGE_EXECUTION_ACTION Action;
2149 WIN_CERTIFICATE *WinCertificate;
2150 UINT32 Policy;
2151 UINT8 *VarData;
2152 UINT8 SecureBoot;
2153 UINT8 AuditMode;
2154 PE_COFF_LOADER_IMAGE_CONTEXT ImageContext;
2155 UINT32 NumberOfRvaAndSizes;
2156 WIN_CERTIFICATE_EFI_PKCS *PkcsCertData;
2157 WIN_CERTIFICATE_UEFI_GUID *WinCertUefiGuid;
2158 UINT8 *AuthData;
2159 UINTN AuthDataSize;
2160 EFI_IMAGE_DATA_DIRECTORY *SecDataDir;
2161 UINT32 OffSet;
2162 CHAR16 *NameStr;
2163
2164 SignatureList = NULL;
2165 SignatureListSize = 0;
2166 WinCertificate = NULL;
2167 SecDataDir = NULL;
2168 PkcsCertData = NULL;
2169 Action = EFI_IMAGE_EXECUTION_AUTH_UNTESTED;
2170 Status = EFI_ACCESS_DENIED;
2171 VerifyStatus = EFI_ACCESS_DENIED;
2172
2173 GetEfiGlobalVariable2 (EFI_AUDIT_MODE_NAME, (VOID**)&VarData, NULL);
2174 //
2175 // Skip verification if AuditMode variable doesn't exist. AuditMode should always exist
2176 //
2177 if (VarData == NULL) {
2178 return EFI_SUCCESS;
2179 }
2180 AuditMode = *VarData;
2181 FreePool(VarData);
2182
2183 if (AuditMode == AUDIT_MODE_ENABLE) {
2184 return ImageVerificationInAuditMode(AuthenticationStatus, File, FileBuffer, FileSize, BootPolicy);
2185 }
2186
2187 //
2188 // Check the image type and get policy setting.
2189 //
2190 switch (GetImageType (File)) {
2191
2192 case IMAGE_FROM_FV:
2193 Policy = ALWAYS_EXECUTE;
2194 break;
2195
2196 case IMAGE_FROM_OPTION_ROM:
2197 Policy = PcdGet32 (PcdOptionRomImageVerificationPolicy);
2198 break;
2199
2200 case IMAGE_FROM_REMOVABLE_MEDIA:
2201 Policy = PcdGet32 (PcdRemovableMediaImageVerificationPolicy);
2202 break;
2203
2204 case IMAGE_FROM_FIXED_MEDIA:
2205 Policy = PcdGet32 (PcdFixedMediaImageVerificationPolicy);
2206 break;
2207
2208 default:
2209 Policy = DENY_EXECUTE_ON_SECURITY_VIOLATION;
2210 break;
2211 }
2212 //
2213 // If policy is always/never execute, return directly.
2214 //
2215 if (Policy == ALWAYS_EXECUTE) {
2216 return EFI_SUCCESS;
2217 } else if (Policy == NEVER_EXECUTE) {
2218 return EFI_ACCESS_DENIED;
2219 }
2220
2221 //
2222 // The policy QUERY_USER_ON_SECURITY_VIOLATION and ALLOW_EXECUTE_ON_SECURITY_VIOLATION
2223 // violates the UEFI spec and has been removed.
2224 //
2225 ASSERT (Policy != QUERY_USER_ON_SECURITY_VIOLATION && Policy != ALLOW_EXECUTE_ON_SECURITY_VIOLATION);
2226 if (Policy == QUERY_USER_ON_SECURITY_VIOLATION || Policy == ALLOW_EXECUTE_ON_SECURITY_VIOLATION) {
2227 CpuDeadLoop ();
2228 }
2229
2230 GetEfiGlobalVariable2 (EFI_SECURE_BOOT_MODE_NAME, (VOID**)&VarData, NULL);
2231 //
2232 // Skip verification if SecureBoot variable doesn't exist.
2233 //
2234 if (VarData == NULL) {
2235 return EFI_SUCCESS;
2236 }
2237 SecureBoot = *VarData;
2238 FreePool(VarData);
2239
2240 //
2241 // Skip verification if SecureBoot is disabled but not AuditMode
2242 //
2243 if (SecureBoot == SECURE_BOOT_MODE_DISABLE) {
2244 return EFI_SUCCESS;
2245 }
2246
2247 //
2248 // Read the Dos header.
2249 //
2250 if (FileBuffer == NULL) {
2251 return EFI_INVALID_PARAMETER;
2252 }
2253
2254 mImageBase = (UINT8 *) FileBuffer;
2255 mImageSize = FileSize;
2256
2257 ZeroMem (&ImageContext, sizeof (ImageContext));
2258 ImageContext.Handle = (VOID *) FileBuffer;
2259 ImageContext.ImageRead = (PE_COFF_LOADER_READ_FILE) DxeImageVerificationLibImageRead;
2260
2261 //
2262 // Get information about the image being loaded
2263 //
2264 Status = PeCoffLoaderGetImageInfo (&ImageContext);
2265 if (EFI_ERROR (Status)) {
2266 //
2267 // The information can't be got from the invalid PeImage
2268 //
2269 goto Done;
2270 }
2271
2272 Status = EFI_ACCESS_DENIED;
2273
2274 DosHdr = (EFI_IMAGE_DOS_HEADER *) mImageBase;
2275 if (DosHdr->e_magic == EFI_IMAGE_DOS_SIGNATURE) {
2276 //
2277 // DOS image header is present,
2278 // so read the PE header after the DOS image header.
2279 //
2280 mPeCoffHeaderOffset = DosHdr->e_lfanew;
2281 } else {
2282 mPeCoffHeaderOffset = 0;
2283 }
2284 //
2285 // Check PE/COFF image.
2286 //
2287 mNtHeader.Pe32 = (EFI_IMAGE_NT_HEADERS32 *) (mImageBase + mPeCoffHeaderOffset);
2288 if (mNtHeader.Pe32->Signature != EFI_IMAGE_NT_SIGNATURE) {
2289 //
2290 // It is not a valid Pe/Coff file.
2291 //
2292 goto Done;
2293 }
2294
2295 if (mNtHeader.Pe32->FileHeader.Machine == IMAGE_FILE_MACHINE_IA64 && mNtHeader.Pe32->OptionalHeader.Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
2296 //
2297 // NOTE: Some versions of Linux ELILO for Itanium have an incorrect magic value
2298 // in the PE/COFF Header. If the MachineType is Itanium(IA64) and the
2299 // Magic value in the OptionalHeader is EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC
2300 // then override the magic value to EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC
2301 //
2302 Magic = EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC;
2303 } else {
2304 //
2305 // Get the magic value from the PE/COFF Optional Header
2306 //
2307 Magic = mNtHeader.Pe32->OptionalHeader.Magic;
2308 }
2309
2310 if (Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
2311 //
2312 // Use PE32 offset.
2313 //
2314 NumberOfRvaAndSizes = mNtHeader.Pe32->OptionalHeader.NumberOfRvaAndSizes;
2315 if (NumberOfRvaAndSizes > EFI_IMAGE_DIRECTORY_ENTRY_SECURITY) {
2316 SecDataDir = (EFI_IMAGE_DATA_DIRECTORY *) &mNtHeader.Pe32->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY];
2317 }
2318 } else {
2319 //
2320 // Use PE32+ offset.
2321 //
2322 NumberOfRvaAndSizes = mNtHeader.Pe32Plus->OptionalHeader.NumberOfRvaAndSizes;
2323 if (NumberOfRvaAndSizes > EFI_IMAGE_DIRECTORY_ENTRY_SECURITY) {
2324 SecDataDir = (EFI_IMAGE_DATA_DIRECTORY *) &mNtHeader.Pe32Plus->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY];
2325 }
2326 }
2327
2328 //
2329 // Start Image Validation.
2330 //
2331 if (SecDataDir == NULL || SecDataDir->Size == 0) {
2332 //
2333 // This image is not signed. The SHA256 hash value of the image must match a record in the security database "db",
2334 // and not be reflected in the security data base "dbx".
2335 //
2336 if (!HashPeImage (HASHALG_SHA256)) {
2337 goto Done;
2338 }
2339
2340 if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE1, mImageDigest, &mCertType, mImageDigestSize)) {
2341 //
2342 // Image Hash is in forbidden database (DBX).
2343 //
2344 goto Done;
2345 }
2346
2347 if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE, mImageDigest, &mCertType, mImageDigestSize)) {
2348 //
2349 // Image Hash is in allowed database (DB).
2350 //
2351 return EFI_SUCCESS;
2352 }
2353
2354 //
2355 // Image Hash is not found in both forbidden and allowed database.
2356 //
2357 goto Done;
2358 }
2359
2360 //
2361 // Verify the signature of the image, multiple signatures are allowed as per PE/COFF Section 4.7
2362 // "Attribute Certificate Table".
2363 // The first certificate starts at offset (SecDataDir->VirtualAddress) from the start of the file.
2364 //
2365 for (OffSet = SecDataDir->VirtualAddress;
2366 OffSet < (SecDataDir->VirtualAddress + SecDataDir->Size);
2367 OffSet += (WinCertificate->dwLength + ALIGN_SIZE (WinCertificate->dwLength))) {
2368 WinCertificate = (WIN_CERTIFICATE *) (mImageBase + OffSet);
2369 if ((SecDataDir->VirtualAddress + SecDataDir->Size - OffSet) <= sizeof (WIN_CERTIFICATE) ||
2370 (SecDataDir->VirtualAddress + SecDataDir->Size - OffSet) < WinCertificate->dwLength) {
2371 break;
2372 }
2373
2374 //
2375 // Verify the image's Authenticode signature, only DER-encoded PKCS#7 signed data is supported.
2376 //
2377 if (WinCertificate->wCertificateType == WIN_CERT_TYPE_PKCS_SIGNED_DATA) {
2378 //
2379 // The certificate is formatted as WIN_CERTIFICATE_EFI_PKCS which is described in the
2380 // Authenticode specification.
2381 //
2382 PkcsCertData = (WIN_CERTIFICATE_EFI_PKCS *) WinCertificate;
2383 if (PkcsCertData->Hdr.dwLength <= sizeof (PkcsCertData->Hdr)) {
2384 break;
2385 }
2386 AuthData = PkcsCertData->CertData;
2387 AuthDataSize = PkcsCertData->Hdr.dwLength - sizeof(PkcsCertData->Hdr);
2388 } else if (WinCertificate->wCertificateType == WIN_CERT_TYPE_EFI_GUID) {
2389 //
2390 // The certificate is formatted as WIN_CERTIFICATE_UEFI_GUID which is described in UEFI Spec.
2391 //
2392 WinCertUefiGuid = (WIN_CERTIFICATE_UEFI_GUID *) WinCertificate;
2393 if (WinCertUefiGuid->Hdr.dwLength <= OFFSET_OF(WIN_CERTIFICATE_UEFI_GUID, CertData)) {
2394 break;
2395 }
2396 if (!CompareGuid (&WinCertUefiGuid->CertType, &gEfiCertPkcs7Guid)) {
2397 continue;
2398 }
2399 AuthData = WinCertUefiGuid->CertData;
2400 AuthDataSize = WinCertUefiGuid->Hdr.dwLength - OFFSET_OF(WIN_CERTIFICATE_UEFI_GUID, CertData);
2401 } else {
2402 if (WinCertificate->dwLength < sizeof (WIN_CERTIFICATE)) {
2403 break;
2404 }
2405 continue;
2406 }
2407
2408 Status = HashPeImageByType (AuthData, AuthDataSize);
2409 if (EFI_ERROR (Status)) {
2410 continue;
2411 }
2412
2413 //
2414 // Check the digital signature against the revoked certificate in forbidden database (dbx).
2415 //
2416 if (IsForbiddenByDbx (AuthData, AuthDataSize, FALSE, NULL, NULL)) {
2417 Action = EFI_IMAGE_EXECUTION_AUTH_SIG_FAILED;
2418 VerifyStatus = EFI_ACCESS_DENIED;
2419 break;
2420 }
2421
2422 //
2423 // Check the digital signature against the valid certificate in allowed database (db).
2424 //
2425 if (EFI_ERROR (VerifyStatus)) {
2426 if (IsAllowedByDb (AuthData, AuthDataSize, FALSE, NULL, NULL)) {
2427 VerifyStatus = EFI_SUCCESS;
2428 }
2429 }
2430
2431 //
2432 // Check the image's hash value.
2433 //
2434 if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE1, mImageDigest, &mCertType, mImageDigestSize)) {
2435 Action = EFI_IMAGE_EXECUTION_AUTH_SIG_FOUND;
2436 VerifyStatus = EFI_ACCESS_DENIED;
2437 break;
2438 } else if (EFI_ERROR (VerifyStatus)) {
2439 if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE, mImageDigest, &mCertType, mImageDigestSize)) {
2440 VerifyStatus = EFI_SUCCESS;
2441 }
2442 }
2443 }
2444
2445 if (OffSet != (SecDataDir->VirtualAddress + SecDataDir->Size)) {
2446 //
2447 // The Size in Certificate Table or the attribute certicate table is corrupted.
2448 //
2449 VerifyStatus = EFI_ACCESS_DENIED;
2450 }
2451
2452 if (!EFI_ERROR (VerifyStatus)) {
2453 return EFI_SUCCESS;
2454 } else {
2455 Status = EFI_ACCESS_DENIED;
2456 if (Action == EFI_IMAGE_EXECUTION_AUTH_SIG_FAILED || Action == EFI_IMAGE_EXECUTION_AUTH_SIG_FOUND) {
2457 //
2458 // Get image hash value as executable's signature.
2459 //
2460 SignatureListSize = sizeof (EFI_SIGNATURE_LIST) + sizeof (EFI_SIGNATURE_DATA) - 1 + mImageDigestSize;
2461 SignatureList = (EFI_SIGNATURE_LIST *) AllocateZeroPool (SignatureListSize);
2462 if (SignatureList == NULL) {
2463 Status = EFI_OUT_OF_RESOURCES;
2464 goto Done;
2465 }
2466 SignatureList->SignatureHeaderSize = 0;
2467 SignatureList->SignatureListSize = (UINT32) SignatureListSize;
2468 SignatureList->SignatureSize = (UINT32) (sizeof (EFI_SIGNATURE_DATA) - 1 + mImageDigestSize);
2469 CopyMem (&SignatureList->SignatureType, &mCertType, sizeof (EFI_GUID));
2470 Signature = (EFI_SIGNATURE_DATA *) ((UINT8 *) SignatureList + sizeof (EFI_SIGNATURE_LIST));
2471 CopyMem (Signature->SignatureData, mImageDigest, mImageDigestSize);
2472 }
2473 }
2474
2475 Done:
2476 if (Status != EFI_SUCCESS) {
2477 //
2478 // Policy decides to defer or reject the image; add its information in image executable information table.
2479 //
2480 NameStr = ConvertDevicePathToText (File, FALSE, TRUE);
2481 AddImageExeInfo (Action, NameStr, File, SignatureList, SignatureListSize);
2482 if (NameStr != NULL) {
2483 DEBUG((EFI_D_INFO, "The image doesn't pass verification: %s\n", NameStr));
2484 FreePool(NameStr);
2485 }
2486 Status = EFI_SECURITY_VIOLATION;
2487 }
2488
2489 if (SignatureList != NULL) {
2490 FreePool (SignatureList);
2491 }
2492
2493 return Status;
2494 }
2495
2496 /**
2497 On Ready To Boot Services Event notification handler.
2498
2499 Add the image execution information table if it is not in system configuration table.
2500
2501 @param[in] Event Event whose notification function is being invoked
2502 @param[in] Context Pointer to the notification function's context
2503
2504 **/
2505 VOID
2506 EFIAPI
2507 OnReadyToBoot (
2508 IN EFI_EVENT Event,
2509 IN VOID *Context
2510 )
2511 {
2512 EFI_IMAGE_EXECUTION_INFO_TABLE *ImageExeInfoTable;
2513 UINTN ImageExeInfoTableSize;
2514
2515 EfiGetSystemConfigurationTable (&gEfiImageSecurityDatabaseGuid, (VOID **) &ImageExeInfoTable);
2516 if (ImageExeInfoTable != NULL) {
2517 return;
2518 }
2519
2520 ImageExeInfoTableSize = sizeof (EFI_IMAGE_EXECUTION_INFO_TABLE);
2521 ImageExeInfoTable = (EFI_IMAGE_EXECUTION_INFO_TABLE *) AllocateRuntimePool (ImageExeInfoTableSize);
2522 if (ImageExeInfoTable == NULL) {
2523 return ;
2524 }
2525
2526 ImageExeInfoTable->NumberOfImages = 0;
2527 gBS->InstallConfigurationTable (&gEfiImageSecurityDatabaseGuid, (VOID *) ImageExeInfoTable);
2528
2529 }
2530
2531 /**
2532 Register security measurement handler.
2533
2534 @param ImageHandle ImageHandle of the loaded driver.
2535 @param SystemTable Pointer to the EFI System Table.
2536
2537 @retval EFI_SUCCESS The handlers were registered successfully.
2538 **/
2539 EFI_STATUS
2540 EFIAPI
2541 DxeImageVerificationLibConstructor (
2542 IN EFI_HANDLE ImageHandle,
2543 IN EFI_SYSTEM_TABLE *SystemTable
2544 )
2545 {
2546 EFI_EVENT Event;
2547
2548 //
2549 // Register the event to publish the image execution table.
2550 //
2551 EfiCreateEventReadyToBootEx (
2552 TPL_CALLBACK,
2553 OnReadyToBoot,
2554 NULL,
2555 &Event
2556 );
2557
2558 return RegisterSecurity2Handler (
2559 DxeImageVerificationHandler,
2560 EFI_AUTH_OPERATION_VERIFY_IMAGE | EFI_AUTH_OPERATION_IMAGE_REQUIRED
2561 );
2562 }
EFI Development Kit II mirror for PVE