Correct the alignment calculation of PE/COFF attribute certificate entry.
[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 - 2014, 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) + 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 EFI_STATUS 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
856 IsFound = FALSE;
857 DbxList = SignatureList;
858 DbxSize = SignatureListSize;
859 HashCtx = NULL;
860 HashAlg = HASHALG_MAX;
861
862 ASSERT (RevocationTime != NULL);
863
864 while ((DbxSize > 0) && (SignatureListSize >= DbxList->SignatureListSize)) {
865 //
866 // Determine Hash Algorithm of Certificate in the forbidden database.
867 //
868 if (CompareGuid (&DbxList->SignatureType, &gEfiCertX509Sha256Guid)) {
869 HashAlg = HASHALG_SHA256;
870 } else if (CompareGuid (&DbxList->SignatureType, &gEfiCertX509Sha384Guid)) {
871 HashAlg = HASHALG_SHA384;
872 } else if (CompareGuid (&DbxList->SignatureType, &gEfiCertX509Sha512Guid)) {
873 HashAlg = HASHALG_SHA512;
874 } else {
875 DbxSize -= DbxList->SignatureListSize;
876 DbxList = (EFI_SIGNATURE_LIST *) ((UINT8 *) DbxList + DbxList->SignatureListSize);
877 continue;
878 }
879
880 //
881 // Calculate the hash value of current db certificate for comparision.
882 //
883 if (mHash[HashAlg].GetContextSize == NULL) {
884 goto Done;
885 }
886 ZeroMem (CertDigest, MAX_DIGEST_SIZE);
887 HashCtx = AllocatePool (mHash[HashAlg].GetContextSize ());
888 if (HashCtx == NULL) {
889 goto Done;
890 }
891 Status = mHash[HashAlg].HashInit (HashCtx);
892 if (!Status) {
893 goto Done;
894 }
895 Status = mHash[HashAlg].HashUpdate (HashCtx, Certificate, CertSize);
896 if (!Status) {
897 goto Done;
898 }
899 Status = mHash[HashAlg].HashFinal (HashCtx, CertDigest);
900 if (!Status) {
901 goto Done;
902 }
903
904 SiglistHeaderSize = sizeof (EFI_SIGNATURE_LIST) + DbxList->SignatureHeaderSize;
905 CertHash = (EFI_SIGNATURE_DATA *) ((UINT8 *) DbxList + SiglistHeaderSize);
906 CertHashCount = (DbxList->SignatureListSize - SiglistHeaderSize) / DbxList->SignatureSize;
907 for (Index = 0; Index < CertHashCount; Index++) {
908 //
909 // Iterate each Signature Data Node within this CertList for verify.
910 //
911 DbxCertHash = CertHash->SignatureData;
912 if (CompareMem (DbxCertHash, CertDigest, mHash[HashAlg].DigestLength) == 0) {
913 //
914 // Hash of Certificate is found in forbidden database.
915 //
916 IsFound = TRUE;
917
918 //
919 // Return the revocation time.
920 //
921 CopyMem (RevocationTime, (EFI_TIME *)(DbxCertHash + mHash[HashAlg].DigestLength), sizeof (EFI_TIME));
922 goto Done;
923 }
924 CertHash = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertHash + DbxList->SignatureSize);
925 }
926
927 DbxSize -= DbxList->SignatureListSize;
928 DbxList = (EFI_SIGNATURE_LIST *) ((UINT8 *) DbxList + DbxList->SignatureListSize);
929 }
930
931 Done:
932 if (HashCtx != NULL) {
933 FreePool (HashCtx);
934 }
935
936 return IsFound;
937 }
938
939 /**
940 Check whether signature is in specified database.
941
942 @param[in] VariableName Name of database variable that is searched in.
943 @param[in] Signature Pointer to signature that is searched for.
944 @param[in] CertType Pointer to hash algrithom.
945 @param[in] SignatureSize Size of Signature.
946
947 @return TRUE Found the signature in the variable database.
948 @return FALSE Not found the signature in the variable database.
949
950 **/
951 BOOLEAN
952 IsSignatureFoundInDatabase (
953 IN CHAR16 *VariableName,
954 IN UINT8 *Signature,
955 IN EFI_GUID *CertType,
956 IN UINTN SignatureSize
957 )
958 {
959 EFI_STATUS Status;
960 EFI_SIGNATURE_LIST *CertList;
961 EFI_SIGNATURE_DATA *Cert;
962 UINTN DataSize;
963 UINT8 *Data;
964 UINTN Index;
965 UINTN CertCount;
966 BOOLEAN IsFound;
967
968 //
969 // Read signature database variable.
970 //
971 IsFound = FALSE;
972 Data = NULL;
973 DataSize = 0;
974 Status = gRT->GetVariable (VariableName, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, NULL);
975 if (Status != EFI_BUFFER_TOO_SMALL) {
976 return FALSE;
977 }
978
979 Data = (UINT8 *) AllocateZeroPool (DataSize);
980 if (Data == NULL) {
981 return FALSE;
982 }
983
984 Status = gRT->GetVariable (VariableName, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, Data);
985 if (EFI_ERROR (Status)) {
986 goto Done;
987 }
988 //
989 // Enumerate all signature data in SigDB to check if executable's signature exists.
990 //
991 CertList = (EFI_SIGNATURE_LIST *) Data;
992 while ((DataSize > 0) && (DataSize >= CertList->SignatureListSize)) {
993 CertCount = (CertList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - CertList->SignatureHeaderSize) / CertList->SignatureSize;
994 Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertList + sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize);
995 if ((CertList->SignatureSize == sizeof(EFI_SIGNATURE_DATA) - 1 + SignatureSize) && (CompareGuid(&CertList->SignatureType, CertType))) {
996 for (Index = 0; Index < CertCount; Index++) {
997 if (CompareMem (Cert->SignatureData, Signature, SignatureSize) == 0) {
998 //
999 // Find the signature in database.
1000 //
1001 IsFound = TRUE;
1002 SecureBootHook (VariableName, &gEfiImageSecurityDatabaseGuid, CertList->SignatureSize, Cert);
1003 break;
1004 }
1005
1006 Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) Cert + CertList->SignatureSize);
1007 }
1008
1009 if (IsFound) {
1010 break;
1011 }
1012 }
1013
1014 DataSize -= CertList->SignatureListSize;
1015 CertList = (EFI_SIGNATURE_LIST *) ((UINT8 *) CertList + CertList->SignatureListSize);
1016 }
1017
1018 Done:
1019 if (Data != NULL) {
1020 FreePool (Data);
1021 }
1022
1023 return IsFound;
1024 }
1025
1026 /**
1027 Check whether the timestamp is valid by comparing the signing time and the revocation time.
1028
1029 @param SigningTime A pointer to the signing time.
1030 @param RevocationTime A pointer to the revocation time.
1031
1032 @retval TRUE The SigningTime is not later than the RevocationTime.
1033 @retval FALSE The SigningTime is later than the RevocationTime.
1034
1035 **/
1036 BOOLEAN
1037 IsValidSignatureByTimestamp (
1038 IN EFI_TIME *SigningTime,
1039 IN EFI_TIME *RevocationTime
1040 )
1041 {
1042 if (SigningTime->Year != RevocationTime->Year) {
1043 return (BOOLEAN) (SigningTime->Year < RevocationTime->Year);
1044 } else if (SigningTime->Month != RevocationTime->Month) {
1045 return (BOOLEAN) (SigningTime->Month < RevocationTime->Month);
1046 } else if (SigningTime->Day != RevocationTime->Day) {
1047 return (BOOLEAN) (SigningTime->Day < RevocationTime->Day);
1048 } else if (SigningTime->Hour != RevocationTime->Hour) {
1049 return (BOOLEAN) (SigningTime->Hour < RevocationTime->Hour);
1050 } else if (SigningTime->Minute != RevocationTime->Minute) {
1051 return (BOOLEAN) (SigningTime->Minute < RevocationTime->Minute);
1052 }
1053
1054 return (BOOLEAN) (SigningTime->Second <= RevocationTime->Second);
1055 }
1056
1057 /**
1058 Check if the given time value is zero.
1059
1060 @param[in] Time Pointer of a time value.
1061
1062 @retval TRUE The Time is Zero.
1063 @retval FALSE The Time is not Zero.
1064
1065 **/
1066 BOOLEAN
1067 IsTimeZero (
1068 IN EFI_TIME *Time
1069 )
1070 {
1071 if ((Time->Year == 0) && (Time->Month == 0) && (Time->Day == 0) &&
1072 (Time->Hour == 0) && (Time->Minute == 0) && (Time->Second == 0)) {
1073 return TRUE;
1074 }
1075
1076 return FALSE;
1077 }
1078
1079 /**
1080 Check whether the timestamp signature is valid and the signing time is also earlier than
1081 the revocation time.
1082
1083 @param[in] AuthData Pointer to the Authenticode signature retrieved from signed image.
1084 @param[in] AuthDataSize Size of the Authenticode signature in bytes.
1085 @param[in] RevocationTime The time that the certificate was revoked.
1086
1087 @retval TRUE Timestamp signature is valid and signing time is no later than the
1088 revocation time.
1089 @retval FALSE Timestamp signature is not valid or the signing time is later than the
1090 revocation time.
1091
1092 **/
1093 BOOLEAN
1094 PassTimestampCheck (
1095 IN UINT8 *AuthData,
1096 IN UINTN AuthDataSize,
1097 IN EFI_TIME *RevocationTime
1098 )
1099 {
1100 EFI_STATUS Status;
1101 BOOLEAN VerifyStatus;
1102 EFI_SIGNATURE_LIST *CertList;
1103 EFI_SIGNATURE_DATA *Cert;
1104 UINT8 *DbtData;
1105 UINTN DbtDataSize;
1106 UINT8 *RootCert;
1107 UINTN RootCertSize;
1108 UINTN Index;
1109 UINTN CertCount;
1110 EFI_TIME SigningTime;
1111
1112 //
1113 // Variable Initialization
1114 //
1115 VerifyStatus = FALSE;
1116 DbtData = NULL;
1117 CertList = NULL;
1118 Cert = NULL;
1119 RootCert = NULL;
1120 RootCertSize = 0;
1121
1122 //
1123 // If RevocationTime is zero, the certificate shall be considered to always be revoked.
1124 //
1125 if (IsTimeZero (RevocationTime)) {
1126 return FALSE;
1127 }
1128
1129 //
1130 // RevocationTime is non-zero, the certificate should be considered to be revoked from that time and onwards.
1131 // Using the dbt to get the trusted TSA certificates.
1132 //
1133 DbtDataSize = 0;
1134 Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE2, &gEfiImageSecurityDatabaseGuid, NULL, &DbtDataSize, NULL);
1135 if (Status == EFI_BUFFER_TOO_SMALL) {
1136 DbtData = (UINT8 *) AllocateZeroPool (DbtDataSize);
1137 if (DbtData == NULL) {
1138 goto Done;
1139 }
1140 Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE2, &gEfiImageSecurityDatabaseGuid, NULL, &DbtDataSize, (VOID *) DbtData);
1141 if (EFI_ERROR (Status)) {
1142 goto Done;
1143 }
1144 }
1145
1146 CertList = (EFI_SIGNATURE_LIST *) DbtData;
1147 while ((DbtDataSize > 0) && (DbtDataSize >= CertList->SignatureListSize)) {
1148 if (CompareGuid (&CertList->SignatureType, &gEfiCertX509Guid)) {
1149 Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertList + sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize);
1150 CertCount = (CertList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - CertList->SignatureHeaderSize) / CertList->SignatureSize;
1151 for (Index = 0; Index < CertCount; Index++) {
1152 //
1153 // Iterate each Signature Data Node within this CertList for verify.
1154 //
1155 RootCert = Cert->SignatureData;
1156 RootCertSize = CertList->SignatureSize - sizeof (EFI_GUID);
1157 //
1158 // Get the signing time if the timestamp signature is valid.
1159 //
1160 if (ImageTimestampVerify (AuthData, AuthDataSize, RootCert, RootCertSize, &SigningTime)) {
1161 //
1162 // The signer signature is valid only when the signing time is earlier than revocation time.
1163 //
1164 if (IsValidSignatureByTimestamp (&SigningTime, RevocationTime)) {
1165 VerifyStatus = TRUE;
1166 goto Done;
1167 }
1168 }
1169 Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) Cert + CertList->SignatureSize);
1170 }
1171 }
1172 DbtDataSize -= CertList->SignatureListSize;
1173 CertList = (EFI_SIGNATURE_LIST *) ((UINT8 *) CertList + CertList->SignatureListSize);
1174 }
1175
1176 Done:
1177 if (DbtData != NULL) {
1178 FreePool (DbtData);
1179 }
1180
1181 return VerifyStatus;
1182 }
1183
1184 /**
1185 Check whether the image signature is forbidden by the forbidden database (dbx).
1186 The image is forbidden to load if any certificates for signing are revoked before signing time.
1187
1188 @param[in] AuthData Pointer to the Authenticode signature retrieved from the signed image.
1189 @param[in] AuthDataSize Size of the Authenticode signature in bytes.
1190
1191 @retval TRUE Image is forbidden by dbx.
1192 @retval FALSE Image is not forbidden by dbx.
1193
1194 **/
1195 BOOLEAN
1196 IsForbiddenByDbx (
1197 IN UINT8 *AuthData,
1198 IN UINTN AuthDataSize
1199 )
1200 {
1201 EFI_STATUS Status;
1202 BOOLEAN IsForbidden;
1203 UINT8 *Data;
1204 UINTN DataSize;
1205 UINTN Index;
1206 UINT8 *CertBuffer;
1207 UINTN BufferLength;
1208 UINT8 *TrustedCert;
1209 UINTN TrustedCertLength;
1210 UINT8 CertNumber;
1211 UINT8 *CertPtr;
1212 UINT8 *Cert;
1213 UINTN CertSize;
1214 EFI_TIME RevocationTime;
1215
1216 //
1217 // Variable Initialization
1218 //
1219 IsForbidden = FALSE;
1220 Data = NULL;
1221 Cert = NULL;
1222 CertBuffer = NULL;
1223 BufferLength = 0;
1224 TrustedCert = NULL;
1225 TrustedCertLength = 0;
1226
1227 //
1228 // The image will not be forbidden if dbx can't be got.
1229 //
1230 DataSize = 0;
1231 Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE1, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, NULL);
1232 if (Status == EFI_BUFFER_TOO_SMALL) {
1233 Data = (UINT8 *) AllocateZeroPool (DataSize);
1234 if (Data == NULL) {
1235 return IsForbidden;
1236 }
1237
1238 Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE1, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, (VOID *) Data);
1239 }
1240 if (EFI_ERROR (Status)) {
1241 return IsForbidden;
1242 }
1243
1244 //
1245 // Retrieve the certificate stack from AuthData
1246 // The output CertStack format will be:
1247 // UINT8 CertNumber;
1248 // UINT32 Cert1Length;
1249 // UINT8 Cert1[];
1250 // UINT32 Cert2Length;
1251 // UINT8 Cert2[];
1252 // ...
1253 // UINT32 CertnLength;
1254 // UINT8 Certn[];
1255 //
1256 Pkcs7GetSigners (AuthData, AuthDataSize, &CertBuffer, &BufferLength, &TrustedCert, &TrustedCertLength);
1257 if (BufferLength == 0) {
1258 IsForbidden = TRUE;
1259 goto Done;
1260 }
1261
1262 //
1263 // Check if any certificates in AuthData is in the forbidden database.
1264 //
1265 CertNumber = (UINT8) (*CertBuffer);
1266 CertPtr = CertBuffer + 1;
1267 for (Index = 0; Index < CertNumber; Index++) {
1268 CertSize = (UINTN) ReadUnaligned32 ((UINT32 *)CertPtr);
1269 Cert = (UINT8 *)CertPtr + sizeof (UINT32);
1270 if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE1, Cert, &gEfiCertX509Guid, CertSize)) {
1271 //
1272 // Raw certificate in dbx means the image signed by the certificate is forbidden.
1273 //
1274 IsForbidden = TRUE;
1275 goto Done;
1276 }
1277
1278 if (IsCertHashFoundInDatabase (Cert, CertSize, (EFI_SIGNATURE_LIST *)Data, DataSize, &RevocationTime)) {
1279 //
1280 // Check the timestamp signature and signing time to determine if the image can be trusted.
1281 //
1282 IsForbidden = TRUE;
1283 if (PassTimestampCheck (AuthData, AuthDataSize, &RevocationTime)) {
1284 IsForbidden = FALSE;
1285 }
1286 goto Done;
1287 }
1288
1289 CertPtr = CertPtr + sizeof (UINT32) + CertSize;
1290 }
1291
1292 Done:
1293 if (Data != NULL) {
1294 FreePool (Data);
1295 }
1296
1297 Pkcs7FreeSigners (CertBuffer);
1298 Pkcs7FreeSigners (TrustedCert);
1299
1300 return IsForbidden;
1301 }
1302
1303 /**
1304 Check whether the image signature can be verified by the trusted certificates in DB database.
1305
1306 @param[in] AuthData Pointer to the Authenticode signature retrieved from signed image.
1307 @param[in] AuthDataSize Size of the Authenticode signature in bytes.
1308
1309 @retval TRUE Image passed verification using certificate in db.
1310 @retval FALSE Image didn't pass verification using certificate in db.
1311
1312 **/
1313 BOOLEAN
1314 IsAllowedByDb (
1315 IN UINT8 *AuthData,
1316 IN UINTN AuthDataSize
1317 )
1318 {
1319 EFI_STATUS Status;
1320 BOOLEAN VerifyStatus;
1321 EFI_SIGNATURE_LIST *CertList;
1322 EFI_SIGNATURE_DATA *Cert;
1323 UINTN DataSize;
1324 UINT8 *Data;
1325 UINT8 *RootCert;
1326 UINTN RootCertSize;
1327 UINTN Index;
1328 UINTN CertCount;
1329
1330 Data = NULL;
1331 CertList = NULL;
1332 Cert = NULL;
1333 RootCert = NULL;
1334 RootCertSize = 0;
1335 VerifyStatus = FALSE;
1336
1337 DataSize = 0;
1338 Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, NULL);
1339 if (Status == EFI_BUFFER_TOO_SMALL) {
1340 Data = (UINT8 *) AllocateZeroPool (DataSize);
1341 if (Data == NULL) {
1342 return VerifyStatus;
1343 }
1344
1345 Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, (VOID *) Data);
1346 if (EFI_ERROR (Status)) {
1347 goto Done;
1348 }
1349
1350 //
1351 // Find X509 certificate in Signature List to verify the signature in pkcs7 signed data.
1352 //
1353 CertList = (EFI_SIGNATURE_LIST *) Data;
1354 while ((DataSize > 0) && (DataSize >= CertList->SignatureListSize)) {
1355 if (CompareGuid (&CertList->SignatureType, &gEfiCertX509Guid)) {
1356 Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertList + sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize);
1357 CertCount = (CertList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - CertList->SignatureHeaderSize) / CertList->SignatureSize;
1358
1359 for (Index = 0; Index < CertCount; Index++) {
1360 //
1361 // Iterate each Signature Data Node within this CertList for verify.
1362 //
1363 RootCert = Cert->SignatureData;
1364 RootCertSize = CertList->SignatureSize - sizeof (EFI_GUID);
1365
1366 //
1367 // Call AuthenticodeVerify library to Verify Authenticode struct.
1368 //
1369 VerifyStatus = AuthenticodeVerify (
1370 AuthData,
1371 AuthDataSize,
1372 RootCert,
1373 RootCertSize,
1374 mImageDigest,
1375 mImageDigestSize
1376 );
1377 if (VerifyStatus) {
1378 SecureBootHook (EFI_IMAGE_SECURITY_DATABASE, &gEfiImageSecurityDatabaseGuid, CertList->SignatureSize, Cert);
1379 goto Done;
1380 }
1381
1382 Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) Cert + CertList->SignatureSize);
1383 }
1384 }
1385
1386 DataSize -= CertList->SignatureListSize;
1387 CertList = (EFI_SIGNATURE_LIST *) ((UINT8 *) CertList + CertList->SignatureListSize);
1388 }
1389 }
1390
1391 Done:
1392 if (Data != NULL) {
1393 FreePool (Data);
1394 }
1395
1396 return VerifyStatus;
1397 }
1398
1399 /**
1400 Provide verification service for signed images, which include both signature validation
1401 and platform policy control. For signature types, both UEFI WIN_CERTIFICATE_UEFI_GUID and
1402 MSFT Authenticode type signatures are supported.
1403
1404 In this implementation, only verify external executables when in USER MODE.
1405 Executables from FV is bypass, so pass in AuthenticationStatus is ignored.
1406
1407 The image verification policy is:
1408 If the image is signed,
1409 At least one valid signature or at least one hash value of the image must match a record
1410 in the security database "db", and no valid signature nor any hash value of the image may
1411 be reflected in the security database "dbx".
1412 Otherwise, the image is not signed,
1413 The SHA256 hash value of the image must match a record in the security database "db", and
1414 not be reflected in the security data base "dbx".
1415
1416 Caution: This function may receive untrusted input.
1417 PE/COFF image is external input, so this function will validate its data structure
1418 within this image buffer before use.
1419
1420 @param[in] AuthenticationStatus
1421 This is the authentication status returned from the security
1422 measurement services for the input file.
1423 @param[in] File This is a pointer to the device path of the file that is
1424 being dispatched. This will optionally be used for logging.
1425 @param[in] FileBuffer File buffer matches the input file device path.
1426 @param[in] FileSize Size of File buffer matches the input file device path.
1427 @param[in] BootPolicy A boot policy that was used to call LoadImage() UEFI service.
1428
1429 @retval EFI_SUCCESS The file specified by DevicePath and non-NULL
1430 FileBuffer did authenticate, and the platform policy dictates
1431 that the DXE Foundation may use the file.
1432 @retval EFI_SUCCESS The device path specified by NULL device path DevicePath
1433 and non-NULL FileBuffer did authenticate, and the platform
1434 policy dictates that the DXE Foundation may execute the image in
1435 FileBuffer.
1436 @retval EFI_OUT_RESOURCE Fail to allocate memory.
1437 @retval EFI_SECURITY_VIOLATION The file specified by File did not authenticate, and
1438 the platform policy dictates that File should be placed
1439 in the untrusted state. The image has been added to the file
1440 execution table.
1441 @retval EFI_ACCESS_DENIED The file specified by File and FileBuffer did not
1442 authenticate, and the platform policy dictates that the DXE
1443 Foundation many not use File.
1444
1445 **/
1446 EFI_STATUS
1447 EFIAPI
1448 DxeImageVerificationHandler (
1449 IN UINT32 AuthenticationStatus,
1450 IN CONST EFI_DEVICE_PATH_PROTOCOL *File,
1451 IN VOID *FileBuffer,
1452 IN UINTN FileSize,
1453 IN BOOLEAN BootPolicy
1454 )
1455 {
1456 EFI_STATUS Status;
1457 UINT16 Magic;
1458 EFI_IMAGE_DOS_HEADER *DosHdr;
1459 EFI_STATUS VerifyStatus;
1460 EFI_SIGNATURE_LIST *SignatureList;
1461 UINTN SignatureListSize;
1462 EFI_SIGNATURE_DATA *Signature;
1463 EFI_IMAGE_EXECUTION_ACTION Action;
1464 WIN_CERTIFICATE *WinCertificate;
1465 UINT32 Policy;
1466 UINT8 *SecureBoot;
1467 PE_COFF_LOADER_IMAGE_CONTEXT ImageContext;
1468 UINT32 NumberOfRvaAndSizes;
1469 WIN_CERTIFICATE_EFI_PKCS *PkcsCertData;
1470 WIN_CERTIFICATE_UEFI_GUID *WinCertUefiGuid;
1471 UINT8 *AuthData;
1472 UINTN AuthDataSize;
1473 EFI_IMAGE_DATA_DIRECTORY *SecDataDir;
1474 UINT32 OffSet;
1475
1476 SignatureList = NULL;
1477 SignatureListSize = 0;
1478 WinCertificate = NULL;
1479 SecDataDir = NULL;
1480 PkcsCertData = NULL;
1481 Action = EFI_IMAGE_EXECUTION_AUTH_UNTESTED;
1482 Status = EFI_ACCESS_DENIED;
1483 VerifyStatus = EFI_ACCESS_DENIED;
1484
1485 //
1486 // Check the image type and get policy setting.
1487 //
1488 switch (GetImageType (File)) {
1489
1490 case IMAGE_FROM_FV:
1491 Policy = ALWAYS_EXECUTE;
1492 break;
1493
1494 case IMAGE_FROM_OPTION_ROM:
1495 Policy = PcdGet32 (PcdOptionRomImageVerificationPolicy);
1496 break;
1497
1498 case IMAGE_FROM_REMOVABLE_MEDIA:
1499 Policy = PcdGet32 (PcdRemovableMediaImageVerificationPolicy);
1500 break;
1501
1502 case IMAGE_FROM_FIXED_MEDIA:
1503 Policy = PcdGet32 (PcdFixedMediaImageVerificationPolicy);
1504 break;
1505
1506 default:
1507 Policy = DENY_EXECUTE_ON_SECURITY_VIOLATION;
1508 break;
1509 }
1510 //
1511 // If policy is always/never execute, return directly.
1512 //
1513 if (Policy == ALWAYS_EXECUTE) {
1514 return EFI_SUCCESS;
1515 } else if (Policy == NEVER_EXECUTE) {
1516 return EFI_ACCESS_DENIED;
1517 }
1518
1519 //
1520 // The policy QUERY_USER_ON_SECURITY_VIOLATION and ALLOW_EXECUTE_ON_SECURITY_VIOLATION
1521 // violates the UEFI spec and has been removed.
1522 //
1523 ASSERT (Policy != QUERY_USER_ON_SECURITY_VIOLATION && Policy != ALLOW_EXECUTE_ON_SECURITY_VIOLATION);
1524 if (Policy == QUERY_USER_ON_SECURITY_VIOLATION || Policy == ALLOW_EXECUTE_ON_SECURITY_VIOLATION) {
1525 CpuDeadLoop ();
1526 }
1527
1528 GetEfiGlobalVariable2 (EFI_SECURE_BOOT_MODE_NAME, (VOID**)&SecureBoot, NULL);
1529 //
1530 // Skip verification if SecureBoot variable doesn't exist.
1531 //
1532 if (SecureBoot == NULL) {
1533 return EFI_SUCCESS;
1534 }
1535
1536 //
1537 // Skip verification if SecureBoot is disabled.
1538 //
1539 if (*SecureBoot == SECURE_BOOT_MODE_DISABLE) {
1540 FreePool (SecureBoot);
1541 return EFI_SUCCESS;
1542 }
1543 FreePool (SecureBoot);
1544
1545 //
1546 // Read the Dos header.
1547 //
1548 if (FileBuffer == NULL) {
1549 return EFI_INVALID_PARAMETER;
1550 }
1551
1552 mImageBase = (UINT8 *) FileBuffer;
1553 mImageSize = FileSize;
1554
1555 ZeroMem (&ImageContext, sizeof (ImageContext));
1556 ImageContext.Handle = (VOID *) FileBuffer;
1557 ImageContext.ImageRead = (PE_COFF_LOADER_READ_FILE) DxeImageVerificationLibImageRead;
1558
1559 //
1560 // Get information about the image being loaded
1561 //
1562 Status = PeCoffLoaderGetImageInfo (&ImageContext);
1563 if (EFI_ERROR (Status)) {
1564 //
1565 // The information can't be got from the invalid PeImage
1566 //
1567 goto Done;
1568 }
1569
1570 Status = EFI_ACCESS_DENIED;
1571
1572 DosHdr = (EFI_IMAGE_DOS_HEADER *) mImageBase;
1573 if (DosHdr->e_magic == EFI_IMAGE_DOS_SIGNATURE) {
1574 //
1575 // DOS image header is present,
1576 // so read the PE header after the DOS image header.
1577 //
1578 mPeCoffHeaderOffset = DosHdr->e_lfanew;
1579 } else {
1580 mPeCoffHeaderOffset = 0;
1581 }
1582 //
1583 // Check PE/COFF image.
1584 //
1585 mNtHeader.Pe32 = (EFI_IMAGE_NT_HEADERS32 *) (mImageBase + mPeCoffHeaderOffset);
1586 if (mNtHeader.Pe32->Signature != EFI_IMAGE_NT_SIGNATURE) {
1587 //
1588 // It is not a valid Pe/Coff file.
1589 //
1590 goto Done;
1591 }
1592
1593 if (mNtHeader.Pe32->FileHeader.Machine == IMAGE_FILE_MACHINE_IA64 && mNtHeader.Pe32->OptionalHeader.Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
1594 //
1595 // NOTE: Some versions of Linux ELILO for Itanium have an incorrect magic value
1596 // in the PE/COFF Header. If the MachineType is Itanium(IA64) and the
1597 // Magic value in the OptionalHeader is EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC
1598 // then override the magic value to EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC
1599 //
1600 Magic = EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC;
1601 } else {
1602 //
1603 // Get the magic value from the PE/COFF Optional Header
1604 //
1605 Magic = mNtHeader.Pe32->OptionalHeader.Magic;
1606 }
1607
1608 if (Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
1609 //
1610 // Use PE32 offset.
1611 //
1612 NumberOfRvaAndSizes = mNtHeader.Pe32->OptionalHeader.NumberOfRvaAndSizes;
1613 if (NumberOfRvaAndSizes > EFI_IMAGE_DIRECTORY_ENTRY_SECURITY) {
1614 SecDataDir = (EFI_IMAGE_DATA_DIRECTORY *) &mNtHeader.Pe32->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY];
1615 }
1616 } else {
1617 //
1618 // Use PE32+ offset.
1619 //
1620 NumberOfRvaAndSizes = mNtHeader.Pe32Plus->OptionalHeader.NumberOfRvaAndSizes;
1621 if (NumberOfRvaAndSizes > EFI_IMAGE_DIRECTORY_ENTRY_SECURITY) {
1622 SecDataDir = (EFI_IMAGE_DATA_DIRECTORY *) &mNtHeader.Pe32Plus->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY];
1623 }
1624 }
1625
1626 //
1627 // Start Image Validation.
1628 //
1629 if (SecDataDir == NULL || SecDataDir->Size == 0) {
1630 //
1631 // This image is not signed. The SHA256 hash value of the image must match a record in the security database "db",
1632 // and not be reflected in the security data base "dbx".
1633 //
1634 if (!HashPeImage (HASHALG_SHA256)) {
1635 goto Done;
1636 }
1637
1638 if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE1, mImageDigest, &mCertType, mImageDigestSize)) {
1639 //
1640 // Image Hash is in forbidden database (DBX).
1641 //
1642 goto Done;
1643 }
1644
1645 if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE, mImageDigest, &mCertType, mImageDigestSize)) {
1646 //
1647 // Image Hash is in allowed database (DB).
1648 //
1649 return EFI_SUCCESS;
1650 }
1651
1652 //
1653 // Image Hash is not found in both forbidden and allowed database.
1654 //
1655 goto Done;
1656 }
1657
1658 //
1659 // Verify the signature of the image, multiple signatures are allowed as per PE/COFF Section 4.7
1660 // "Attribute Certificate Table".
1661 // The first certificate starts at offset (SecDataDir->VirtualAddress) from the start of the file.
1662 //
1663 for (OffSet = SecDataDir->VirtualAddress;
1664 OffSet < (SecDataDir->VirtualAddress + SecDataDir->Size);
1665 OffSet += (WinCertificate->dwLength + ALIGN_SIZE (WinCertificate->dwLength))) {
1666 WinCertificate = (WIN_CERTIFICATE *) (mImageBase + OffSet);
1667 if ((SecDataDir->VirtualAddress + SecDataDir->Size - OffSet) <= sizeof (WIN_CERTIFICATE) ||
1668 (SecDataDir->VirtualAddress + SecDataDir->Size - OffSet) < WinCertificate->dwLength) {
1669 break;
1670 }
1671
1672 //
1673 // Verify the image's Authenticode signature, only DER-encoded PKCS#7 signed data is supported.
1674 //
1675 if (WinCertificate->wCertificateType == WIN_CERT_TYPE_PKCS_SIGNED_DATA) {
1676 //
1677 // The certificate is formatted as WIN_CERTIFICATE_EFI_PKCS which is described in the
1678 // Authenticode specification.
1679 //
1680 PkcsCertData = (WIN_CERTIFICATE_EFI_PKCS *) WinCertificate;
1681 if (PkcsCertData->Hdr.dwLength <= sizeof (PkcsCertData->Hdr)) {
1682 break;
1683 }
1684 AuthData = PkcsCertData->CertData;
1685 AuthDataSize = PkcsCertData->Hdr.dwLength - sizeof(PkcsCertData->Hdr);
1686 } else if (WinCertificate->wCertificateType == WIN_CERT_TYPE_EFI_GUID) {
1687 //
1688 // The certificate is formatted as WIN_CERTIFICATE_UEFI_GUID which is described in UEFI Spec.
1689 //
1690 WinCertUefiGuid = (WIN_CERTIFICATE_UEFI_GUID *) WinCertificate;
1691 if (WinCertUefiGuid->Hdr.dwLength <= OFFSET_OF(WIN_CERTIFICATE_UEFI_GUID, CertData)) {
1692 break;
1693 }
1694 if (!CompareGuid (&WinCertUefiGuid->CertType, &gEfiCertPkcs7Guid)) {
1695 continue;
1696 }
1697 AuthData = WinCertUefiGuid->CertData;
1698 AuthDataSize = WinCertUefiGuid->Hdr.dwLength - OFFSET_OF(WIN_CERTIFICATE_UEFI_GUID, CertData);
1699 } else {
1700 if (WinCertificate->dwLength < sizeof (WIN_CERTIFICATE)) {
1701 break;
1702 }
1703 continue;
1704 }
1705
1706 Status = HashPeImageByType (AuthData, AuthDataSize);
1707 if (EFI_ERROR (Status)) {
1708 continue;
1709 }
1710
1711 //
1712 // Check the digital signature against the revoked certificate in forbidden database (dbx).
1713 //
1714 if (IsForbiddenByDbx (AuthData, AuthDataSize)) {
1715 Action = EFI_IMAGE_EXECUTION_AUTH_SIG_FAILED;
1716 VerifyStatus = EFI_ACCESS_DENIED;
1717 break;
1718 }
1719
1720 //
1721 // Check the digital signature against the valid certificate in allowed database (db).
1722 //
1723 if (EFI_ERROR (VerifyStatus)) {
1724 if (IsAllowedByDb (AuthData, AuthDataSize)) {
1725 VerifyStatus = EFI_SUCCESS;
1726 }
1727 }
1728
1729 //
1730 // Check the image's hash value.
1731 //
1732 if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE1, mImageDigest, &mCertType, mImageDigestSize)) {
1733 Action = EFI_IMAGE_EXECUTION_AUTH_SIG_FOUND;
1734 VerifyStatus = EFI_ACCESS_DENIED;
1735 break;
1736 } else if (EFI_ERROR (VerifyStatus)) {
1737 if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE, mImageDigest, &mCertType, mImageDigestSize)) {
1738 VerifyStatus = EFI_SUCCESS;
1739 }
1740 }
1741 }
1742
1743 if (OffSet != (SecDataDir->VirtualAddress + SecDataDir->Size)) {
1744 //
1745 // The Size in Certificate Table or the attribute certicate table is corrupted.
1746 //
1747 VerifyStatus = EFI_ACCESS_DENIED;
1748 }
1749
1750 if (!EFI_ERROR (VerifyStatus)) {
1751 return EFI_SUCCESS;
1752 } else {
1753 Status = EFI_ACCESS_DENIED;
1754 if (Action == EFI_IMAGE_EXECUTION_AUTH_SIG_FAILED || Action == EFI_IMAGE_EXECUTION_AUTH_SIG_FOUND) {
1755 //
1756 // Get image hash value as executable's signature.
1757 //
1758 SignatureListSize = sizeof (EFI_SIGNATURE_LIST) + sizeof (EFI_SIGNATURE_DATA) - 1 + mImageDigestSize;
1759 SignatureList = (EFI_SIGNATURE_LIST *) AllocateZeroPool (SignatureListSize);
1760 if (SignatureList == NULL) {
1761 Status = EFI_OUT_OF_RESOURCES;
1762 goto Done;
1763 }
1764 SignatureList->SignatureHeaderSize = 0;
1765 SignatureList->SignatureListSize = (UINT32) SignatureListSize;
1766 SignatureList->SignatureSize = (UINT32) mImageDigestSize;
1767 CopyMem (&SignatureList->SignatureType, &mCertType, sizeof (EFI_GUID));
1768 Signature = (EFI_SIGNATURE_DATA *) ((UINT8 *) SignatureList + sizeof (EFI_SIGNATURE_LIST));
1769 CopyMem (Signature->SignatureData, mImageDigest, mImageDigestSize);
1770 }
1771 }
1772
1773 Done:
1774 if (Status != EFI_SUCCESS) {
1775 //
1776 // Policy decides to defer or reject the image; add its information in image executable information table.
1777 //
1778 AddImageExeInfo (Action, NULL, File, SignatureList, SignatureListSize);
1779 Status = EFI_SECURITY_VIOLATION;
1780 }
1781
1782 if (SignatureList != NULL) {
1783 FreePool (SignatureList);
1784 }
1785
1786 return Status;
1787 }
1788
1789 /**
1790 On Ready To Boot Services Event notification handler.
1791
1792 Add the image execution information table if it is not in system configuration table.
1793
1794 @param[in] Event Event whose notification function is being invoked
1795 @param[in] Context Pointer to the notification function's context
1796
1797 **/
1798 VOID
1799 EFIAPI
1800 OnReadyToBoot (
1801 IN EFI_EVENT Event,
1802 IN VOID *Context
1803 )
1804 {
1805 EFI_IMAGE_EXECUTION_INFO_TABLE *ImageExeInfoTable;
1806 UINTN ImageExeInfoTableSize;
1807
1808 EfiGetSystemConfigurationTable (&gEfiImageSecurityDatabaseGuid, (VOID **) &ImageExeInfoTable);
1809 if (ImageExeInfoTable != NULL) {
1810 return;
1811 }
1812
1813 ImageExeInfoTableSize = sizeof (EFI_IMAGE_EXECUTION_INFO_TABLE);
1814 ImageExeInfoTable = (EFI_IMAGE_EXECUTION_INFO_TABLE *) AllocateRuntimePool (ImageExeInfoTableSize);
1815 if (ImageExeInfoTable == NULL) {
1816 return ;
1817 }
1818
1819 ImageExeInfoTable->NumberOfImages = 0;
1820 gBS->InstallConfigurationTable (&gEfiImageSecurityDatabaseGuid, (VOID *) ImageExeInfoTable);
1821
1822 }
1823
1824 /**
1825 Register security measurement handler.
1826
1827 @param ImageHandle ImageHandle of the loaded driver.
1828 @param SystemTable Pointer to the EFI System Table.
1829
1830 @retval EFI_SUCCESS The handlers were registered successfully.
1831 **/
1832 EFI_STATUS
1833 EFIAPI
1834 DxeImageVerificationLibConstructor (
1835 IN EFI_HANDLE ImageHandle,
1836 IN EFI_SYSTEM_TABLE *SystemTable
1837 )
1838 {
1839 EFI_EVENT Event;
1840
1841 //
1842 // Register the event to publish the image execution table.
1843 //
1844 EfiCreateEventReadyToBootEx (
1845 TPL_CALLBACK,
1846 OnReadyToBoot,
1847 NULL,
1848 &Event
1849 );
1850
1851 return RegisterSecurity2Handler (
1852 DxeImageVerificationHandler,
1853 EFI_AUTH_OPERATION_VERIFY_IMAGE | EFI_AUTH_OPERATION_IMAGE_REQUIRED
1854 );
1855 }