From 0d88d54f987fa0e464177febbc04c93257a17b40 Mon Sep 17 00:00:00 2001
From: kavsrf <kavsrf@gmail.com>
Date: Sat, 28 Jan 2017 14:12:08 +0300
Subject: full disk encryption support

---
 Library/CommonLib/CommonLib.inf |   1 +
 Library/CommonLib/GptRead.c     | 215 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 216 insertions(+)
 create mode 100644 Library/CommonLib/GptRead.c

(limited to 'Library/CommonLib')

diff --git a/Library/CommonLib/CommonLib.inf b/Library/CommonLib/CommonLib.inf
index b5758f5..dde5c61 100644
--- a/Library/CommonLib/CommonLib.inf
+++ b/Library/CommonLib/CommonLib.inf
@@ -38,6 +38,7 @@
   EfiTouch.c
   EfiBluetooth.c
   EfiTpm.c
+  GptRead.c
 
 [Sources.IA32]
   IA32/EfiCpuHalt.asm
diff --git a/Library/CommonLib/GptRead.c b/Library/CommonLib/GptRead.c
new file mode 100644
index 0000000..0eab963
--- /dev/null
+++ b/Library/CommonLib/GptRead.c
@@ -0,0 +1,215 @@
+/** @file
+GPT low level actions
+
+Copyright (c) 2016. Disk Cryptography Services for EFI (DCS), Alex Kolotnikov
+
+This program and the accompanying materials
+are licensed and made available under the terms and conditions
+of the GNU Lesser General Public License, version 3.0 (LGPL-3.0).
+
+The full text of the license may be found at
+https://opensource.org/licenses/LGPL-3.0
+**/
+
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/DevicePathLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Uefi/UefiGpt.h>
+#include <Guid/Gpt.h>
+
+#include <Library/CommonLib.h>
+
+/**
+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
+GptHeaderCheckCrcAltSize(
+	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)) {
+		return FALSE;
+	}
+	//
+	// clear old crc from header
+	//
+	OrgCrc = Hdr->CRC32;
+	Hdr->CRC32 = 0;
+
+	Status = gBS->CalculateCrc32((UINT8 *)Hdr, Size, &Crc);
+	if (EFI_ERROR(Status)) {
+		return FALSE;
+	}
+	//
+	// set results
+	//
+	Hdr->CRC32 = OrgCrc;
+
+	return (BOOLEAN)(OrgCrc == 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
+GptHeaderCheckCrc(
+	IN UINTN                 MaxSize,
+	IN OUT EFI_TABLE_HEADER  *Hdr
+	)
+{
+	return GptHeaderCheckCrcAltSize(MaxSize, Hdr->HeaderSize, Hdr);
+}
+
+EFI_STATUS
+GptCheckEntryArray(
+	IN  EFI_PARTITION_TABLE_HEADER  *PartHeader,
+	IN  EFI_PARTITION_ENTRY         *Entrys
+	)
+{
+	EFI_STATUS  Status;
+	UINT32      Crc;
+	UINTN       Size;
+
+	Size = (UINTN)PartHeader->NumberOfPartitionEntries * (UINTN)PartHeader->SizeOfPartitionEntry;
+	Status = gBS->CalculateCrc32(Entrys, Size, &Crc);
+	if (EFI_ERROR(Status)) {
+		return EFI_CRC_ERROR;
+	}
+	Status = (PartHeader->PartitionEntryArrayCRC32 == Crc) ? EFI_SUCCESS : EFI_CRC_ERROR;
+	return Status;
+}
+
+EFI_STATUS
+GptUpdateCRC(
+	IN  EFI_PARTITION_TABLE_HEADER  *PartHeader,
+	IN  EFI_PARTITION_ENTRY         *Entrys
+	)
+{
+	EFI_STATUS  Status;
+	UINT32      Crc;
+	UINTN       Size;
+
+	Size = (UINTN)PartHeader->NumberOfPartitionEntries * (UINTN)PartHeader->SizeOfPartitionEntry;
+	Status = gBS->CalculateCrc32(Entrys, Size, &Crc);
+	if (EFI_ERROR(Status)) {
+		return Status;
+	}
+	PartHeader->PartitionEntryArrayCRC32 = Crc;
+	PartHeader->Header.CRC32 = 0;
+
+	Status = gBS->CalculateCrc32((UINT8 *)PartHeader, PartHeader->Header.HeaderSize, &Crc);
+	if (EFI_ERROR(Status)) {
+		return Status;
+	}
+	PartHeader->Header.CRC32 = Crc;
+	return Status;
+}
+
+/**
+Read GPT
+Check if the CRC field in the Partition table header is valid
+for Partition entry array.
+
+@param[in]  BlockIo     Disk Io Protocol.
+@param[in]  PartHeader  Partition table header structure
+
+@retval EFI_SUCCESS     the CRC is valid
+**/
+EFI_STATUS
+GptReadEntryArray(
+	IN  EFI_BLOCK_IO_PROTOCOL*      BlockIo,
+	IN  EFI_PARTITION_TABLE_HEADER  *PartHeader,
+	OUT EFI_PARTITION_ENTRY         **Entrys
+	)
+{
+	EFI_STATUS  Status;
+	UINT8       *Ptr;
+
+	//
+	// Read the EFI Partition Entries
+	//
+	Ptr = MEM_ALLOC(PartHeader->NumberOfPartitionEntries * PartHeader->SizeOfPartitionEntry);
+	if (Ptr == NULL) {
+		return EFI_BUFFER_TOO_SMALL;
+	}
+
+	Status = BlockIo->ReadBlocks(
+		BlockIo,
+		BlockIo->Media->MediaId,
+		PartHeader->PartitionEntryLBA,
+		PartHeader->NumberOfPartitionEntries * PartHeader->SizeOfPartitionEntry,
+		Ptr
+		);
+	if (EFI_ERROR(Status)) {
+		MEM_FREE(Ptr);
+		return Status;
+	}
+
+	*Entrys = (EFI_PARTITION_ENTRY*)Ptr;
+	return GptCheckEntryArray(PartHeader, *Entrys);
+}
+
+EFI_STATUS
+GptReadHeader(
+	IN  EFI_BLOCK_IO_PROTOCOL*      BlockIo,
+	IN  EFI_LBA                     HeaderLba,
+	OUT EFI_PARTITION_TABLE_HEADER  **PartHeader
+	)
+{
+	EFI_STATUS                  res = EFI_SUCCESS;
+	UINT32                      BlockSize;
+	EFI_PARTITION_TABLE_HEADER  *PartHdr;
+	UINT32                      MediaId;
+
+	BlockSize = BlockIo->Media->BlockSize;
+	MediaId = BlockIo->Media->MediaId;
+	PartHdr = MEM_ALLOC(BlockSize);
+
+	res = BlockIo->ReadBlocks(BlockIo, MediaId, HeaderLba, BlockSize, PartHdr);
+	if (EFI_ERROR(res)) {
+		MEM_FREE(PartHdr);
+		return res;
+	}
+
+	// Check header
+	if ((PartHdr->Header.Signature != EFI_PTAB_HEADER_ID) ||
+		!GptHeaderCheckCrc(BlockSize, &PartHdr->Header) ||
+		PartHdr->MyLBA != HeaderLba ||
+		(PartHdr->SizeOfPartitionEntry < sizeof(EFI_PARTITION_ENTRY))
+		) {
+		MEM_FREE(PartHdr);
+		return EFI_CRC_ERROR;
+	}
+	*PartHeader = PartHdr;
+	return EFI_SUCCESS;
+}
-- 
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