2 Implement image verification services for secure boot service
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.
9 DxeImageVerificationLibImageRead() function will make sure the PE/COFF image content
10 read is within the image buffer.
12 DxeImageVerificationHandler(), HashPeImageByType(), HashPeImage() function will accept
13 untrusted PE/COFF image and validate its data structure within this image buffer before use.
15 Copyright (c) 2009 - 2018, Intel Corporation. All rights reserved.<BR>
16 (C) Copyright 2016 Hewlett Packard Enterprise Development LP<BR>
17 SPDX-License-Identifier: BSD-2-Clause-Patent
21 #include "DxeImageVerificationLib.h"
24 // Caution: This is used by a function which may receive untrusted input.
25 // These global variables hold PE/COFF image data, and they should be validated before use.
27 EFI_IMAGE_OPTIONAL_HEADER_PTR_UNION mNtHeader
;
28 UINT32 mPeCoffHeaderOffset
;
32 // Information on current PE/COFF image
35 UINT8
*mImageBase
= NULL
;
36 UINT8 mImageDigest
[MAX_DIGEST_SIZE
];
37 UINTN mImageDigestSize
;
40 // Notify string for authorization UI.
42 CHAR16 mNotifyString1
[MAX_NOTIFY_STRING_LEN
] = L
"Image verification pass but not found in authorized database!";
43 CHAR16 mNotifyString2
[MAX_NOTIFY_STRING_LEN
] = L
"Launch this image anyway? (Yes/Defer/No)";
45 // Public Exponent of RSA Key.
47 CONST UINT8 mRsaE
[] = { 0x01, 0x00, 0x01 };
51 // OID ASN.1 Value for Hash Algorithms
53 UINT8 mHashOidValue
[] = {
54 0x2B, 0x0E, 0x03, 0x02, 0x1A, // OBJ_sha1
55 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04, // OBJ_sha224
56 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, // OBJ_sha256
57 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02, // OBJ_sha384
58 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03, // OBJ_sha512
61 HASH_TABLE mHash
[] = {
62 { L
"SHA1", 20, &mHashOidValue
[0], 5, Sha1GetContextSize
, Sha1Init
, Sha1Update
, Sha1Final
},
63 { L
"SHA224", 28, &mHashOidValue
[5], 9, NULL
, NULL
, NULL
, NULL
},
64 { L
"SHA256", 32, &mHashOidValue
[14], 9, Sha256GetContextSize
, Sha256Init
, Sha256Update
, Sha256Final
},
65 { L
"SHA384", 48, &mHashOidValue
[23], 9, Sha384GetContextSize
, Sha384Init
, Sha384Update
, Sha384Final
},
66 { L
"SHA512", 64, &mHashOidValue
[32], 9, Sha512GetContextSize
, Sha512Init
, Sha512Update
, Sha512Final
}
69 EFI_STRING mHashTypeStr
;
72 SecureBoot Hook for processing image verification.
74 @param[in] VariableName Name of Variable to be found.
75 @param[in] VendorGuid Variable vendor GUID.
76 @param[in] DataSize Size of Data found. If size is less than the
77 data, this value contains the required size.
78 @param[in] Data Data pointer.
84 IN CHAR16
*VariableName
,
85 IN EFI_GUID
*VendorGuid
,
91 Reads contents of a PE/COFF image in memory buffer.
93 Caution: This function may receive untrusted input.
94 PE/COFF image is external input, so this function will make sure the PE/COFF image content
95 read is within the image buffer.
97 @param FileHandle Pointer to the file handle to read the PE/COFF image.
98 @param FileOffset Offset into the PE/COFF image to begin the read operation.
99 @param ReadSize On input, the size in bytes of the requested read operation.
100 On output, the number of bytes actually read.
101 @param Buffer Output buffer that contains the data read from the PE/COFF image.
103 @retval EFI_SUCCESS The specified portion of the PE/COFF image was read and the size
107 DxeImageVerificationLibImageRead (
110 IN OUT UINTN
*ReadSize
,
116 if (FileHandle
== NULL
|| ReadSize
== NULL
|| Buffer
== NULL
) {
117 return EFI_INVALID_PARAMETER
;
120 if (MAX_ADDRESS
- FileOffset
< *ReadSize
) {
121 return EFI_INVALID_PARAMETER
;
124 EndPosition
= FileOffset
+ *ReadSize
;
125 if (EndPosition
> mImageSize
) {
126 *ReadSize
= (UINT32
)(mImageSize
- FileOffset
);
129 if (FileOffset
>= mImageSize
) {
133 CopyMem (Buffer
, (UINT8
*)((UINTN
) FileHandle
+ FileOffset
), *ReadSize
);
142 @param[in] File This is a pointer to the device path of the file that is
145 @return UINT32 Image Type
150 IN CONST EFI_DEVICE_PATH_PROTOCOL
*File
154 EFI_HANDLE DeviceHandle
;
155 EFI_DEVICE_PATH_PROTOCOL
*TempDevicePath
;
156 EFI_BLOCK_IO_PROTOCOL
*BlockIo
;
159 return IMAGE_UNKNOWN
;
163 // First check to see if File is from a Firmware Volume
166 TempDevicePath
= (EFI_DEVICE_PATH_PROTOCOL
*) File
;
167 Status
= gBS
->LocateDevicePath (
168 &gEfiFirmwareVolume2ProtocolGuid
,
172 if (!EFI_ERROR (Status
)) {
173 Status
= gBS
->OpenProtocol (
175 &gEfiFirmwareVolume2ProtocolGuid
,
179 EFI_OPEN_PROTOCOL_TEST_PROTOCOL
181 if (!EFI_ERROR (Status
)) {
182 return IMAGE_FROM_FV
;
187 // Next check to see if File is from a Block I/O device
190 TempDevicePath
= (EFI_DEVICE_PATH_PROTOCOL
*) File
;
191 Status
= gBS
->LocateDevicePath (
192 &gEfiBlockIoProtocolGuid
,
196 if (!EFI_ERROR (Status
)) {
198 Status
= gBS
->OpenProtocol (
200 &gEfiBlockIoProtocolGuid
,
204 EFI_OPEN_PROTOCOL_GET_PROTOCOL
206 if (!EFI_ERROR (Status
) && BlockIo
!= NULL
) {
207 if (BlockIo
->Media
!= NULL
) {
208 if (BlockIo
->Media
->RemovableMedia
) {
210 // Block I/O is present and specifies the media is removable
212 return IMAGE_FROM_REMOVABLE_MEDIA
;
215 // Block I/O is present and specifies the media is not removable
217 return IMAGE_FROM_FIXED_MEDIA
;
224 // File is not in a Firmware Volume or on a Block I/O device, so check to see if
225 // the device path supports the Simple File System Protocol.
228 TempDevicePath
= (EFI_DEVICE_PATH_PROTOCOL
*) File
;
229 Status
= gBS
->LocateDevicePath (
230 &gEfiSimpleFileSystemProtocolGuid
,
234 if (!EFI_ERROR (Status
)) {
236 // Simple File System is present without Block I/O, so assume media is fixed.
238 return IMAGE_FROM_FIXED_MEDIA
;
242 // File is not from an FV, Block I/O or Simple File System, so the only options
243 // left are a PCI Option ROM and a Load File Protocol such as a PXE Boot from a NIC.
245 TempDevicePath
= (EFI_DEVICE_PATH_PROTOCOL
*) File
;
246 while (!IsDevicePathEndType (TempDevicePath
)) {
247 switch (DevicePathType (TempDevicePath
)) {
249 case MEDIA_DEVICE_PATH
:
250 if (DevicePathSubType (TempDevicePath
) == MEDIA_RELATIVE_OFFSET_RANGE_DP
) {
251 return IMAGE_FROM_OPTION_ROM
;
255 case MESSAGING_DEVICE_PATH
:
256 if (DevicePathSubType(TempDevicePath
) == MSG_MAC_ADDR_DP
) {
257 return IMAGE_FROM_REMOVABLE_MEDIA
;
264 TempDevicePath
= NextDevicePathNode (TempDevicePath
);
266 return IMAGE_UNKNOWN
;
270 Calculate hash of Pe/Coff image based on the authenticode image hashing in
271 PE/COFF Specification 8.0 Appendix A
273 Caution: This function may receive untrusted input.
274 PE/COFF image is external input, so this function will validate its data structure
275 within this image buffer before use.
277 Notes: PE/COFF image has been checked by BasePeCoffLib PeCoffLoaderGetImageInfo() in
278 its caller function DxeImageVerificationHandler().
280 @param[in] HashAlg Hash algorithm type.
282 @retval TRUE Successfully hash image.
283 @retval FALSE Fail in hash image.
292 EFI_IMAGE_SECTION_HEADER
*Section
;
297 UINTN SumOfBytesHashed
;
298 EFI_IMAGE_SECTION_HEADER
*SectionHeader
;
302 UINT32 NumberOfRvaAndSizes
;
305 SectionHeader
= NULL
;
308 if ((HashAlg
>= HASHALG_MAX
)) {
313 // Initialize context of hash.
315 ZeroMem (mImageDigest
, MAX_DIGEST_SIZE
);
319 mImageDigestSize
= SHA1_DIGEST_SIZE
;
320 mCertType
= gEfiCertSha1Guid
;
324 mImageDigestSize
= SHA256_DIGEST_SIZE
;
325 mCertType
= gEfiCertSha256Guid
;
329 mImageDigestSize
= SHA384_DIGEST_SIZE
;
330 mCertType
= gEfiCertSha384Guid
;
334 mImageDigestSize
= SHA512_DIGEST_SIZE
;
335 mCertType
= gEfiCertSha512Guid
;
342 mHashTypeStr
= mHash
[HashAlg
].Name
;
343 CtxSize
= mHash
[HashAlg
].GetContextSize();
345 HashCtx
= AllocatePool (CtxSize
);
346 if (HashCtx
== NULL
) {
350 // 1. Load the image header into memory.
352 // 2. Initialize a SHA hash context.
353 Status
= mHash
[HashAlg
].HashInit(HashCtx
);
360 // Measuring PE/COFF Image Header;
361 // But CheckSum field and SECURITY data directory (certificate) are excluded
365 // 3. Calculate the distance from the base of the image header to the image checksum address.
366 // 4. Hash the image header from its base to beginning of the image checksum.
368 HashBase
= mImageBase
;
369 if (mNtHeader
.Pe32
->OptionalHeader
.Magic
== EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC
) {
373 HashSize
= (UINTN
) (&mNtHeader
.Pe32
->OptionalHeader
.CheckSum
) - (UINTN
) HashBase
;
374 NumberOfRvaAndSizes
= mNtHeader
.Pe32
->OptionalHeader
.NumberOfRvaAndSizes
;
375 } else if (mNtHeader
.Pe32
->OptionalHeader
.Magic
== EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC
) {
379 HashSize
= (UINTN
) (&mNtHeader
.Pe32Plus
->OptionalHeader
.CheckSum
) - (UINTN
) HashBase
;
380 NumberOfRvaAndSizes
= mNtHeader
.Pe32Plus
->OptionalHeader
.NumberOfRvaAndSizes
;
383 // Invalid header magic number.
389 Status
= mHash
[HashAlg
].HashUpdate(HashCtx
, HashBase
, HashSize
);
395 // 5. Skip over the image checksum (it occupies a single ULONG).
397 if (NumberOfRvaAndSizes
<= EFI_IMAGE_DIRECTORY_ENTRY_SECURITY
) {
399 // 6. Since there is no Cert Directory in optional header, hash everything
400 // from the end of the checksum to the end of image header.
402 if (mNtHeader
.Pe32
->OptionalHeader
.Magic
== EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC
) {
406 HashBase
= (UINT8
*) &mNtHeader
.Pe32
->OptionalHeader
.CheckSum
+ sizeof (UINT32
);
407 HashSize
= mNtHeader
.Pe32
->OptionalHeader
.SizeOfHeaders
- ((UINTN
) HashBase
- (UINTN
) mImageBase
);
412 HashBase
= (UINT8
*) &mNtHeader
.Pe32Plus
->OptionalHeader
.CheckSum
+ sizeof (UINT32
);
413 HashSize
= mNtHeader
.Pe32Plus
->OptionalHeader
.SizeOfHeaders
- ((UINTN
) HashBase
- (UINTN
) mImageBase
);
417 Status
= mHash
[HashAlg
].HashUpdate(HashCtx
, HashBase
, HashSize
);
424 // 7. Hash everything from the end of the checksum to the start of the Cert Directory.
426 if (mNtHeader
.Pe32
->OptionalHeader
.Magic
== EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC
) {
430 HashBase
= (UINT8
*) &mNtHeader
.Pe32
->OptionalHeader
.CheckSum
+ sizeof (UINT32
);
431 HashSize
= (UINTN
) (&mNtHeader
.Pe32
->OptionalHeader
.DataDirectory
[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY
]) - (UINTN
) HashBase
;
436 HashBase
= (UINT8
*) &mNtHeader
.Pe32Plus
->OptionalHeader
.CheckSum
+ sizeof (UINT32
);
437 HashSize
= (UINTN
) (&mNtHeader
.Pe32Plus
->OptionalHeader
.DataDirectory
[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY
]) - (UINTN
) HashBase
;
441 Status
= mHash
[HashAlg
].HashUpdate(HashCtx
, HashBase
, HashSize
);
448 // 8. Skip over the Cert Directory. (It is sizeof(IMAGE_DATA_DIRECTORY) bytes.)
449 // 9. Hash everything from the end of the Cert Directory to the end of image header.
451 if (mNtHeader
.Pe32
->OptionalHeader
.Magic
== EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC
) {
455 HashBase
= (UINT8
*) &mNtHeader
.Pe32
->OptionalHeader
.DataDirectory
[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY
+ 1];
456 HashSize
= mNtHeader
.Pe32
->OptionalHeader
.SizeOfHeaders
- ((UINTN
) HashBase
- (UINTN
) mImageBase
);
461 HashBase
= (UINT8
*) &mNtHeader
.Pe32Plus
->OptionalHeader
.DataDirectory
[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY
+ 1];
462 HashSize
= mNtHeader
.Pe32Plus
->OptionalHeader
.SizeOfHeaders
- ((UINTN
) HashBase
- (UINTN
) mImageBase
);
466 Status
= mHash
[HashAlg
].HashUpdate(HashCtx
, HashBase
, HashSize
);
474 // 10. Set the SUM_OF_BYTES_HASHED to the size of the header.
476 if (mNtHeader
.Pe32
->OptionalHeader
.Magic
== EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC
) {
480 SumOfBytesHashed
= mNtHeader
.Pe32
->OptionalHeader
.SizeOfHeaders
;
485 SumOfBytesHashed
= mNtHeader
.Pe32Plus
->OptionalHeader
.SizeOfHeaders
;
489 Section
= (EFI_IMAGE_SECTION_HEADER
*) (
491 mPeCoffHeaderOffset
+
493 sizeof (EFI_IMAGE_FILE_HEADER
) +
494 mNtHeader
.Pe32
->FileHeader
.SizeOfOptionalHeader
498 // 11. Build a temporary table of pointers to all the IMAGE_SECTION_HEADER
499 // structures in the image. The 'NumberOfSections' field of the image
500 // header indicates how big the table should be. Do not include any
501 // IMAGE_SECTION_HEADERs in the table whose 'SizeOfRawData' field is zero.
503 SectionHeader
= (EFI_IMAGE_SECTION_HEADER
*) AllocateZeroPool (sizeof (EFI_IMAGE_SECTION_HEADER
) * mNtHeader
.Pe32
->FileHeader
.NumberOfSections
);
504 if (SectionHeader
== NULL
) {
509 // 12. Using the 'PointerToRawData' in the referenced section headers as
510 // a key, arrange the elements in the table in ascending order. In other
511 // words, sort the section headers according to the disk-file offset of
514 for (Index
= 0; Index
< mNtHeader
.Pe32
->FileHeader
.NumberOfSections
; Index
++) {
516 while ((Pos
> 0) && (Section
->PointerToRawData
< SectionHeader
[Pos
- 1].PointerToRawData
)) {
517 CopyMem (&SectionHeader
[Pos
], &SectionHeader
[Pos
- 1], sizeof (EFI_IMAGE_SECTION_HEADER
));
520 CopyMem (&SectionHeader
[Pos
], Section
, sizeof (EFI_IMAGE_SECTION_HEADER
));
525 // 13. Walk through the sorted table, bring the corresponding section
526 // into memory, and hash the entire section (using the 'SizeOfRawData'
527 // field in the section header to determine the amount of data to hash).
528 // 14. Add the section's 'SizeOfRawData' to SUM_OF_BYTES_HASHED .
529 // 15. Repeat steps 13 and 14 for all the sections in the sorted table.
531 for (Index
= 0; Index
< mNtHeader
.Pe32
->FileHeader
.NumberOfSections
; Index
++) {
532 Section
= &SectionHeader
[Index
];
533 if (Section
->SizeOfRawData
== 0) {
536 HashBase
= mImageBase
+ Section
->PointerToRawData
;
537 HashSize
= (UINTN
) Section
->SizeOfRawData
;
539 Status
= mHash
[HashAlg
].HashUpdate(HashCtx
, HashBase
, HashSize
);
544 SumOfBytesHashed
+= HashSize
;
548 // 16. If the file size is greater than SUM_OF_BYTES_HASHED, there is extra
549 // data in the file that needs to be added to the hash. This data begins
550 // at file offset SUM_OF_BYTES_HASHED and its length is:
551 // FileSize - (CertDirectory->Size)
553 if (mImageSize
> SumOfBytesHashed
) {
554 HashBase
= mImageBase
+ SumOfBytesHashed
;
556 if (NumberOfRvaAndSizes
<= EFI_IMAGE_DIRECTORY_ENTRY_SECURITY
) {
559 if (mNtHeader
.Pe32
->OptionalHeader
.Magic
== EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC
) {
563 CertSize
= mNtHeader
.Pe32
->OptionalHeader
.DataDirectory
[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY
].Size
;
568 CertSize
= mNtHeader
.Pe32Plus
->OptionalHeader
.DataDirectory
[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY
].Size
;
572 if (mImageSize
> CertSize
+ SumOfBytesHashed
) {
573 HashSize
= (UINTN
) (mImageSize
- CertSize
- SumOfBytesHashed
);
575 Status
= mHash
[HashAlg
].HashUpdate(HashCtx
, HashBase
, HashSize
);
579 } else if (mImageSize
< CertSize
+ SumOfBytesHashed
) {
585 Status
= mHash
[HashAlg
].HashFinal(HashCtx
, mImageDigest
);
588 if (HashCtx
!= NULL
) {
591 if (SectionHeader
!= NULL
) {
592 FreePool (SectionHeader
);
598 Recognize the Hash algorithm in PE/COFF Authenticode and calculate hash of
599 Pe/Coff image based on the authenticode image hashing in PE/COFF Specification
602 Caution: This function may receive untrusted input.
603 PE/COFF image is external input, so this function will validate its data structure
604 within this image buffer before use.
606 @param[in] AuthData Pointer to the Authenticode Signature retrieved from signed image.
607 @param[in] AuthDataSize Size of the Authenticode Signature in bytes.
609 @retval EFI_UNSUPPORTED Hash algorithm is not supported.
610 @retval EFI_SUCCESS Hash successfully.
616 IN UINTN AuthDataSize
621 for (Index
= 0; Index
< HASHALG_MAX
; Index
++) {
623 // Check the Hash algorithm in PE/COFF Authenticode.
624 // According to PKCS#7 Definition:
625 // SignedData ::= SEQUENCE {
627 // digestAlgorithms DigestAlgorithmIdentifiers,
628 // contentInfo ContentInfo,
630 // The DigestAlgorithmIdentifiers can be used to determine the hash algorithm in PE/COFF hashing
631 // This field has the fixed offset (+32) in final Authenticode ASN.1 data.
632 // Fixed offset (+32) is calculated based on two bytes of length encoding.
634 if ((*(AuthData
+ 1) & TWO_BYTE_ENCODE
) != TWO_BYTE_ENCODE
) {
636 // Only support two bytes of Long Form of Length Encoding.
641 if (AuthDataSize
< 32 + mHash
[Index
].OidLength
) {
642 return EFI_UNSUPPORTED
;
645 if (CompareMem (AuthData
+ 32, mHash
[Index
].OidValue
, mHash
[Index
].OidLength
) == 0) {
650 if (Index
== HASHALG_MAX
) {
651 return EFI_UNSUPPORTED
;
655 // HASH PE Image based on Hash algorithm in PE/COFF Authenticode.
657 if (!HashPeImage(Index
)) {
658 return EFI_UNSUPPORTED
;
666 Returns the size of a given image execution info table in bytes.
668 This function returns the size, in bytes, of the image execution info table specified by
669 ImageExeInfoTable. If ImageExeInfoTable is NULL, then 0 is returned.
671 @param ImageExeInfoTable A pointer to a image execution info table structure.
673 @retval 0 If ImageExeInfoTable is NULL.
674 @retval Others The size of a image execution info table in bytes.
678 GetImageExeInfoTableSize (
679 EFI_IMAGE_EXECUTION_INFO_TABLE
*ImageExeInfoTable
683 EFI_IMAGE_EXECUTION_INFO
*ImageExeInfoItem
;
686 if (ImageExeInfoTable
== NULL
) {
690 ImageExeInfoItem
= (EFI_IMAGE_EXECUTION_INFO
*) ((UINT8
*) ImageExeInfoTable
+ sizeof (EFI_IMAGE_EXECUTION_INFO_TABLE
));
691 TotalSize
= sizeof (EFI_IMAGE_EXECUTION_INFO_TABLE
);
692 for (Index
= 0; Index
< ImageExeInfoTable
->NumberOfImages
; Index
++) {
693 TotalSize
+= ReadUnaligned32 ((UINT32
*) &ImageExeInfoItem
->InfoSize
);
694 ImageExeInfoItem
= (EFI_IMAGE_EXECUTION_INFO
*) ((UINT8
*) ImageExeInfoItem
+ ReadUnaligned32 ((UINT32
*) &ImageExeInfoItem
->InfoSize
));
701 Create an Image Execution Information Table entry and add it to system configuration table.
703 @param[in] Action Describes the action taken by the firmware regarding this image.
704 @param[in] Name Input a null-terminated, user-friendly name.
705 @param[in] DevicePath Input device path pointer.
706 @param[in] Signature Input signature info in EFI_SIGNATURE_LIST data structure.
707 @param[in] SignatureSize Size of signature.
712 IN EFI_IMAGE_EXECUTION_ACTION Action
,
713 IN CHAR16
*Name OPTIONAL
,
714 IN CONST EFI_DEVICE_PATH_PROTOCOL
*DevicePath
,
715 IN EFI_SIGNATURE_LIST
*Signature OPTIONAL
,
716 IN UINTN SignatureSize
719 EFI_IMAGE_EXECUTION_INFO_TABLE
*ImageExeInfoTable
;
720 EFI_IMAGE_EXECUTION_INFO_TABLE
*NewImageExeInfoTable
;
721 EFI_IMAGE_EXECUTION_INFO
*ImageExeInfoEntry
;
722 UINTN ImageExeInfoTableSize
;
723 UINTN NewImageExeInfoEntrySize
;
725 UINTN DevicePathSize
;
728 ImageExeInfoTable
= NULL
;
729 NewImageExeInfoTable
= NULL
;
730 ImageExeInfoEntry
= NULL
;
734 if (DevicePath
== NULL
) {
739 NameStringLen
= StrSize (Name
);
741 NameStringLen
= sizeof (CHAR16
);
744 EfiGetSystemConfigurationTable (&gEfiImageSecurityDatabaseGuid
, (VOID
**) &ImageExeInfoTable
);
745 if (ImageExeInfoTable
!= NULL
) {
747 // The table has been found!
748 // We must enlarge the table to accommodate the new exe info entry.
750 ImageExeInfoTableSize
= GetImageExeInfoTableSize (ImageExeInfoTable
);
754 // We should create a new table to append to the configuration table.
756 ImageExeInfoTableSize
= sizeof (EFI_IMAGE_EXECUTION_INFO_TABLE
);
759 DevicePathSize
= GetDevicePathSize (DevicePath
);
762 // Signature size can be odd. Pad after signature to ensure next EXECUTION_INFO entry align
764 NewImageExeInfoEntrySize
= sizeof (EFI_IMAGE_EXECUTION_INFO
) + NameStringLen
+ DevicePathSize
+ SignatureSize
;
766 NewImageExeInfoTable
= (EFI_IMAGE_EXECUTION_INFO_TABLE
*) AllocateRuntimePool (ImageExeInfoTableSize
+ NewImageExeInfoEntrySize
);
767 if (NewImageExeInfoTable
== NULL
) {
771 if (ImageExeInfoTable
!= NULL
) {
772 CopyMem (NewImageExeInfoTable
, ImageExeInfoTable
, ImageExeInfoTableSize
);
774 NewImageExeInfoTable
->NumberOfImages
= 0;
776 NewImageExeInfoTable
->NumberOfImages
++;
777 ImageExeInfoEntry
= (EFI_IMAGE_EXECUTION_INFO
*) ((UINT8
*) NewImageExeInfoTable
+ ImageExeInfoTableSize
);
779 // Update new item's information.
781 WriteUnaligned32 ((UINT32
*) ImageExeInfoEntry
, Action
);
782 WriteUnaligned32 ((UINT32
*) ((UINT8
*) ImageExeInfoEntry
+ sizeof (EFI_IMAGE_EXECUTION_ACTION
)), (UINT32
) NewImageExeInfoEntrySize
);
784 NameStr
= (CHAR16
*)(ImageExeInfoEntry
+ 1);
786 CopyMem ((UINT8
*) NameStr
, Name
, NameStringLen
);
788 ZeroMem ((UINT8
*) NameStr
, sizeof (CHAR16
));
792 (UINT8
*) NameStr
+ NameStringLen
,
796 if (Signature
!= NULL
) {
798 (UINT8
*) NameStr
+ NameStringLen
+ DevicePathSize
,
804 // Update/replace the image execution table.
806 gBS
->InstallConfigurationTable (&gEfiImageSecurityDatabaseGuid
, (VOID
*) NewImageExeInfoTable
);
809 // Free Old table data!
811 if (ImageExeInfoTable
!= NULL
) {
812 FreePool (ImageExeInfoTable
);
817 Check whether the hash of an given X.509 certificate is in forbidden database (DBX).
819 @param[in] Certificate Pointer to X.509 Certificate that is searched for.
820 @param[in] CertSize Size of X.509 Certificate.
821 @param[in] SignatureList Pointer to the Signature List in forbidden database.
822 @param[in] SignatureListSize Size of Signature List.
823 @param[out] RevocationTime Return the time that the certificate was revoked.
825 @return TRUE The certificate hash is found in the forbidden database.
826 @return FALSE The certificate hash is not found in the forbidden database.
830 IsCertHashFoundInDatabase (
831 IN UINT8
*Certificate
,
833 IN EFI_SIGNATURE_LIST
*SignatureList
,
834 IN UINTN SignatureListSize
,
835 OUT EFI_TIME
*RevocationTime
840 EFI_SIGNATURE_LIST
*DbxList
;
842 EFI_SIGNATURE_DATA
*CertHash
;
847 UINT8 CertDigest
[MAX_DIGEST_SIZE
];
849 UINTN SiglistHeaderSize
;
854 DbxList
= SignatureList
;
855 DbxSize
= SignatureListSize
;
857 HashAlg
= HASHALG_MAX
;
859 if ((RevocationTime
== NULL
) || (DbxList
== NULL
)) {
864 // Retrieve the TBSCertificate from the X.509 Certificate.
866 if (!X509GetTBSCert (Certificate
, CertSize
, &TBSCert
, &TBSCertSize
)) {
870 while ((DbxSize
> 0) && (SignatureListSize
>= DbxList
->SignatureListSize
)) {
872 // Determine Hash Algorithm of Certificate in the forbidden database.
874 if (CompareGuid (&DbxList
->SignatureType
, &gEfiCertX509Sha256Guid
)) {
875 HashAlg
= HASHALG_SHA256
;
876 } else if (CompareGuid (&DbxList
->SignatureType
, &gEfiCertX509Sha384Guid
)) {
877 HashAlg
= HASHALG_SHA384
;
878 } else if (CompareGuid (&DbxList
->SignatureType
, &gEfiCertX509Sha512Guid
)) {
879 HashAlg
= HASHALG_SHA512
;
881 DbxSize
-= DbxList
->SignatureListSize
;
882 DbxList
= (EFI_SIGNATURE_LIST
*) ((UINT8
*) DbxList
+ DbxList
->SignatureListSize
);
887 // Calculate the hash value of current TBSCertificate for comparision.
889 if (mHash
[HashAlg
].GetContextSize
== NULL
) {
892 ZeroMem (CertDigest
, MAX_DIGEST_SIZE
);
893 HashCtx
= AllocatePool (mHash
[HashAlg
].GetContextSize ());
894 if (HashCtx
== NULL
) {
897 Status
= mHash
[HashAlg
].HashInit (HashCtx
);
901 Status
= mHash
[HashAlg
].HashUpdate (HashCtx
, TBSCert
, TBSCertSize
);
905 Status
= mHash
[HashAlg
].HashFinal (HashCtx
, CertDigest
);
910 SiglistHeaderSize
= sizeof (EFI_SIGNATURE_LIST
) + DbxList
->SignatureHeaderSize
;
911 CertHash
= (EFI_SIGNATURE_DATA
*) ((UINT8
*) DbxList
+ SiglistHeaderSize
);
912 CertHashCount
= (DbxList
->SignatureListSize
- SiglistHeaderSize
) / DbxList
->SignatureSize
;
913 for (Index
= 0; Index
< CertHashCount
; Index
++) {
915 // Iterate each Signature Data Node within this CertList for verify.
917 DbxCertHash
= CertHash
->SignatureData
;
918 if (CompareMem (DbxCertHash
, CertDigest
, mHash
[HashAlg
].DigestLength
) == 0) {
920 // Hash of Certificate is found in forbidden database.
925 // Return the revocation time.
927 CopyMem (RevocationTime
, (EFI_TIME
*)(DbxCertHash
+ mHash
[HashAlg
].DigestLength
), sizeof (EFI_TIME
));
930 CertHash
= (EFI_SIGNATURE_DATA
*) ((UINT8
*) CertHash
+ DbxList
->SignatureSize
);
933 DbxSize
-= DbxList
->SignatureListSize
;
934 DbxList
= (EFI_SIGNATURE_LIST
*) ((UINT8
*) DbxList
+ DbxList
->SignatureListSize
);
938 if (HashCtx
!= NULL
) {
946 Check whether signature is in specified database.
948 @param[in] VariableName Name of database variable that is searched in.
949 @param[in] Signature Pointer to signature that is searched for.
950 @param[in] CertType Pointer to hash algorithm.
951 @param[in] SignatureSize Size of Signature.
953 @return TRUE Found the signature in the variable database.
954 @return FALSE Not found the signature in the variable database.
958 IsSignatureFoundInDatabase (
959 IN CHAR16
*VariableName
,
961 IN EFI_GUID
*CertType
,
962 IN UINTN SignatureSize
966 EFI_SIGNATURE_LIST
*CertList
;
967 EFI_SIGNATURE_DATA
*Cert
;
975 // Read signature database variable.
980 Status
= gRT
->GetVariable (VariableName
, &gEfiImageSecurityDatabaseGuid
, NULL
, &DataSize
, NULL
);
981 if (Status
!= EFI_BUFFER_TOO_SMALL
) {
985 Data
= (UINT8
*) AllocateZeroPool (DataSize
);
990 Status
= gRT
->GetVariable (VariableName
, &gEfiImageSecurityDatabaseGuid
, NULL
, &DataSize
, Data
);
991 if (EFI_ERROR (Status
)) {
995 // Enumerate all signature data in SigDB to check if signature exists for executable.
997 CertList
= (EFI_SIGNATURE_LIST
*) Data
;
998 while ((DataSize
> 0) && (DataSize
>= CertList
->SignatureListSize
)) {
999 CertCount
= (CertList
->SignatureListSize
- sizeof (EFI_SIGNATURE_LIST
) - CertList
->SignatureHeaderSize
) / CertList
->SignatureSize
;
1000 Cert
= (EFI_SIGNATURE_DATA
*) ((UINT8
*) CertList
+ sizeof (EFI_SIGNATURE_LIST
) + CertList
->SignatureHeaderSize
);
1001 if ((CertList
->SignatureSize
== sizeof(EFI_SIGNATURE_DATA
) - 1 + SignatureSize
) && (CompareGuid(&CertList
->SignatureType
, CertType
))) {
1002 for (Index
= 0; Index
< CertCount
; Index
++) {
1003 if (CompareMem (Cert
->SignatureData
, Signature
, SignatureSize
) == 0) {
1005 // Find the signature in database.
1009 // Entries in UEFI_IMAGE_SECURITY_DATABASE that are used to validate image should be measured
1011 if (StrCmp(VariableName
, EFI_IMAGE_SECURITY_DATABASE
) == 0) {
1012 SecureBootHook (VariableName
, &gEfiImageSecurityDatabaseGuid
, CertList
->SignatureSize
, Cert
);
1017 Cert
= (EFI_SIGNATURE_DATA
*) ((UINT8
*) Cert
+ CertList
->SignatureSize
);
1025 DataSize
-= CertList
->SignatureListSize
;
1026 CertList
= (EFI_SIGNATURE_LIST
*) ((UINT8
*) CertList
+ CertList
->SignatureListSize
);
1038 Check whether the timestamp is valid by comparing the signing time and the revocation time.
1040 @param SigningTime A pointer to the signing time.
1041 @param RevocationTime A pointer to the revocation time.
1043 @retval TRUE The SigningTime is not later than the RevocationTime.
1044 @retval FALSE The SigningTime is later than the RevocationTime.
1048 IsValidSignatureByTimestamp (
1049 IN EFI_TIME
*SigningTime
,
1050 IN EFI_TIME
*RevocationTime
1053 if (SigningTime
->Year
!= RevocationTime
->Year
) {
1054 return (BOOLEAN
) (SigningTime
->Year
< RevocationTime
->Year
);
1055 } else if (SigningTime
->Month
!= RevocationTime
->Month
) {
1056 return (BOOLEAN
) (SigningTime
->Month
< RevocationTime
->Month
);
1057 } else if (SigningTime
->Day
!= RevocationTime
->Day
) {
1058 return (BOOLEAN
) (SigningTime
->Day
< RevocationTime
->Day
);
1059 } else if (SigningTime
->Hour
!= RevocationTime
->Hour
) {
1060 return (BOOLEAN
) (SigningTime
->Hour
< RevocationTime
->Hour
);
1061 } else if (SigningTime
->Minute
!= RevocationTime
->Minute
) {
1062 return (BOOLEAN
) (SigningTime
->Minute
< RevocationTime
->Minute
);
1065 return (BOOLEAN
) (SigningTime
->Second
<= RevocationTime
->Second
);
1069 Check if the given time value is zero.
1071 @param[in] Time Pointer of a time value.
1073 @retval TRUE The Time is Zero.
1074 @retval FALSE The Time is not Zero.
1082 if ((Time
->Year
== 0) && (Time
->Month
== 0) && (Time
->Day
== 0) &&
1083 (Time
->Hour
== 0) && (Time
->Minute
== 0) && (Time
->Second
== 0)) {
1091 Check whether the timestamp signature is valid and the signing time is also earlier than
1092 the revocation time.
1094 @param[in] AuthData Pointer to the Authenticode signature retrieved from signed image.
1095 @param[in] AuthDataSize Size of the Authenticode signature in bytes.
1096 @param[in] RevocationTime The time that the certificate was revoked.
1098 @retval TRUE Timestamp signature is valid and signing time is no later than the
1100 @retval FALSE Timestamp signature is not valid or the signing time is later than the
1105 PassTimestampCheck (
1107 IN UINTN AuthDataSize
,
1108 IN EFI_TIME
*RevocationTime
1112 BOOLEAN VerifyStatus
;
1113 EFI_SIGNATURE_LIST
*CertList
;
1114 EFI_SIGNATURE_DATA
*Cert
;
1121 EFI_TIME SigningTime
;
1124 // Variable Initialization
1126 VerifyStatus
= FALSE
;
1134 // If RevocationTime is zero, the certificate shall be considered to always be revoked.
1136 if (IsTimeZero (RevocationTime
)) {
1141 // RevocationTime is non-zero, the certificate should be considered to be revoked from that time and onwards.
1142 // Using the dbt to get the trusted TSA certificates.
1145 Status
= gRT
->GetVariable (EFI_IMAGE_SECURITY_DATABASE2
, &gEfiImageSecurityDatabaseGuid
, NULL
, &DbtDataSize
, NULL
);
1146 if (Status
!= EFI_BUFFER_TOO_SMALL
) {
1149 DbtData
= (UINT8
*) AllocateZeroPool (DbtDataSize
);
1150 if (DbtData
== NULL
) {
1153 Status
= gRT
->GetVariable (EFI_IMAGE_SECURITY_DATABASE2
, &gEfiImageSecurityDatabaseGuid
, NULL
, &DbtDataSize
, (VOID
*) DbtData
);
1154 if (EFI_ERROR (Status
)) {
1158 CertList
= (EFI_SIGNATURE_LIST
*) DbtData
;
1159 while ((DbtDataSize
> 0) && (DbtDataSize
>= CertList
->SignatureListSize
)) {
1160 if (CompareGuid (&CertList
->SignatureType
, &gEfiCertX509Guid
)) {
1161 Cert
= (EFI_SIGNATURE_DATA
*) ((UINT8
*) CertList
+ sizeof (EFI_SIGNATURE_LIST
) + CertList
->SignatureHeaderSize
);
1162 CertCount
= (CertList
->SignatureListSize
- sizeof (EFI_SIGNATURE_LIST
) - CertList
->SignatureHeaderSize
) / CertList
->SignatureSize
;
1163 for (Index
= 0; Index
< CertCount
; Index
++) {
1165 // Iterate each Signature Data Node within this CertList for verify.
1167 RootCert
= Cert
->SignatureData
;
1168 RootCertSize
= CertList
->SignatureSize
- sizeof (EFI_GUID
);
1170 // Get the signing time if the timestamp signature is valid.
1172 if (ImageTimestampVerify (AuthData
, AuthDataSize
, RootCert
, RootCertSize
, &SigningTime
)) {
1174 // The signer signature is valid only when the signing time is earlier than revocation time.
1176 if (IsValidSignatureByTimestamp (&SigningTime
, RevocationTime
)) {
1177 VerifyStatus
= TRUE
;
1181 Cert
= (EFI_SIGNATURE_DATA
*) ((UINT8
*) Cert
+ CertList
->SignatureSize
);
1184 DbtDataSize
-= CertList
->SignatureListSize
;
1185 CertList
= (EFI_SIGNATURE_LIST
*) ((UINT8
*) CertList
+ CertList
->SignatureListSize
);
1189 if (DbtData
!= NULL
) {
1193 return VerifyStatus
;
1197 Check whether the image signature is forbidden by the forbidden database (dbx).
1198 The image is forbidden to load if any certificates for signing are revoked before signing time.
1200 @param[in] AuthData Pointer to the Authenticode signature retrieved from the signed image.
1201 @param[in] AuthDataSize Size of the Authenticode signature in bytes.
1203 @retval TRUE Image is forbidden by dbx.
1204 @retval FALSE Image is not forbidden by dbx.
1210 IN UINTN AuthDataSize
1214 BOOLEAN IsForbidden
;
1217 EFI_SIGNATURE_LIST
*CertList
;
1219 EFI_SIGNATURE_DATA
*CertData
;
1227 UINTN TrustedCertLength
;
1232 EFI_TIME RevocationTime
;
1234 // Variable Initialization
1236 IsForbidden
= FALSE
;
1246 TrustedCertLength
= 0;
1249 // The image will not be forbidden if dbx can't be got.
1252 Status
= gRT
->GetVariable (EFI_IMAGE_SECURITY_DATABASE1
, &gEfiImageSecurityDatabaseGuid
, NULL
, &DataSize
, NULL
);
1253 if (Status
!= EFI_BUFFER_TOO_SMALL
) {
1256 Data
= (UINT8
*) AllocateZeroPool (DataSize
);
1261 Status
= gRT
->GetVariable (EFI_IMAGE_SECURITY_DATABASE1
, &gEfiImageSecurityDatabaseGuid
, NULL
, &DataSize
, (VOID
*) Data
);
1262 if (EFI_ERROR (Status
)) {
1267 // Verify image signature with RAW X509 certificates in DBX database.
1268 // If passed, the image will be forbidden.
1270 CertList
= (EFI_SIGNATURE_LIST
*) Data
;
1271 CertListSize
= DataSize
;
1272 while ((CertListSize
> 0) && (CertListSize
>= CertList
->SignatureListSize
)) {
1273 if (CompareGuid (&CertList
->SignatureType
, &gEfiCertX509Guid
)) {
1274 CertData
= (EFI_SIGNATURE_DATA
*) ((UINT8
*) CertList
+ sizeof (EFI_SIGNATURE_LIST
) + CertList
->SignatureHeaderSize
);
1275 CertCount
= (CertList
->SignatureListSize
- sizeof (EFI_SIGNATURE_LIST
) - CertList
->SignatureHeaderSize
) / CertList
->SignatureSize
;
1277 for (Index
= 0; Index
< CertCount
; Index
++) {
1279 // Iterate each Signature Data Node within this CertList for verify.
1281 RootCert
= CertData
->SignatureData
;
1282 RootCertSize
= CertList
->SignatureSize
- sizeof (EFI_GUID
);
1285 // Call AuthenticodeVerify library to Verify Authenticode struct.
1287 IsForbidden
= AuthenticodeVerify (
1296 DEBUG ((DEBUG_INFO
, "DxeImageVerificationLib: Image is signed but signature is forbidden by DBX.\n"));
1300 CertData
= (EFI_SIGNATURE_DATA
*) ((UINT8
*) CertData
+ CertList
->SignatureSize
);
1304 CertListSize
-= CertList
->SignatureListSize
;
1305 CertList
= (EFI_SIGNATURE_LIST
*) ((UINT8
*) CertList
+ CertList
->SignatureListSize
);
1309 // Check X.509 Certificate Hash & Possible Timestamp.
1313 // Retrieve the certificate stack from AuthData
1314 // The output CertStack format will be:
1315 // UINT8 CertNumber;
1316 // UINT32 Cert1Length;
1318 // UINT32 Cert2Length;
1321 // UINT32 CertnLength;
1324 Pkcs7GetSigners (AuthData
, AuthDataSize
, &CertBuffer
, &BufferLength
, &TrustedCert
, &TrustedCertLength
);
1325 if ((BufferLength
== 0) || (CertBuffer
== NULL
)) {
1331 // Check if any hash of certificates embedded in AuthData is in the forbidden database.
1333 CertNumber
= (UINT8
) (*CertBuffer
);
1334 CertPtr
= CertBuffer
+ 1;
1335 for (Index
= 0; Index
< CertNumber
; Index
++) {
1336 CertSize
= (UINTN
) ReadUnaligned32 ((UINT32
*)CertPtr
);
1337 Cert
= (UINT8
*)CertPtr
+ sizeof (UINT32
);
1339 // Advance CertPtr to the next cert in image signer's cert list
1341 CertPtr
= CertPtr
+ sizeof (UINT32
) + CertSize
;
1343 if (IsCertHashFoundInDatabase (Cert
, CertSize
, (EFI_SIGNATURE_LIST
*)Data
, DataSize
, &RevocationTime
)) {
1345 // Check the timestamp signature and signing time to determine if the image can be trusted.
1348 if (PassTimestampCheck (AuthData
, AuthDataSize
, &RevocationTime
)) {
1349 IsForbidden
= FALSE
;
1351 // Pass DBT check. Continue to check other certs in image signer's cert list against DBX, DBT
1355 DEBUG ((DEBUG_INFO
, "DxeImageVerificationLib: Image is signed but signature failed the timestamp check.\n"));
1366 Pkcs7FreeSigners (CertBuffer
);
1367 Pkcs7FreeSigners (TrustedCert
);
1374 Check whether the image signature can be verified by the trusted certificates in DB database.
1376 @param[in] AuthData Pointer to the Authenticode signature retrieved from signed image.
1377 @param[in] AuthDataSize Size of the Authenticode signature in bytes.
1379 @retval TRUE Image passed verification using certificate in db.
1380 @retval FALSE Image didn't pass verification using certificate in db.
1386 IN UINTN AuthDataSize
1390 BOOLEAN VerifyStatus
;
1391 EFI_SIGNATURE_LIST
*CertList
;
1392 EFI_SIGNATURE_DATA
*CertData
;
1401 EFI_TIME RevocationTime
;
1409 VerifyStatus
= FALSE
;
1412 Status
= gRT
->GetVariable (EFI_IMAGE_SECURITY_DATABASE
, &gEfiImageSecurityDatabaseGuid
, NULL
, &DataSize
, NULL
);
1413 if (Status
== EFI_BUFFER_TOO_SMALL
) {
1414 Data
= (UINT8
*) AllocateZeroPool (DataSize
);
1416 return VerifyStatus
;
1419 Status
= gRT
->GetVariable (EFI_IMAGE_SECURITY_DATABASE
, &gEfiImageSecurityDatabaseGuid
, NULL
, &DataSize
, (VOID
*) Data
);
1420 if (EFI_ERROR (Status
)) {
1425 // Find X509 certificate in Signature List to verify the signature in pkcs7 signed data.
1427 CertList
= (EFI_SIGNATURE_LIST
*) Data
;
1428 while ((DataSize
> 0) && (DataSize
>= CertList
->SignatureListSize
)) {
1429 if (CompareGuid (&CertList
->SignatureType
, &gEfiCertX509Guid
)) {
1430 CertData
= (EFI_SIGNATURE_DATA
*) ((UINT8
*) CertList
+ sizeof (EFI_SIGNATURE_LIST
) + CertList
->SignatureHeaderSize
);
1431 CertCount
= (CertList
->SignatureListSize
- sizeof (EFI_SIGNATURE_LIST
) - CertList
->SignatureHeaderSize
) / CertList
->SignatureSize
;
1433 for (Index
= 0; Index
< CertCount
; Index
++) {
1435 // Iterate each Signature Data Node within this CertList for verify.
1437 RootCert
= CertData
->SignatureData
;
1438 RootCertSize
= CertList
->SignatureSize
- sizeof (EFI_GUID
);
1441 // Call AuthenticodeVerify library to Verify Authenticode struct.
1443 VerifyStatus
= AuthenticodeVerify (
1453 // Here We still need to check if this RootCert's Hash is revoked
1455 Status
= gRT
->GetVariable (EFI_IMAGE_SECURITY_DATABASE1
, &gEfiImageSecurityDatabaseGuid
, NULL
, &DbxDataSize
, NULL
);
1456 if (Status
== EFI_BUFFER_TOO_SMALL
) {
1459 DbxData
= (UINT8
*) AllocateZeroPool (DbxDataSize
);
1460 if (DbxData
== NULL
) {
1464 Status
= gRT
->GetVariable (EFI_IMAGE_SECURITY_DATABASE1
, &gEfiImageSecurityDatabaseGuid
, NULL
, &DbxDataSize
, (VOID
*) DbxData
);
1465 if (EFI_ERROR (Status
)) {
1469 if (IsCertHashFoundInDatabase (RootCert
, RootCertSize
, (EFI_SIGNATURE_LIST
*)DbxData
, DbxDataSize
, &RevocationTime
)) {
1471 // Check the timestamp signature and signing time to determine if the RootCert can be trusted.
1473 VerifyStatus
= PassTimestampCheck (AuthData
, AuthDataSize
, &RevocationTime
);
1474 if (!VerifyStatus
) {
1475 DEBUG ((DEBUG_INFO
, "DxeImageVerificationLib: Image is signed and signature is accepted by DB, but its root cert failed the timestamp check.\n"));
1482 CertData
= (EFI_SIGNATURE_DATA
*) ((UINT8
*) CertData
+ CertList
->SignatureSize
);
1486 DataSize
-= CertList
->SignatureListSize
;
1487 CertList
= (EFI_SIGNATURE_LIST
*) ((UINT8
*) CertList
+ CertList
->SignatureListSize
);
1494 SecureBootHook (EFI_IMAGE_SECURITY_DATABASE
, &gEfiImageSecurityDatabaseGuid
, CertList
->SignatureSize
, CertData
);
1500 if (DbxData
!= NULL
) {
1504 return VerifyStatus
;
1508 Provide verification service for signed images, which include both signature validation
1509 and platform policy control. For signature types, both UEFI WIN_CERTIFICATE_UEFI_GUID and
1510 MSFT Authenticode type signatures are supported.
1512 In this implementation, only verify external executables when in USER MODE.
1513 Executables from FV is bypass, so pass in AuthenticationStatus is ignored.
1515 The image verification policy is:
1516 If the image is signed,
1517 At least one valid signature or at least one hash value of the image must match a record
1518 in the security database "db", and no valid signature nor any hash value of the image may
1519 be reflected in the security database "dbx".
1520 Otherwise, the image is not signed,
1521 The SHA256 hash value of the image must match a record in the security database "db", and
1522 not be reflected in the security data base "dbx".
1524 Caution: This function may receive untrusted input.
1525 PE/COFF image is external input, so this function will validate its data structure
1526 within this image buffer before use.
1528 @param[in] AuthenticationStatus
1529 This is the authentication status returned from the security
1530 measurement services for the input file.
1531 @param[in] File This is a pointer to the device path of the file that is
1532 being dispatched. This will optionally be used for logging.
1533 @param[in] FileBuffer File buffer matches the input file device path.
1534 @param[in] FileSize Size of File buffer matches the input file device path.
1535 @param[in] BootPolicy A boot policy that was used to call LoadImage() UEFI service.
1537 @retval EFI_SUCCESS The file specified by DevicePath and non-NULL
1538 FileBuffer did authenticate, and the platform policy dictates
1539 that the DXE Foundation may use the file.
1540 @retval EFI_SUCCESS The device path specified by NULL device path DevicePath
1541 and non-NULL FileBuffer did authenticate, and the platform
1542 policy dictates that the DXE Foundation may execute the image in
1544 @retval EFI_SECURITY_VIOLATION The file specified by File did not authenticate, and
1545 the platform policy dictates that File should be placed
1546 in the untrusted state. The image has been added to the file
1548 @retval EFI_ACCESS_DENIED The file specified by File and FileBuffer did not
1549 authenticate, and the platform policy dictates that the DXE
1550 Foundation many not use File.
1555 DxeImageVerificationHandler (
1556 IN UINT32 AuthenticationStatus
,
1557 IN CONST EFI_DEVICE_PATH_PROTOCOL
*File
,
1558 IN VOID
*FileBuffer
,
1560 IN BOOLEAN BootPolicy
1564 EFI_IMAGE_DOS_HEADER
*DosHdr
;
1566 EFI_SIGNATURE_LIST
*SignatureList
;
1567 UINTN SignatureListSize
;
1568 EFI_SIGNATURE_DATA
*Signature
;
1569 EFI_IMAGE_EXECUTION_ACTION Action
;
1570 WIN_CERTIFICATE
*WinCertificate
;
1573 PE_COFF_LOADER_IMAGE_CONTEXT ImageContext
;
1574 UINT32 NumberOfRvaAndSizes
;
1575 WIN_CERTIFICATE_EFI_PKCS
*PkcsCertData
;
1576 WIN_CERTIFICATE_UEFI_GUID
*WinCertUefiGuid
;
1579 EFI_IMAGE_DATA_DIRECTORY
*SecDataDir
;
1582 RETURN_STATUS PeCoffStatus
;
1583 EFI_STATUS HashStatus
;
1585 SignatureList
= NULL
;
1586 SignatureListSize
= 0;
1587 WinCertificate
= NULL
;
1589 PkcsCertData
= NULL
;
1590 Action
= EFI_IMAGE_EXECUTION_AUTH_UNTESTED
;
1591 Status
= EFI_ACCESS_DENIED
;
1596 // Check the image type and get policy setting.
1598 switch (GetImageType (File
)) {
1601 Policy
= ALWAYS_EXECUTE
;
1604 case IMAGE_FROM_OPTION_ROM
:
1605 Policy
= PcdGet32 (PcdOptionRomImageVerificationPolicy
);
1608 case IMAGE_FROM_REMOVABLE_MEDIA
:
1609 Policy
= PcdGet32 (PcdRemovableMediaImageVerificationPolicy
);
1612 case IMAGE_FROM_FIXED_MEDIA
:
1613 Policy
= PcdGet32 (PcdFixedMediaImageVerificationPolicy
);
1617 Policy
= DENY_EXECUTE_ON_SECURITY_VIOLATION
;
1621 // If policy is always/never execute, return directly.
1623 if (Policy
== ALWAYS_EXECUTE
) {
1626 if (Policy
== NEVER_EXECUTE
) {
1627 return EFI_ACCESS_DENIED
;
1631 // The policy QUERY_USER_ON_SECURITY_VIOLATION and ALLOW_EXECUTE_ON_SECURITY_VIOLATION
1632 // violates the UEFI spec and has been removed.
1634 ASSERT (Policy
!= QUERY_USER_ON_SECURITY_VIOLATION
&& Policy
!= ALLOW_EXECUTE_ON_SECURITY_VIOLATION
);
1635 if (Policy
== QUERY_USER_ON_SECURITY_VIOLATION
|| Policy
== ALLOW_EXECUTE_ON_SECURITY_VIOLATION
) {
1639 GetEfiGlobalVariable2 (EFI_SECURE_BOOT_MODE_NAME
, (VOID
**)&SecureBoot
, NULL
);
1641 // Skip verification if SecureBoot variable doesn't exist.
1643 if (SecureBoot
== NULL
) {
1648 // Skip verification if SecureBoot is disabled but not AuditMode
1650 if (*SecureBoot
== SECURE_BOOT_MODE_DISABLE
) {
1651 FreePool (SecureBoot
);
1654 FreePool (SecureBoot
);
1657 // Read the Dos header.
1659 if (FileBuffer
== NULL
) {
1660 return EFI_INVALID_PARAMETER
;
1663 mImageBase
= (UINT8
*) FileBuffer
;
1664 mImageSize
= FileSize
;
1666 ZeroMem (&ImageContext
, sizeof (ImageContext
));
1667 ImageContext
.Handle
= (VOID
*) FileBuffer
;
1668 ImageContext
.ImageRead
= (PE_COFF_LOADER_READ_FILE
) DxeImageVerificationLibImageRead
;
1671 // Get information about the image being loaded
1673 PeCoffStatus
= PeCoffLoaderGetImageInfo (&ImageContext
);
1674 if (RETURN_ERROR (PeCoffStatus
)) {
1676 // The information can't be got from the invalid PeImage
1678 DEBUG ((DEBUG_INFO
, "DxeImageVerificationLib: PeImage invalid. Cannot retrieve image information.\n"));
1682 DosHdr
= (EFI_IMAGE_DOS_HEADER
*) mImageBase
;
1683 if (DosHdr
->e_magic
== EFI_IMAGE_DOS_SIGNATURE
) {
1685 // DOS image header is present,
1686 // so read the PE header after the DOS image header.
1688 mPeCoffHeaderOffset
= DosHdr
->e_lfanew
;
1690 mPeCoffHeaderOffset
= 0;
1693 // Check PE/COFF image.
1695 mNtHeader
.Pe32
= (EFI_IMAGE_NT_HEADERS32
*) (mImageBase
+ mPeCoffHeaderOffset
);
1696 if (mNtHeader
.Pe32
->Signature
!= EFI_IMAGE_NT_SIGNATURE
) {
1698 // It is not a valid Pe/Coff file.
1700 DEBUG ((DEBUG_INFO
, "DxeImageVerificationLib: Not a valid PE/COFF image.\n"));
1704 if (mNtHeader
.Pe32
->OptionalHeader
.Magic
== EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC
) {
1708 NumberOfRvaAndSizes
= mNtHeader
.Pe32
->OptionalHeader
.NumberOfRvaAndSizes
;
1709 if (NumberOfRvaAndSizes
> EFI_IMAGE_DIRECTORY_ENTRY_SECURITY
) {
1710 SecDataDir
= (EFI_IMAGE_DATA_DIRECTORY
*) &mNtHeader
.Pe32
->OptionalHeader
.DataDirectory
[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY
];
1714 // Use PE32+ offset.
1716 NumberOfRvaAndSizes
= mNtHeader
.Pe32Plus
->OptionalHeader
.NumberOfRvaAndSizes
;
1717 if (NumberOfRvaAndSizes
> EFI_IMAGE_DIRECTORY_ENTRY_SECURITY
) {
1718 SecDataDir
= (EFI_IMAGE_DATA_DIRECTORY
*) &mNtHeader
.Pe32Plus
->OptionalHeader
.DataDirectory
[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY
];
1723 // Start Image Validation.
1725 if (SecDataDir
== NULL
|| SecDataDir
->Size
== 0) {
1727 // This image is not signed. The SHA256 hash value of the image must match a record in the security database "db",
1728 // and not be reflected in the security data base "dbx".
1730 if (!HashPeImage (HASHALG_SHA256
)) {
1731 DEBUG ((DEBUG_INFO
, "DxeImageVerificationLib: Failed to hash this image using %s.\n", mHashTypeStr
));
1735 if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE1
, mImageDigest
, &mCertType
, mImageDigestSize
)) {
1737 // Image Hash is in forbidden database (DBX).
1739 DEBUG ((DEBUG_INFO
, "DxeImageVerificationLib: Image is not signed and %s hash of image is forbidden by DBX.\n", mHashTypeStr
));
1743 if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE
, mImageDigest
, &mCertType
, mImageDigestSize
)) {
1745 // Image Hash is in allowed database (DB).
1751 // Image Hash is not found in both forbidden and allowed database.
1753 DEBUG ((DEBUG_INFO
, "DxeImageVerificationLib: Image is not signed and %s hash of image is not found in DB/DBX.\n", mHashTypeStr
));
1758 // Verify the signature of the image, multiple signatures are allowed as per PE/COFF Section 4.7
1759 // "Attribute Certificate Table".
1760 // The first certificate starts at offset (SecDataDir->VirtualAddress) from the start of the file.
1762 for (OffSet
= SecDataDir
->VirtualAddress
;
1763 OffSet
< (SecDataDir
->VirtualAddress
+ SecDataDir
->Size
);
1764 OffSet
+= (WinCertificate
->dwLength
+ ALIGN_SIZE (WinCertificate
->dwLength
))) {
1765 WinCertificate
= (WIN_CERTIFICATE
*) (mImageBase
+ OffSet
);
1766 if ((SecDataDir
->VirtualAddress
+ SecDataDir
->Size
- OffSet
) <= sizeof (WIN_CERTIFICATE
) ||
1767 (SecDataDir
->VirtualAddress
+ SecDataDir
->Size
- OffSet
) < WinCertificate
->dwLength
) {
1772 // Verify the image's Authenticode signature, only DER-encoded PKCS#7 signed data is supported.
1774 if (WinCertificate
->wCertificateType
== WIN_CERT_TYPE_PKCS_SIGNED_DATA
) {
1776 // The certificate is formatted as WIN_CERTIFICATE_EFI_PKCS which is described in the
1777 // Authenticode specification.
1779 PkcsCertData
= (WIN_CERTIFICATE_EFI_PKCS
*) WinCertificate
;
1780 if (PkcsCertData
->Hdr
.dwLength
<= sizeof (PkcsCertData
->Hdr
)) {
1783 AuthData
= PkcsCertData
->CertData
;
1784 AuthDataSize
= PkcsCertData
->Hdr
.dwLength
- sizeof(PkcsCertData
->Hdr
);
1785 } else if (WinCertificate
->wCertificateType
== WIN_CERT_TYPE_EFI_GUID
) {
1787 // The certificate is formatted as WIN_CERTIFICATE_UEFI_GUID which is described in UEFI Spec.
1789 WinCertUefiGuid
= (WIN_CERTIFICATE_UEFI_GUID
*) WinCertificate
;
1790 if (WinCertUefiGuid
->Hdr
.dwLength
<= OFFSET_OF(WIN_CERTIFICATE_UEFI_GUID
, CertData
)) {
1793 if (!CompareGuid (&WinCertUefiGuid
->CertType
, &gEfiCertPkcs7Guid
)) {
1796 AuthData
= WinCertUefiGuid
->CertData
;
1797 AuthDataSize
= WinCertUefiGuid
->Hdr
.dwLength
- OFFSET_OF(WIN_CERTIFICATE_UEFI_GUID
, CertData
);
1799 if (WinCertificate
->dwLength
< sizeof (WIN_CERTIFICATE
)) {
1805 HashStatus
= HashPeImageByType (AuthData
, AuthDataSize
);
1806 if (EFI_ERROR (HashStatus
)) {
1811 // Check the digital signature against the revoked certificate in forbidden database (dbx).
1813 if (IsForbiddenByDbx (AuthData
, AuthDataSize
)) {
1814 Action
= EFI_IMAGE_EXECUTION_AUTH_SIG_FAILED
;
1820 // Check the digital signature against the valid certificate in allowed database (db).
1823 if (IsAllowedByDb (AuthData
, AuthDataSize
)) {
1829 // Check the image's hash value.
1831 if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE1
, mImageDigest
, &mCertType
, mImageDigestSize
)) {
1832 Action
= EFI_IMAGE_EXECUTION_AUTH_SIG_FOUND
;
1833 DEBUG ((DEBUG_INFO
, "DxeImageVerificationLib: Image is signed but %s hash of image is found in DBX.\n", mHashTypeStr
));
1838 if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE
, mImageDigest
, &mCertType
, mImageDigestSize
)) {
1841 DEBUG ((DEBUG_INFO
, "DxeImageVerificationLib: Image is signed but signature is not allowed by DB and %s hash of image is not found in DB/DBX.\n", mHashTypeStr
));
1846 if (OffSet
!= (SecDataDir
->VirtualAddress
+ SecDataDir
->Size
)) {
1848 // The Size in Certificate Table or the attribute certificate table is corrupted.
1856 Status
= EFI_ACCESS_DENIED
;
1857 if (Action
== EFI_IMAGE_EXECUTION_AUTH_SIG_FAILED
|| Action
== EFI_IMAGE_EXECUTION_AUTH_SIG_FOUND
) {
1859 // Get image hash value as signature of executable.
1861 SignatureListSize
= sizeof (EFI_SIGNATURE_LIST
) + sizeof (EFI_SIGNATURE_DATA
) - 1 + mImageDigestSize
;
1862 SignatureList
= (EFI_SIGNATURE_LIST
*) AllocateZeroPool (SignatureListSize
);
1863 if (SignatureList
== NULL
) {
1866 SignatureList
->SignatureHeaderSize
= 0;
1867 SignatureList
->SignatureListSize
= (UINT32
) SignatureListSize
;
1868 SignatureList
->SignatureSize
= (UINT32
) (sizeof (EFI_SIGNATURE_DATA
) - 1 + mImageDigestSize
);
1869 CopyMem (&SignatureList
->SignatureType
, &mCertType
, sizeof (EFI_GUID
));
1870 Signature
= (EFI_SIGNATURE_DATA
*) ((UINT8
*) SignatureList
+ sizeof (EFI_SIGNATURE_LIST
));
1871 CopyMem (Signature
->SignatureData
, mImageDigest
, mImageDigestSize
);
1875 if (Status
!= EFI_SUCCESS
) {
1877 // Policy decides to defer or reject the image; add its information in image executable information table.
1879 NameStr
= ConvertDevicePathToText (File
, FALSE
, TRUE
);
1880 AddImageExeInfo (Action
, NameStr
, File
, SignatureList
, SignatureListSize
);
1881 if (NameStr
!= NULL
) {
1882 DEBUG((EFI_D_INFO
, "The image doesn't pass verification: %s\n", NameStr
));
1885 Status
= EFI_SECURITY_VIOLATION
;
1888 if (SignatureList
!= NULL
) {
1889 FreePool (SignatureList
);
1896 On Ready To Boot Services Event notification handler.
1898 Add the image execution information table if it is not in system configuration table.
1900 @param[in] Event Event whose notification function is being invoked
1901 @param[in] Context Pointer to the notification function's context
1911 EFI_IMAGE_EXECUTION_INFO_TABLE
*ImageExeInfoTable
;
1912 UINTN ImageExeInfoTableSize
;
1914 EfiGetSystemConfigurationTable (&gEfiImageSecurityDatabaseGuid
, (VOID
**) &ImageExeInfoTable
);
1915 if (ImageExeInfoTable
!= NULL
) {
1919 ImageExeInfoTableSize
= sizeof (EFI_IMAGE_EXECUTION_INFO_TABLE
);
1920 ImageExeInfoTable
= (EFI_IMAGE_EXECUTION_INFO_TABLE
*) AllocateRuntimePool (ImageExeInfoTableSize
);
1921 if (ImageExeInfoTable
== NULL
) {
1925 ImageExeInfoTable
->NumberOfImages
= 0;
1926 gBS
->InstallConfigurationTable (&gEfiImageSecurityDatabaseGuid
, (VOID
*) ImageExeInfoTable
);
1931 Register security measurement handler.
1933 @param ImageHandle ImageHandle of the loaded driver.
1934 @param SystemTable Pointer to the EFI System Table.
1936 @retval EFI_SUCCESS The handlers were registered successfully.
1940 DxeImageVerificationLibConstructor (
1941 IN EFI_HANDLE ImageHandle
,
1942 IN EFI_SYSTEM_TABLE
*SystemTable
1948 // Register the event to publish the image execution table.
1950 EfiCreateEventReadyToBootEx (
1957 return RegisterSecurity2Handler (
1958 DxeImageVerificationHandler
,
1959 EFI_AUTH_OPERATION_VERIFY_IMAGE
| EFI_AUTH_OPERATION_IMAGE_REQUIRED