| /** @file | |
| Implement image verification services for secure boot service | |
| Caution: This file requires additional review when modified. | |
| This library will have external input - PE/COFF image. | |
| This external input must be validated carefully to avoid security issue like | |
| buffer overflow, integer overflow. | |
| DxeImageVerificationLibImageRead() function will make sure the PE/COFF image content | |
| read is within the image buffer. | |
| DxeImageVerificationHandler(), HashPeImageByType(), HashPeImage() function will accept | |
| untrusted PE/COFF image and validate its data structure within this image buffer before use. | |
| Copyright (c) 2009 - 2016, Intel Corporation. All rights reserved.<BR> | |
| (C) Copyright 2016 Hewlett Packard Enterprise Development LP<BR> | |
| This program and the accompanying materials | |
| are licensed and made available under the terms and conditions of the BSD License | |
| which accompanies this distribution. The full text of the license may be found at | |
| http://opensource.org/licenses/bsd-license.php | |
| THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, | |
| WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. | |
| **/ | |
| #include "DxeImageVerificationLib.h" | |
| // | |
| // Caution: This is used by a function which may receive untrusted input. | |
| // These global variables hold PE/COFF image data, and they should be validated before use. | |
| // | |
| EFI_IMAGE_OPTIONAL_HEADER_PTR_UNION mNtHeader; | |
| UINT32 mPeCoffHeaderOffset; | |
| EFI_GUID mCertType; | |
| // | |
| // Information on current PE/COFF image | |
| // | |
| UINTN mImageSize; | |
| UINT8 *mImageBase = NULL; | |
| UINT8 mImageDigest[MAX_DIGEST_SIZE]; | |
| UINTN mImageDigestSize; | |
| // | |
| // Notify string for authorization UI. | |
| // | |
| CHAR16 mNotifyString1[MAX_NOTIFY_STRING_LEN] = L"Image verification pass but not found in authorized database!"; | |
| CHAR16 mNotifyString2[MAX_NOTIFY_STRING_LEN] = L"Launch this image anyway? (Yes/Defer/No)"; | |
| // | |
| // Public Exponent of RSA Key. | |
| // | |
| CONST UINT8 mRsaE[] = { 0x01, 0x00, 0x01 }; | |
| // | |
| // OID ASN.1 Value for Hash Algorithms | |
| // | |
| UINT8 mHashOidValue[] = { | |
| 0x2B, 0x0E, 0x03, 0x02, 0x1A, // OBJ_sha1 | |
| 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04, // OBJ_sha224 | |
| 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, // OBJ_sha256 | |
| 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02, // OBJ_sha384 | |
| 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03, // OBJ_sha512 | |
| }; | |
| HASH_TABLE mHash[] = { | |
| { L"SHA1", 20, &mHashOidValue[0], 5, Sha1GetContextSize, Sha1Init, Sha1Update, Sha1Final }, | |
| { L"SHA224", 28, &mHashOidValue[5], 9, NULL, NULL, NULL, NULL }, | |
| { L"SHA256", 32, &mHashOidValue[14], 9, Sha256GetContextSize, Sha256Init, Sha256Update, Sha256Final}, | |
| { L"SHA384", 48, &mHashOidValue[23], 9, Sha384GetContextSize, Sha384Init, Sha384Update, Sha384Final}, | |
| { L"SHA512", 64, &mHashOidValue[32], 9, Sha512GetContextSize, Sha512Init, Sha512Update, Sha512Final} | |
| }; | |
| EFI_STRING mHashTypeStr; | |
| /** | |
| SecureBoot Hook for processing image verification. | |
| @param[in] VariableName Name of Variable to be found. | |
| @param[in] VendorGuid Variable vendor GUID. | |
| @param[in] DataSize Size of Data found. If size is less than the | |
| data, this value contains the required size. | |
| @param[in] Data Data pointer. | |
| **/ | |
| VOID | |
| EFIAPI | |
| SecureBootHook ( | |
| IN CHAR16 *VariableName, | |
| IN EFI_GUID *VendorGuid, | |
| IN UINTN DataSize, | |
| IN VOID *Data | |
| ); | |
| /** | |
| Reads contents of a PE/COFF image in memory buffer. | |
| Caution: This function may receive untrusted input. | |
| PE/COFF image is external input, so this function will make sure the PE/COFF image content | |
| read is within the image buffer. | |
| @param FileHandle Pointer to the file handle to read the PE/COFF image. | |
| @param FileOffset Offset into the PE/COFF image to begin the read operation. | |
| @param ReadSize On input, the size in bytes of the requested read operation. | |
| On output, the number of bytes actually read. | |
| @param Buffer Output buffer that contains the data read from the PE/COFF image. | |
| @retval EFI_SUCCESS The specified portion of the PE/COFF image was read and the size | |
| **/ | |
| EFI_STATUS | |
| EFIAPI | |
| DxeImageVerificationLibImageRead ( | |
| IN VOID *FileHandle, | |
| IN UINTN FileOffset, | |
| IN OUT UINTN *ReadSize, | |
| OUT VOID *Buffer | |
| ) | |
| { | |
| UINTN EndPosition; | |
| if (FileHandle == NULL || ReadSize == NULL || Buffer == NULL) { | |
| return EFI_INVALID_PARAMETER; | |
| } | |
| if (MAX_ADDRESS - FileOffset < *ReadSize) { | |
| return EFI_INVALID_PARAMETER; | |
| } | |
| EndPosition = FileOffset + *ReadSize; | |
| if (EndPosition > mImageSize) { | |
| *ReadSize = (UINT32)(mImageSize - FileOffset); | |
| } | |
| if (FileOffset >= mImageSize) { | |
| *ReadSize = 0; | |
| } | |
| CopyMem (Buffer, (UINT8 *)((UINTN) FileHandle + FileOffset), *ReadSize); | |
| return EFI_SUCCESS; | |
| } | |
| /** | |
| Get the image type. | |
| @param[in] File This is a pointer to the device path of the file that is | |
| being dispatched. | |
| @return UINT32 Image Type | |
| **/ | |
| UINT32 | |
| GetImageType ( | |
| IN CONST EFI_DEVICE_PATH_PROTOCOL *File | |
| ) | |
| { | |
| EFI_STATUS Status; | |
| EFI_HANDLE DeviceHandle; | |
| EFI_DEVICE_PATH_PROTOCOL *TempDevicePath; | |
| EFI_BLOCK_IO_PROTOCOL *BlockIo; | |
| if (File == NULL) { | |
| return IMAGE_UNKNOWN; | |
| } | |
| // | |
| // First check to see if File is from a Firmware Volume | |
| // | |
| DeviceHandle = NULL; | |
| TempDevicePath = (EFI_DEVICE_PATH_PROTOCOL *) File; | |
| Status = gBS->LocateDevicePath ( | |
| &gEfiFirmwareVolume2ProtocolGuid, | |
| &TempDevicePath, | |
| &DeviceHandle | |
| ); | |
| if (!EFI_ERROR (Status)) { | |
| Status = gBS->OpenProtocol ( | |
| DeviceHandle, | |
| &gEfiFirmwareVolume2ProtocolGuid, | |
| NULL, | |
| NULL, | |
| NULL, | |
| EFI_OPEN_PROTOCOL_TEST_PROTOCOL | |
| ); | |
| if (!EFI_ERROR (Status)) { | |
| return IMAGE_FROM_FV; | |
| } | |
| } | |
| // | |
| // Next check to see if File is from a Block I/O device | |
| // | |
| DeviceHandle = NULL; | |
| TempDevicePath = (EFI_DEVICE_PATH_PROTOCOL *) File; | |
| Status = gBS->LocateDevicePath ( | |
| &gEfiBlockIoProtocolGuid, | |
| &TempDevicePath, | |
| &DeviceHandle | |
| ); | |
| if (!EFI_ERROR (Status)) { | |
| BlockIo = NULL; | |
| Status = gBS->OpenProtocol ( | |
| DeviceHandle, | |
| &gEfiBlockIoProtocolGuid, | |
| (VOID **) &BlockIo, | |
| NULL, | |
| NULL, | |
| EFI_OPEN_PROTOCOL_GET_PROTOCOL | |
| ); | |
| if (!EFI_ERROR (Status) && BlockIo != NULL) { | |
| if (BlockIo->Media != NULL) { | |
| if (BlockIo->Media->RemovableMedia) { | |
| // | |
| // Block I/O is present and specifies the media is removable | |
| // | |
| return IMAGE_FROM_REMOVABLE_MEDIA; | |
| } else { | |
| // | |
| // Block I/O is present and specifies the media is not removable | |
| // | |
| return IMAGE_FROM_FIXED_MEDIA; | |
| } | |
| } | |
| } | |
| } | |
| // | |
| // File is not in a Firmware Volume or on a Block I/O device, so check to see if | |
| // the device path supports the Simple File System Protocol. | |
| // | |
| DeviceHandle = NULL; | |
| TempDevicePath = (EFI_DEVICE_PATH_PROTOCOL *) File; | |
| Status = gBS->LocateDevicePath ( | |
| &gEfiSimpleFileSystemProtocolGuid, | |
| &TempDevicePath, | |
| &DeviceHandle | |
| ); | |
| if (!EFI_ERROR (Status)) { | |
| // | |
| // Simple File System is present without Block I/O, so assume media is fixed. | |
| // | |
| return IMAGE_FROM_FIXED_MEDIA; | |
| } | |
| // | |
| // File is not from an FV, Block I/O or Simple File System, so the only options | |
| // left are a PCI Option ROM and a Load File Protocol such as a PXE Boot from a NIC. | |
| // | |
| TempDevicePath = (EFI_DEVICE_PATH_PROTOCOL *) File; | |
| while (!IsDevicePathEndType (TempDevicePath)) { | |
| switch (DevicePathType (TempDevicePath)) { | |
| case MEDIA_DEVICE_PATH: | |
| if (DevicePathSubType (TempDevicePath) == MEDIA_RELATIVE_OFFSET_RANGE_DP) { | |
| return IMAGE_FROM_OPTION_ROM; | |
| } | |
| break; | |
| case MESSAGING_DEVICE_PATH: | |
| if (DevicePathSubType(TempDevicePath) == MSG_MAC_ADDR_DP) { | |
| return IMAGE_FROM_REMOVABLE_MEDIA; | |
| } | |
| break; | |
| default: | |
| break; | |
| } | |
| TempDevicePath = NextDevicePathNode (TempDevicePath); | |
| } | |
| return IMAGE_UNKNOWN; | |
| } | |
| /** | |
| Calculate hash of Pe/Coff image based on the authenticode image hashing in | |
| PE/COFF Specification 8.0 Appendix A | |
| Caution: This function may receive untrusted input. | |
| PE/COFF image is external input, so this function will validate its data structure | |
| within this image buffer before use. | |
| Notes: PE/COFF image has been checked by BasePeCoffLib PeCoffLoaderGetImageInfo() in | |
| its caller function DxeImageVerificationHandler(). | |
| @param[in] HashAlg Hash algorithm type. | |
| @retval TRUE Successfully hash image. | |
| @retval FALSE Fail in hash image. | |
| **/ | |
| BOOLEAN | |
| HashPeImage ( | |
| IN UINT32 HashAlg | |
| ) | |
| { | |
| BOOLEAN Status; | |
| UINT16 Magic; | |
| EFI_IMAGE_SECTION_HEADER *Section; | |
| VOID *HashCtx; | |
| UINTN CtxSize; | |
| UINT8 *HashBase; | |
| UINTN HashSize; | |
| UINTN SumOfBytesHashed; | |
| EFI_IMAGE_SECTION_HEADER *SectionHeader; | |
| UINTN Index; | |
| UINTN Pos; | |
| UINT32 CertSize; | |
| UINT32 NumberOfRvaAndSizes; | |
| HashCtx = NULL; | |
| SectionHeader = NULL; | |
| Status = FALSE; | |
| if ((HashAlg >= HASHALG_MAX)) { | |
| return FALSE; | |
| } | |
| // | |
| // Initialize context of hash. | |
| // | |
| ZeroMem (mImageDigest, MAX_DIGEST_SIZE); | |
| switch (HashAlg) { | |
| case HASHALG_SHA1: | |
| mImageDigestSize = SHA1_DIGEST_SIZE; | |
| mCertType = gEfiCertSha1Guid; | |
| break; | |
| case HASHALG_SHA256: | |
| mImageDigestSize = SHA256_DIGEST_SIZE; | |
| mCertType = gEfiCertSha256Guid; | |
| break; | |
| case HASHALG_SHA384: | |
| mImageDigestSize = SHA384_DIGEST_SIZE; | |
| mCertType = gEfiCertSha384Guid; | |
| break; | |
| case HASHALG_SHA512: | |
| mImageDigestSize = SHA512_DIGEST_SIZE; | |
| mCertType = gEfiCertSha512Guid; | |
| break; | |
| default: | |
| return FALSE; | |
| } | |
| mHashTypeStr = mHash[HashAlg].Name; | |
| CtxSize = mHash[HashAlg].GetContextSize(); | |
| HashCtx = AllocatePool (CtxSize); | |
| if (HashCtx == NULL) { | |
| return FALSE; | |
| } | |
| // 1. Load the image header into memory. | |
| // 2. Initialize a SHA hash context. | |
| Status = mHash[HashAlg].HashInit(HashCtx); | |
| if (!Status) { | |
| goto Done; | |
| } | |
| // | |
| // Measuring PE/COFF Image Header; | |
| // But CheckSum field and SECURITY data directory (certificate) are excluded | |
| // | |
| if (mNtHeader.Pe32->FileHeader.Machine == IMAGE_FILE_MACHINE_IA64 && mNtHeader.Pe32->OptionalHeader.Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) { | |
| // | |
| // NOTE: Some versions of Linux ELILO for Itanium have an incorrect magic value | |
| // in the PE/COFF Header. If the MachineType is Itanium(IA64) and the | |
| // Magic value in the OptionalHeader is EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC | |
| // then override the magic value to EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC | |
| // | |
| Magic = EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC; | |
| } else { | |
| // | |
| // Get the magic value from the PE/COFF Optional Header | |
| // | |
| Magic = mNtHeader.Pe32->OptionalHeader.Magic; | |
| } | |
| // | |
| // 3. Calculate the distance from the base of the image header to the image checksum address. | |
| // 4. Hash the image header from its base to beginning of the image checksum. | |
| // | |
| HashBase = mImageBase; | |
| if (Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) { | |
| // | |
| // Use PE32 offset. | |
| // | |
| HashSize = (UINTN) ((UINT8 *) (&mNtHeader.Pe32->OptionalHeader.CheckSum) - HashBase); | |
| NumberOfRvaAndSizes = mNtHeader.Pe32->OptionalHeader.NumberOfRvaAndSizes; | |
| } else if (Magic == EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC) { | |
| // | |
| // Use PE32+ offset. | |
| // | |
| HashSize = (UINTN) ((UINT8 *) (&mNtHeader.Pe32Plus->OptionalHeader.CheckSum) - HashBase); | |
| NumberOfRvaAndSizes = mNtHeader.Pe32Plus->OptionalHeader.NumberOfRvaAndSizes; | |
| } else { | |
| // | |
| // Invalid header magic number. | |
| // | |
| Status = FALSE; | |
| goto Done; | |
| } | |
| Status = mHash[HashAlg].HashUpdate(HashCtx, HashBase, HashSize); | |
| if (!Status) { | |
| goto Done; | |
| } | |
| // | |
| // 5. Skip over the image checksum (it occupies a single ULONG). | |
| // | |
| if (NumberOfRvaAndSizes <= EFI_IMAGE_DIRECTORY_ENTRY_SECURITY) { | |
| // | |
| // 6. Since there is no Cert Directory in optional header, hash everything | |
| // from the end of the checksum to the end of image header. | |
| // | |
| if (Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) { | |
| // | |
| // Use PE32 offset. | |
| // | |
| HashBase = (UINT8 *) &mNtHeader.Pe32->OptionalHeader.CheckSum + sizeof (UINT32); | |
| HashSize = mNtHeader.Pe32->OptionalHeader.SizeOfHeaders - (UINTN) (HashBase - mImageBase); | |
| } else { | |
| // | |
| // Use PE32+ offset. | |
| // | |
| HashBase = (UINT8 *) &mNtHeader.Pe32Plus->OptionalHeader.CheckSum + sizeof (UINT32); | |
| HashSize = mNtHeader.Pe32Plus->OptionalHeader.SizeOfHeaders - (UINTN) (HashBase - mImageBase); | |
| } | |
| if (HashSize != 0) { | |
| Status = mHash[HashAlg].HashUpdate(HashCtx, HashBase, HashSize); | |
| if (!Status) { | |
| goto Done; | |
| } | |
| } | |
| } else { | |
| // | |
| // 7. Hash everything from the end of the checksum to the start of the Cert Directory. | |
| // | |
| if (Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) { | |
| // | |
| // Use PE32 offset. | |
| // | |
| HashBase = (UINT8 *) &mNtHeader.Pe32->OptionalHeader.CheckSum + sizeof (UINT32); | |
| HashSize = (UINTN) ((UINT8 *) (&mNtHeader.Pe32->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY]) - HashBase); | |
| } else { | |
| // | |
| // Use PE32+ offset. | |
| // | |
| HashBase = (UINT8 *) &mNtHeader.Pe32Plus->OptionalHeader.CheckSum + sizeof (UINT32); | |
| HashSize = (UINTN) ((UINT8 *) (&mNtHeader.Pe32Plus->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY]) - HashBase); | |
| } | |
| if (HashSize != 0) { | |
| Status = mHash[HashAlg].HashUpdate(HashCtx, HashBase, HashSize); | |
| if (!Status) { | |
| goto Done; | |
| } | |
| } | |
| // | |
| // 8. Skip over the Cert Directory. (It is sizeof(IMAGE_DATA_DIRECTORY) bytes.) | |
| // 9. Hash everything from the end of the Cert Directory to the end of image header. | |
| // | |
| if (Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) { | |
| // | |
| // Use PE32 offset | |
| // | |
| HashBase = (UINT8 *) &mNtHeader.Pe32->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY + 1]; | |
| HashSize = mNtHeader.Pe32->OptionalHeader.SizeOfHeaders - (UINTN) (HashBase - mImageBase); | |
| } else { | |
| // | |
| // Use PE32+ offset. | |
| // | |
| HashBase = (UINT8 *) &mNtHeader.Pe32Plus->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY + 1]; | |
| HashSize = mNtHeader.Pe32Plus->OptionalHeader.SizeOfHeaders - (UINTN) (HashBase - mImageBase); | |
| } | |
| if (HashSize != 0) { | |
| Status = mHash[HashAlg].HashUpdate(HashCtx, HashBase, HashSize); | |
| if (!Status) { | |
| goto Done; | |
| } | |
| } | |
| } | |
| // | |
| // 10. Set the SUM_OF_BYTES_HASHED to the size of the header. | |
| // | |
| if (Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) { | |
| // | |
| // Use PE32 offset. | |
| // | |
| SumOfBytesHashed = mNtHeader.Pe32->OptionalHeader.SizeOfHeaders; | |
| } else { | |
| // | |
| // Use PE32+ offset | |
| // | |
| SumOfBytesHashed = mNtHeader.Pe32Plus->OptionalHeader.SizeOfHeaders; | |
| } | |
| Section = (EFI_IMAGE_SECTION_HEADER *) ( | |
| mImageBase + | |
| mPeCoffHeaderOffset + | |
| sizeof (UINT32) + | |
| sizeof (EFI_IMAGE_FILE_HEADER) + | |
| mNtHeader.Pe32->FileHeader.SizeOfOptionalHeader | |
| ); | |
| // | |
| // 11. Build a temporary table of pointers to all the IMAGE_SECTION_HEADER | |
| // structures in the image. The 'NumberOfSections' field of the image | |
| // header indicates how big the table should be. Do not include any | |
| // IMAGE_SECTION_HEADERs in the table whose 'SizeOfRawData' field is zero. | |
| // | |
| SectionHeader = (EFI_IMAGE_SECTION_HEADER *) AllocateZeroPool (sizeof (EFI_IMAGE_SECTION_HEADER) * mNtHeader.Pe32->FileHeader.NumberOfSections); | |
| if (SectionHeader == NULL) { | |
| Status = FALSE; | |
| goto Done; | |
| } | |
| // | |
| // 12. Using the 'PointerToRawData' in the referenced section headers as | |
| // a key, arrange the elements in the table in ascending order. In other | |
| // words, sort the section headers according to the disk-file offset of | |
| // the section. | |
| // | |
| for (Index = 0; Index < mNtHeader.Pe32->FileHeader.NumberOfSections; Index++) { | |
| Pos = Index; | |
| while ((Pos > 0) && (Section->PointerToRawData < SectionHeader[Pos - 1].PointerToRawData)) { | |
| CopyMem (&SectionHeader[Pos], &SectionHeader[Pos - 1], sizeof (EFI_IMAGE_SECTION_HEADER)); | |
| Pos--; | |
| } | |
| CopyMem (&SectionHeader[Pos], Section, sizeof (EFI_IMAGE_SECTION_HEADER)); | |
| Section += 1; | |
| } | |
| // | |
| // 13. Walk through the sorted table, bring the corresponding section | |
| // into memory, and hash the entire section (using the 'SizeOfRawData' | |
| // field in the section header to determine the amount of data to hash). | |
| // 14. Add the section's 'SizeOfRawData' to SUM_OF_BYTES_HASHED . | |
| // 15. Repeat steps 13 and 14 for all the sections in the sorted table. | |
| // | |
| for (Index = 0; Index < mNtHeader.Pe32->FileHeader.NumberOfSections; Index++) { | |
| Section = &SectionHeader[Index]; | |
| if (Section->SizeOfRawData == 0) { | |
| continue; | |
| } | |
| HashBase = mImageBase + Section->PointerToRawData; | |
| HashSize = (UINTN) Section->SizeOfRawData; | |
| Status = mHash[HashAlg].HashUpdate(HashCtx, HashBase, HashSize); | |
| if (!Status) { | |
| goto Done; | |
| } | |
| SumOfBytesHashed += HashSize; | |
| } | |
| // | |
| // 16. If the file size is greater than SUM_OF_BYTES_HASHED, there is extra | |
| // data in the file that needs to be added to the hash. This data begins | |
| // at file offset SUM_OF_BYTES_HASHED and its length is: | |
| // FileSize - (CertDirectory->Size) | |
| // | |
| if (mImageSize > SumOfBytesHashed) { | |
| HashBase = mImageBase + SumOfBytesHashed; | |
| if (NumberOfRvaAndSizes <= EFI_IMAGE_DIRECTORY_ENTRY_SECURITY) { | |
| CertSize = 0; | |
| } else { | |
| if (Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) { | |
| // | |
| // Use PE32 offset. | |
| // | |
| CertSize = mNtHeader.Pe32->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY].Size; | |
| } else { | |
| // | |
| // Use PE32+ offset. | |
| // | |
| CertSize = mNtHeader.Pe32Plus->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY].Size; | |
| } | |
| } | |
| if (mImageSize > CertSize + SumOfBytesHashed) { | |
| HashSize = (UINTN) (mImageSize - CertSize - SumOfBytesHashed); | |
| Status = mHash[HashAlg].HashUpdate(HashCtx, HashBase, HashSize); | |
| if (!Status) { | |
| goto Done; | |
| } | |
| } else if (mImageSize < CertSize + SumOfBytesHashed) { | |
| Status = FALSE; | |
| goto Done; | |
| } | |
| } | |
| Status = mHash[HashAlg].HashFinal(HashCtx, mImageDigest); | |
| Done: | |
| if (HashCtx != NULL) { | |
| FreePool (HashCtx); | |
| } | |
| if (SectionHeader != NULL) { | |
| FreePool (SectionHeader); | |
| } | |
| return Status; | |
| } | |
| /** | |
| Recognize the Hash algorithm in PE/COFF Authenticode and calculate hash of | |
| Pe/Coff image based on the authenticode image hashing in PE/COFF Specification | |
| 8.0 Appendix A | |
| Caution: This function may receive untrusted input. | |
| PE/COFF image is external input, so this function will validate its data structure | |
| within this image buffer before use. | |
| @param[in] AuthData Pointer to the Authenticode Signature retrieved from signed image. | |
| @param[in] AuthDataSize Size of the Authenticode Signature in bytes. | |
| @retval EFI_UNSUPPORTED Hash algorithm is not supported. | |
| @retval EFI_SUCCESS Hash successfully. | |
| **/ | |
| EFI_STATUS | |
| HashPeImageByType ( | |
| IN UINT8 *AuthData, | |
| IN UINTN AuthDataSize | |
| ) | |
| { | |
| UINT8 Index; | |
| for (Index = 0; Index < HASHALG_MAX; Index++) { | |
| // | |
| // Check the Hash algorithm in PE/COFF Authenticode. | |
| // According to PKCS#7 Definition: | |
| // SignedData ::= SEQUENCE { | |
| // version Version, | |
| // digestAlgorithms DigestAlgorithmIdentifiers, | |
| // contentInfo ContentInfo, | |
| // .... } | |
| // The DigestAlgorithmIdentifiers can be used to determine the hash algorithm in PE/COFF hashing | |
| // This field has the fixed offset (+32) in final Authenticode ASN.1 data. | |
| // Fixed offset (+32) is calculated based on two bytes of length encoding. | |
| // | |
| if ((*(AuthData + 1) & TWO_BYTE_ENCODE) != TWO_BYTE_ENCODE) { | |
| // | |
| // Only support two bytes of Long Form of Length Encoding. | |
| // | |
| continue; | |
| } | |
| if (AuthDataSize < 32 + mHash[Index].OidLength) { | |
| return EFI_UNSUPPORTED; | |
| } | |
| if (CompareMem (AuthData + 32, mHash[Index].OidValue, mHash[Index].OidLength) == 0) { | |
| break; | |
| } | |
| } | |
| if (Index == HASHALG_MAX) { | |
| return EFI_UNSUPPORTED; | |
| } | |
| // | |
| // HASH PE Image based on Hash algorithm in PE/COFF Authenticode. | |
| // | |
| if (!HashPeImage(Index)) { | |
| return EFI_UNSUPPORTED; | |
| } | |
| return EFI_SUCCESS; | |
| } | |
| /** | |
| Returns the size of a given image execution info table in bytes. | |
| This function returns the size, in bytes, of the image execution info table specified by | |
| ImageExeInfoTable. If ImageExeInfoTable is NULL, then 0 is returned. | |
| @param ImageExeInfoTable A pointer to a image execution info table structure. | |
| @retval 0 If ImageExeInfoTable is NULL. | |
| @retval Others The size of a image execution info table in bytes. | |
| **/ | |
| UINTN | |
| GetImageExeInfoTableSize ( | |
| EFI_IMAGE_EXECUTION_INFO_TABLE *ImageExeInfoTable | |
| ) | |
| { | |
| UINTN Index; | |
| EFI_IMAGE_EXECUTION_INFO *ImageExeInfoItem; | |
| UINTN TotalSize; | |
| if (ImageExeInfoTable == NULL) { | |
| return 0; | |
| } | |
| ImageExeInfoItem = (EFI_IMAGE_EXECUTION_INFO *) ((UINT8 *) ImageExeInfoTable + sizeof (EFI_IMAGE_EXECUTION_INFO_TABLE)); | |
| TotalSize = sizeof (EFI_IMAGE_EXECUTION_INFO_TABLE); | |
| for (Index = 0; Index < ImageExeInfoTable->NumberOfImages; Index++) { | |
| TotalSize += ReadUnaligned32 ((UINT32 *) &ImageExeInfoItem->InfoSize); | |
| ImageExeInfoItem = (EFI_IMAGE_EXECUTION_INFO *) ((UINT8 *) ImageExeInfoItem + ReadUnaligned32 ((UINT32 *) &ImageExeInfoItem->InfoSize)); | |
| } | |
| return TotalSize; | |
| } | |
| /** | |
| Create an Image Execution Information Table entry and add it to system configuration table. | |
| @param[in] Action Describes the action taken by the firmware regarding this image. | |
| @param[in] Name Input a null-terminated, user-friendly name. | |
| @param[in] DevicePath Input device path pointer. | |
| @param[in] Signature Input signature info in EFI_SIGNATURE_LIST data structure. | |
| @param[in] SignatureSize Size of signature. | |
| **/ | |
| VOID | |
| AddImageExeInfo ( | |
| IN EFI_IMAGE_EXECUTION_ACTION Action, | |
| IN CHAR16 *Name OPTIONAL, | |
| IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath, | |
| IN EFI_SIGNATURE_LIST *Signature OPTIONAL, | |
| IN UINTN SignatureSize | |
| ) | |
| { | |
| EFI_IMAGE_EXECUTION_INFO_TABLE *ImageExeInfoTable; | |
| EFI_IMAGE_EXECUTION_INFO_TABLE *NewImageExeInfoTable; | |
| EFI_IMAGE_EXECUTION_INFO *ImageExeInfoEntry; | |
| UINTN ImageExeInfoTableSize; | |
| UINTN NewImageExeInfoEntrySize; | |
| UINTN NameStringLen; | |
| UINTN DevicePathSize; | |
| CHAR16 *NameStr; | |
| ImageExeInfoTable = NULL; | |
| NewImageExeInfoTable = NULL; | |
| ImageExeInfoEntry = NULL; | |
| NameStringLen = 0; | |
| NameStr = NULL; | |
| if (DevicePath == NULL) { | |
| return ; | |
| } | |
| if (Name != NULL) { | |
| NameStringLen = StrSize (Name); | |
| } else { | |
| NameStringLen = sizeof (CHAR16); | |
| } | |
| EfiGetSystemConfigurationTable (&gEfiImageSecurityDatabaseGuid, (VOID **) &ImageExeInfoTable); | |
| if (ImageExeInfoTable != NULL) { | |
| // | |
| // The table has been found! | |
| // We must enlarge the table to accomodate the new exe info entry. | |
| // | |
| ImageExeInfoTableSize = GetImageExeInfoTableSize (ImageExeInfoTable); | |
| } else { | |
| // | |
| // Not Found! | |
| // We should create a new table to append to the configuration table. | |
| // | |
| ImageExeInfoTableSize = sizeof (EFI_IMAGE_EXECUTION_INFO_TABLE); | |
| } | |
| DevicePathSize = GetDevicePathSize (DevicePath); | |
| // | |
| // Signature size can be odd. Pad after signature to ensure next EXECUTION_INFO entry align | |
| // | |
| NewImageExeInfoEntrySize = sizeof (EFI_IMAGE_EXECUTION_INFO) + NameStringLen + DevicePathSize + SignatureSize; | |
| NewImageExeInfoTable = (EFI_IMAGE_EXECUTION_INFO_TABLE *) AllocateRuntimePool (ImageExeInfoTableSize + NewImageExeInfoEntrySize); | |
| if (NewImageExeInfoTable == NULL) { | |
| return ; | |
| } | |
| if (ImageExeInfoTable != NULL) { | |
| CopyMem (NewImageExeInfoTable, ImageExeInfoTable, ImageExeInfoTableSize); | |
| } else { | |
| NewImageExeInfoTable->NumberOfImages = 0; | |
| } | |
| NewImageExeInfoTable->NumberOfImages++; | |
| ImageExeInfoEntry = (EFI_IMAGE_EXECUTION_INFO *) ((UINT8 *) NewImageExeInfoTable + ImageExeInfoTableSize); | |
| // | |
| // Update new item's information. | |
| // | |
| WriteUnaligned32 ((UINT32 *) ImageExeInfoEntry, Action); | |
| WriteUnaligned32 ((UINT32 *) ((UINT8 *) ImageExeInfoEntry + sizeof (EFI_IMAGE_EXECUTION_ACTION)), (UINT32) NewImageExeInfoEntrySize); | |
| NameStr = (CHAR16 *)(ImageExeInfoEntry + 1); | |
| if (Name != NULL) { | |
| CopyMem ((UINT8 *) NameStr, Name, NameStringLen); | |
| } else { | |
| ZeroMem ((UINT8 *) NameStr, sizeof (CHAR16)); | |
| } | |
| CopyMem ( | |
| (UINT8 *) NameStr + NameStringLen, | |
| DevicePath, | |
| DevicePathSize | |
| ); | |
| if (Signature != NULL) { | |
| CopyMem ( | |
| (UINT8 *) NameStr + NameStringLen + DevicePathSize, | |
| Signature, | |
| SignatureSize | |
| ); | |
| } | |
| // | |
| // Update/replace the image execution table. | |
| // | |
| gBS->InstallConfigurationTable (&gEfiImageSecurityDatabaseGuid, (VOID *) NewImageExeInfoTable); | |
| // | |
| // Free Old table data! | |
| // | |
| if (ImageExeInfoTable != NULL) { | |
| FreePool (ImageExeInfoTable); | |
| } | |
| } | |
| /** | |
| Check whether the hash of an given X.509 certificate is in forbidden database (DBX). | |
| @param[in] Certificate Pointer to X.509 Certificate that is searched for. | |
| @param[in] CertSize Size of X.509 Certificate. | |
| @param[in] SignatureList Pointer to the Signature List in forbidden database. | |
| @param[in] SignatureListSize Size of Signature List. | |
| @param[out] RevocationTime Return the time that the certificate was revoked. | |
| @return TRUE The certificate hash is found in the forbidden database. | |
| @return FALSE The certificate hash is not found in the forbidden database. | |
| **/ | |
| BOOLEAN | |
| IsCertHashFoundInDatabase ( | |
| IN UINT8 *Certificate, | |
| IN UINTN CertSize, | |
| IN EFI_SIGNATURE_LIST *SignatureList, | |
| IN UINTN SignatureListSize, | |
| OUT EFI_TIME *RevocationTime | |
| ) | |
| { | |
| BOOLEAN IsFound; | |
| BOOLEAN Status; | |
| EFI_SIGNATURE_LIST *DbxList; | |
| UINTN DbxSize; | |
| EFI_SIGNATURE_DATA *CertHash; | |
| UINTN CertHashCount; | |
| UINTN Index; | |
| UINT32 HashAlg; | |
| VOID *HashCtx; | |
| UINT8 CertDigest[MAX_DIGEST_SIZE]; | |
| UINT8 *DbxCertHash; | |
| UINTN SiglistHeaderSize; | |
| UINT8 *TBSCert; | |
| UINTN TBSCertSize; | |
| IsFound = FALSE; | |
| DbxList = SignatureList; | |
| DbxSize = SignatureListSize; | |
| HashCtx = NULL; | |
| HashAlg = HASHALG_MAX; | |
| if ((RevocationTime == NULL) || (DbxList == NULL)) { | |
| return FALSE; | |
| } | |
| // | |
| // Retrieve the TBSCertificate from the X.509 Certificate. | |
| // | |
| if (!X509GetTBSCert (Certificate, CertSize, &TBSCert, &TBSCertSize)) { | |
| return FALSE; | |
| } | |
| while ((DbxSize > 0) && (SignatureListSize >= DbxList->SignatureListSize)) { | |
| // | |
| // Determine Hash Algorithm of Certificate in the forbidden database. | |
| // | |
| if (CompareGuid (&DbxList->SignatureType, &gEfiCertX509Sha256Guid)) { | |
| HashAlg = HASHALG_SHA256; | |
| } else if (CompareGuid (&DbxList->SignatureType, &gEfiCertX509Sha384Guid)) { | |
| HashAlg = HASHALG_SHA384; | |
| } else if (CompareGuid (&DbxList->SignatureType, &gEfiCertX509Sha512Guid)) { | |
| HashAlg = HASHALG_SHA512; | |
| } else { | |
| DbxSize -= DbxList->SignatureListSize; | |
| DbxList = (EFI_SIGNATURE_LIST *) ((UINT8 *) DbxList + DbxList->SignatureListSize); | |
| continue; | |
| } | |
| // | |
| // Calculate the hash value of current TBSCertificate for comparision. | |
| // | |
| if (mHash[HashAlg].GetContextSize == NULL) { | |
| goto Done; | |
| } | |
| ZeroMem (CertDigest, MAX_DIGEST_SIZE); | |
| HashCtx = AllocatePool (mHash[HashAlg].GetContextSize ()); | |
| if (HashCtx == NULL) { | |
| goto Done; | |
| } | |
| Status = mHash[HashAlg].HashInit (HashCtx); | |
| if (!Status) { | |
| goto Done; | |
| } | |
| Status = mHash[HashAlg].HashUpdate (HashCtx, TBSCert, TBSCertSize); | |
| if (!Status) { | |
| goto Done; | |
| } | |
| Status = mHash[HashAlg].HashFinal (HashCtx, CertDigest); | |
| if (!Status) { | |
| goto Done; | |
| } | |
| SiglistHeaderSize = sizeof (EFI_SIGNATURE_LIST) + DbxList->SignatureHeaderSize; | |
| CertHash = (EFI_SIGNATURE_DATA *) ((UINT8 *) DbxList + SiglistHeaderSize); | |
| CertHashCount = (DbxList->SignatureListSize - SiglistHeaderSize) / DbxList->SignatureSize; | |
| for (Index = 0; Index < CertHashCount; Index++) { | |
| // | |
| // Iterate each Signature Data Node within this CertList for verify. | |
| // | |
| DbxCertHash = CertHash->SignatureData; | |
| if (CompareMem (DbxCertHash, CertDigest, mHash[HashAlg].DigestLength) == 0) { | |
| // | |
| // Hash of Certificate is found in forbidden database. | |
| // | |
| IsFound = TRUE; | |
| // | |
| // Return the revocation time. | |
| // | |
| CopyMem (RevocationTime, (EFI_TIME *)(DbxCertHash + mHash[HashAlg].DigestLength), sizeof (EFI_TIME)); | |
| goto Done; | |
| } | |
| CertHash = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertHash + DbxList->SignatureSize); | |
| } | |
| DbxSize -= DbxList->SignatureListSize; | |
| DbxList = (EFI_SIGNATURE_LIST *) ((UINT8 *) DbxList + DbxList->SignatureListSize); | |
| } | |
| Done: | |
| if (HashCtx != NULL) { | |
| FreePool (HashCtx); | |
| } | |
| return IsFound; | |
| } | |
| /** | |
| Check whether signature is in specified database. | |
| @param[in] VariableName Name of database variable that is searched in. | |
| @param[in] Signature Pointer to signature that is searched for. | |
| @param[in] CertType Pointer to hash algrithom. | |
| @param[in] SignatureSize Size of Signature. | |
| @return TRUE Found the signature in the variable database. | |
| @return FALSE Not found the signature in the variable database. | |
| **/ | |
| BOOLEAN | |
| IsSignatureFoundInDatabase ( | |
| IN CHAR16 *VariableName, | |
| IN UINT8 *Signature, | |
| IN EFI_GUID *CertType, | |
| IN UINTN SignatureSize | |
| ) | |
| { | |
| EFI_STATUS Status; | |
| EFI_SIGNATURE_LIST *CertList; | |
| EFI_SIGNATURE_DATA *Cert; | |
| UINTN DataSize; | |
| UINT8 *Data; | |
| UINTN Index; | |
| UINTN CertCount; | |
| BOOLEAN IsFound; | |
| // | |
| // Read signature database variable. | |
| // | |
| IsFound = FALSE; | |
| Data = NULL; | |
| DataSize = 0; | |
| Status = gRT->GetVariable (VariableName, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, NULL); | |
| if (Status != EFI_BUFFER_TOO_SMALL) { | |
| return FALSE; | |
| } | |
| Data = (UINT8 *) AllocateZeroPool (DataSize); | |
| if (Data == NULL) { | |
| return FALSE; | |
| } | |
| Status = gRT->GetVariable (VariableName, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, Data); | |
| if (EFI_ERROR (Status)) { | |
| goto Done; | |
| } | |
| // | |
| // Enumerate all signature data in SigDB to check if executable's signature exists. | |
| // | |
| CertList = (EFI_SIGNATURE_LIST *) Data; | |
| while ((DataSize > 0) && (DataSize >= CertList->SignatureListSize)) { | |
| CertCount = (CertList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - CertList->SignatureHeaderSize) / CertList->SignatureSize; | |
| Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertList + sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize); | |
| if ((CertList->SignatureSize == sizeof(EFI_SIGNATURE_DATA) - 1 + SignatureSize) && (CompareGuid(&CertList->SignatureType, CertType))) { | |
| for (Index = 0; Index < CertCount; Index++) { | |
| if (CompareMem (Cert->SignatureData, Signature, SignatureSize) == 0) { | |
| // | |
| // Find the signature in database. | |
| // | |
| IsFound = TRUE; | |
| SecureBootHook (VariableName, &gEfiImageSecurityDatabaseGuid, CertList->SignatureSize, Cert); | |
| break; | |
| } | |
| Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) Cert + CertList->SignatureSize); | |
| } | |
| if (IsFound) { | |
| break; | |
| } | |
| } | |
| DataSize -= CertList->SignatureListSize; | |
| CertList = (EFI_SIGNATURE_LIST *) ((UINT8 *) CertList + CertList->SignatureListSize); | |
| } | |
| Done: | |
| if (Data != NULL) { | |
| FreePool (Data); | |
| } | |
| return IsFound; | |
| } | |
| /** | |
| Check whether the timestamp is valid by comparing the signing time and the revocation time. | |
| @param SigningTime A pointer to the signing time. | |
| @param RevocationTime A pointer to the revocation time. | |
| @retval TRUE The SigningTime is not later than the RevocationTime. | |
| @retval FALSE The SigningTime is later than the RevocationTime. | |
| **/ | |
| BOOLEAN | |
| IsValidSignatureByTimestamp ( | |
| IN EFI_TIME *SigningTime, | |
| IN EFI_TIME *RevocationTime | |
| ) | |
| { | |
| if (SigningTime->Year != RevocationTime->Year) { | |
| return (BOOLEAN) (SigningTime->Year < RevocationTime->Year); | |
| } else if (SigningTime->Month != RevocationTime->Month) { | |
| return (BOOLEAN) (SigningTime->Month < RevocationTime->Month); | |
| } else if (SigningTime->Day != RevocationTime->Day) { | |
| return (BOOLEAN) (SigningTime->Day < RevocationTime->Day); | |
| } else if (SigningTime->Hour != RevocationTime->Hour) { | |
| return (BOOLEAN) (SigningTime->Hour < RevocationTime->Hour); | |
| } else if (SigningTime->Minute != RevocationTime->Minute) { | |
| return (BOOLEAN) (SigningTime->Minute < RevocationTime->Minute); | |
| } | |
| return (BOOLEAN) (SigningTime->Second <= RevocationTime->Second); | |
| } | |
| /** | |
| Check if the given time value is zero. | |
| @param[in] Time Pointer of a time value. | |
| @retval TRUE The Time is Zero. | |
| @retval FALSE The Time is not Zero. | |
| **/ | |
| BOOLEAN | |
| IsTimeZero ( | |
| IN EFI_TIME *Time | |
| ) | |
| { | |
| if ((Time->Year == 0) && (Time->Month == 0) && (Time->Day == 0) && | |
| (Time->Hour == 0) && (Time->Minute == 0) && (Time->Second == 0)) { | |
| return TRUE; | |
| } | |
| return FALSE; | |
| } | |
| /** | |
| Check whether the timestamp signature is valid and the signing time is also earlier than | |
| the revocation time. | |
| @param[in] AuthData Pointer to the Authenticode signature retrieved from signed image. | |
| @param[in] AuthDataSize Size of the Authenticode signature in bytes. | |
| @param[in] RevocationTime The time that the certificate was revoked. | |
| @retval TRUE Timestamp signature is valid and signing time is no later than the | |
| revocation time. | |
| @retval FALSE Timestamp signature is not valid or the signing time is later than the | |
| revocation time. | |
| **/ | |
| BOOLEAN | |
| PassTimestampCheck ( | |
| IN UINT8 *AuthData, | |
| IN UINTN AuthDataSize, | |
| IN EFI_TIME *RevocationTime | |
| ) | |
| { | |
| EFI_STATUS Status; | |
| BOOLEAN VerifyStatus; | |
| EFI_SIGNATURE_LIST *CertList; | |
| EFI_SIGNATURE_DATA *Cert; | |
| UINT8 *DbtData; | |
| UINTN DbtDataSize; | |
| UINT8 *RootCert; | |
| UINTN RootCertSize; | |
| UINTN Index; | |
| UINTN CertCount; | |
| EFI_TIME SigningTime; | |
| // | |
| // Variable Initialization | |
| // | |
| VerifyStatus = FALSE; | |
| DbtData = NULL; | |
| CertList = NULL; | |
| Cert = NULL; | |
| RootCert = NULL; | |
| RootCertSize = 0; | |
| // | |
| // If RevocationTime is zero, the certificate shall be considered to always be revoked. | |
| // | |
| if (IsTimeZero (RevocationTime)) { | |
| return FALSE; | |
| } | |
| // | |
| // RevocationTime is non-zero, the certificate should be considered to be revoked from that time and onwards. | |
| // Using the dbt to get the trusted TSA certificates. | |
| // | |
| DbtDataSize = 0; | |
| Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE2, &gEfiImageSecurityDatabaseGuid, NULL, &DbtDataSize, NULL); | |
| if (Status != EFI_BUFFER_TOO_SMALL) { | |
| goto Done; | |
| } | |
| DbtData = (UINT8 *) AllocateZeroPool (DbtDataSize); | |
| if (DbtData == NULL) { | |
| goto Done; | |
| } | |
| Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE2, &gEfiImageSecurityDatabaseGuid, NULL, &DbtDataSize, (VOID *) DbtData); | |
| if (EFI_ERROR (Status)) { | |
| goto Done; | |
| } | |
| CertList = (EFI_SIGNATURE_LIST *) DbtData; | |
| while ((DbtDataSize > 0) && (DbtDataSize >= CertList->SignatureListSize)) { | |
| if (CompareGuid (&CertList->SignatureType, &gEfiCertX509Guid)) { | |
| Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertList + sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize); | |
| CertCount = (CertList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - CertList->SignatureHeaderSize) / CertList->SignatureSize; | |
| for (Index = 0; Index < CertCount; Index++) { | |
| // | |
| // Iterate each Signature Data Node within this CertList for verify. | |
| // | |
| RootCert = Cert->SignatureData; | |
| RootCertSize = CertList->SignatureSize - sizeof (EFI_GUID); | |
| // | |
| // Get the signing time if the timestamp signature is valid. | |
| // | |
| if (ImageTimestampVerify (AuthData, AuthDataSize, RootCert, RootCertSize, &SigningTime)) { | |
| // | |
| // The signer signature is valid only when the signing time is earlier than revocation time. | |
| // | |
| if (IsValidSignatureByTimestamp (&SigningTime, RevocationTime)) { | |
| VerifyStatus = TRUE; | |
| goto Done; | |
| } | |
| } | |
| Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) Cert + CertList->SignatureSize); | |
| } | |
| } | |
| DbtDataSize -= CertList->SignatureListSize; | |
| CertList = (EFI_SIGNATURE_LIST *) ((UINT8 *) CertList + CertList->SignatureListSize); | |
| } | |
| Done: | |
| if (DbtData != NULL) { | |
| FreePool (DbtData); | |
| } | |
| return VerifyStatus; | |
| } | |
| /** | |
| Check whether the image signature is forbidden by the forbidden database (dbx). | |
| The image is forbidden to load if any certificates for signing are revoked before signing time. | |
| @param[in] AuthData Pointer to the Authenticode signature retrieved from the signed image. | |
| @param[in] AuthDataSize Size of the Authenticode signature in bytes. | |
| @retval TRUE Image is forbidden by dbx. | |
| @retval FALSE Image is not forbidden by dbx. | |
| **/ | |
| BOOLEAN | |
| IsForbiddenByDbx ( | |
| IN UINT8 *AuthData, | |
| IN UINTN AuthDataSize | |
| ) | |
| { | |
| EFI_STATUS Status; | |
| BOOLEAN IsForbidden; | |
| UINT8 *Data; | |
| UINTN DataSize; | |
| EFI_SIGNATURE_LIST *CertList; | |
| UINTN CertListSize; | |
| EFI_SIGNATURE_DATA *CertData; | |
| UINT8 *RootCert; | |
| UINTN RootCertSize; | |
| UINTN CertCount; | |
| UINTN Index; | |
| UINT8 *CertBuffer; | |
| UINTN BufferLength; | |
| UINT8 *TrustedCert; | |
| UINTN TrustedCertLength; | |
| UINT8 CertNumber; | |
| UINT8 *CertPtr; | |
| UINT8 *Cert; | |
| UINTN CertSize; | |
| EFI_TIME RevocationTime; | |
| // | |
| // Variable Initialization | |
| // | |
| IsForbidden = FALSE; | |
| Data = NULL; | |
| CertList = NULL; | |
| CertData = NULL; | |
| RootCert = NULL; | |
| RootCertSize = 0; | |
| Cert = NULL; | |
| CertBuffer = NULL; | |
| BufferLength = 0; | |
| TrustedCert = NULL; | |
| TrustedCertLength = 0; | |
| // | |
| // The image will not be forbidden if dbx can't be got. | |
| // | |
| DataSize = 0; | |
| Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE1, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, NULL); | |
| if (Status != EFI_BUFFER_TOO_SMALL) { | |
| return IsForbidden; | |
| } | |
| Data = (UINT8 *) AllocateZeroPool (DataSize); | |
| if (Data == NULL) { | |
| return IsForbidden; | |
| } | |
| Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE1, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, (VOID *) Data); | |
| if (EFI_ERROR (Status)) { | |
| return IsForbidden; | |
| } | |
| // | |
| // Verify image signature with RAW X509 certificates in DBX database. | |
| // If passed, the image will be forbidden. | |
| // | |
| CertList = (EFI_SIGNATURE_LIST *) Data; | |
| CertListSize = DataSize; | |
| while ((CertListSize > 0) && (CertListSize >= CertList->SignatureListSize)) { | |
| if (CompareGuid (&CertList->SignatureType, &gEfiCertX509Guid)) { | |
| CertData = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertList + sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize); | |
| CertCount = (CertList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - CertList->SignatureHeaderSize) / CertList->SignatureSize; | |
| for (Index = 0; Index < CertCount; Index++) { | |
| // | |
| // Iterate each Signature Data Node within this CertList for verify. | |
| // | |
| RootCert = CertData->SignatureData; | |
| RootCertSize = CertList->SignatureSize - sizeof (EFI_GUID); | |
| // | |
| // Call AuthenticodeVerify library to Verify Authenticode struct. | |
| // | |
| IsForbidden = AuthenticodeVerify ( | |
| AuthData, | |
| AuthDataSize, | |
| RootCert, | |
| RootCertSize, | |
| mImageDigest, | |
| mImageDigestSize | |
| ); | |
| if (IsForbidden) { | |
| SecureBootHook (EFI_IMAGE_SECURITY_DATABASE1, &gEfiImageSecurityDatabaseGuid, CertList->SignatureSize, CertData); | |
| DEBUG ((DEBUG_INFO, "DxeImageVerificationLib: Image is signed but signature is forbidden by DBX.\n")); | |
| goto Done; | |
| } | |
| CertData = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertData + CertList->SignatureSize); | |
| } | |
| } | |
| CertListSize -= CertList->SignatureListSize; | |
| CertList = (EFI_SIGNATURE_LIST *) ((UINT8 *) CertList + CertList->SignatureListSize); | |
| } | |
| // | |
| // Check X.509 Certificate Hash & Possible Timestamp. | |
| // | |
| // | |
| // Retrieve the certificate stack from AuthData | |
| // The output CertStack format will be: | |
| // UINT8 CertNumber; | |
| // UINT32 Cert1Length; | |
| // UINT8 Cert1[]; | |
| // UINT32 Cert2Length; | |
| // UINT8 Cert2[]; | |
| // ... | |
| // UINT32 CertnLength; | |
| // UINT8 Certn[]; | |
| // | |
| Pkcs7GetSigners (AuthData, AuthDataSize, &CertBuffer, &BufferLength, &TrustedCert, &TrustedCertLength); | |
| if ((BufferLength == 0) || (CertBuffer == NULL)) { | |
| IsForbidden = TRUE; | |
| goto Done; | |
| } | |
| // | |
| // Check if any hash of certificates embedded in AuthData is in the forbidden database. | |
| // | |
| CertNumber = (UINT8) (*CertBuffer); | |
| CertPtr = CertBuffer + 1; | |
| for (Index = 0; Index < CertNumber; Index++) { | |
| CertSize = (UINTN) ReadUnaligned32 ((UINT32 *)CertPtr); | |
| Cert = (UINT8 *)CertPtr + sizeof (UINT32); | |
| // | |
| // Advance CertPtr to the next cert in image signer's cert list | |
| // | |
| CertPtr = CertPtr + sizeof (UINT32) + CertSize; | |
| if (IsCertHashFoundInDatabase (Cert, CertSize, (EFI_SIGNATURE_LIST *)Data, DataSize, &RevocationTime)) { | |
| // | |
| // Check the timestamp signature and signing time to determine if the image can be trusted. | |
| // | |
| IsForbidden = TRUE; | |
| if (PassTimestampCheck (AuthData, AuthDataSize, &RevocationTime)) { | |
| IsForbidden = FALSE; | |
| // | |
| // Pass DBT check. Continue to check other certs in image signer's cert list against DBX, DBT | |
| // | |
| continue; | |
| } | |
| DEBUG ((DEBUG_INFO, "DxeImageVerificationLib: Image is signed but signature failed the timestamp check.\n")); | |
| goto Done; | |
| } | |
| } | |
| Done: | |
| if (Data != NULL) { | |
| FreePool (Data); | |
| } | |
| Pkcs7FreeSigners (CertBuffer); | |
| Pkcs7FreeSigners (TrustedCert); | |
| return IsForbidden; | |
| } | |
| /** | |
| Check whether the image signature can be verified by the trusted certificates in DB database. | |
| @param[in] AuthData Pointer to the Authenticode signature retrieved from signed image. | |
| @param[in] AuthDataSize Size of the Authenticode signature in bytes. | |
| @retval TRUE Image passed verification using certificate in db. | |
| @retval FALSE Image didn't pass verification using certificate in db. | |
| **/ | |
| BOOLEAN | |
| IsAllowedByDb ( | |
| IN UINT8 *AuthData, | |
| IN UINTN AuthDataSize | |
| ) | |
| { | |
| EFI_STATUS Status; | |
| BOOLEAN VerifyStatus; | |
| EFI_SIGNATURE_LIST *CertList; | |
| EFI_SIGNATURE_DATA *CertData; | |
| UINTN DataSize; | |
| UINT8 *Data; | |
| UINT8 *RootCert; | |
| UINTN RootCertSize; | |
| UINTN Index; | |
| UINTN CertCount; | |
| UINTN DbxDataSize; | |
| UINT8 *DbxData; | |
| EFI_TIME RevocationTime; | |
| Data = NULL; | |
| CertList = NULL; | |
| CertData = NULL; | |
| RootCert = NULL; | |
| DbxData = NULL; | |
| RootCertSize = 0; | |
| VerifyStatus = FALSE; | |
| DataSize = 0; | |
| Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, NULL); | |
| if (Status == EFI_BUFFER_TOO_SMALL) { | |
| Data = (UINT8 *) AllocateZeroPool (DataSize); | |
| if (Data == NULL) { | |
| return VerifyStatus; | |
| } | |
| Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, (VOID *) Data); | |
| if (EFI_ERROR (Status)) { | |
| goto Done; | |
| } | |
| // | |
| // Find X509 certificate in Signature List to verify the signature in pkcs7 signed data. | |
| // | |
| CertList = (EFI_SIGNATURE_LIST *) Data; | |
| while ((DataSize > 0) && (DataSize >= CertList->SignatureListSize)) { | |
| if (CompareGuid (&CertList->SignatureType, &gEfiCertX509Guid)) { | |
| CertData = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertList + sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize); | |
| CertCount = (CertList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - CertList->SignatureHeaderSize) / CertList->SignatureSize; | |
| for (Index = 0; Index < CertCount; Index++) { | |
| // | |
| // Iterate each Signature Data Node within this CertList for verify. | |
| // | |
| RootCert = CertData->SignatureData; | |
| RootCertSize = CertList->SignatureSize - sizeof (EFI_GUID); | |
| // | |
| // Call AuthenticodeVerify library to Verify Authenticode struct. | |
| // | |
| VerifyStatus = AuthenticodeVerify ( | |
| AuthData, | |
| AuthDataSize, | |
| RootCert, | |
| RootCertSize, | |
| mImageDigest, | |
| mImageDigestSize | |
| ); | |
| if (VerifyStatus) { | |
| // | |
| // Here We still need to check if this RootCert's Hash is revoked | |
| // | |
| Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE1, &gEfiImageSecurityDatabaseGuid, NULL, &DbxDataSize, NULL); | |
| if (Status == EFI_BUFFER_TOO_SMALL) { | |
| goto Done; | |
| } | |
| DbxData = (UINT8 *) AllocateZeroPool (DbxDataSize); | |
| if (DbxData == NULL) { | |
| goto Done; | |
| } | |
| Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE1, &gEfiImageSecurityDatabaseGuid, NULL, &DbxDataSize, (VOID *) DbxData); | |
| if (EFI_ERROR (Status)) { | |
| goto Done; | |
| } | |
| if (IsCertHashFoundInDatabase (RootCert, RootCertSize, (EFI_SIGNATURE_LIST *)DbxData, DbxDataSize, &RevocationTime)) { | |
| // | |
| // Check the timestamp signature and signing time to determine if the RootCert can be trusted. | |
| // | |
| VerifyStatus = PassTimestampCheck (AuthData, AuthDataSize, &RevocationTime); | |
| if (!VerifyStatus) { | |
| DEBUG ((DEBUG_INFO, "DxeImageVerificationLib: Image is signed and signature is accepted by DB, but its root cert failed the timestamp check.\n")); | |
| } | |
| } | |
| goto Done; | |
| } | |
| CertData = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertData + CertList->SignatureSize); | |
| } | |
| } | |
| DataSize -= CertList->SignatureListSize; | |
| CertList = (EFI_SIGNATURE_LIST *) ((UINT8 *) CertList + CertList->SignatureListSize); | |
| } | |
| } | |
| Done: | |
| if (VerifyStatus) { | |
| SecureBootHook (EFI_IMAGE_SECURITY_DATABASE, &gEfiImageSecurityDatabaseGuid, CertList->SignatureSize, CertData); | |
| } | |
| if (Data != NULL) { | |
| FreePool (Data); | |
| } | |
| if (DbxData != NULL) { | |
| FreePool (DbxData); | |
| } | |
| return VerifyStatus; | |
| } | |
| /** | |
| Provide verification service for signed images, which include both signature validation | |
| and platform policy control. For signature types, both UEFI WIN_CERTIFICATE_UEFI_GUID and | |
| MSFT Authenticode type signatures are supported. | |
| In this implementation, only verify external executables when in USER MODE. | |
| Executables from FV is bypass, so pass in AuthenticationStatus is ignored. | |
| The image verification policy is: | |
| If the image is signed, | |
| At least one valid signature or at least one hash value of the image must match a record | |
| in the security database "db", and no valid signature nor any hash value of the image may | |
| be reflected in the security database "dbx". | |
| Otherwise, the image is not signed, | |
| The SHA256 hash value of the image must match a record in the security database "db", and | |
| not be reflected in the security data base "dbx". | |
| Caution: This function may receive untrusted input. | |
| PE/COFF image is external input, so this function will validate its data structure | |
| within this image buffer before use. | |
| @param[in] AuthenticationStatus | |
| This is the authentication status returned from the security | |
| measurement services for the input file. | |
| @param[in] File This is a pointer to the device path of the file that is | |
| being dispatched. This will optionally be used for logging. | |
| @param[in] FileBuffer File buffer matches the input file device path. | |
| @param[in] FileSize Size of File buffer matches the input file device path. | |
| @param[in] BootPolicy A boot policy that was used to call LoadImage() UEFI service. | |
| @retval EFI_SUCCESS The file specified by DevicePath and non-NULL | |
| FileBuffer did authenticate, and the platform policy dictates | |
| that the DXE Foundation may use the file. | |
| @retval EFI_SUCCESS The device path specified by NULL device path DevicePath | |
| and non-NULL FileBuffer did authenticate, and the platform | |
| policy dictates that the DXE Foundation may execute the image in | |
| FileBuffer. | |
| @retval EFI_OUT_RESOURCE Fail to allocate memory. | |
| @retval EFI_SECURITY_VIOLATION The file specified by File did not authenticate, and | |
| the platform policy dictates that File should be placed | |
| in the untrusted state. The image has been added to the file | |
| execution table. | |
| @retval EFI_ACCESS_DENIED The file specified by File and FileBuffer did not | |
| authenticate, and the platform policy dictates that the DXE | |
| Foundation many not use File. | |
| **/ | |
| EFI_STATUS | |
| EFIAPI | |
| DxeImageVerificationHandler ( | |
| IN UINT32 AuthenticationStatus, | |
| IN CONST EFI_DEVICE_PATH_PROTOCOL *File, | |
| IN VOID *FileBuffer, | |
| IN UINTN FileSize, | |
| IN BOOLEAN BootPolicy | |
| ) | |
| { | |
| EFI_STATUS Status; | |
| UINT16 Magic; | |
| EFI_IMAGE_DOS_HEADER *DosHdr; | |
| EFI_STATUS VerifyStatus; | |
| EFI_SIGNATURE_LIST *SignatureList; | |
| UINTN SignatureListSize; | |
| EFI_SIGNATURE_DATA *Signature; | |
| EFI_IMAGE_EXECUTION_ACTION Action; | |
| WIN_CERTIFICATE *WinCertificate; | |
| UINT32 Policy; | |
| UINT8 *SecureBoot; | |
| PE_COFF_LOADER_IMAGE_CONTEXT ImageContext; | |
| UINT32 NumberOfRvaAndSizes; | |
| WIN_CERTIFICATE_EFI_PKCS *PkcsCertData; | |
| WIN_CERTIFICATE_UEFI_GUID *WinCertUefiGuid; | |
| UINT8 *AuthData; | |
| UINTN AuthDataSize; | |
| EFI_IMAGE_DATA_DIRECTORY *SecDataDir; | |
| UINT32 OffSet; | |
| CHAR16 *NameStr; | |
| SignatureList = NULL; | |
| SignatureListSize = 0; | |
| WinCertificate = NULL; | |
| SecDataDir = NULL; | |
| PkcsCertData = NULL; | |
| Action = EFI_IMAGE_EXECUTION_AUTH_UNTESTED; | |
| Status = EFI_ACCESS_DENIED; | |
| VerifyStatus = EFI_ACCESS_DENIED; | |
| // | |
| // Check the image type and get policy setting. | |
| // | |
| switch (GetImageType (File)) { | |
| case IMAGE_FROM_FV: | |
| Policy = ALWAYS_EXECUTE; | |
| break; | |
| case IMAGE_FROM_OPTION_ROM: | |
| Policy = PcdGet32 (PcdOptionRomImageVerificationPolicy); | |
| break; | |
| case IMAGE_FROM_REMOVABLE_MEDIA: | |
| Policy = PcdGet32 (PcdRemovableMediaImageVerificationPolicy); | |
| break; | |
| case IMAGE_FROM_FIXED_MEDIA: | |
| Policy = PcdGet32 (PcdFixedMediaImageVerificationPolicy); | |
| break; | |
| default: | |
| Policy = DENY_EXECUTE_ON_SECURITY_VIOLATION; | |
| break; | |
| } | |
| // | |
| // If policy is always/never execute, return directly. | |
| // | |
| if (Policy == ALWAYS_EXECUTE) { | |
| return EFI_SUCCESS; | |
| } else if (Policy == NEVER_EXECUTE) { | |
| return EFI_ACCESS_DENIED; | |
| } | |
| // | |
| // The policy QUERY_USER_ON_SECURITY_VIOLATION and ALLOW_EXECUTE_ON_SECURITY_VIOLATION | |
| // violates the UEFI spec and has been removed. | |
| // | |
| ASSERT (Policy != QUERY_USER_ON_SECURITY_VIOLATION && Policy != ALLOW_EXECUTE_ON_SECURITY_VIOLATION); | |
| if (Policy == QUERY_USER_ON_SECURITY_VIOLATION || Policy == ALLOW_EXECUTE_ON_SECURITY_VIOLATION) { | |
| CpuDeadLoop (); | |
| } | |
| GetEfiGlobalVariable2 (EFI_SECURE_BOOT_MODE_NAME, (VOID**)&SecureBoot, NULL); | |
| // | |
| // Skip verification if SecureBoot variable doesn't exist. | |
| // | |
| if (SecureBoot == NULL) { | |
| return EFI_SUCCESS; | |
| } | |
| // | |
| // Skip verification if SecureBoot is disabled but not AuditMode | |
| // | |
| if (*SecureBoot == SECURE_BOOT_MODE_DISABLE) { | |
| FreePool (SecureBoot); | |
| return EFI_SUCCESS; | |
| } | |
| FreePool (SecureBoot); | |
| // | |
| // Read the Dos header. | |
| // | |
| if (FileBuffer == NULL) { | |
| return EFI_INVALID_PARAMETER; | |
| } | |
| mImageBase = (UINT8 *) FileBuffer; | |
| mImageSize = FileSize; | |
| ZeroMem (&ImageContext, sizeof (ImageContext)); | |
| ImageContext.Handle = (VOID *) FileBuffer; | |
| ImageContext.ImageRead = (PE_COFF_LOADER_READ_FILE) DxeImageVerificationLibImageRead; | |
| // | |
| // Get information about the image being loaded | |
| // | |
| Status = PeCoffLoaderGetImageInfo (&ImageContext); | |
| if (EFI_ERROR (Status)) { | |
| // | |
| // The information can't be got from the invalid PeImage | |
| // | |
| DEBUG ((DEBUG_INFO, "DxeImageVerificationLib: PeImage invalid. Cannot retrieve image information.\n")); | |
| goto Done; | |
| } | |
| Status = EFI_ACCESS_DENIED; | |
| DosHdr = (EFI_IMAGE_DOS_HEADER *) mImageBase; | |
| if (DosHdr->e_magic == EFI_IMAGE_DOS_SIGNATURE) { | |
| // | |
| // DOS image header is present, | |
| // so read the PE header after the DOS image header. | |
| // | |
| mPeCoffHeaderOffset = DosHdr->e_lfanew; | |
| } else { | |
| mPeCoffHeaderOffset = 0; | |
| } | |
| // | |
| // Check PE/COFF image. | |
| // | |
| mNtHeader.Pe32 = (EFI_IMAGE_NT_HEADERS32 *) (mImageBase + mPeCoffHeaderOffset); | |
| if (mNtHeader.Pe32->Signature != EFI_IMAGE_NT_SIGNATURE) { | |
| // | |
| // It is not a valid Pe/Coff file. | |
| // | |
| DEBUG ((DEBUG_INFO, "DxeImageVerificationLib: Not a valid PE/COFF image.\n")); | |
| goto Done; | |
| } | |
| if (mNtHeader.Pe32->FileHeader.Machine == IMAGE_FILE_MACHINE_IA64 && mNtHeader.Pe32->OptionalHeader.Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) { | |
| // | |
| // NOTE: Some versions of Linux ELILO for Itanium have an incorrect magic value | |
| // in the PE/COFF Header. If the MachineType is Itanium(IA64) and the | |
| // Magic value in the OptionalHeader is EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC | |
| // then override the magic value to EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC | |
| // | |
| Magic = EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC; | |
| } else { | |
| // | |
| // Get the magic value from the PE/COFF Optional Header | |
| // | |
| Magic = mNtHeader.Pe32->OptionalHeader.Magic; | |
| } | |
| if (Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) { | |
| // | |
| // Use PE32 offset. | |
| // | |
| NumberOfRvaAndSizes = mNtHeader.Pe32->OptionalHeader.NumberOfRvaAndSizes; | |
| if (NumberOfRvaAndSizes > EFI_IMAGE_DIRECTORY_ENTRY_SECURITY) { | |
| SecDataDir = (EFI_IMAGE_DATA_DIRECTORY *) &mNtHeader.Pe32->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY]; | |
| } | |
| } else { | |
| // | |
| // Use PE32+ offset. | |
| // | |
| NumberOfRvaAndSizes = mNtHeader.Pe32Plus->OptionalHeader.NumberOfRvaAndSizes; | |
| if (NumberOfRvaAndSizes > EFI_IMAGE_DIRECTORY_ENTRY_SECURITY) { | |
| SecDataDir = (EFI_IMAGE_DATA_DIRECTORY *) &mNtHeader.Pe32Plus->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY]; | |
| } | |
| } | |
| // | |
| // Start Image Validation. | |
| // | |
| if (SecDataDir == NULL || SecDataDir->Size == 0) { | |
| // | |
| // This image is not signed. The SHA256 hash value of the image must match a record in the security database "db", | |
| // and not be reflected in the security data base "dbx". | |
| // | |
| if (!HashPeImage (HASHALG_SHA256)) { | |
| DEBUG ((DEBUG_INFO, "DxeImageVerificationLib: Failed to hash this image using %s.\n", mHashTypeStr)); | |
| goto Done; | |
| } | |
| if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE1, mImageDigest, &mCertType, mImageDigestSize)) { | |
| // | |
| // Image Hash is in forbidden database (DBX). | |
| // | |
| DEBUG ((DEBUG_INFO, "DxeImageVerificationLib: Image is not signed and %s hash of image is forbidden by DBX.\n", mHashTypeStr)); | |
| goto Done; | |
| } | |
| if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE, mImageDigest, &mCertType, mImageDigestSize)) { | |
| // | |
| // Image Hash is in allowed database (DB). | |
| // | |
| return EFI_SUCCESS; | |
| } | |
| // | |
| // Image Hash is not found in both forbidden and allowed database. | |
| // | |
| DEBUG ((DEBUG_INFO, "DxeImageVerificationLib: Image is not signed and %s hash of image is not found in DB/DBX.\n", mHashTypeStr)); | |
| goto Done; | |
| } | |
| // | |
| // Verify the signature of the image, multiple signatures are allowed as per PE/COFF Section 4.7 | |
| // "Attribute Certificate Table". | |
| // The first certificate starts at offset (SecDataDir->VirtualAddress) from the start of the file. | |
| // | |
| for (OffSet = SecDataDir->VirtualAddress; | |
| OffSet < (SecDataDir->VirtualAddress + SecDataDir->Size); | |
| OffSet += (WinCertificate->dwLength + ALIGN_SIZE (WinCertificate->dwLength))) { | |
| WinCertificate = (WIN_CERTIFICATE *) (mImageBase + OffSet); | |
| if ((SecDataDir->VirtualAddress + SecDataDir->Size - OffSet) <= sizeof (WIN_CERTIFICATE) || | |
| (SecDataDir->VirtualAddress + SecDataDir->Size - OffSet) < WinCertificate->dwLength) { | |
| break; | |
| } | |
| // | |
| // Verify the image's Authenticode signature, only DER-encoded PKCS#7 signed data is supported. | |
| // | |
| if (WinCertificate->wCertificateType == WIN_CERT_TYPE_PKCS_SIGNED_DATA) { | |
| // | |
| // The certificate is formatted as WIN_CERTIFICATE_EFI_PKCS which is described in the | |
| // Authenticode specification. | |
| // | |
| PkcsCertData = (WIN_CERTIFICATE_EFI_PKCS *) WinCertificate; | |
| if (PkcsCertData->Hdr.dwLength <= sizeof (PkcsCertData->Hdr)) { | |
| break; | |
| } | |
| AuthData = PkcsCertData->CertData; | |
| AuthDataSize = PkcsCertData->Hdr.dwLength - sizeof(PkcsCertData->Hdr); | |
| } else if (WinCertificate->wCertificateType == WIN_CERT_TYPE_EFI_GUID) { | |
| // | |
| // The certificate is formatted as WIN_CERTIFICATE_UEFI_GUID which is described in UEFI Spec. | |
| // | |
| WinCertUefiGuid = (WIN_CERTIFICATE_UEFI_GUID *) WinCertificate; | |
| if (WinCertUefiGuid->Hdr.dwLength <= OFFSET_OF(WIN_CERTIFICATE_UEFI_GUID, CertData)) { | |
| break; | |
| } | |
| if (!CompareGuid (&WinCertUefiGuid->CertType, &gEfiCertPkcs7Guid)) { | |
| continue; | |
| } | |
| AuthData = WinCertUefiGuid->CertData; | |
| AuthDataSize = WinCertUefiGuid->Hdr.dwLength - OFFSET_OF(WIN_CERTIFICATE_UEFI_GUID, CertData); | |
| } else { | |
| if (WinCertificate->dwLength < sizeof (WIN_CERTIFICATE)) { | |
| break; | |
| } | |
| continue; | |
| } | |
| Status = HashPeImageByType (AuthData, AuthDataSize); | |
| if (EFI_ERROR (Status)) { | |
| continue; | |
| } | |
| // | |
| // Check the digital signature against the revoked certificate in forbidden database (dbx). | |
| // | |
| if (IsForbiddenByDbx (AuthData, AuthDataSize)) { | |
| Action = EFI_IMAGE_EXECUTION_AUTH_SIG_FAILED; | |
| VerifyStatus = EFI_ACCESS_DENIED; | |
| break; | |
| } | |
| // | |
| // Check the digital signature against the valid certificate in allowed database (db). | |
| // | |
| if (EFI_ERROR (VerifyStatus)) { | |
| if (IsAllowedByDb (AuthData, AuthDataSize)) { | |
| VerifyStatus = EFI_SUCCESS; | |
| } | |
| } | |
| // | |
| // Check the image's hash value. | |
| // | |
| if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE1, mImageDigest, &mCertType, mImageDigestSize)) { | |
| Action = EFI_IMAGE_EXECUTION_AUTH_SIG_FOUND; | |
| DEBUG ((DEBUG_INFO, "DxeImageVerificationLib: Image is signed but %s hash of image is found in DBX.\n", mHashTypeStr)); | |
| VerifyStatus = EFI_ACCESS_DENIED; | |
| break; | |
| } else if (EFI_ERROR (VerifyStatus)) { | |
| if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE, mImageDigest, &mCertType, mImageDigestSize)) { | |
| VerifyStatus = EFI_SUCCESS; | |
| } else { | |
| 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)); | |
| } | |
| } | |
| } | |
| if (OffSet != (SecDataDir->VirtualAddress + SecDataDir->Size)) { | |
| // | |
| // The Size in Certificate Table or the attribute certicate table is corrupted. | |
| // | |
| VerifyStatus = EFI_ACCESS_DENIED; | |
| } | |
| if (!EFI_ERROR (VerifyStatus)) { | |
| return EFI_SUCCESS; | |
| } else { | |
| Status = EFI_ACCESS_DENIED; | |
| if (Action == EFI_IMAGE_EXECUTION_AUTH_SIG_FAILED || Action == EFI_IMAGE_EXECUTION_AUTH_SIG_FOUND) { | |
| // | |
| // Get image hash value as executable's signature. | |
| // | |
| SignatureListSize = sizeof (EFI_SIGNATURE_LIST) + sizeof (EFI_SIGNATURE_DATA) - 1 + mImageDigestSize; | |
| SignatureList = (EFI_SIGNATURE_LIST *) AllocateZeroPool (SignatureListSize); | |
| if (SignatureList == NULL) { | |
| Status = EFI_OUT_OF_RESOURCES; | |
| goto Done; | |
| } | |
| SignatureList->SignatureHeaderSize = 0; | |
| SignatureList->SignatureListSize = (UINT32) SignatureListSize; | |
| SignatureList->SignatureSize = (UINT32) (sizeof (EFI_SIGNATURE_DATA) - 1 + mImageDigestSize); | |
| CopyMem (&SignatureList->SignatureType, &mCertType, sizeof (EFI_GUID)); | |
| Signature = (EFI_SIGNATURE_DATA *) ((UINT8 *) SignatureList + sizeof (EFI_SIGNATURE_LIST)); | |
| CopyMem (Signature->SignatureData, mImageDigest, mImageDigestSize); | |
| } | |
| } | |
| Done: | |
| if (Status != EFI_SUCCESS) { | |
| // | |
| // Policy decides to defer or reject the image; add its information in image executable information table. | |
| // | |
| NameStr = ConvertDevicePathToText (File, FALSE, TRUE); | |
| AddImageExeInfo (Action, NameStr, File, SignatureList, SignatureListSize); | |
| if (NameStr != NULL) { | |
| DEBUG((EFI_D_INFO, "The image doesn't pass verification: %s\n", NameStr)); | |
| FreePool(NameStr); | |
| } | |
| Status = EFI_SECURITY_VIOLATION; | |
| } | |
| if (SignatureList != NULL) { | |
| FreePool (SignatureList); | |
| } | |
| return Status; | |
| } | |
| /** | |
| On Ready To Boot Services Event notification handler. | |
| Add the image execution information table if it is not in system configuration table. | |
| @param[in] Event Event whose notification function is being invoked | |
| @param[in] Context Pointer to the notification function's context | |
| **/ | |
| VOID | |
| EFIAPI | |
| OnReadyToBoot ( | |
| IN EFI_EVENT Event, | |
| IN VOID *Context | |
| ) | |
| { | |
| EFI_IMAGE_EXECUTION_INFO_TABLE *ImageExeInfoTable; | |
| UINTN ImageExeInfoTableSize; | |
| EfiGetSystemConfigurationTable (&gEfiImageSecurityDatabaseGuid, (VOID **) &ImageExeInfoTable); | |
| if (ImageExeInfoTable != NULL) { | |
| return; | |
| } | |
| ImageExeInfoTableSize = sizeof (EFI_IMAGE_EXECUTION_INFO_TABLE); | |
| ImageExeInfoTable = (EFI_IMAGE_EXECUTION_INFO_TABLE *) AllocateRuntimePool (ImageExeInfoTableSize); | |
| if (ImageExeInfoTable == NULL) { | |
| return ; | |
| } | |
| ImageExeInfoTable->NumberOfImages = 0; | |
| gBS->InstallConfigurationTable (&gEfiImageSecurityDatabaseGuid, (VOID *) ImageExeInfoTable); | |
| } | |
| /** | |
| Register security measurement handler. | |
| @param ImageHandle ImageHandle of the loaded driver. | |
| @param SystemTable Pointer to the EFI System Table. | |
| @retval EFI_SUCCESS The handlers were registered successfully. | |
| **/ | |
| EFI_STATUS | |
| EFIAPI | |
| DxeImageVerificationLibConstructor ( | |
| IN EFI_HANDLE ImageHandle, | |
| IN EFI_SYSTEM_TABLE *SystemTable | |
| ) | |
| { | |
| EFI_EVENT Event; | |
| // | |
| // Register the event to publish the image execution table. | |
| // | |
| EfiCreateEventReadyToBootEx ( | |
| TPL_CALLBACK, | |
| OnReadyToBoot, | |
| NULL, | |
| &Event | |
| ); | |
| return RegisterSecurity2Handler ( | |
| DxeImageVerificationHandler, | |
| EFI_AUTH_OPERATION_VERIFY_IMAGE | EFI_AUTH_OPERATION_IMAGE_REQUIRED | |
| ); | |
| } |