X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=blobdiff_plain;f=SecurityPkg%2FLibrary%2FDxeImageVerificationLib%2FDxeImageVerificationLib.c;h=a713d0d4ae1949e23622a3da29b8d6294c3083ff;hp=a591970e45cceefeac06dfb6b75e942f601f47e9;hb=3f63bc365d685375ffcfa09a74ec79288fa572ef;hpb=551d808116c09d88d68edef5d2454bdd268fcf1d diff --git a/SecurityPkg/Library/DxeImageVerificationLib/DxeImageVerificationLib.c b/SecurityPkg/Library/DxeImageVerificationLib/DxeImageVerificationLib.c index a591970e45..a713d0d4ae 100644 --- a/SecurityPkg/Library/DxeImageVerificationLib/DxeImageVerificationLib.c +++ b/SecurityPkg/Library/DxeImageVerificationLib/DxeImageVerificationLib.c @@ -1,7 +1,18 @@ /** @file Implement image verification services for secure boot service in UEFI2.3.1. -Copyright (c) 2009 - 2012, Intel Corporation. All rights reserved.
+ 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 - 2015, Intel Corporation. All rights reserved.
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 @@ -14,14 +25,21 @@ 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; -UINTN mImageSize; UINT32 mPeCoffHeaderOffset; +EFI_GUID mCertType; + +// +// Information on current PE/COFF image +// +UINTN mImageSize; +UINT8 *mImageBase = NULL; UINT8 mImageDigest[MAX_DIGEST_SIZE]; UINTN mImageDigestSize; -EFI_IMAGE_DATA_DIRECTORY *mSecDataDir = NULL; -UINT8 *mImageBase = NULL; -EFI_GUID mCertType; // // Notify string for authorization UI. @@ -38,7 +56,6 @@ CONST UINT8 mRsaE[] = { 0x01, 0x00, 0x01 }; // OID ASN.1 Value for Hash Algorithms // UINT8 mHashOidValue[] = { - 0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x02, 0x05, // OBJ_md5 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 @@ -47,23 +64,46 @@ UINT8 mHashOidValue[] = { }; HASH_TABLE mHash[] = { - { L"SHA1", 20, &mHashOidValue[8], 5, Sha1GetContextSize, Sha1Init, Sha1Update, Sha1Final }, - { L"SHA224", 28, &mHashOidValue[13], 9, NULL, NULL, NULL, NULL }, - { L"SHA256", 32, &mHashOidValue[22], 9, Sha256GetContextSize,Sha256Init, Sha256Update, Sha256Final}, - { L"SHA384", 48, &mHashOidValue[31], 9, NULL, NULL, NULL, NULL }, - { L"SHA512", 64, &mHashOidValue[40], 9, NULL, NULL, NULL, NULL } + { 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} }; +/** + 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. + @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 + + @retval EFI_SUCCESS The specified portion of the PE/COFF image was read and the size **/ EFI_STATUS EFIAPI @@ -77,7 +117,7 @@ DxeImageVerificationLibImageRead ( UINTN EndPosition; if (FileHandle == NULL || ReadSize == NULL || Buffer == NULL) { - return EFI_INVALID_PARAMETER; + return EFI_INVALID_PARAMETER; } if (MAX_ADDRESS - FileOffset < *ReadSize) { @@ -118,6 +158,10 @@ GetImageType ( 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 // @@ -229,6 +273,10 @@ GetImageType ( Caculate 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] HashAlg Hash algorithm type. @retval TRUE Successfully hash image. @@ -251,8 +299,6 @@ HashPeImage ( EFI_IMAGE_SECTION_HEADER *SectionHeader; UINTN Index; UINTN Pos; - UINTN SumOfSectionBytes; - EFI_IMAGE_SECTION_HEADER *SectionCache; UINT32 CertSize; UINT32 NumberOfRvaAndSizes; @@ -260,7 +306,7 @@ HashPeImage ( SectionHeader = NULL; Status = FALSE; - if ((HashAlg != HASHALG_SHA1) && (HashAlg != HASHALG_SHA256)) { + if ((HashAlg >= HASHALG_MAX)) { return FALSE; } @@ -269,13 +315,28 @@ HashPeImage ( // ZeroMem (mImageDigest, MAX_DIGEST_SIZE); - if (HashAlg == HASHALG_SHA1) { - mImageDigestSize = SHA1_DIGEST_SIZE; - mCertType = gEfiCertSha1Guid; - } else if (HashAlg == HASHALG_SHA256) { - mImageDigestSize = SHA256_DIGEST_SIZE; - mCertType = gEfiCertSha256Guid; - } else { + 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; } @@ -299,7 +360,21 @@ HashPeImage ( // Measuring PE/COFF Image Header; // But CheckSum field and SECURITY data directory (certificate) are excluded // - Magic = mNtHeader.Pe32->OptionalHeader.Magic; + 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. @@ -406,7 +481,7 @@ HashPeImage ( if (!Status) { goto Done; } - } + } } // @@ -433,11 +508,6 @@ HashPeImage ( mNtHeader.Pe32->FileHeader.SizeOfOptionalHeader ); - SectionCache = Section; - for (Index = 0, SumOfSectionBytes = 0; Index < mNtHeader.Pe32->FileHeader.NumberOfSections; Index++, SectionCache++) { - SumOfSectionBytes += SectionCache->SizeOfRawData; - } - // // 11. Build a temporary table of pointers to all the IMAGE_SECTION_HEADER // structures in the image. The 'NumberOfSections' field of the image @@ -543,19 +613,24 @@ Done: 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 ( - VOID + IN UINT8 *AuthData, + IN UINTN AuthDataSize ) { UINT8 Index; - WIN_CERTIFICATE_EFI_PKCS *PkcsCertData; - - PkcsCertData = (WIN_CERTIFICATE_EFI_PKCS *) (mImageBase + mSecDataDir->VirtualAddress); for (Index = 0; Index < HASHALG_MAX; Index++) { // @@ -570,14 +645,18 @@ HashPeImageByType ( // 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 ((*(PkcsCertData->CertData + 1) & TWO_BYTE_ENCODE) != TWO_BYTE_ENCODE) { + if ((*(AuthData + 1) & TWO_BYTE_ENCODE) != TWO_BYTE_ENCODE) { // // Only support two bytes of Long Form of Length Encoding. // continue; } - if (CompareMem (PkcsCertData->CertData + 32, mHash[Index].OidValue, mHash[Index].OidLength) == 0) { + if (AuthDataSize < 32 + mHash[Index].OidLength) { + return EFI_UNSUPPORTED; + } + + if (CompareMem (AuthData + 32, mHash[Index].OidValue, mHash[Index].OidLength) == 0) { break; } } @@ -670,14 +749,15 @@ AddImageExeInfo ( if (Name != NULL) { NameStringLen = StrSize (Name); + } else { + NameStringLen = sizeof (CHAR16); } - ImageExeInfoTable = NULL; EfiGetSystemConfigurationTable (&gEfiImageSecurityDatabaseGuid, (VOID **) &ImageExeInfoTable); if (ImageExeInfoTable != NULL) { // // The table has been found! - // We must enlarge the table to accmodate the new exe info entry. + // We must enlarge the table to accomodate the new exe info entry. // ImageExeInfoTableSize = GetImageExeInfoTableSize (ImageExeInfoTable); } else { @@ -689,7 +769,7 @@ AddImageExeInfo ( } DevicePathSize = GetDevicePathSize (DevicePath); - NewImageExeInfoEntrySize = sizeof (EFI_IMAGE_EXECUTION_INFO) + NameStringLen + DevicePathSize + SignatureSize; + NewImageExeInfoEntrySize = sizeof (EFI_IMAGE_EXECUTION_INFO) - sizeof (EFI_SIGNATURE_LIST) + NameStringLen + DevicePathSize + SignatureSize; NewImageExeInfoTable = (EFI_IMAGE_EXECUTION_INFO_TABLE *) AllocateRuntimePool (ImageExeInfoTableSize + NewImageExeInfoEntrySize); if (NewImageExeInfoTable == NULL) { return ; @@ -703,22 +783,24 @@ AddImageExeInfo ( NewImageExeInfoTable->NumberOfImages++; ImageExeInfoEntry = (EFI_IMAGE_EXECUTION_INFO *) ((UINT8 *) NewImageExeInfoTable + ImageExeInfoTableSize); // - // Update new item's infomation. + // Update new item's information. // - WriteUnaligned32 ((UINT32 *) &ImageExeInfoEntry->Action, Action); - WriteUnaligned32 ((UINT32 *) &ImageExeInfoEntry->InfoSize, (UINT32) NewImageExeInfoEntrySize); + WriteUnaligned32 ((UINT32 *) ImageExeInfoEntry, Action); + WriteUnaligned32 ((UINT32 *) ((UINT8 *) ImageExeInfoEntry + sizeof (EFI_IMAGE_EXECUTION_ACTION)), (UINT32) NewImageExeInfoEntrySize); if (Name != NULL) { - CopyMem ((UINT8 *) &ImageExeInfoEntry->InfoSize + sizeof (UINT32), Name, NameStringLen); + CopyMem ((UINT8 *) ImageExeInfoEntry + sizeof (EFI_IMAGE_EXECUTION_ACTION) + sizeof (UINT32), Name, NameStringLen); + } else { + ZeroMem ((UINT8 *) ImageExeInfoEntry + sizeof (EFI_IMAGE_EXECUTION_ACTION) + sizeof (UINT32), sizeof (CHAR16)); } CopyMem ( - (UINT8 *) &ImageExeInfoEntry->InfoSize + sizeof (UINT32) + NameStringLen, + (UINT8 *) ImageExeInfoEntry + sizeof (EFI_IMAGE_EXECUTION_ACTION) + sizeof (UINT32) + NameStringLen, DevicePath, DevicePathSize ); if (Signature != NULL) { CopyMem ( - (UINT8 *) &ImageExeInfoEntry->InfoSize + sizeof (UINT32) + NameStringLen + DevicePathSize, + (UINT8 *) ImageExeInfoEntry + sizeof (EFI_IMAGE_EXECUTION_ACTION) + sizeof (UINT32) + NameStringLen + DevicePathSize, Signature, SignatureSize ); @@ -737,57 +819,132 @@ AddImageExeInfo ( } /** - Discover if the UEFI image is authorized by user's policy setting. + Check whether the hash of an given X.509 certificate is in forbidden database (DBX). - @param[in] Policy Specify platform's policy setting. + @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. - @retval EFI_ACCESS_DENIED Image is not allowed to run. - @retval EFI_SECURITY_VIOLATION Image is deferred. - @retval EFI_SUCCESS Image is authorized to run. + @return TRUE The certificate hash is found in the forbidden database. + @return FALSE The certificate hash is not found in the forbidden database. **/ -EFI_STATUS -ImageAuthorization ( - IN UINT32 Policy +BOOLEAN +IsCertHashFoundInDatabase ( + IN UINT8 *Certificate, + IN UINTN CertSize, + IN EFI_SIGNATURE_LIST *SignatureList, + IN UINTN SignatureListSize, + OUT EFI_TIME *RevocationTime ) { - EFI_STATUS Status; - EFI_INPUT_KEY Key; + 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; + } - Status = EFI_ACCESS_DENIED; + // + // Retrieve the TBSCertificate from the X.509 Certificate. + // + if (!X509GetTBSCert (Certificate, CertSize, &TBSCert, &TBSCertSize)) { + return FALSE; + } - switch (Policy) { + 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; + } - case QUERY_USER_ON_SECURITY_VIOLATION: - do { - CreatePopUp (EFI_LIGHTGRAY | EFI_BACKGROUND_BLUE, &Key, mNotifyString1, mNotifyString2, NULL); - if (Key.UnicodeChar == L'Y' || Key.UnicodeChar == L'y') { - Status = EFI_SUCCESS; - break; - } else if (Key.UnicodeChar == L'N' || Key.UnicodeChar == L'n') { - Status = EFI_ACCESS_DENIED; - break; - } else if (Key.UnicodeChar == L'D' || Key.UnicodeChar == L'd') { - Status = EFI_SECURITY_VIOLATION; - break; - } - } while (TRUE); - break; + // + // 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; + } - case ALLOW_EXECUTE_ON_SECURITY_VIOLATION: - Status = EFI_SUCCESS; - break; + 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; - case DEFER_EXECUTE_ON_SECURITY_VIOLATION: - Status = EFI_SECURITY_VIOLATION; - break; + // + // 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); + } - case DENY_EXECUTE_ON_SECURITY_VIOLATION: - Status = EFI_ACCESS_DENIED; - break; + DbxSize -= DbxList->SignatureListSize; + DbxList = (EFI_SIGNATURE_LIST *) ((UINT8 *) DbxList + DbxList->SignatureListSize); } - return Status; +Done: + if (HashCtx != NULL) { + FreePool (HashCtx); + } + + return IsFound; } /** @@ -818,6 +975,7 @@ IsSignatureFoundInDatabase ( UINTN Index; UINTN CertCount; BOOLEAN IsFound; + // // Read signature database variable. // @@ -843,7 +1001,7 @@ IsSignatureFoundInDatabase ( // CertList = (EFI_SIGNATURE_LIST *) Data; while ((DataSize > 0) && (DataSize >= CertList->SignatureListSize)) { - CertCount = (CertList->SignatureListSize - CertList->SignatureHeaderSize) / CertList->SignatureSize; + 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++) { @@ -852,6 +1010,7 @@ IsSignatureFoundInDatabase ( // Find the signature in database. // IsFound = TRUE; + SecureBootHook (VariableName, &gEfiImageSecurityDatabaseGuid, CertList->SignatureSize, Cert); break; } @@ -876,271 +1035,461 @@ Done: } /** - Verify PKCS#7 SignedData using certificate found in Variable which formatted - as EFI_SIGNATURE_LIST. The Variable may be PK, KEK, DB or DBX. + Check whether the timestamp is valid by comparing the signing time and the revocation time. - @param VariableName Name of Variable to search for Certificate. - @param VendorGuid Variable vendor GUID. + @param SigningTime A pointer to the signing time. + @param RevocationTime A pointer to the revocation time. - @retval TRUE Image pass verification. - @retval FALSE Image fail verification. + @retval TRUE The SigningTime is not later than the RevocationTime. + @retval FALSE The SigningTime is later than the RevocationTime. **/ BOOLEAN -IsPkcsSignedDataVerifiedBySignatureList ( - IN CHAR16 *VariableName, - IN EFI_GUID *VendorGuid +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; - WIN_CERTIFICATE_EFI_PKCS *PkcsCertData; EFI_SIGNATURE_LIST *CertList; EFI_SIGNATURE_DATA *Cert; - UINTN DataSize; - UINT8 *Data; + UINT8 *DbtData; + UINTN DbtDataSize; UINT8 *RootCert; UINTN RootCertSize; UINTN Index; UINTN CertCount; + EFI_TIME SigningTime; - Data = NULL; - CertList = NULL; - Cert = NULL; - RootCert = NULL; - RootCertSize = 0; - VerifyStatus = FALSE; - PkcsCertData = (WIN_CERTIFICATE_EFI_PKCS *) (mImageBase + mSecDataDir->VirtualAddress); - - DataSize = 0; - Status = gRT->GetVariable (VariableName, VendorGuid, NULL, &DataSize, NULL); - if (Status == EFI_BUFFER_TOO_SMALL) { - Data = (UINT8 *) AllocateZeroPool (DataSize); - if (Data == NULL) { - return VerifyStatus; - } + // + // Variable Initialization + // + VerifyStatus = FALSE; + DbtData = NULL; + CertList = NULL; + Cert = NULL; + RootCert = NULL; + RootCertSize = 0; - Status = gRT->GetVariable (VariableName, VendorGuid, NULL, &DataSize, (VOID *) Data); - if (EFI_ERROR (Status)) { - goto Done; - } + // + // If RevocationTime is zero, the certificate shall be considered to always be revoked. + // + if (IsTimeZero (RevocationTime)) { + return FALSE; + } - // - // 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)) { - 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; + // + // 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)) { // - // Call AuthenticodeVerify library to Verify Authenticode struct. + // The signer signature is valid only when the signing time is earlier than revocation time. // - VerifyStatus = AuthenticodeVerify ( - PkcsCertData->CertData, - mSecDataDir->Size - sizeof(PkcsCertData->Hdr), - RootCert, - RootCertSize, - mImageDigest, - mImageDigestSize - ); - if (VerifyStatus) { + if (IsValidSignatureByTimestamp (&SigningTime, RevocationTime)) { + VerifyStatus = TRUE; goto Done; } - Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) Cert + CertList->SignatureSize); } + Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) Cert + CertList->SignatureSize); } - DataSize -= CertList->SignatureListSize; - CertList = (EFI_SIGNATURE_LIST *) ((UINT8 *) CertList + CertList->SignatureListSize); } + DbtDataSize -= CertList->SignatureListSize; + CertList = (EFI_SIGNATURE_LIST *) ((UINT8 *) CertList + CertList->SignatureListSize); } Done: - if (Data != NULL) { - FreePool (Data); + if (DbtData != NULL) { + FreePool (DbtData); } return VerifyStatus; } /** - Verify certificate in WIN_CERT_TYPE_PKCS_SIGNED_DATA format. + 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 EFI_SUCCESS Image pass verification. - @retval EFI_SECURITY_VIOLATION Image fail verification. + @retval TRUE Image is forbidden by dbx. + @retval FALSE Image is not forbidden by dbx. **/ -EFI_STATUS -VerifyCertPkcsSignedData ( - VOID +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. // - // 1: Find certificate from DBX forbidden database for revoked certificate. - // - if (IsPkcsSignedDataVerifiedBySignatureList (EFI_IMAGE_SECURITY_DATABASE1, &gEfiImageSecurityDatabaseGuid)) { - // - // DBX is forbidden database, if Authenticode verification pass with - // one of the certificate in DBX, this image should be rejected. - // - return EFI_SECURITY_VIOLATION; + 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; } - // - // 2: Find certificate from KEK database and try to verify authenticode struct. - // - if (IsPkcsSignedDataVerifiedBySignatureList (EFI_KEY_EXCHANGE_KEY_NAME, &gEfiGlobalVariableGuid)) { - return EFI_SUCCESS; + Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE1, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, (VOID *) Data); + if (EFI_ERROR (Status)) { + return IsForbidden; } // - // 3: Find certificate from DB database and try to verify authenticode struct. + // Verify image signature with RAW X509 certificates in DBX database. + // If passed, the image will be forbidden. // - if (IsPkcsSignedDataVerifiedBySignatureList (EFI_IMAGE_SECURITY_DATABASE, &gEfiImageSecurityDatabaseGuid)) { - return EFI_SUCCESS; - } else { - return EFI_SECURITY_VIOLATION; - } -} + 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; -/** - Verify certificate in WIN_CERTIFICATE_UEFI_GUID format. + 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); - @retval EFI_SUCCESS Image pass verification. - @retval EFI_SECURITY_VIOLATION Image fail verification. - @retval other error value + // + // 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, Cert); + goto Done; + } -**/ -EFI_STATUS -VerifyCertUefiGuid ( - VOID - ) -{ - BOOLEAN Status; - WIN_CERTIFICATE_UEFI_GUID *EfiCert; - EFI_SIGNATURE_LIST *KekList; - EFI_SIGNATURE_DATA *KekItem; - EFI_CERT_BLOCK_RSA_2048_SHA256 *CertBlock; - VOID *Rsa; - UINTN KekCount; - UINTN Index; - UINTN KekDataSize; - BOOLEAN IsFound; - EFI_STATUS Result; - - EfiCert = NULL; - KekList = NULL; - KekItem = NULL; - CertBlock = NULL; - Rsa = NULL; - Status = FALSE; - IsFound = FALSE; - KekDataSize = 0; + CertData = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertData + CertList->SignatureSize); + } + } - EfiCert = (WIN_CERTIFICATE_UEFI_GUID *) (mImageBase + mSecDataDir->VirtualAddress); - CertBlock = (EFI_CERT_BLOCK_RSA_2048_SHA256 *) EfiCert->CertData; - if (!CompareGuid (&EfiCert->CertType, &gEfiCertTypeRsa2048Sha256Guid)) { - // - // Invalid Certificate Data Type. - // - return EFI_SECURITY_VIOLATION; + CertListSize -= CertList->SignatureListSize; + CertList = (EFI_SIGNATURE_LIST *) ((UINT8 *) CertList + CertList->SignatureListSize); } // - // Get KEK database variable data size + // Check X.509 Certificate Hash & Possible Timestamp. // - Result = gRT->GetVariable (EFI_KEY_EXCHANGE_KEY_NAME, &gEfiGlobalVariableGuid, NULL, &KekDataSize, NULL); - if (Result != EFI_BUFFER_TOO_SMALL) { - return EFI_SECURITY_VIOLATION; - } // - // Get KEK database variable. + // 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[]; // - KekList = GetEfiGlobalVariable (EFI_KEY_EXCHANGE_KEY_NAME); - if (KekList == NULL) { - return EFI_SECURITY_VIOLATION; + Pkcs7GetSigners (AuthData, AuthDataSize, &CertBuffer, &BufferLength, &TrustedCert, &TrustedCertLength); + if ((BufferLength == 0) || (CertBuffer == NULL)) { + IsForbidden = TRUE; + goto Done; } // - // Enumerate all Kek items in this list to verify the variable certificate data. - // If anyone is authenticated successfully, it means the variable is correct! + // Check if any hash of certificates embedded in AuthData is in the forbidden database. // - while ((KekDataSize > 0) && (KekDataSize >= KekList->SignatureListSize)) { - if (CompareGuid (&KekList->SignatureType, &gEfiCertRsa2048Guid)) { - KekItem = (EFI_SIGNATURE_DATA *) ((UINT8 *) KekList + sizeof (EFI_SIGNATURE_LIST) + KekList->SignatureHeaderSize); - KekCount = (KekList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - KekList->SignatureHeaderSize) / KekList->SignatureSize; - for (Index = 0; Index < KekCount; Index++) { - if (CompareMem (KekItem->SignatureData, CertBlock->PublicKey, EFI_CERT_TYPE_RSA2048_SIZE) == 0) { - IsFound = TRUE; - break; - } - KekItem = (EFI_SIGNATURE_DATA *) ((UINT8 *) KekItem + KekList->SignatureSize); + CertNumber = (UINT8) (*CertBuffer); + CertPtr = CertBuffer + 1; + for (Index = 0; Index < CertNumber; Index++) { + CertSize = (UINTN) ReadUnaligned32 ((UINT32 *)CertPtr); + Cert = (UINT8 *)CertPtr + sizeof (UINT32); + + 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; } + goto Done; } - KekDataSize -= KekList->SignatureListSize; - KekList = (EFI_SIGNATURE_LIST *) ((UINT8 *) KekList + KekList->SignatureListSize); + + CertPtr = CertPtr + sizeof (UINT32) + CertSize; + } + +Done: + if (Data != NULL) { + FreePool (Data); } - if (!IsFound) { + 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 *Cert; + UINTN DataSize; + UINT8 *Data; + UINT8 *RootCert; + UINTN RootCertSize; + UINTN Index; + UINTN CertCount; + UINTN DbxDataSize; + UINT8 *DbxData; + EFI_TIME RevocationTime; + + Data = NULL; + CertList = NULL; + Cert = 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; + } + // - // Signed key is not a trust one. + // Find X509 certificate in Signature List to verify the signature in pkcs7 signed data. // - goto Done; - } + CertList = (EFI_SIGNATURE_LIST *) Data; + while ((DataSize > 0) && (DataSize >= 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; - // - // Now, we found the corresponding security policy. - // Verify the data payload. - // - Rsa = RsaNew (); - if (Rsa == NULL) { - Status = FALSE; - goto Done; - } + 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); - // - // Set RSA Key Components. - // NOTE: Only N and E are needed to be set as RSA public key for signature verification. - // - Status = RsaSetKey (Rsa, RsaKeyN, CertBlock->PublicKey, EFI_CERT_TYPE_RSA2048_SIZE); - if (!Status) { - goto Done; - } - Status = RsaSetKey (Rsa, RsaKeyE, mRsaE, sizeof (mRsaE)); - if (!Status) { - goto Done; + // + // 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 (DataSize); + 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 image can be trusted. + // + VerifyStatus = PassTimestampCheck (AuthData, AuthDataSize, &RevocationTime); + } + + goto Done; + } + + Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) Cert + CertList->SignatureSize); + } + } + + DataSize -= CertList->SignatureListSize; + CertList = (EFI_SIGNATURE_LIST *) ((UINT8 *) CertList + CertList->SignatureListSize); + } } - // - // Verify the signature. - // - Status = RsaPkcs1Verify ( - Rsa, - mImageDigest, - mImageDigestSize, - CertBlock->Signature, - EFI_CERT_TYPE_RSA2048_SHA256_SIZE - ); Done: - if (KekList != NULL) { - FreePool (KekList); + if (VerifyStatus) { + SecureBootHook (EFI_IMAGE_SECURITY_DATABASE, &gEfiImageSecurityDatabaseGuid, CertList->SignatureSize, Cert); } - if (Rsa != NULL ) { - RsaFree (Rsa); + + if (Data != NULL) { + FreePool (Data); } - if (Status) { - return EFI_SUCCESS; - } else { - return EFI_SECURITY_VIOLATION; + if (DbxData != NULL) { + FreePool (DbxData); } + + return VerifyStatus; } /** @@ -1151,23 +1500,18 @@ Done: 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 process is: - Is the Image signed? - If yes, - Does the image verify against a certificate (root or intermediate) in the allowed db? - Run it - Image verification fail - Is the Image's Hash not in forbidden database and the Image's Hash in allowed db? - Run it - If no, - Is the Image's Hash in the forbidden database (DBX)? - if yes, - Error out - Is the Image's Hash in the allowed database (DB)? - If yes, - Run it - If no, - Error out + 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 @@ -1176,19 +1520,23 @@ Done: 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. - - @retval EFI_SUCCESS The file specified by File did authenticate, and the - platform policy dictates that the DXE Core may use File. - @retval EFI_INVALID_PARAMETER Input argument is incorrect. + @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. A file may be promoted from - the untrusted to the trusted state at a future time - with a call to the Trust() DXE Service. - @retval EFI_ACCESS_DENIED The file specified by File did not authenticate, and - the platform policy dictates that File should not be - used for any purpose. + 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 @@ -1197,33 +1545,40 @@ DxeImageVerificationHandler ( IN UINT32 AuthenticationStatus, IN CONST EFI_DEVICE_PATH_PROTOCOL *File, IN VOID *FileBuffer, - IN UINTN FileSize + IN UINTN FileSize, + IN BOOLEAN BootPolicy ) { EFI_STATUS Status; UINT16 Magic; EFI_IMAGE_DOS_HEADER *DosHdr; EFI_STATUS VerifyStatus; - UINT8 *SetupMode; EFI_SIGNATURE_LIST *SignatureList; UINTN SignatureListSize; EFI_SIGNATURE_DATA *Signature; EFI_IMAGE_EXECUTION_ACTION Action; WIN_CERTIFICATE *WinCertificate; UINT32 Policy; - UINT8 *SecureBootEnable; + UINT8 *SecureBoot; PE_COFF_LOADER_IMAGE_CONTEXT ImageContext; UINT32 NumberOfRvaAndSizes; - - if (File == NULL) { - return EFI_INVALID_PARAMETER; - } + 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. // @@ -1258,43 +1613,31 @@ DxeImageVerificationHandler ( return EFI_ACCESS_DENIED; } - SecureBootEnable = GetVariable (EFI_SECURE_BOOT_ENABLE_NAME, &gEfiSecureBootEnableDisableGuid); // - // Skip verification if SecureBootEnable variable doesn't exist. + // The policy QUERY_USER_ON_SECURITY_VIOLATION and ALLOW_EXECUTE_ON_SECURITY_VIOLATION + // violates the UEFI spec and has been removed. // - if (SecureBootEnable == NULL) { - return EFI_SUCCESS; + 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 SecureBootEnable is disabled. + // Skip verification if SecureBoot variable doesn't exist. // - if (*SecureBootEnable == SECURE_BOOT_DISABLE) { - FreePool (SecureBootEnable); + if (SecureBoot == NULL) { return EFI_SUCCESS; } - FreePool (SecureBootEnable); - - SetupMode = GetEfiGlobalVariable (EFI_SETUP_MODE_NAME); - // - // SetupMode doesn't exist means no AuthVar driver is dispatched, - // skip verification. + // Skip verification if SecureBoot is disabled. // - if (SetupMode == NULL) { + if (*SecureBoot == SECURE_BOOT_MODE_DISABLE) { + FreePool (SecureBoot); return EFI_SUCCESS; } - - // - // If platform is in SETUP MODE, skip verification. - // - if (*SetupMode == SETUP_MODE) { - FreePool (SetupMode); - return EFI_SUCCESS; - } - - FreePool (SetupMode); + FreePool (SecureBoot); // // Read the Dos header. @@ -1321,7 +1664,9 @@ DxeImageVerificationHandler ( goto Done; } - DosHdr = (EFI_IMAGE_DOS_HEADER *) mImageBase; + Status = EFI_ACCESS_DENIED; + + DosHdr = (EFI_IMAGE_DOS_HEADER *) mImageBase; if (DosHdr->e_magic == EFI_IMAGE_DOS_SIGNATURE) { // // DOS image header is present, @@ -1339,32 +1684,49 @@ DxeImageVerificationHandler ( // // It is not a valid Pe/Coff file. // - Status = EFI_ACCESS_DENIED; goto Done; } - Magic = mNtHeader.Pe32->OptionalHeader.Magic; + 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) { - mSecDataDir = (EFI_IMAGE_DATA_DIRECTORY *) &mNtHeader.Pe32->OptionalHeader.DataDirectory[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) { - mSecDataDir = (EFI_IMAGE_DATA_DIRECTORY *) &mNtHeader.Pe32Plus->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY]; + SecDataDir = (EFI_IMAGE_DATA_DIRECTORY *) &mNtHeader.Pe32Plus->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY]; } } - if ((mSecDataDir == NULL) || ((mSecDataDir != NULL) && (mSecDataDir->Size == 0))) { + // + // Start Image Validation. + // + if (SecDataDir == NULL || SecDataDir->Size == 0) { // - // This image is not signed. + // 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)) { goto Done; @@ -1374,8 +1736,6 @@ DxeImageVerificationHandler ( // // Image Hash is in forbidden database (DBX). // - Action = EFI_IMAGE_EXECUTION_AUTH_UNTESTED; - Status = EFI_ACCESS_DENIED; goto Done; } @@ -1389,106 +1749,122 @@ DxeImageVerificationHandler ( // // Image Hash is not found in both forbidden and allowed database. // - Action = EFI_IMAGE_EXECUTION_AUTH_UNTESTED; - Status = EFI_ACCESS_DENIED; goto Done; } // - // Verify signature of executables. + // 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. // - WinCertificate = (WIN_CERTIFICATE *) (mImageBase + mSecDataDir->VirtualAddress); - - switch (WinCertificate->wCertificateType) { + 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; + } - case WIN_CERT_TYPE_EFI_GUID: // - // Verify UEFI GUID type. + // Verify the image's Authenticode signature, only DER-encoded PKCS#7 signed data is supported. // - if (!HashPeImage (HASHALG_SHA256)) { - goto Done; + 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; } - VerifyStatus = VerifyCertUefiGuid (); - break; + Status = HashPeImageByType (AuthData, AuthDataSize); + if (EFI_ERROR (Status)) { + continue; + } - case WIN_CERT_TYPE_PKCS_SIGNED_DATA: // - // Verify Pkcs signed data type. + // Check the digital signature against the revoked certificate in forbidden database (dbx). // - Status = HashPeImageByType(); - if (EFI_ERROR (Status)) { - goto Done; + if (IsForbiddenByDbx (AuthData, AuthDataSize)) { + Action = EFI_IMAGE_EXECUTION_AUTH_SIG_FAILED; + VerifyStatus = EFI_ACCESS_DENIED; + break; } - VerifyStatus = VerifyCertPkcsSignedData (); - // - // For image verification against enrolled certificate(root or intermediate), - // no need to check image's hash in the allowed database. + // Check the digital signature against the valid certificate in allowed database (db). // - if (!EFI_ERROR (VerifyStatus)) { - if (!IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE1, mImageDigest, &mCertType, mImageDigestSize)) { - return EFI_SUCCESS; + if (EFI_ERROR (VerifyStatus)) { + if (IsAllowedByDb (AuthData, AuthDataSize)) { + VerifyStatus = EFI_SUCCESS; } } - break; - default: - Status = EFI_ACCESS_DENIED; - goto Done; - } - // - // 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) mImageDigestSize; - CopyMem (&SignatureList->SignatureType, &mCertType, sizeof (EFI_GUID)); - Signature = (EFI_SIGNATURE_DATA *) ((UINT8 *) SignatureList + sizeof (EFI_SIGNATURE_LIST)); - CopyMem (Signature->SignatureData, mImageDigest, mImageDigestSize); - // - // Signature database check after verification. - // - if (EFI_ERROR (VerifyStatus)) { // - // Verification failure. + // Check the image's hash value. // - if (!IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE1, mImageDigest, &mCertType, mImageDigestSize) && - IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE, mImageDigest, &mCertType, mImageDigestSize)) { - // - // Verification fail, Image Hash is not in forbidden database (DBX), - // and Image Hash is in allowed database (DB). - // - Status = EFI_SUCCESS; - } else { - Action = EFI_IMAGE_EXECUTION_AUTH_SIG_FAILED; - Status = EFI_ACCESS_DENIED; + if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE1, mImageDigest, &mCertType, mImageDigestSize)) { + Action = EFI_IMAGE_EXECUTION_AUTH_SIG_FOUND; + VerifyStatus = EFI_ACCESS_DENIED; + break; + } else if (EFI_ERROR (VerifyStatus)) { + if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE, mImageDigest, &mCertType, mImageDigestSize)) { + VerifyStatus = EFI_SUCCESS; + } } - } else if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE1, Signature->SignatureData, &mCertType, mImageDigestSize)) { - // - // Executable signature verification passes, but is found in forbidden signature database. - // - Action = EFI_IMAGE_EXECUTION_AUTH_SIG_FOUND; - Status = EFI_ACCESS_DENIED; - } else if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE, Signature->SignatureData, &mCertType, mImageDigestSize)) { + } + + if (OffSet != (SecDataDir->VirtualAddress + SecDataDir->Size)) { // - // Executable signature is found in authorized signature database. + // The Size in Certificate Table or the attribute certicate table is corrupted. // - Status = EFI_SUCCESS; + VerifyStatus = EFI_ACCESS_DENIED; + } + + if (!EFI_ERROR (VerifyStatus)) { + return EFI_SUCCESS; } else { - // - // Executable signature verification passes, but cannot be found in authorized signature database. - // Get platform policy to determine the action. - // - Action = EFI_IMAGE_EXECUTION_AUTH_SIG_PASSED; - Status = ImageAuthorization (Policy); + 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) mImageDigestSize; + CopyMem (&SignatureList->SignatureType, &mCertType, sizeof (EFI_GUID)); + Signature = (EFI_SIGNATURE_DATA *) ((UINT8 *) SignatureList + sizeof (EFI_SIGNATURE_LIST)); + CopyMem (Signature->SignatureData, mImageDigest, mImageDigestSize); + } } Done: @@ -1496,7 +1872,13 @@ Done: // // Policy decides to defer or reject the image; add its information in image executable information table. // - AddImageExeInfo (Action, NULL, File, SignatureList, SignatureListSize); + 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) { @@ -1507,50 +1889,38 @@ Done: } /** - When VariableWriteArchProtocol install, create "SecureBoot" variable. + 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. + @param[in] Event Event whose notification function is being invoked + @param[in] Context Pointer to the notification function's context **/ VOID EFIAPI -VariableWriteCallBack ( - IN EFI_EVENT Event, - IN VOID *Context +OnReadyToBoot ( + IN EFI_EVENT Event, + IN VOID *Context ) { - UINT8 SecureBootMode; - UINT8 *SecureBootModePtr; - EFI_STATUS Status; - VOID *ProtocolPointer; + EFI_IMAGE_EXECUTION_INFO_TABLE *ImageExeInfoTable; + UINTN ImageExeInfoTableSize; - Status = gBS->LocateProtocol (&gEfiVariableWriteArchProtocolGuid, NULL, &ProtocolPointer); - if (EFI_ERROR (Status)) { + EfiGetSystemConfigurationTable (&gEfiImageSecurityDatabaseGuid, (VOID **) &ImageExeInfoTable); + if (ImageExeInfoTable != NULL) { return; } - // - // Check whether "SecureBoot" variable exists. - // If this library is built-in, it means firmware has capability to perform - // driver signing verification. - // - SecureBootModePtr = GetEfiGlobalVariable (EFI_SECURE_BOOT_MODE_NAME); - if (SecureBootModePtr == NULL) { - SecureBootMode = SECURE_BOOT_MODE_DISABLE; - // - // Authenticated variable driver will update "SecureBoot" depending on SetupMode variable. - // - gRT->SetVariable ( - EFI_SECURE_BOOT_MODE_NAME, - &gEfiGlobalVariableGuid, - EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS | EFI_VARIABLE_NON_VOLATILE, - sizeof (UINT8), - &SecureBootMode - ); - } else { - FreePool (SecureBootModePtr); + 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); + } /** @@ -1568,20 +1938,19 @@ DxeImageVerificationLibConstructor ( IN EFI_SYSTEM_TABLE *SystemTable ) { - VOID *Registration; + EFI_EVENT Event; // - // Register callback function upon VariableWriteArchProtocol. + // Register the event to publish the image execution table. // - EfiCreateProtocolNotifyEvent ( - &gEfiVariableWriteArchProtocolGuid, + EfiCreateEventReadyToBootEx ( TPL_CALLBACK, - VariableWriteCallBack, + OnReadyToBoot, NULL, - &Registration + &Event ); - return RegisterSecurityHandler ( + return RegisterSecurity2Handler ( DxeImageVerificationHandler, EFI_AUTH_OPERATION_VERIFY_IMAGE | EFI_AUTH_OPERATION_IMAGE_REQUIRED );