EFI_STATUS
VerifyFfsFile (
IN EFI_FFS_FILE_HEADER *FfsHeader
)
/*++
Routine Description:
Verify the current pointer points to a FFS file header.
Arguments:
FfsHeader Pointer to an alleged FFS file.
Returns:
EFI_SUCCESS The Ffs header is valid.
EFI_NOT_FOUND This "file" is the beginning of free space.
EFI_VOLUME_CORRUPTED The Ffs header is not valid.
EFI_ABORTED The erase polarity is not known.
--*/
{
BOOLEAN ErasePolarity;
EFI_STATUS Status;
EFI_FFS_FILE_HEADER2 BlankHeader;
UINT8 Checksum;
UINT32 FileLength;
UINT8 SavedChecksum;
UINT8 SavedState;
UINT8 FileGuidString[80];
UINT32 FfsHeaderSize;
//
// Verify library has been initialized.
//
if (mFvHeader == NULL || mFvLength == 0) {
return EFI_ABORTED;
}
//
// Verify FV header
//
Status = VerifyFv (mFvHeader);
if (EFI_ERROR (Status)) {
return EFI_ABORTED;
}
//
// Get the erase polarity.
//
Status = GetErasePolarity (&ErasePolarity);
if (EFI_ERROR (Status)) {
return EFI_ABORTED;
}
FfsHeaderSize = GetFfsHeaderLength(FfsHeader);
//
// Check if we have free space
//
if (ErasePolarity) {
memset (&BlankHeader, -1, FfsHeaderSize);
} else {
memset (&BlankHeader, 0, FfsHeaderSize);
}
if (memcmp (&BlankHeader, FfsHeader, FfsHeaderSize) == 0) {
return EFI_NOT_FOUND;
}
//
// Convert the GUID to a string so we can at least report which file
// if we find an error.
//
PrintGuidToBuffer (&FfsHeader->Name, FileGuidString, sizeof (FileGuidString), TRUE);
//
// Verify file header checksum
//
SavedState = FfsHeader->State;
FfsHeader->State = 0;
SavedChecksum = FfsHeader->IntegrityCheck.Checksum.File;
FfsHeader->IntegrityCheck.Checksum.File = 0;
Checksum = CalculateSum8 ((UINT8 *) FfsHeader, FfsHeaderSize);
FfsHeader->State = SavedState;
FfsHeader->IntegrityCheck.Checksum.File = SavedChecksum;
if (Checksum != 0) {
Error (NULL, 0, 0006, "invalid FFS file header checksum", "Ffs file with Guid %s", FileGuidString);
return EFI_ABORTED;
}
//
// Verify file checksum
//
if (FfsHeader->Attributes & FFS_ATTRIB_CHECKSUM) {
//
// Verify file data checksum
//
FileLength = GetFfsFileLength (FfsHeader);
Checksum = CalculateSum8 ((UINT8 *) ((UINT8 *)FfsHeader + FfsHeaderSize), FileLength - FfsHeaderSize);
Checksum = Checksum + FfsHeader->IntegrityCheck.Checksum.File;
if (Checksum != 0) {
Error (NULL, 0, 0006, "invalid FFS file checksum", "Ffs file with Guid %s", FileGuidString);
return EFI_ABORTED;
}
} else {
//
// File does not have a checksum
// Verify contents are 0xAA as spec'd
//
if (FfsHeader->IntegrityCheck.Checksum.File != FFS_FIXED_CHECKSUM) {
Error (NULL, 0, 0006, "invalid fixed FFS file header checksum", "Ffs file with Guid %s", FileGuidString);
return EFI_ABORTED;
}
}
return EFI_SUCCESS;
}
EFI_STATUS
VerifyFfsFile (
IN EFI_FFS_FILE_HEADER *FfsHeader
)
/*++
Routine Description:
Verify the current pointer points to a FFS file header.
Arguments:
FfsHeader Pointer to an alleged FFS file.
Returns:
EFI_SUCCESS The Ffs header is valid.
EFI_NOT_FOUND This "file" is the beginning of free space.
EFI_VOLUME_CORRUPTED The Ffs header is not valid.
EFI_ABORTED The erase polarity is not known.
--*/
{
BOOLEAN ErasePolarity;
EFI_STATUS Status;
EFI_FFS_FILE_HEADER BlankHeader;
UINT8 Checksum;
UINT32 FileLength;
UINT32 OccupiedFileLength;
UINT8 SavedChecksum;
UINT8 SavedState;
UINT8 FileGuidString[80];
UINT32 TailSize;
#if (PI_SPECIFICATION_VERSION < 0x00010000)
EFI_FFS_FILE_TAIL *Tail;
#endif
//
// Verify library has been initialized.
//
if (mFvHeader == NULL || mFvLength == 0) {
return EFI_ABORTED;
}
//
// Verify FV header
//
Status = VerifyFv (mFvHeader);
if (EFI_ERROR (Status)) {
return EFI_ABORTED;
}
//
// Get the erase polarity.
//
Status = GetErasePolarity (&ErasePolarity);
if (EFI_ERROR (Status)) {
return EFI_ABORTED;
}
//
// Check if we have free space
//
if (ErasePolarity) {
memset (&BlankHeader, -1, sizeof (EFI_FFS_FILE_HEADER));
} else {
memset (&BlankHeader, 0, sizeof (EFI_FFS_FILE_HEADER));
}
if (memcmp (&BlankHeader, FfsHeader, sizeof (EFI_FFS_FILE_HEADER)) == 0) {
return EFI_NOT_FOUND;
}
//
// Convert the GUID to a string so we can at least report which file
// if we find an error.
//
PrintGuidToBuffer (&FfsHeader->Name, FileGuidString, sizeof (FileGuidString), TRUE);
if (FfsHeader->Attributes & FFS_ATTRIB_TAIL_PRESENT) {
TailSize = sizeof (EFI_FFS_FILE_TAIL);
} else {
TailSize = 0;
}
//
// Verify file header checksum
//
SavedState = FfsHeader->State;
FfsHeader->State = 0;
SavedChecksum = FfsHeader->IntegrityCheck.Checksum.File;
FfsHeader->IntegrityCheck.Checksum.File = 0;
Checksum = CalculateSum8 ((UINT8 *) FfsHeader, sizeof (EFI_FFS_FILE_HEADER));
FfsHeader->State = SavedState;
FfsHeader->IntegrityCheck.Checksum.File = SavedChecksum;
if (Checksum != 0) {
Error (NULL, 0, 0, FileGuidString, "invalid FFS file header checksum");
return EFI_ABORTED;
}
//
// Verify file checksum
//
if (FfsHeader->Attributes & FFS_ATTRIB_CHECKSUM) {
//
// Verify file data checksum
//
FileLength = GetLength (FfsHeader->Size);
OccupiedFileLength = (FileLength + 0x07) & (-1 << 3);
#if (PI_SPECIFICATION_VERSION < 0x00010000)
Checksum = CalculateSum8 ((UINT8 *) FfsHeader, FileLength - TailSize);
Checksum = (UINT8) (Checksum - FfsHeader->State);
#else
Checksum = CalculateSum8 ((UINT8 *) ((UINTN)FfsHeader + sizeof (EFI_FFS_FILE_HEADER)), FileLength - TailSize - sizeof (EFI_FFS_FILE_HEADER));
Checksum = Checksum + (UINT8)FfsHeader->IntegrityCheck.Checksum.File;
#endif
if (Checksum != 0) {
Error (NULL, 0, 0, FileGuidString, "invalid FFS file checksum");
return EFI_ABORTED;
}
} else {
//
// File does not have a checksum
// Verify contents are 0x5A(Framework) and 0xAA(PI 1.0) as spec'd
//
if (FfsHeader->IntegrityCheck.Checksum.File != FFS_FIXED_CHECKSUM) {
Error (NULL, 0, 0, FileGuidString, "invalid fixed file checksum");
return EFI_ABORTED;
}
}
#if (PI_SPECIFICATION_VERSION < 0x00010000)
//
// Check if the tail is present and verify it if it is.
//
if (FfsHeader->Attributes & FFS_ATTRIB_TAIL_PRESENT) {
//
// Verify tail is complement of integrity check field in the header.
//
Tail = (EFI_FFS_FILE_TAIL *) ((UINTN) FfsHeader + GetLength (FfsHeader->Size) - sizeof (EFI_FFS_FILE_TAIL));
if (FfsHeader->IntegrityCheck.TailReference != (EFI_FFS_FILE_TAIL)~(*Tail)) {
Error (NULL, 0, 0, FileGuidString, "invalid FFS file tail");
return EFI_ABORTED;
}
}
#endif
return EFI_SUCCESS;
}
