Add the missed local variable initialization to remove the possible warning.
[mirror_edk2.git] / SecurityPkg / Library / DxeImageVerificationLib / DxeImageVerificationLib.c
1 /** @file
2 Implement image verification services for secure boot service in UEFI2.3.1.
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 - 2015, 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 Caculate 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 caculate 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 an Image Execution Information Table entry and add it to system configuration table.
716
717 @param[in] Action Describes the action taken by the firmware regarding this image.
718 @param[in] Name Input a null-terminated, user-friendly name.
719 @param[in] DevicePath Input device path pointer.
720 @param[in] Signature Input signature info in EFI_SIGNATURE_LIST data structure.
721 @param[in] SignatureSize Size of signature.
722
723 **/
724 VOID
725 AddImageExeInfo (
726 IN EFI_IMAGE_EXECUTION_ACTION Action,
727 IN CHAR16 *Name OPTIONAL,
728 IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath,
729 IN EFI_SIGNATURE_LIST *Signature OPTIONAL,
730 IN UINTN SignatureSize
731 )
732 {
733 EFI_IMAGE_EXECUTION_INFO_TABLE *ImageExeInfoTable;
734 EFI_IMAGE_EXECUTION_INFO_TABLE *NewImageExeInfoTable;
735 EFI_IMAGE_EXECUTION_INFO *ImageExeInfoEntry;
736 UINTN ImageExeInfoTableSize;
737 UINTN NewImageExeInfoEntrySize;
738 UINTN NameStringLen;
739 UINTN DevicePathSize;
740
741 ImageExeInfoTable = NULL;
742 NewImageExeInfoTable = NULL;
743 ImageExeInfoEntry = NULL;
744 NameStringLen = 0;
745
746 if (DevicePath == NULL) {
747 return ;
748 }
749
750 if (Name != NULL) {
751 NameStringLen = StrSize (Name);
752 } else {
753 NameStringLen = sizeof (CHAR16);
754 }
755
756 EfiGetSystemConfigurationTable (&gEfiImageSecurityDatabaseGuid, (VOID **) &ImageExeInfoTable);
757 if (ImageExeInfoTable != NULL) {
758 //
759 // The table has been found!
760 // We must enlarge the table to accomodate the new exe info entry.
761 //
762 ImageExeInfoTableSize = GetImageExeInfoTableSize (ImageExeInfoTable);
763 } else {
764 //
765 // Not Found!
766 // We should create a new table to append to the configuration table.
767 //
768 ImageExeInfoTableSize = sizeof (EFI_IMAGE_EXECUTION_INFO_TABLE);
769 }
770
771 DevicePathSize = GetDevicePathSize (DevicePath);
772 NewImageExeInfoEntrySize = sizeof (EFI_IMAGE_EXECUTION_INFO) - sizeof (EFI_SIGNATURE_LIST) + NameStringLen + DevicePathSize + SignatureSize;
773 NewImageExeInfoTable = (EFI_IMAGE_EXECUTION_INFO_TABLE *) AllocateRuntimePool (ImageExeInfoTableSize + NewImageExeInfoEntrySize);
774 if (NewImageExeInfoTable == NULL) {
775 return ;
776 }
777
778 if (ImageExeInfoTable != NULL) {
779 CopyMem (NewImageExeInfoTable, ImageExeInfoTable, ImageExeInfoTableSize);
780 } else {
781 NewImageExeInfoTable->NumberOfImages = 0;
782 }
783 NewImageExeInfoTable->NumberOfImages++;
784 ImageExeInfoEntry = (EFI_IMAGE_EXECUTION_INFO *) ((UINT8 *) NewImageExeInfoTable + ImageExeInfoTableSize);
785 //
786 // Update new item's information.
787 //
788 WriteUnaligned32 ((UINT32 *) ImageExeInfoEntry, Action);
789 WriteUnaligned32 ((UINT32 *) ((UINT8 *) ImageExeInfoEntry + sizeof (EFI_IMAGE_EXECUTION_ACTION)), (UINT32) NewImageExeInfoEntrySize);
790
791 if (Name != NULL) {
792 CopyMem ((UINT8 *) ImageExeInfoEntry + sizeof (EFI_IMAGE_EXECUTION_ACTION) + sizeof (UINT32), Name, NameStringLen);
793 } else {
794 ZeroMem ((UINT8 *) ImageExeInfoEntry + sizeof (EFI_IMAGE_EXECUTION_ACTION) + sizeof (UINT32), sizeof (CHAR16));
795 }
796 CopyMem (
797 (UINT8 *) ImageExeInfoEntry + sizeof (EFI_IMAGE_EXECUTION_ACTION) + sizeof (UINT32) + NameStringLen,
798 DevicePath,
799 DevicePathSize
800 );
801 if (Signature != NULL) {
802 CopyMem (
803 (UINT8 *) ImageExeInfoEntry + sizeof (EFI_IMAGE_EXECUTION_ACTION) + sizeof (UINT32) + NameStringLen + DevicePathSize,
804 Signature,
805 SignatureSize
806 );
807 }
808 //
809 // Update/replace the image execution table.
810 //
811 gBS->InstallConfigurationTable (&gEfiImageSecurityDatabaseGuid, (VOID *) NewImageExeInfoTable);
812
813 //
814 // Free Old table data!
815 //
816 if (ImageExeInfoTable != NULL) {
817 FreePool (ImageExeInfoTable);
818 }
819 }
820
821 /**
822 Check whether the hash of an given X.509 certificate is in forbidden database (DBX).
823
824 @param[in] Certificate Pointer to X.509 Certificate that is searched for.
825 @param[in] CertSize Size of X.509 Certificate.
826 @param[in] SignatureList Pointer to the Signature List in forbidden database.
827 @param[in] SignatureListSize Size of Signature List.
828 @param[out] RevocationTime Return the time that the certificate was revoked.
829
830 @return TRUE The certificate hash is found in the forbidden database.
831 @return FALSE The certificate hash is not found in the forbidden database.
832
833 **/
834 BOOLEAN
835 IsCertHashFoundInDatabase (
836 IN UINT8 *Certificate,
837 IN UINTN CertSize,
838 IN EFI_SIGNATURE_LIST *SignatureList,
839 IN UINTN SignatureListSize,
840 OUT EFI_TIME *RevocationTime
841 )
842 {
843 BOOLEAN IsFound;
844 BOOLEAN Status;
845 EFI_SIGNATURE_LIST *DbxList;
846 UINTN DbxSize;
847 EFI_SIGNATURE_DATA *CertHash;
848 UINTN CertHashCount;
849 UINTN Index;
850 UINT32 HashAlg;
851 VOID *HashCtx;
852 UINT8 CertDigest[MAX_DIGEST_SIZE];
853 UINT8 *DbxCertHash;
854 UINTN SiglistHeaderSize;
855 UINT8 *TBSCert;
856 UINTN TBSCertSize;
857
858 IsFound = FALSE;
859 DbxList = SignatureList;
860 DbxSize = SignatureListSize;
861 HashCtx = NULL;
862 HashAlg = HASHALG_MAX;
863
864 if ((RevocationTime == NULL) || (DbxList == NULL)) {
865 return FALSE;
866 }
867
868 //
869 // Retrieve the TBSCertificate from the X.509 Certificate.
870 //
871 if (!X509GetTBSCert (Certificate, CertSize, &TBSCert, &TBSCertSize)) {
872 return FALSE;
873 }
874
875 while ((DbxSize > 0) && (SignatureListSize >= DbxList->SignatureListSize)) {
876 //
877 // Determine Hash Algorithm of Certificate in the forbidden database.
878 //
879 if (CompareGuid (&DbxList->SignatureType, &gEfiCertX509Sha256Guid)) {
880 HashAlg = HASHALG_SHA256;
881 } else if (CompareGuid (&DbxList->SignatureType, &gEfiCertX509Sha384Guid)) {
882 HashAlg = HASHALG_SHA384;
883 } else if (CompareGuid (&DbxList->SignatureType, &gEfiCertX509Sha512Guid)) {
884 HashAlg = HASHALG_SHA512;
885 } else {
886 DbxSize -= DbxList->SignatureListSize;
887 DbxList = (EFI_SIGNATURE_LIST *) ((UINT8 *) DbxList + DbxList->SignatureListSize);
888 continue;
889 }
890
891 //
892 // Calculate the hash value of current TBSCertificate for comparision.
893 //
894 if (mHash[HashAlg].GetContextSize == NULL) {
895 goto Done;
896 }
897 ZeroMem (CertDigest, MAX_DIGEST_SIZE);
898 HashCtx = AllocatePool (mHash[HashAlg].GetContextSize ());
899 if (HashCtx == NULL) {
900 goto Done;
901 }
902 Status = mHash[HashAlg].HashInit (HashCtx);
903 if (!Status) {
904 goto Done;
905 }
906 Status = mHash[HashAlg].HashUpdate (HashCtx, TBSCert, TBSCertSize);
907 if (!Status) {
908 goto Done;
909 }
910 Status = mHash[HashAlg].HashFinal (HashCtx, CertDigest);
911 if (!Status) {
912 goto Done;
913 }
914
915 SiglistHeaderSize = sizeof (EFI_SIGNATURE_LIST) + DbxList->SignatureHeaderSize;
916 CertHash = (EFI_SIGNATURE_DATA *) ((UINT8 *) DbxList + SiglistHeaderSize);
917 CertHashCount = (DbxList->SignatureListSize - SiglistHeaderSize) / DbxList->SignatureSize;
918 for (Index = 0; Index < CertHashCount; Index++) {
919 //
920 // Iterate each Signature Data Node within this CertList for verify.
921 //
922 DbxCertHash = CertHash->SignatureData;
923 if (CompareMem (DbxCertHash, CertDigest, mHash[HashAlg].DigestLength) == 0) {
924 //
925 // Hash of Certificate is found in forbidden database.
926 //
927 IsFound = TRUE;
928
929 //
930 // Return the revocation time.
931 //
932 CopyMem (RevocationTime, (EFI_TIME *)(DbxCertHash + mHash[HashAlg].DigestLength), sizeof (EFI_TIME));
933 goto Done;
934 }
935 CertHash = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertHash + DbxList->SignatureSize);
936 }
937
938 DbxSize -= DbxList->SignatureListSize;
939 DbxList = (EFI_SIGNATURE_LIST *) ((UINT8 *) DbxList + DbxList->SignatureListSize);
940 }
941
942 Done:
943 if (HashCtx != NULL) {
944 FreePool (HashCtx);
945 }
946
947 return IsFound;
948 }
949
950 /**
951 Check whether signature is in specified database.
952
953 @param[in] VariableName Name of database variable that is searched in.
954 @param[in] Signature Pointer to signature that is searched for.
955 @param[in] CertType Pointer to hash algrithom.
956 @param[in] SignatureSize Size of Signature.
957
958 @return TRUE Found the signature in the variable database.
959 @return FALSE Not found the signature in the variable database.
960
961 **/
962 BOOLEAN
963 IsSignatureFoundInDatabase (
964 IN CHAR16 *VariableName,
965 IN UINT8 *Signature,
966 IN EFI_GUID *CertType,
967 IN UINTN SignatureSize
968 )
969 {
970 EFI_STATUS Status;
971 EFI_SIGNATURE_LIST *CertList;
972 EFI_SIGNATURE_DATA *Cert;
973 UINTN DataSize;
974 UINT8 *Data;
975 UINTN Index;
976 UINTN CertCount;
977 BOOLEAN IsFound;
978
979 //
980 // Read signature database variable.
981 //
982 IsFound = FALSE;
983 Data = NULL;
984 DataSize = 0;
985 Status = gRT->GetVariable (VariableName, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, NULL);
986 if (Status != EFI_BUFFER_TOO_SMALL) {
987 return FALSE;
988 }
989
990 Data = (UINT8 *) AllocateZeroPool (DataSize);
991 if (Data == NULL) {
992 return FALSE;
993 }
994
995 Status = gRT->GetVariable (VariableName, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, Data);
996 if (EFI_ERROR (Status)) {
997 goto Done;
998 }
999 //
1000 // Enumerate all signature data in SigDB to check if executable's signature exists.
1001 //
1002 CertList = (EFI_SIGNATURE_LIST *) Data;
1003 while ((DataSize > 0) && (DataSize >= CertList->SignatureListSize)) {
1004 CertCount = (CertList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - CertList->SignatureHeaderSize) / CertList->SignatureSize;
1005 Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertList + sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize);
1006 if ((CertList->SignatureSize == sizeof(EFI_SIGNATURE_DATA) - 1 + SignatureSize) && (CompareGuid(&CertList->SignatureType, CertType))) {
1007 for (Index = 0; Index < CertCount; Index++) {
1008 if (CompareMem (Cert->SignatureData, Signature, SignatureSize) == 0) {
1009 //
1010 // Find the signature in database.
1011 //
1012 IsFound = TRUE;
1013 SecureBootHook (VariableName, &gEfiImageSecurityDatabaseGuid, CertList->SignatureSize, Cert);
1014 break;
1015 }
1016
1017 Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) Cert + CertList->SignatureSize);
1018 }
1019
1020 if (IsFound) {
1021 break;
1022 }
1023 }
1024
1025 DataSize -= CertList->SignatureListSize;
1026 CertList = (EFI_SIGNATURE_LIST *) ((UINT8 *) CertList + CertList->SignatureListSize);
1027 }
1028
1029 Done:
1030 if (Data != NULL) {
1031 FreePool (Data);
1032 }
1033
1034 return IsFound;
1035 }
1036
1037 /**
1038 Check whether the timestamp is valid by comparing the signing time and the revocation time.
1039
1040 @param SigningTime A pointer to the signing time.
1041 @param RevocationTime A pointer to the revocation time.
1042
1043 @retval TRUE The SigningTime is not later than the RevocationTime.
1044 @retval FALSE The SigningTime is later than the RevocationTime.
1045
1046 **/
1047 BOOLEAN
1048 IsValidSignatureByTimestamp (
1049 IN EFI_TIME *SigningTime,
1050 IN EFI_TIME *RevocationTime
1051 )
1052 {
1053 if (SigningTime->Year != RevocationTime->Year) {
1054 return (BOOLEAN) (SigningTime->Year < RevocationTime->Year);
1055 } else if (SigningTime->Month != RevocationTime->Month) {
1056 return (BOOLEAN) (SigningTime->Month < RevocationTime->Month);
1057 } else if (SigningTime->Day != RevocationTime->Day) {
1058 return (BOOLEAN) (SigningTime->Day < RevocationTime->Day);
1059 } else if (SigningTime->Hour != RevocationTime->Hour) {
1060 return (BOOLEAN) (SigningTime->Hour < RevocationTime->Hour);
1061 } else if (SigningTime->Minute != RevocationTime->Minute) {
1062 return (BOOLEAN) (SigningTime->Minute < RevocationTime->Minute);
1063 }
1064
1065 return (BOOLEAN) (SigningTime->Second <= RevocationTime->Second);
1066 }
1067
1068 /**
1069 Check if the given time value is zero.
1070
1071 @param[in] Time Pointer of a time value.
1072
1073 @retval TRUE The Time is Zero.
1074 @retval FALSE The Time is not Zero.
1075
1076 **/
1077 BOOLEAN
1078 IsTimeZero (
1079 IN EFI_TIME *Time
1080 )
1081 {
1082 if ((Time->Year == 0) && (Time->Month == 0) && (Time->Day == 0) &&
1083 (Time->Hour == 0) && (Time->Minute == 0) && (Time->Second == 0)) {
1084 return TRUE;
1085 }
1086
1087 return FALSE;
1088 }
1089
1090 /**
1091 Check whether the timestamp signature is valid and the signing time is also earlier than
1092 the revocation time.
1093
1094 @param[in] AuthData Pointer to the Authenticode signature retrieved from signed image.
1095 @param[in] AuthDataSize Size of the Authenticode signature in bytes.
1096 @param[in] RevocationTime The time that the certificate was revoked.
1097
1098 @retval TRUE Timestamp signature is valid and signing time is no later than the
1099 revocation time.
1100 @retval FALSE Timestamp signature is not valid or the signing time is later than the
1101 revocation time.
1102
1103 **/
1104 BOOLEAN
1105 PassTimestampCheck (
1106 IN UINT8 *AuthData,
1107 IN UINTN AuthDataSize,
1108 IN EFI_TIME *RevocationTime
1109 )
1110 {
1111 EFI_STATUS Status;
1112 BOOLEAN VerifyStatus;
1113 EFI_SIGNATURE_LIST *CertList;
1114 EFI_SIGNATURE_DATA *Cert;
1115 UINT8 *DbtData;
1116 UINTN DbtDataSize;
1117 UINT8 *RootCert;
1118 UINTN RootCertSize;
1119 UINTN Index;
1120 UINTN CertCount;
1121 EFI_TIME SigningTime;
1122
1123 //
1124 // Variable Initialization
1125 //
1126 VerifyStatus = FALSE;
1127 DbtData = NULL;
1128 CertList = NULL;
1129 Cert = NULL;
1130 RootCert = NULL;
1131 RootCertSize = 0;
1132
1133 //
1134 // If RevocationTime is zero, the certificate shall be considered to always be revoked.
1135 //
1136 if (IsTimeZero (RevocationTime)) {
1137 return FALSE;
1138 }
1139
1140 //
1141 // RevocationTime is non-zero, the certificate should be considered to be revoked from that time and onwards.
1142 // Using the dbt to get the trusted TSA certificates.
1143 //
1144 DbtDataSize = 0;
1145 Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE2, &gEfiImageSecurityDatabaseGuid, NULL, &DbtDataSize, NULL);
1146 if (Status != EFI_BUFFER_TOO_SMALL) {
1147 goto Done;
1148 }
1149 DbtData = (UINT8 *) AllocateZeroPool (DbtDataSize);
1150 if (DbtData == NULL) {
1151 goto Done;
1152 }
1153 Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE2, &gEfiImageSecurityDatabaseGuid, NULL, &DbtDataSize, (VOID *) DbtData);
1154 if (EFI_ERROR (Status)) {
1155 goto Done;
1156 }
1157
1158 CertList = (EFI_SIGNATURE_LIST *) DbtData;
1159 while ((DbtDataSize > 0) && (DbtDataSize >= CertList->SignatureListSize)) {
1160 if (CompareGuid (&CertList->SignatureType, &gEfiCertX509Guid)) {
1161 Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertList + sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize);
1162 CertCount = (CertList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - CertList->SignatureHeaderSize) / CertList->SignatureSize;
1163 for (Index = 0; Index < CertCount; Index++) {
1164 //
1165 // Iterate each Signature Data Node within this CertList for verify.
1166 //
1167 RootCert = Cert->SignatureData;
1168 RootCertSize = CertList->SignatureSize - sizeof (EFI_GUID);
1169 //
1170 // Get the signing time if the timestamp signature is valid.
1171 //
1172 if (ImageTimestampVerify (AuthData, AuthDataSize, RootCert, RootCertSize, &SigningTime)) {
1173 //
1174 // The signer signature is valid only when the signing time is earlier than revocation time.
1175 //
1176 if (IsValidSignatureByTimestamp (&SigningTime, RevocationTime)) {
1177 VerifyStatus = TRUE;
1178 goto Done;
1179 }
1180 }
1181 Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) Cert + CertList->SignatureSize);
1182 }
1183 }
1184 DbtDataSize -= CertList->SignatureListSize;
1185 CertList = (EFI_SIGNATURE_LIST *) ((UINT8 *) CertList + CertList->SignatureListSize);
1186 }
1187
1188 Done:
1189 if (DbtData != NULL) {
1190 FreePool (DbtData);
1191 }
1192
1193 return VerifyStatus;
1194 }
1195
1196 /**
1197 Check whether the image signature is forbidden by the forbidden database (dbx).
1198 The image is forbidden to load if any certificates for signing are revoked before signing time.
1199
1200 @param[in] AuthData Pointer to the Authenticode signature retrieved from the signed image.
1201 @param[in] AuthDataSize Size of the Authenticode signature in bytes.
1202
1203 @retval TRUE Image is forbidden by dbx.
1204 @retval FALSE Image is not forbidden by dbx.
1205
1206 **/
1207 BOOLEAN
1208 IsForbiddenByDbx (
1209 IN UINT8 *AuthData,
1210 IN UINTN AuthDataSize
1211 )
1212 {
1213 EFI_STATUS Status;
1214 BOOLEAN IsForbidden;
1215 UINT8 *Data;
1216 UINTN DataSize;
1217 EFI_SIGNATURE_LIST *CertList;
1218 UINTN CertListSize;
1219 EFI_SIGNATURE_DATA *CertData;
1220 UINT8 *RootCert;
1221 UINTN RootCertSize;
1222 UINTN CertCount;
1223 UINTN Index;
1224 UINT8 *CertBuffer;
1225 UINTN BufferLength;
1226 UINT8 *TrustedCert;
1227 UINTN TrustedCertLength;
1228 UINT8 CertNumber;
1229 UINT8 *CertPtr;
1230 UINT8 *Cert;
1231 UINTN CertSize;
1232 EFI_TIME RevocationTime;
1233
1234 //
1235 // Variable Initialization
1236 //
1237 IsForbidden = FALSE;
1238 Data = NULL;
1239 CertList = NULL;
1240 CertData = NULL;
1241 RootCert = NULL;
1242 RootCertSize = 0;
1243 Cert = NULL;
1244 CertBuffer = NULL;
1245 BufferLength = 0;
1246 TrustedCert = NULL;
1247 TrustedCertLength = 0;
1248
1249 //
1250 // The image will not be forbidden if dbx can't be got.
1251 //
1252 DataSize = 0;
1253 Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE1, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, NULL);
1254 if (Status != EFI_BUFFER_TOO_SMALL) {
1255 return IsForbidden;
1256 }
1257 Data = (UINT8 *) AllocateZeroPool (DataSize);
1258 if (Data == NULL) {
1259 return IsForbidden;
1260 }
1261
1262 Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE1, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, (VOID *) Data);
1263 if (EFI_ERROR (Status)) {
1264 return IsForbidden;
1265 }
1266
1267 //
1268 // Verify image signature with RAW X509 certificates in DBX database.
1269 // If passed, the image will be forbidden.
1270 //
1271 CertList = (EFI_SIGNATURE_LIST *) Data;
1272 CertListSize = DataSize;
1273 while ((CertListSize > 0) && (CertListSize >= CertList->SignatureListSize)) {
1274 if (CompareGuid (&CertList->SignatureType, &gEfiCertX509Guid)) {
1275 CertData = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertList + sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize);
1276 CertCount = (CertList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - CertList->SignatureHeaderSize) / CertList->SignatureSize;
1277
1278 for (Index = 0; Index < CertCount; Index++) {
1279 //
1280 // Iterate each Signature Data Node within this CertList for verify.
1281 //
1282 RootCert = CertData->SignatureData;
1283 RootCertSize = CertList->SignatureSize - sizeof (EFI_GUID);
1284
1285 //
1286 // Call AuthenticodeVerify library to Verify Authenticode struct.
1287 //
1288 IsForbidden = AuthenticodeVerify (
1289 AuthData,
1290 AuthDataSize,
1291 RootCert,
1292 RootCertSize,
1293 mImageDigest,
1294 mImageDigestSize
1295 );
1296 if (IsForbidden) {
1297 SecureBootHook (EFI_IMAGE_SECURITY_DATABASE1, &gEfiImageSecurityDatabaseGuid, CertList->SignatureSize, Cert);
1298 goto Done;
1299 }
1300
1301 CertData = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertData + CertList->SignatureSize);
1302 }
1303 }
1304
1305 CertListSize -= CertList->SignatureListSize;
1306 CertList = (EFI_SIGNATURE_LIST *) ((UINT8 *) CertList + CertList->SignatureListSize);
1307 }
1308
1309 //
1310 // Check X.509 Certificate Hash & Possible Timestamp.
1311 //
1312
1313 //
1314 // Retrieve the certificate stack from AuthData
1315 // The output CertStack format will be:
1316 // UINT8 CertNumber;
1317 // UINT32 Cert1Length;
1318 // UINT8 Cert1[];
1319 // UINT32 Cert2Length;
1320 // UINT8 Cert2[];
1321 // ...
1322 // UINT32 CertnLength;
1323 // UINT8 Certn[];
1324 //
1325 Pkcs7GetSigners (AuthData, AuthDataSize, &CertBuffer, &BufferLength, &TrustedCert, &TrustedCertLength);
1326 if ((BufferLength == 0) || (CertBuffer == NULL)) {
1327 IsForbidden = TRUE;
1328 goto Done;
1329 }
1330
1331 //
1332 // Check if any hash of certificates embedded in AuthData is in the forbidden database.
1333 //
1334 CertNumber = (UINT8) (*CertBuffer);
1335 CertPtr = CertBuffer + 1;
1336 for (Index = 0; Index < CertNumber; Index++) {
1337 CertSize = (UINTN) ReadUnaligned32 ((UINT32 *)CertPtr);
1338 Cert = (UINT8 *)CertPtr + sizeof (UINT32);
1339
1340 if (IsCertHashFoundInDatabase (Cert, CertSize, (EFI_SIGNATURE_LIST *)Data, DataSize, &RevocationTime)) {
1341 //
1342 // Check the timestamp signature and signing time to determine if the image can be trusted.
1343 //
1344 IsForbidden = TRUE;
1345 if (PassTimestampCheck (AuthData, AuthDataSize, &RevocationTime)) {
1346 IsForbidden = FALSE;
1347 }
1348 goto Done;
1349 }
1350
1351 CertPtr = CertPtr + sizeof (UINT32) + CertSize;
1352 }
1353
1354 Done:
1355 if (Data != NULL) {
1356 FreePool (Data);
1357 }
1358
1359 Pkcs7FreeSigners (CertBuffer);
1360 Pkcs7FreeSigners (TrustedCert);
1361
1362 return IsForbidden;
1363 }
1364
1365 /**
1366 Check whether the image signature can be verified by the trusted certificates in DB database.
1367
1368 @param[in] AuthData Pointer to the Authenticode signature retrieved from signed image.
1369 @param[in] AuthDataSize Size of the Authenticode signature in bytes.
1370
1371 @retval TRUE Image passed verification using certificate in db.
1372 @retval FALSE Image didn't pass verification using certificate in db.
1373
1374 **/
1375 BOOLEAN
1376 IsAllowedByDb (
1377 IN UINT8 *AuthData,
1378 IN UINTN AuthDataSize
1379 )
1380 {
1381 EFI_STATUS Status;
1382 BOOLEAN VerifyStatus;
1383 EFI_SIGNATURE_LIST *CertList;
1384 EFI_SIGNATURE_DATA *Cert;
1385 UINTN DataSize;
1386 UINT8 *Data;
1387 UINT8 *RootCert;
1388 UINTN RootCertSize;
1389 UINTN Index;
1390 UINTN CertCount;
1391 UINTN DbxDataSize;
1392 UINT8 *DbxData;
1393 EFI_TIME RevocationTime;
1394
1395 Data = NULL;
1396 CertList = NULL;
1397 Cert = NULL;
1398 RootCert = NULL;
1399 DbxData = NULL;
1400 RootCertSize = 0;
1401 VerifyStatus = FALSE;
1402
1403 DataSize = 0;
1404 Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, NULL);
1405 if (Status == EFI_BUFFER_TOO_SMALL) {
1406 Data = (UINT8 *) AllocateZeroPool (DataSize);
1407 if (Data == NULL) {
1408 return VerifyStatus;
1409 }
1410
1411 Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, (VOID *) Data);
1412 if (EFI_ERROR (Status)) {
1413 goto Done;
1414 }
1415
1416 //
1417 // Find X509 certificate in Signature List to verify the signature in pkcs7 signed data.
1418 //
1419 CertList = (EFI_SIGNATURE_LIST *) Data;
1420 while ((DataSize > 0) && (DataSize >= CertList->SignatureListSize)) {
1421 if (CompareGuid (&CertList->SignatureType, &gEfiCertX509Guid)) {
1422 Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertList + sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize);
1423 CertCount = (CertList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - CertList->SignatureHeaderSize) / CertList->SignatureSize;
1424
1425 for (Index = 0; Index < CertCount; Index++) {
1426 //
1427 // Iterate each Signature Data Node within this CertList for verify.
1428 //
1429 RootCert = Cert->SignatureData;
1430 RootCertSize = CertList->SignatureSize - sizeof (EFI_GUID);
1431
1432 //
1433 // Call AuthenticodeVerify library to Verify Authenticode struct.
1434 //
1435 VerifyStatus = AuthenticodeVerify (
1436 AuthData,
1437 AuthDataSize,
1438 RootCert,
1439 RootCertSize,
1440 mImageDigest,
1441 mImageDigestSize
1442 );
1443 if (VerifyStatus) {
1444 //
1445 // Here We still need to check if this RootCert's Hash is revoked
1446 //
1447 Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE1, &gEfiImageSecurityDatabaseGuid, NULL, &DbxDataSize, NULL);
1448 if (Status == EFI_BUFFER_TOO_SMALL) {
1449 goto Done;
1450 }
1451 DbxData = (UINT8 *) AllocateZeroPool (DataSize);
1452 if (DbxData == NULL) {
1453 goto Done;
1454 }
1455
1456 Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE1, &gEfiImageSecurityDatabaseGuid, NULL, &DbxDataSize, (VOID *) DbxData);
1457 if (EFI_ERROR (Status)) {
1458 goto Done;
1459 }
1460
1461 if (IsCertHashFoundInDatabase (RootCert, RootCertSize, (EFI_SIGNATURE_LIST *)DbxData, DbxDataSize, &RevocationTime)) {
1462 //
1463 // Check the timestamp signature and signing time to determine if the image can be trusted.
1464 //
1465 VerifyStatus = PassTimestampCheck (AuthData, AuthDataSize, &RevocationTime);
1466 }
1467
1468 goto Done;
1469 }
1470
1471 Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) Cert + CertList->SignatureSize);
1472 }
1473 }
1474
1475 DataSize -= CertList->SignatureListSize;
1476 CertList = (EFI_SIGNATURE_LIST *) ((UINT8 *) CertList + CertList->SignatureListSize);
1477 }
1478 }
1479
1480 Done:
1481 if (VerifyStatus) {
1482 SecureBootHook (EFI_IMAGE_SECURITY_DATABASE, &gEfiImageSecurityDatabaseGuid, CertList->SignatureSize, Cert);
1483 }
1484
1485 if (Data != NULL) {
1486 FreePool (Data);
1487 }
1488 if (DbxData != NULL) {
1489 FreePool (DbxData);
1490 }
1491
1492 return VerifyStatus;
1493 }
1494
1495 /**
1496 Provide verification service for signed images, which include both signature validation
1497 and platform policy control. For signature types, both UEFI WIN_CERTIFICATE_UEFI_GUID and
1498 MSFT Authenticode type signatures are supported.
1499
1500 In this implementation, only verify external executables when in USER MODE.
1501 Executables from FV is bypass, so pass in AuthenticationStatus is ignored.
1502
1503 The image verification policy is:
1504 If the image is signed,
1505 At least one valid signature or at least one hash value of the image must match a record
1506 in the security database "db", and no valid signature nor any hash value of the image may
1507 be reflected in the security database "dbx".
1508 Otherwise, the image is not signed,
1509 The SHA256 hash value of the image must match a record in the security database "db", and
1510 not be reflected in the security data base "dbx".
1511
1512 Caution: This function may receive untrusted input.
1513 PE/COFF image is external input, so this function will validate its data structure
1514 within this image buffer before use.
1515
1516 @param[in] AuthenticationStatus
1517 This is the authentication status returned from the security
1518 measurement services for the input file.
1519 @param[in] File This is a pointer to the device path of the file that is
1520 being dispatched. This will optionally be used for logging.
1521 @param[in] FileBuffer File buffer matches the input file device path.
1522 @param[in] FileSize Size of File buffer matches the input file device path.
1523 @param[in] BootPolicy A boot policy that was used to call LoadImage() UEFI service.
1524
1525 @retval EFI_SUCCESS The file specified by DevicePath and non-NULL
1526 FileBuffer did authenticate, and the platform policy dictates
1527 that the DXE Foundation may use the file.
1528 @retval EFI_SUCCESS The device path specified by NULL device path DevicePath
1529 and non-NULL FileBuffer did authenticate, and the platform
1530 policy dictates that the DXE Foundation may execute the image in
1531 FileBuffer.
1532 @retval EFI_OUT_RESOURCE Fail to allocate memory.
1533 @retval EFI_SECURITY_VIOLATION The file specified by File did not authenticate, and
1534 the platform policy dictates that File should be placed
1535 in the untrusted state. The image has been added to the file
1536 execution table.
1537 @retval EFI_ACCESS_DENIED The file specified by File and FileBuffer did not
1538 authenticate, and the platform policy dictates that the DXE
1539 Foundation many not use File.
1540
1541 **/
1542 EFI_STATUS
1543 EFIAPI
1544 DxeImageVerificationHandler (
1545 IN UINT32 AuthenticationStatus,
1546 IN CONST EFI_DEVICE_PATH_PROTOCOL *File,
1547 IN VOID *FileBuffer,
1548 IN UINTN FileSize,
1549 IN BOOLEAN BootPolicy
1550 )
1551 {
1552 EFI_STATUS Status;
1553 UINT16 Magic;
1554 EFI_IMAGE_DOS_HEADER *DosHdr;
1555 EFI_STATUS VerifyStatus;
1556 EFI_SIGNATURE_LIST *SignatureList;
1557 UINTN SignatureListSize;
1558 EFI_SIGNATURE_DATA *Signature;
1559 EFI_IMAGE_EXECUTION_ACTION Action;
1560 WIN_CERTIFICATE *WinCertificate;
1561 UINT32 Policy;
1562 UINT8 *SecureBoot;
1563 PE_COFF_LOADER_IMAGE_CONTEXT ImageContext;
1564 UINT32 NumberOfRvaAndSizes;
1565 WIN_CERTIFICATE_EFI_PKCS *PkcsCertData;
1566 WIN_CERTIFICATE_UEFI_GUID *WinCertUefiGuid;
1567 UINT8 *AuthData;
1568 UINTN AuthDataSize;
1569 EFI_IMAGE_DATA_DIRECTORY *SecDataDir;
1570 UINT32 OffSet;
1571 CHAR16 *NameStr;
1572
1573 SignatureList = NULL;
1574 SignatureListSize = 0;
1575 WinCertificate = NULL;
1576 SecDataDir = NULL;
1577 PkcsCertData = NULL;
1578 Action = EFI_IMAGE_EXECUTION_AUTH_UNTESTED;
1579 Status = EFI_ACCESS_DENIED;
1580 VerifyStatus = EFI_ACCESS_DENIED;
1581
1582 //
1583 // Check the image type and get policy setting.
1584 //
1585 switch (GetImageType (File)) {
1586
1587 case IMAGE_FROM_FV:
1588 Policy = ALWAYS_EXECUTE;
1589 break;
1590
1591 case IMAGE_FROM_OPTION_ROM:
1592 Policy = PcdGet32 (PcdOptionRomImageVerificationPolicy);
1593 break;
1594
1595 case IMAGE_FROM_REMOVABLE_MEDIA:
1596 Policy = PcdGet32 (PcdRemovableMediaImageVerificationPolicy);
1597 break;
1598
1599 case IMAGE_FROM_FIXED_MEDIA:
1600 Policy = PcdGet32 (PcdFixedMediaImageVerificationPolicy);
1601 break;
1602
1603 default:
1604 Policy = DENY_EXECUTE_ON_SECURITY_VIOLATION;
1605 break;
1606 }
1607 //
1608 // If policy is always/never execute, return directly.
1609 //
1610 if (Policy == ALWAYS_EXECUTE) {
1611 return EFI_SUCCESS;
1612 } else if (Policy == NEVER_EXECUTE) {
1613 return EFI_ACCESS_DENIED;
1614 }
1615
1616 //
1617 // The policy QUERY_USER_ON_SECURITY_VIOLATION and ALLOW_EXECUTE_ON_SECURITY_VIOLATION
1618 // violates the UEFI spec and has been removed.
1619 //
1620 ASSERT (Policy != QUERY_USER_ON_SECURITY_VIOLATION && Policy != ALLOW_EXECUTE_ON_SECURITY_VIOLATION);
1621 if (Policy == QUERY_USER_ON_SECURITY_VIOLATION || Policy == ALLOW_EXECUTE_ON_SECURITY_VIOLATION) {
1622 CpuDeadLoop ();
1623 }
1624
1625 GetEfiGlobalVariable2 (EFI_SECURE_BOOT_MODE_NAME, (VOID**)&SecureBoot, NULL);
1626 //
1627 // Skip verification if SecureBoot variable doesn't exist.
1628 //
1629 if (SecureBoot == NULL) {
1630 return EFI_SUCCESS;
1631 }
1632
1633 //
1634 // Skip verification if SecureBoot is disabled.
1635 //
1636 if (*SecureBoot == SECURE_BOOT_MODE_DISABLE) {
1637 FreePool (SecureBoot);
1638 return EFI_SUCCESS;
1639 }
1640 FreePool (SecureBoot);
1641
1642 //
1643 // Read the Dos header.
1644 //
1645 if (FileBuffer == NULL) {
1646 return EFI_INVALID_PARAMETER;
1647 }
1648
1649 mImageBase = (UINT8 *) FileBuffer;
1650 mImageSize = FileSize;
1651
1652 ZeroMem (&ImageContext, sizeof (ImageContext));
1653 ImageContext.Handle = (VOID *) FileBuffer;
1654 ImageContext.ImageRead = (PE_COFF_LOADER_READ_FILE) DxeImageVerificationLibImageRead;
1655
1656 //
1657 // Get information about the image being loaded
1658 //
1659 Status = PeCoffLoaderGetImageInfo (&ImageContext);
1660 if (EFI_ERROR (Status)) {
1661 //
1662 // The information can't be got from the invalid PeImage
1663 //
1664 goto Done;
1665 }
1666
1667 Status = EFI_ACCESS_DENIED;
1668
1669 DosHdr = (EFI_IMAGE_DOS_HEADER *) mImageBase;
1670 if (DosHdr->e_magic == EFI_IMAGE_DOS_SIGNATURE) {
1671 //
1672 // DOS image header is present,
1673 // so read the PE header after the DOS image header.
1674 //
1675 mPeCoffHeaderOffset = DosHdr->e_lfanew;
1676 } else {
1677 mPeCoffHeaderOffset = 0;
1678 }
1679 //
1680 // Check PE/COFF image.
1681 //
1682 mNtHeader.Pe32 = (EFI_IMAGE_NT_HEADERS32 *) (mImageBase + mPeCoffHeaderOffset);
1683 if (mNtHeader.Pe32->Signature != EFI_IMAGE_NT_SIGNATURE) {
1684 //
1685 // It is not a valid Pe/Coff file.
1686 //
1687 goto Done;
1688 }
1689
1690 if (mNtHeader.Pe32->FileHeader.Machine == IMAGE_FILE_MACHINE_IA64 && mNtHeader.Pe32->OptionalHeader.Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
1691 //
1692 // NOTE: Some versions of Linux ELILO for Itanium have an incorrect magic value
1693 // in the PE/COFF Header. If the MachineType is Itanium(IA64) and the
1694 // Magic value in the OptionalHeader is EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC
1695 // then override the magic value to EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC
1696 //
1697 Magic = EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC;
1698 } else {
1699 //
1700 // Get the magic value from the PE/COFF Optional Header
1701 //
1702 Magic = mNtHeader.Pe32->OptionalHeader.Magic;
1703 }
1704
1705 if (Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
1706 //
1707 // Use PE32 offset.
1708 //
1709 NumberOfRvaAndSizes = mNtHeader.Pe32->OptionalHeader.NumberOfRvaAndSizes;
1710 if (NumberOfRvaAndSizes > EFI_IMAGE_DIRECTORY_ENTRY_SECURITY) {
1711 SecDataDir = (EFI_IMAGE_DATA_DIRECTORY *) &mNtHeader.Pe32->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY];
1712 }
1713 } else {
1714 //
1715 // Use PE32+ offset.
1716 //
1717 NumberOfRvaAndSizes = mNtHeader.Pe32Plus->OptionalHeader.NumberOfRvaAndSizes;
1718 if (NumberOfRvaAndSizes > EFI_IMAGE_DIRECTORY_ENTRY_SECURITY) {
1719 SecDataDir = (EFI_IMAGE_DATA_DIRECTORY *) &mNtHeader.Pe32Plus->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY];
1720 }
1721 }
1722
1723 //
1724 // Start Image Validation.
1725 //
1726 if (SecDataDir == NULL || SecDataDir->Size == 0) {
1727 //
1728 // This image is not signed. The SHA256 hash value of the image must match a record in the security database "db",
1729 // and not be reflected in the security data base "dbx".
1730 //
1731 if (!HashPeImage (HASHALG_SHA256)) {
1732 goto Done;
1733 }
1734
1735 if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE1, mImageDigest, &mCertType, mImageDigestSize)) {
1736 //
1737 // Image Hash is in forbidden database (DBX).
1738 //
1739 goto Done;
1740 }
1741
1742 if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE, mImageDigest, &mCertType, mImageDigestSize)) {
1743 //
1744 // Image Hash is in allowed database (DB).
1745 //
1746 return EFI_SUCCESS;
1747 }
1748
1749 //
1750 // Image Hash is not found in both forbidden and allowed database.
1751 //
1752 goto Done;
1753 }
1754
1755 //
1756 // Verify the signature of the image, multiple signatures are allowed as per PE/COFF Section 4.7
1757 // "Attribute Certificate Table".
1758 // The first certificate starts at offset (SecDataDir->VirtualAddress) from the start of the file.
1759 //
1760 for (OffSet = SecDataDir->VirtualAddress;
1761 OffSet < (SecDataDir->VirtualAddress + SecDataDir->Size);
1762 OffSet += (WinCertificate->dwLength + ALIGN_SIZE (WinCertificate->dwLength))) {
1763 WinCertificate = (WIN_CERTIFICATE *) (mImageBase + OffSet);
1764 if ((SecDataDir->VirtualAddress + SecDataDir->Size - OffSet) <= sizeof (WIN_CERTIFICATE) ||
1765 (SecDataDir->VirtualAddress + SecDataDir->Size - OffSet) < WinCertificate->dwLength) {
1766 break;
1767 }
1768
1769 //
1770 // Verify the image's Authenticode signature, only DER-encoded PKCS#7 signed data is supported.
1771 //
1772 if (WinCertificate->wCertificateType == WIN_CERT_TYPE_PKCS_SIGNED_DATA) {
1773 //
1774 // The certificate is formatted as WIN_CERTIFICATE_EFI_PKCS which is described in the
1775 // Authenticode specification.
1776 //
1777 PkcsCertData = (WIN_CERTIFICATE_EFI_PKCS *) WinCertificate;
1778 if (PkcsCertData->Hdr.dwLength <= sizeof (PkcsCertData->Hdr)) {
1779 break;
1780 }
1781 AuthData = PkcsCertData->CertData;
1782 AuthDataSize = PkcsCertData->Hdr.dwLength - sizeof(PkcsCertData->Hdr);
1783 } else if (WinCertificate->wCertificateType == WIN_CERT_TYPE_EFI_GUID) {
1784 //
1785 // The certificate is formatted as WIN_CERTIFICATE_UEFI_GUID which is described in UEFI Spec.
1786 //
1787 WinCertUefiGuid = (WIN_CERTIFICATE_UEFI_GUID *) WinCertificate;
1788 if (WinCertUefiGuid->Hdr.dwLength <= OFFSET_OF(WIN_CERTIFICATE_UEFI_GUID, CertData)) {
1789 break;
1790 }
1791 if (!CompareGuid (&WinCertUefiGuid->CertType, &gEfiCertPkcs7Guid)) {
1792 continue;
1793 }
1794 AuthData = WinCertUefiGuid->CertData;
1795 AuthDataSize = WinCertUefiGuid->Hdr.dwLength - OFFSET_OF(WIN_CERTIFICATE_UEFI_GUID, CertData);
1796 } else {
1797 if (WinCertificate->dwLength < sizeof (WIN_CERTIFICATE)) {
1798 break;
1799 }
1800 continue;
1801 }
1802
1803 Status = HashPeImageByType (AuthData, AuthDataSize);
1804 if (EFI_ERROR (Status)) {
1805 continue;
1806 }
1807
1808 //
1809 // Check the digital signature against the revoked certificate in forbidden database (dbx).
1810 //
1811 if (IsForbiddenByDbx (AuthData, AuthDataSize)) {
1812 Action = EFI_IMAGE_EXECUTION_AUTH_SIG_FAILED;
1813 VerifyStatus = EFI_ACCESS_DENIED;
1814 break;
1815 }
1816
1817 //
1818 // Check the digital signature against the valid certificate in allowed database (db).
1819 //
1820 if (EFI_ERROR (VerifyStatus)) {
1821 if (IsAllowedByDb (AuthData, AuthDataSize)) {
1822 VerifyStatus = EFI_SUCCESS;
1823 }
1824 }
1825
1826 //
1827 // Check the image's hash value.
1828 //
1829 if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE1, mImageDigest, &mCertType, mImageDigestSize)) {
1830 Action = EFI_IMAGE_EXECUTION_AUTH_SIG_FOUND;
1831 VerifyStatus = EFI_ACCESS_DENIED;
1832 break;
1833 } else if (EFI_ERROR (VerifyStatus)) {
1834 if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE, mImageDigest, &mCertType, mImageDigestSize)) {
1835 VerifyStatus = EFI_SUCCESS;
1836 }
1837 }
1838 }
1839
1840 if (OffSet != (SecDataDir->VirtualAddress + SecDataDir->Size)) {
1841 //
1842 // The Size in Certificate Table or the attribute certicate table is corrupted.
1843 //
1844 VerifyStatus = EFI_ACCESS_DENIED;
1845 }
1846
1847 if (!EFI_ERROR (VerifyStatus)) {
1848 return EFI_SUCCESS;
1849 } else {
1850 Status = EFI_ACCESS_DENIED;
1851 if (Action == EFI_IMAGE_EXECUTION_AUTH_SIG_FAILED || Action == EFI_IMAGE_EXECUTION_AUTH_SIG_FOUND) {
1852 //
1853 // Get image hash value as executable's signature.
1854 //
1855 SignatureListSize = sizeof (EFI_SIGNATURE_LIST) + sizeof (EFI_SIGNATURE_DATA) - 1 + mImageDigestSize;
1856 SignatureList = (EFI_SIGNATURE_LIST *) AllocateZeroPool (SignatureListSize);
1857 if (SignatureList == NULL) {
1858 Status = EFI_OUT_OF_RESOURCES;
1859 goto Done;
1860 }
1861 SignatureList->SignatureHeaderSize = 0;
1862 SignatureList->SignatureListSize = (UINT32) SignatureListSize;
1863 SignatureList->SignatureSize = (UINT32) mImageDigestSize;
1864 CopyMem (&SignatureList->SignatureType, &mCertType, sizeof (EFI_GUID));
1865 Signature = (EFI_SIGNATURE_DATA *) ((UINT8 *) SignatureList + sizeof (EFI_SIGNATURE_LIST));
1866 CopyMem (Signature->SignatureData, mImageDigest, mImageDigestSize);
1867 }
1868 }
1869
1870 Done:
1871 if (Status != EFI_SUCCESS) {
1872 //
1873 // Policy decides to defer or reject the image; add its information in image executable information table.
1874 //
1875 NameStr = ConvertDevicePathToText (File, FALSE, TRUE);
1876 AddImageExeInfo (Action, NameStr, File, SignatureList, SignatureListSize);
1877 if (NameStr != NULL) {
1878 DEBUG((EFI_D_INFO, "The image doesn't pass verification: %s\n", NameStr));
1879 FreePool(NameStr);
1880 }
1881 Status = EFI_SECURITY_VIOLATION;
1882 }
1883
1884 if (SignatureList != NULL) {
1885 FreePool (SignatureList);
1886 }
1887
1888 return Status;
1889 }
1890
1891 /**
1892 On Ready To Boot Services Event notification handler.
1893
1894 Add the image execution information table if it is not in system configuration table.
1895
1896 @param[in] Event Event whose notification function is being invoked
1897 @param[in] Context Pointer to the notification function's context
1898
1899 **/
1900 VOID
1901 EFIAPI
1902 OnReadyToBoot (
1903 IN EFI_EVENT Event,
1904 IN VOID *Context
1905 )
1906 {
1907 EFI_IMAGE_EXECUTION_INFO_TABLE *ImageExeInfoTable;
1908 UINTN ImageExeInfoTableSize;
1909
1910 EfiGetSystemConfigurationTable (&gEfiImageSecurityDatabaseGuid, (VOID **) &ImageExeInfoTable);
1911 if (ImageExeInfoTable != NULL) {
1912 return;
1913 }
1914
1915 ImageExeInfoTableSize = sizeof (EFI_IMAGE_EXECUTION_INFO_TABLE);
1916 ImageExeInfoTable = (EFI_IMAGE_EXECUTION_INFO_TABLE *) AllocateRuntimePool (ImageExeInfoTableSize);
1917 if (ImageExeInfoTable == NULL) {
1918 return ;
1919 }
1920
1921 ImageExeInfoTable->NumberOfImages = 0;
1922 gBS->InstallConfigurationTable (&gEfiImageSecurityDatabaseGuid, (VOID *) ImageExeInfoTable);
1923
1924 }
1925
1926 /**
1927 Register security measurement handler.
1928
1929 @param ImageHandle ImageHandle of the loaded driver.
1930 @param SystemTable Pointer to the EFI System Table.
1931
1932 @retval EFI_SUCCESS The handlers were registered successfully.
1933 **/
1934 EFI_STATUS
1935 EFIAPI
1936 DxeImageVerificationLibConstructor (
1937 IN EFI_HANDLE ImageHandle,
1938 IN EFI_SYSTEM_TABLE *SystemTable
1939 )
1940 {
1941 EFI_EVENT Event;
1942
1943 //
1944 // Register the event to publish the image execution table.
1945 //
1946 EfiCreateEventReadyToBootEx (
1947 TPL_CALLBACK,
1948 OnReadyToBoot,
1949 NULL,
1950 &Event
1951 );
1952
1953 return RegisterSecurity2Handler (
1954 DxeImageVerificationHandler,
1955 EFI_AUTH_OPERATION_VERIFY_IMAGE | EFI_AUTH_OPERATION_IMAGE_REQUIRED
1956 );
1957 }