DxeCrc32GuidedSectionExtractLib.c

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#include <PiDxe.h>
#include <Guid/Crc32GuidedSectionExtraction.h>
#include <Protocol/SecurityPolicy.h>
#include <Library/ExtractGuidedSectionLib.h>
#include <Library/DebugLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/UefiBootServicesTableLib.h>
 
typedef struct {
  EFI_GUID_DEFINED_SECTION    GuidedSectionHeader; 
  UINT32                      CRC32Checksum;       
} CRC32_SECTION_HEADER;
 
typedef struct {
  EFI_GUID_DEFINED_SECTION2    GuidedSectionHeader; 
  UINT32                       CRC32Checksum;       
} CRC32_SECTION2_HEADER;
 
EFI_STATUS
EFIAPI
Crc32GuidedSectionGetInfo (
  IN  CONST VOID  *InputSection,
  OUT UINT32      *OutputBufferSize,
  OUT UINT32      *ScratchBufferSize,
  OUT UINT16      *SectionAttribute
  )
{
  if (IS_SECTION2 (InputSection)) {
    //
    // Check whether the input guid section is recognized.
    //
    if (!CompareGuid (
           &gEfiCrc32GuidedSectionExtractionGuid,
           &(((EFI_GUID_DEFINED_SECTION2 *)InputSection)->SectionDefinitionGuid)
           ))
    {
      return EFI_INVALID_PARAMETER;
    }
 
    //
    // Retrieve the size and attribute of the input section data.
    //
    *SectionAttribute  = ((EFI_GUID_DEFINED_SECTION2 *)InputSection)->Attributes;
    *ScratchBufferSize = 0;
    *OutputBufferSize  = SECTION2_SIZE (InputSection) - ((EFI_GUID_DEFINED_SECTION2 *)InputSection)->DataOffset;
  } else {
    //
    // Check whether the input guid section is recognized.
    //
    if (!CompareGuid (
           &gEfiCrc32GuidedSectionExtractionGuid,
           &(((EFI_GUID_DEFINED_SECTION *)InputSection)->SectionDefinitionGuid)
           ))
    {
      return EFI_INVALID_PARAMETER;
    }
 
    //
    // Retrieve the size and attribute of the input section data.
    //
    *SectionAttribute  = ((EFI_GUID_DEFINED_SECTION *)InputSection)->Attributes;
    *ScratchBufferSize = 0;
    *OutputBufferSize  = SECTION_SIZE (InputSection) - ((EFI_GUID_DEFINED_SECTION *)InputSection)->DataOffset;
  }
 
  return EFI_SUCCESS;
}
 
EFI_STATUS
EFIAPI
Crc32GuidedSectionHandler (
  IN CONST  VOID    *InputSection,
  OUT       VOID    **OutputBuffer,
  IN        VOID    *ScratchBuffer         OPTIONAL,
  OUT       UINT32  *AuthenticationStatus
  )
{
  EFI_STATUS  Status;
  UINT32      SectionCrc32Checksum;
  UINT32      Crc32Checksum;
  UINT32      OutputBufferSize;
  VOID        *DummyInterface;
 
  if (IS_SECTION2 (InputSection)) {
    //
    // Check whether the input guid section is recognized.
    //
    if (!CompareGuid (
           &gEfiCrc32GuidedSectionExtractionGuid,
           &(((EFI_GUID_DEFINED_SECTION2 *)InputSection)->SectionDefinitionGuid)
           ))
    {
      return EFI_INVALID_PARAMETER;
    }
 
    //
    // Get section Crc32 checksum.
    //
    SectionCrc32Checksum = ((CRC32_SECTION2_HEADER *)InputSection)->CRC32Checksum;
    *OutputBuffer        = (UINT8 *)InputSection + ((EFI_GUID_DEFINED_SECTION2 *)InputSection)->DataOffset;
    OutputBufferSize     = SECTION2_SIZE (InputSection) - ((EFI_GUID_DEFINED_SECTION2 *)InputSection)->DataOffset;
 
    //
    // Implicitly CRC32 GUIDed section should have STATUS_VALID bit set
    //
    ASSERT (((EFI_GUID_DEFINED_SECTION2 *)InputSection)->Attributes & EFI_GUIDED_SECTION_AUTH_STATUS_VALID);
    *AuthenticationStatus = EFI_AUTH_STATUS_IMAGE_SIGNED;
  } else {
    //
    // Check whether the input guid section is recognized.
    //
    if (!CompareGuid (
           &gEfiCrc32GuidedSectionExtractionGuid,
           &(((EFI_GUID_DEFINED_SECTION *)InputSection)->SectionDefinitionGuid)
           ))
    {
      return EFI_INVALID_PARAMETER;
    }
 
    //
    // Get section Crc32 checksum.
    //
    SectionCrc32Checksum = ((CRC32_SECTION_HEADER *)InputSection)->CRC32Checksum;
    *OutputBuffer        = (UINT8 *)InputSection + ((EFI_GUID_DEFINED_SECTION *)InputSection)->DataOffset;
    OutputBufferSize     = SECTION_SIZE (InputSection) - ((EFI_GUID_DEFINED_SECTION *)InputSection)->DataOffset;
 
    //
    // Implicitly CRC32 GUIDed section should have STATUS_VALID bit set
    //
    ASSERT (((EFI_GUID_DEFINED_SECTION *)InputSection)->Attributes & EFI_GUIDED_SECTION_AUTH_STATUS_VALID);
    *AuthenticationStatus = EFI_AUTH_STATUS_IMAGE_SIGNED;
  }
 
  //
  // Init Checksum value to Zero.
  //
  Crc32Checksum = 0;
 
  //
  // Check whether there exists EFI_SECURITY_POLICY_PROTOCOL_GUID.
  //
  Status = gBS->LocateProtocol (&gEfiSecurityPolicyProtocolGuid, NULL, &DummyInterface);
  if (!EFI_ERROR (Status)) {
    //
    // If SecurityPolicy Protocol exist, AUTH platform override bit is set.
    //
    *AuthenticationStatus |= EFI_AUTH_STATUS_PLATFORM_OVERRIDE;
  } else {
    //
    // Calculate CRC32 Checksum of Image
    //
    Status = gBS->CalculateCrc32 (*OutputBuffer, OutputBufferSize, &Crc32Checksum);
    if (Status == EFI_SUCCESS) {
      if (Crc32Checksum != SectionCrc32Checksum) {
        //
        // If Crc32 checksum is not matched, AUTH tested failed bit is set.
        //
        *AuthenticationStatus |= EFI_AUTH_STATUS_TEST_FAILED;
      }
    } else {
      //
      // If Crc32 checksum is not calculated, AUTH not tested bit is set.
      //
      *AuthenticationStatus |= EFI_AUTH_STATUS_NOT_TESTED;
    }
  }
 
  return EFI_SUCCESS;
}
 
EFI_STATUS
EFIAPI
DxeCrc32GuidedSectionExtractLibConstructor (
  IN EFI_HANDLE        ImageHandle,
  IN EFI_SYSTEM_TABLE  *SystemTable
  )
{
  return ExtractGuidedSectionRegisterHandlers (
           &gEfiCrc32GuidedSectionExtractionGuid,
           Crc32GuidedSectionGetInfo,
           Crc32GuidedSectionHandler
           );
}