/** @file Decode a hard disk partitioned with the GPT scheme in the UEFI 2.0 specification. Caution: This file requires additional review when modified. This driver will have external input - disk partition. This external input must be validated carefully to avoid security issue like buffer overflow, integer overflow. PartitionInstallGptChildHandles() routine will read disk partition content and do basic validation before PartitionInstallChildHandle(). PartitionValidGptTable(), PartitionCheckGptEntry() routine will accept disk partition content and validate the GPT table and GPT entry. Copyright (c) 2018 Qualcomm Datacenter Technologies, Inc. Copyright (c) 2006 - 2019, Intel Corporation. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent **/ #include "Partition.h" /** Install child handles if the Handle supports GPT partition structure. Caution: This function may receive untrusted input. The GPT partition table header is external input, so this routine will do basic validation for GPT partition table header before return. @param[in] BlockIo Parent BlockIo interface. @param[in] DiskIo Disk Io protocol. @param[in] Lba The starting Lba of the Partition Table @param[out] PartHeader Stores the partition table that is read @retval TRUE The partition table is valid @retval FALSE The partition table is not valid **/ BOOLEAN PartitionValidGptTable ( IN EFI_BLOCK_IO_PROTOCOL *BlockIo, IN EFI_DISK_IO_PROTOCOL *DiskIo, IN EFI_LBA Lba, OUT EFI_PARTITION_TABLE_HEADER *PartHeader ); /** Check if the CRC field in the Partition table header is valid for Partition entry array. @param[in] BlockIo Parent BlockIo interface @param[in] DiskIo Disk Io Protocol. @param[in] PartHeader Partition table header structure @retval TRUE the CRC is valid @retval FALSE the CRC is invalid **/ BOOLEAN PartitionCheckGptEntryArrayCRC ( IN EFI_BLOCK_IO_PROTOCOL *BlockIo, IN EFI_DISK_IO_PROTOCOL *DiskIo, IN EFI_PARTITION_TABLE_HEADER *PartHeader ); /** Restore Partition Table to its alternate place (Primary -> Backup or Backup -> Primary). @param[in] BlockIo Parent BlockIo interface. @param[in] DiskIo Disk Io Protocol. @param[in] PartHeader Partition table header structure. @retval TRUE Restoring succeeds @retval FALSE Restoring failed **/ BOOLEAN PartitionRestoreGptTable ( IN EFI_BLOCK_IO_PROTOCOL *BlockIo, IN EFI_DISK_IO_PROTOCOL *DiskIo, IN EFI_PARTITION_TABLE_HEADER *PartHeader ); /** This routine will check GPT partition entry and return entry status. Caution: This function may receive untrusted input. The GPT partition entry is external input, so this routine will do basic validation for GPT partition entry and report status. @param[in] PartHeader Partition table header structure @param[in] PartEntry The partition entry array @param[out] PEntryStatus the partition entry status array recording the status of each partition **/ VOID PartitionCheckGptEntry ( IN EFI_PARTITION_TABLE_HEADER *PartHeader, IN EFI_PARTITION_ENTRY *PartEntry, OUT EFI_PARTITION_ENTRY_STATUS *PEntryStatus ); /** Checks the CRC32 value in the table header. @param MaxSize Max Size limit @param Size The size of the table @param Hdr Table to check @return TRUE CRC Valid @return FALSE CRC Invalid **/ BOOLEAN PartitionCheckCrcAltSize ( IN UINTN MaxSize, IN UINTN Size, IN OUT EFI_TABLE_HEADER *Hdr ); /** Checks the CRC32 value in the table header. @param MaxSize Max Size limit @param Hdr Table to check @return TRUE CRC Valid @return FALSE CRC Invalid **/ BOOLEAN PartitionCheckCrc ( IN UINTN MaxSize, IN OUT EFI_TABLE_HEADER *Hdr ); /** Updates the CRC32 value in the table header. @param Size The size of the table @param Hdr Table to update **/ VOID PartitionSetCrcAltSize ( IN UINTN Size, IN OUT EFI_TABLE_HEADER *Hdr ); /** Updates the CRC32 value in the table header. @param Hdr Table to update **/ VOID PartitionSetCrc ( IN OUT EFI_TABLE_HEADER *Hdr ); /** Install child handles if the Handle supports GPT partition structure. Caution: This function may receive untrusted input. The GPT partition table is external input, so this routine will do basic validation for GPT partition table before install child handle for each GPT partition. @param[in] This Calling context. @param[in] Handle Parent Handle. @param[in] DiskIo Parent DiskIo interface. @param[in] DiskIo2 Parent DiskIo2 interface. @param[in] BlockIo Parent BlockIo interface. @param[in] BlockIo2 Parent BlockIo2 interface. @param[in] DevicePath Parent Device Path. @retval EFI_SUCCESS Valid GPT disk. @retval EFI_MEDIA_CHANGED Media changed Detected. @retval other Not a valid GPT disk. **/ EFI_STATUS PartitionInstallGptChildHandles ( IN EFI_DRIVER_BINDING_PROTOCOL *This, IN EFI_HANDLE Handle, IN EFI_DISK_IO_PROTOCOL *DiskIo, IN EFI_DISK_IO2_PROTOCOL *DiskIo2, IN EFI_BLOCK_IO_PROTOCOL *BlockIo, IN EFI_BLOCK_IO2_PROTOCOL *BlockIo2, IN EFI_DEVICE_PATH_PROTOCOL *DevicePath ) { EFI_STATUS Status; UINT32 BlockSize; EFI_LBA LastBlock; MASTER_BOOT_RECORD *ProtectiveMbr; EFI_PARTITION_TABLE_HEADER *PrimaryHeader; EFI_PARTITION_TABLE_HEADER *BackupHeader; EFI_PARTITION_ENTRY *PartEntry; EFI_PARTITION_ENTRY *Entry; EFI_PARTITION_ENTRY_STATUS *PEntryStatus; UINTN Index; EFI_STATUS GptValidStatus; HARDDRIVE_DEVICE_PATH HdDev; UINT32 MediaId; EFI_PARTITION_INFO_PROTOCOL PartitionInfo; ProtectiveMbr = NULL; PrimaryHeader = NULL; BackupHeader = NULL; PartEntry = NULL; PEntryStatus = NULL; BlockSize = BlockIo->Media->BlockSize; LastBlock = BlockIo->Media->LastBlock; MediaId = BlockIo->Media->MediaId; DEBUG ((DEBUG_INFO, " BlockSize : %d \n", BlockSize)); DEBUG ((DEBUG_INFO, " LastBlock : %lx \n", LastBlock)); GptValidStatus = EFI_NOT_FOUND; // // Ensure the block size can hold the MBR // if (BlockSize < sizeof (MASTER_BOOT_RECORD)) { return EFI_NOT_FOUND; } // // Allocate a buffer for the Protective MBR // ProtectiveMbr = AllocatePool (BlockSize); if (ProtectiveMbr == NULL) { return EFI_NOT_FOUND; } // // Read the Protective MBR from LBA #0 // Status = DiskIo->ReadDisk ( DiskIo, MediaId, 0, BlockSize, ProtectiveMbr ); if (EFI_ERROR (Status)) { GptValidStatus = Status; goto Done; } // // Verify that the Protective MBR is valid // for (Index = 0; Index < MAX_MBR_PARTITIONS; Index++) { if ((ProtectiveMbr->Partition[Index].OSIndicator == PMBR_GPT_PARTITION) && (UNPACK_UINT32 (ProtectiveMbr->Partition[Index].StartingLBA) == 1) ) { break; } } if (Index == MAX_MBR_PARTITIONS) { goto Done; } // // Allocate the GPT structures // PrimaryHeader = AllocateZeroPool (sizeof (EFI_PARTITION_TABLE_HEADER)); if (PrimaryHeader == NULL) { goto Done; } BackupHeader = AllocateZeroPool (sizeof (EFI_PARTITION_TABLE_HEADER)); if (BackupHeader == NULL) { goto Done; } // // Check primary and backup partition tables // if (!PartitionValidGptTable (BlockIo, DiskIo, PRIMARY_PART_HEADER_LBA, PrimaryHeader)) { DEBUG ((DEBUG_INFO, " Not Valid primary partition table\n")); if (!PartitionValidGptTable (BlockIo, DiskIo, LastBlock, BackupHeader)) { DEBUG ((DEBUG_INFO, " Not Valid backup partition table\n")); goto Done; } else { DEBUG ((DEBUG_INFO, " Valid backup partition table\n")); DEBUG ((DEBUG_INFO, " Restore primary partition table by the backup\n")); if (!PartitionRestoreGptTable (BlockIo, DiskIo, BackupHeader)) { DEBUG ((DEBUG_INFO, " Restore primary partition table error\n")); } if (PartitionValidGptTable (BlockIo, DiskIo, BackupHeader->AlternateLBA, PrimaryHeader)) { DEBUG ((DEBUG_INFO, " Restore backup partition table success\n")); } } } else if (!PartitionValidGptTable (BlockIo, DiskIo, PrimaryHeader->AlternateLBA, BackupHeader)) { DEBUG ((DEBUG_INFO, " Valid primary and !Valid backup partition table\n")); DEBUG ((DEBUG_INFO, " Restore backup partition table by the primary\n")); if (!PartitionRestoreGptTable (BlockIo, DiskIo, PrimaryHeader)) { DEBUG ((DEBUG_INFO, " Restore backup partition table error\n")); } if (PartitionValidGptTable (BlockIo, DiskIo, PrimaryHeader->AlternateLBA, BackupHeader)) { DEBUG ((DEBUG_INFO, " Restore backup partition table success\n")); } } DEBUG ((DEBUG_INFO, " Valid primary and Valid backup partition table\n")); // // Read the EFI Partition Entries // PartEntry = AllocatePool (PrimaryHeader->NumberOfPartitionEntries * PrimaryHeader->SizeOfPartitionEntry); if (PartEntry == NULL) { DEBUG ((DEBUG_ERROR, "Allocate pool error\n")); goto Done; } Status = DiskIo->ReadDisk ( DiskIo, MediaId, MultU64x32 (PrimaryHeader->PartitionEntryLBA, BlockSize), PrimaryHeader->NumberOfPartitionEntries * (PrimaryHeader->SizeOfPartitionEntry), PartEntry ); if (EFI_ERROR (Status)) { GptValidStatus = Status; DEBUG ((DEBUG_ERROR, " Partition Entry ReadDisk error\n")); goto Done; } DEBUG ((DEBUG_INFO, " Partition entries read block success\n")); DEBUG ((DEBUG_INFO, " Number of partition entries: %d\n", PrimaryHeader->NumberOfPartitionEntries)); PEntryStatus = AllocateZeroPool (PrimaryHeader->NumberOfPartitionEntries * sizeof (EFI_PARTITION_ENTRY_STATUS)); if (PEntryStatus == NULL) { DEBUG ((DEBUG_ERROR, "Allocate pool error\n")); goto Done; } // // Check the integrity of partition entries // PartitionCheckGptEntry (PrimaryHeader, PartEntry, PEntryStatus); // // If we got this far the GPT layout of the disk is valid and we should return true // GptValidStatus = EFI_SUCCESS; // // Create child device handles // for (Index = 0; Index < PrimaryHeader->NumberOfPartitionEntries; Index++) { Entry = (EFI_PARTITION_ENTRY *)((UINT8 *)PartEntry + Index * PrimaryHeader->SizeOfPartitionEntry); if (CompareGuid (&Entry->PartitionTypeGUID, &gEfiPartTypeUnusedGuid) || PEntryStatus[Index].OutOfRange || PEntryStatus[Index].Overlap || PEntryStatus[Index].OsSpecific ) { // // Don't use null EFI Partition Entries, Invalid Partition Entries or OS specific // partition Entries // continue; } ZeroMem (&HdDev, sizeof (HdDev)); HdDev.Header.Type = MEDIA_DEVICE_PATH; HdDev.Header.SubType = MEDIA_HARDDRIVE_DP; SetDevicePathNodeLength (&HdDev.Header, sizeof (HdDev)); HdDev.PartitionNumber = (UINT32)Index + 1; HdDev.MBRType = MBR_TYPE_EFI_PARTITION_TABLE_HEADER; HdDev.SignatureType = SIGNATURE_TYPE_GUID; HdDev.PartitionStart = Entry->StartingLBA; HdDev.PartitionSize = Entry->EndingLBA - Entry->StartingLBA + 1; CopyMem (HdDev.Signature, &Entry->UniquePartitionGUID, sizeof (EFI_GUID)); ZeroMem (&PartitionInfo, sizeof (EFI_PARTITION_INFO_PROTOCOL)); PartitionInfo.Revision = EFI_PARTITION_INFO_PROTOCOL_REVISION; PartitionInfo.Type = PARTITION_TYPE_GPT; if (CompareGuid (&Entry->PartitionTypeGUID, &gEfiPartTypeSystemPartGuid)) { PartitionInfo.System = 1; } CopyMem (&PartitionInfo.Info.Gpt, Entry, sizeof (EFI_PARTITION_ENTRY)); DEBUG ((DEBUG_INFO, " Index : %d\n", (UINT32)Index)); DEBUG ((DEBUG_INFO, " Start LBA : %lx\n", (UINT64)HdDev.PartitionStart)); DEBUG ((DEBUG_INFO, " End LBA : %lx\n", (UINT64)Entry->EndingLBA)); DEBUG ((DEBUG_INFO, " Partition size: %lx\n", (UINT64)HdDev.PartitionSize)); DEBUG ((DEBUG_INFO, " Start : %lx", MultU64x32 (Entry->StartingLBA, BlockSize))); DEBUG ((DEBUG_INFO, " End : %lx\n", MultU64x32 (Entry->EndingLBA, BlockSize))); Status = PartitionInstallChildHandle ( This, Handle, DiskIo, DiskIo2, BlockIo, BlockIo2, DevicePath, (EFI_DEVICE_PATH_PROTOCOL *)&HdDev, &PartitionInfo, Entry->StartingLBA, Entry->EndingLBA, BlockSize, &Entry->PartitionTypeGUID ); } DEBUG ((DEBUG_INFO, "Prepare to Free Pool\n")); Done: if (ProtectiveMbr != NULL) { FreePool (ProtectiveMbr); } if (PrimaryHeader != NULL) { FreePool (PrimaryHeader); } if (BackupHeader != NULL) { FreePool (BackupHeader); } if (PartEntry != NULL) { FreePool (PartEntry); } if (PEntryStatus != NULL) { FreePool (PEntryStatus); } return GptValidStatus; } /** This routine will read GPT partition table header and return it. Caution: This function may receive untrusted input. The GPT partition table header is external input, so this routine will do basic validation for GPT partition table header before return. @param[in] BlockIo Parent BlockIo interface. @param[in] DiskIo Disk Io protocol. @param[in] Lba The starting Lba of the Partition Table @param[out] PartHeader Stores the partition table that is read @retval TRUE The partition table is valid @retval FALSE The partition table is not valid **/ BOOLEAN PartitionValidGptTable ( IN EFI_BLOCK_IO_PROTOCOL *BlockIo, IN EFI_DISK_IO_PROTOCOL *DiskIo, IN EFI_LBA Lba, OUT EFI_PARTITION_TABLE_HEADER *PartHeader ) { EFI_STATUS Status; UINT32 BlockSize; EFI_PARTITION_TABLE_HEADER *PartHdr; UINT32 MediaId; BlockSize = BlockIo->Media->BlockSize; MediaId = BlockIo->Media->MediaId; PartHdr = AllocateZeroPool (BlockSize); if (PartHdr == NULL) { DEBUG ((DEBUG_ERROR, "Allocate pool error\n")); return FALSE; } // // Read the EFI Partition Table Header // Status = DiskIo->ReadDisk ( DiskIo, MediaId, MultU64x32 (Lba, BlockSize), BlockSize, PartHdr ); if (EFI_ERROR (Status)) { FreePool (PartHdr); return FALSE; } if ((PartHdr->Header.Signature != EFI_PTAB_HEADER_ID) || !PartitionCheckCrc (BlockSize, &PartHdr->Header) || (PartHdr->MyLBA != Lba) || (PartHdr->SizeOfPartitionEntry < sizeof (EFI_PARTITION_ENTRY)) ) { DEBUG ((DEBUG_INFO, "Invalid efi partition table header\n")); FreePool (PartHdr); return FALSE; } // // Ensure the NumberOfPartitionEntries * SizeOfPartitionEntry doesn't overflow. // if (PartHdr->NumberOfPartitionEntries > DivU64x32 (MAX_UINTN, PartHdr->SizeOfPartitionEntry)) { FreePool (PartHdr); return FALSE; } CopyMem (PartHeader, PartHdr, sizeof (EFI_PARTITION_TABLE_HEADER)); if (!PartitionCheckGptEntryArrayCRC (BlockIo, DiskIo, PartHeader)) { FreePool (PartHdr); return FALSE; } DEBUG ((DEBUG_INFO, " Valid efi partition table header\n")); FreePool (PartHdr); return TRUE; } /** Check if the CRC field in the Partition table header is valid for Partition entry array. @param[in] BlockIo Parent BlockIo interface @param[in] DiskIo Disk Io Protocol. @param[in] PartHeader Partition table header structure @retval TRUE the CRC is valid @retval FALSE the CRC is invalid **/ BOOLEAN PartitionCheckGptEntryArrayCRC ( IN EFI_BLOCK_IO_PROTOCOL *BlockIo, IN EFI_DISK_IO_PROTOCOL *DiskIo, IN EFI_PARTITION_TABLE_HEADER *PartHeader ) { EFI_STATUS Status; UINT8 *Ptr; UINT32 Crc; UINTN Size; // // Read the EFI Partition Entries // Ptr = AllocatePool (PartHeader->NumberOfPartitionEntries * PartHeader->SizeOfPartitionEntry); if (Ptr == NULL) { DEBUG ((DEBUG_ERROR, " Allocate pool error\n")); return FALSE; } Status = DiskIo->ReadDisk ( DiskIo, BlockIo->Media->MediaId, MultU64x32 (PartHeader->PartitionEntryLBA, BlockIo->Media->BlockSize), PartHeader->NumberOfPartitionEntries * PartHeader->SizeOfPartitionEntry, Ptr ); if (EFI_ERROR (Status)) { FreePool (Ptr); return FALSE; } Size = PartHeader->NumberOfPartitionEntries * PartHeader->SizeOfPartitionEntry; Status = gBS->CalculateCrc32 (Ptr, Size, &Crc); if (EFI_ERROR (Status)) { DEBUG ((DEBUG_ERROR, "CheckPEntryArrayCRC: Crc calculation failed\n")); FreePool (Ptr); return FALSE; } FreePool (Ptr); return (BOOLEAN)(PartHeader->PartitionEntryArrayCRC32 == Crc); } /** Restore Partition Table to its alternate place (Primary -> Backup or Backup -> Primary). @param[in] BlockIo Parent BlockIo interface. @param[in] DiskIo Disk Io Protocol. @param[in] PartHeader Partition table header structure. @retval TRUE Restoring succeeds @retval FALSE Restoring failed **/ BOOLEAN PartitionRestoreGptTable ( IN EFI_BLOCK_IO_PROTOCOL *BlockIo, IN EFI_DISK_IO_PROTOCOL *DiskIo, IN EFI_PARTITION_TABLE_HEADER *PartHeader ) { EFI_STATUS Status; UINTN BlockSize; EFI_PARTITION_TABLE_HEADER *PartHdr; EFI_LBA PEntryLBA; UINT8 *Ptr; UINT32 MediaId; PartHdr = NULL; Ptr = NULL; BlockSize = BlockIo->Media->BlockSize; MediaId = BlockIo->Media->MediaId; PartHdr = AllocateZeroPool (BlockSize); if (PartHdr == NULL) { DEBUG ((DEBUG_ERROR, "Allocate pool error\n")); return FALSE; } PEntryLBA = (PartHeader->MyLBA == PRIMARY_PART_HEADER_LBA) ? \ (PartHeader->LastUsableLBA + 1) : \ (PRIMARY_PART_HEADER_LBA + 1); CopyMem (PartHdr, PartHeader, sizeof (EFI_PARTITION_TABLE_HEADER)); PartHdr->MyLBA = PartHeader->AlternateLBA; PartHdr->AlternateLBA = PartHeader->MyLBA; PartHdr->PartitionEntryLBA = PEntryLBA; PartitionSetCrc ((EFI_TABLE_HEADER *)PartHdr); Status = DiskIo->WriteDisk ( DiskIo, MediaId, MultU64x32 (PartHdr->MyLBA, (UINT32)BlockSize), BlockSize, PartHdr ); if (EFI_ERROR (Status)) { goto Done; } Ptr = AllocatePool (PartHeader->NumberOfPartitionEntries * PartHeader->SizeOfPartitionEntry); if (Ptr == NULL) { DEBUG ((DEBUG_ERROR, " Allocate pool error\n")); Status = EFI_OUT_OF_RESOURCES; goto Done; } Status = DiskIo->ReadDisk ( DiskIo, MediaId, MultU64x32 (PartHeader->PartitionEntryLBA, (UINT32)BlockSize), PartHeader->NumberOfPartitionEntries * PartHeader->SizeOfPartitionEntry, Ptr ); if (EFI_ERROR (Status)) { goto Done; } Status = DiskIo->WriteDisk ( DiskIo, MediaId, MultU64x32 (PEntryLBA, (UINT32)BlockSize), PartHeader->NumberOfPartitionEntries * PartHeader->SizeOfPartitionEntry, Ptr ); Done: FreePool (PartHdr); if (Ptr != NULL) { FreePool (Ptr); } if (EFI_ERROR (Status)) { return FALSE; } return TRUE; } /** This routine will check GPT partition entry and return entry status. Caution: This function may receive untrusted input. The GPT partition entry is external input, so this routine will do basic validation for GPT partition entry and report status. @param[in] PartHeader Partition table header structure @param[in] PartEntry The partition entry array @param[out] PEntryStatus the partition entry status array recording the status of each partition **/ VOID PartitionCheckGptEntry ( IN EFI_PARTITION_TABLE_HEADER *PartHeader, IN EFI_PARTITION_ENTRY *PartEntry, OUT EFI_PARTITION_ENTRY_STATUS *PEntryStatus ) { EFI_LBA StartingLBA; EFI_LBA EndingLBA; EFI_PARTITION_ENTRY *Entry; UINTN Index1; UINTN Index2; DEBUG ((DEBUG_INFO, " start check partition entries\n")); for (Index1 = 0; Index1 < PartHeader->NumberOfPartitionEntries; Index1++) { Entry = (EFI_PARTITION_ENTRY *)((UINT8 *)PartEntry + Index1 * PartHeader->SizeOfPartitionEntry); if (CompareGuid (&Entry->PartitionTypeGUID, &gEfiPartTypeUnusedGuid)) { continue; } StartingLBA = Entry->StartingLBA; EndingLBA = Entry->EndingLBA; if ((StartingLBA > EndingLBA) || (StartingLBA < PartHeader->FirstUsableLBA) || (StartingLBA > PartHeader->LastUsableLBA) || (EndingLBA < PartHeader->FirstUsableLBA) || (EndingLBA > PartHeader->LastUsableLBA) ) { PEntryStatus[Index1].OutOfRange = TRUE; continue; } if ((Entry->Attributes & BIT1) != 0) { // // If Bit 1 is set, this indicate that this is an OS specific GUID partition. // PEntryStatus[Index1].OsSpecific = TRUE; } for (Index2 = Index1 + 1; Index2 < PartHeader->NumberOfPartitionEntries; Index2++) { Entry = (EFI_PARTITION_ENTRY *)((UINT8 *)PartEntry + Index2 * PartHeader->SizeOfPartitionEntry); if (CompareGuid (&Entry->PartitionTypeGUID, &gEfiPartTypeUnusedGuid)) { continue; } if ((Entry->EndingLBA >= StartingLBA) && (Entry->StartingLBA <= EndingLBA)) { // // This region overlaps with the Index1'th region // PEntryStatus[Index1].Overlap = TRUE; PEntryStatus[Index2].Overlap = TRUE; continue; } } } DEBUG ((DEBUG_INFO, " End check partition entries\n")); } /** Updates the CRC32 value in the table header. @param Hdr Table to update **/ VOID PartitionSetCrc ( IN OUT EFI_TABLE_HEADER *Hdr ) { PartitionSetCrcAltSize (Hdr->HeaderSize, Hdr); } /** Updates the CRC32 value in the table header. @param Size The size of the table @param Hdr Table to update **/ VOID PartitionSetCrcAltSize ( IN UINTN Size, IN OUT EFI_TABLE_HEADER *Hdr ) { UINT32 Crc; Hdr->CRC32 = 0; gBS->CalculateCrc32 ((UINT8 *)Hdr, Size, &Crc); Hdr->CRC32 = Crc; } /** Checks the CRC32 value in the table header. @param MaxSize Max Size limit @param Hdr Table to check @return TRUE CRC Valid @return FALSE CRC Invalid **/ BOOLEAN PartitionCheckCrc ( IN UINTN MaxSize, IN OUT EFI_TABLE_HEADER *Hdr ) { return PartitionCheckCrcAltSize (MaxSize, Hdr->HeaderSize, Hdr); } /** Checks the CRC32 value in the table header. @param MaxSize Max Size limit @param Size The size of the table @param Hdr Table to check @return TRUE CRC Valid @return FALSE CRC Invalid **/ BOOLEAN PartitionCheckCrcAltSize ( IN UINTN MaxSize, IN UINTN Size, IN OUT EFI_TABLE_HEADER *Hdr ) { UINT32 Crc; UINT32 OrgCrc; EFI_STATUS Status; Crc = 0; if (Size == 0) { // // If header size is 0 CRC will pass so return FALSE here // return FALSE; } if ((MaxSize != 0) && (Size > MaxSize)) { DEBUG ((DEBUG_ERROR, "CheckCrc32: Size > MaxSize\n")); return FALSE; } // // clear old crc from header // OrgCrc = Hdr->CRC32; Hdr->CRC32 = 0; Status = gBS->CalculateCrc32 ((UINT8 *)Hdr, Size, &Crc); if (EFI_ERROR (Status)) { DEBUG ((DEBUG_ERROR, "CheckCrc32: Crc calculation failed\n")); return FALSE; } // // set results // Hdr->CRC32 = Crc; // // return status // DEBUG_CODE_BEGIN (); if (OrgCrc != Crc) { DEBUG ((DEBUG_ERROR, "CheckCrc32: Crc check failed\n")); } DEBUG_CODE_END (); return (BOOLEAN)(OrgCrc == Crc); }