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