KLVEObject Class Reference

KLVEObject class. More...

#include <crypto.h>

Inheritance diagram for KLVEObject:

List of all members.

Public Member Functions
void	SetEncrypt (EncryptPtr NewWrapper)
	Set the encryption wrapper.
void	SetDecrypt (DecryptPtr NewWrapper)
	Set the decryption wrapper.
void	SetWriteHasher (HashPtr &Hasher)
	Set a hasher to use when writing.
void	SetReadHasher (HashPtr &Hasher)
	Set a hasher to use when reading.
virtual bool	SetEncryptIV (size_t IVSize, const UInt8 *IV, bool Force=false)
	Set an encryption Initialization Vector.
virtual bool	SetDecryptIV (size_t IVSize, const UInt8 *IV, bool Force=false)
	Set a decryption Initialization Vector.
virtual DataChunkPtr	GetEncryptIV (void)
	Get the Initialization Vector that will be used for the next encryption.
virtual DataChunkPtr	GetDecryptIV (void)
	Get the Initialization Vector that will be used for the next decryption.
void	SetPlaintextOffset (Length Offset)
	Set the plaintext offset to use when encrypting.
Length	GetPlaintextOffset (void)
	Get the plaintext offset of the encrypted data.
	KLVEObject (ULPtr ObjectUL)
	Construct a new KLVEObject.
	KLVEObject (KLVObjectPtr &Object)
	Construct a KLVEObject linked to an encrypted KLVObject.
virtual void	Init (void)
	Initialise the KLVEObject specifics after basic construction (and KLVObject::Init()).
virtual	~KLVEObject ()
virtual ULPtr	GetUL (void)
	Get the object's UL.
virtual void	SetUL (ULPtr NewUL)
	Set the object's UL.
virtual Int32	GetKLSize (void)
	Get the size of the key and length (not of the value).
virtual GCElementKind	GetGCElementKind (void)
	Get a GCElementKind structure.
virtual UInt32	GetGCTrackNumber (void)
	Get the track number of this KLVObject (if it is a GC KLV, else 0).
virtual std::string	GetSource (void)
	Get text that describes where this item came from.
virtual Int32	ReadKL (void)
	Read the key and length for this KLVObject from the current source.
virtual size_t	ReadData (size_t Size=static_cast< size_t >(-1))
	Read data from the start of the KLV value into the current DataChunk.
virtual size_t	ReadDataFrom (Position Offset, size_t Size=static_cast< size_t >(-1))
	Read data from a specified position in the KLV value field into the DataChunk.
virtual Int32	WriteKL (Int32 LenSize=0)
	Write the key and length of the current DataChunk to the destination file.
virtual size_t	WriteData (size_t Size=static_cast< size_t >(-1))
	Write (some of) the current data to the same location in the destination file.
virtual size_t	WriteDataFrom (Position Start, size_t Size=static_cast< size_t >(-1))
	Write (some of) the current data to the same location in the destination file.
virtual size_t	WriteDataTo (Position Offset, size_t Size=static_cast< size_t >(-1))
	Write (some of) the current data to a different location in the destination file.
virtual size_t	WriteDataFromTo (Position Offset, Position Start, size_t Size=static_cast< size_t >(-1))
	Write (some of) the current data to the same location in the destination file.
virtual size_t	WriteDataTo (const UInt8 *Buffer, Position Offset, size_t Size)
	Write data from a given buffer to a given location in the destination file.
virtual Length	GetLength (void)
	Get the length of the value field.
virtual void	SetLength (Length NewLength)
	Set the length of the value field.
void	SetContextID (UUIDPtr &Context)
	Set the context ID.
UUIDPtr &	GetContextID (void)
	Get the context ID.
Protected Types
enum	{ EncryptionOverhead = 32 }
	The AS-DCP encryption system adds 32 bytes to the start of the encrypted data. More...
enum	{ EncryptionGranularity = 16 }
	The AS-DCP encryption system forces all encrypted data to be in multiples of 16 bytes. More...
Protected Member Functions
bool	LoadData (void)
	Load the AS-DCP set data.
bool	ReadFooter (void)
	Read the AS-DCP footer (if any).
UInt32	CalcFooterLength (void)
	Calculate the size of the AS-DCP footer for this KLVEObject.
bool	WriteFooter (void)
	Write the AS-DCP footer (if fequired).
size_t	ReadCryptoDataFrom (Position Offset, size_t Size=static_cast< size_t >(-1))
	Read data from a specified position in the encrypted portion of the KLV value field into the DataChunk.
size_t	ReadChunkedCryptoDataFrom (Position Offset, size_t Size)
	Read an integer set of chunks from a specified position in the encrypted portion of the KLV value field into the DataChunk.
size_t	WriteCryptoDataTo (const UInt8 *Buffer, Position Offset, size_t Size)
	Write encrypted data from a given buffer to a given location in the destination file.
Protected Attributes
EncryptPtr	Encrypt
	Pointer to the encryption wrapper.
DecryptPtr	Decrypt
	Pointer to the decryption wrapper.
HashPtr	WriteHasher
	Pointer to a hasher being used for hashing data being written.
HashPtr	ReadHasher
	Pointer to a hasher being used for hashing data being read.
bool	DataLoaded
	True once the AS-DCP header data has been read.
UUIDPtr	ContextID
	The context ID used to link to encryption metadata.
Length	PlaintextOffset
	Number of unencrypted bytes at start of source data.
ULPtr	SourceKey
	Key for the plaintext KLV.
Length	EncryptedLength
	Length of the encrypted KLV Value.
int	SourceLengthFormat
	Number of bytes used to encode SourceLength in the KLVE (allows us to faithfully recreate if required).
UInt8	IV [16]
	The Initialization Vector for this KLVE.
UInt8	Check [16]
	The check value for this KLVE.
UUIDPtr	TrackFileID
	The optional TrackFile ID or NULL.
UInt64	SequenceNumber
	The optional Sequence Number of this KLVE within the TrackFile.
bool	HasSequenceNumber
	True if SequenceNumber has been set or read.
DataChunkPtr	MIC
	The optional MIC (if loaded or computed when reading or computed when writing) else NULL.
size_t	DataOffset
	Offset of the start of the encrypted value from the start of the KLV value.
DataChunkPtr	EncryptionIV
	Encryption IV if one has been specified.
Position	CurrentReadOffset
	The location of the next read (if reading in sequence) - used to detect random access attempts.
Position	CurrentWriteOffset
	The location of the next write (if writing in sequence) - used to detect random access attempts.
int	PreDecrypted
	Number of extra bytes decrypted last time that are buffer for the next read.
UInt8	PreDecryptBuffer [EncryptionGranularity]
	Left over bytes from decrypting the last chunk - these will be returned first with the next read call.
int	AwaitingEncryption
	Number of left over bytes not encrypted last time that are buffer for the next write.
UInt8	AwaitingEncryptionBuffer [EncryptionGranularity]
	Left over bytes from encrypting the last chunk - these will be written first at the next write call.
UInt32	FooterLength
	The size of the AS-DCP footer to be written for this KLVEObject.

---

Detailed Description

KLVEObject class.

This class gives access to single AS-DCP encrypted KLV items within an MXF file with KLVObject interfacing

---

Member Enumeration Documentation

anonymous enum [protected]

The AS-DCP encryption system adds 32 bytes to the start of the encrypted data.

Enumerator:

EncryptionOverhead

anonymous enum [protected]

The AS-DCP encryption system forces all encrypted data to be in multiples of 16 bytes.

Enumerator:

EncryptionGranularity

---

Constructor & Destructor Documentation

KLVEObject

(

ULPtr

ObjectUL

)

Construct a new KLVEObject.

KLVEObject

(

KLVObjectPtr &

Object

)

Construct a KLVEObject linked to an encrypted KLVObject.

virtual ~KLVEObject

(

)

[inline, virtual]

---

Member Function Documentation

void SetEncrypt

(

EncryptPtr

NewWrapper

)

[inline]

Set the encryption wrapper.

void SetDecrypt

(

DecryptPtr

NewWrapper

)

[inline]

Set the decryption wrapper.

void SetWriteHasher

(

HashPtr &

Hasher

)

[inline]

Set a hasher to use when writing.

The hasher must be initialized and ready to start hashing

void SetReadHasher

(

HashPtr &

Hasher

)

[inline]

Set a hasher to use when reading.

The hasher must be initialized and ready to start hashing

virtual bool SetEncryptIV	(	size_t	IVSize,
		const UInt8 *	IV,
		bool	Force = false
	)			[inline, virtual]

Set an encryption Initialization Vector.

Returns:

False if Initialization Vector is rejected

bool SetDecryptIV	(	size_t	IVSize,
		const UInt8 *	IV,
		bool	Force = false
	)			[virtual]

Set a decryption Initialization Vector.

Returns:

False if Initialization Vector is rejected

DataChunkPtr GetEncryptIV

(

void

)

[virtual]

Get the Initialization Vector that will be used for the next encryption.

DataChunkPtr GetDecryptIV

(

void

)

[virtual]

Get the Initialization Vector that will be used for the next decryption.

void SetPlaintextOffset

(

Length

Offset

)

[inline]

Set the plaintext offset to use when encrypting.

Length GetPlaintextOffset

(

void

)

[inline]

Get the plaintext offset of the encrypted data.

void Init

(

void

)

[virtual]

Initialise the KLVEObject specifics after basic construction (and KLVObject::Init()).

Reimplemented from KLVObject.

virtual ULPtr GetUL

(

void

)

[inline, virtual]

Get the object's UL.

Reimplemented from KLVObject.

virtual void SetUL

(

ULPtr

NewUL

)

[inline, virtual]

Set the object's UL.

Reimplemented from KLVObject.

Int32 GetKLSize

(

void

)

[virtual]

Get the size of the key and length (not of the value).

Note:

For an KLVEObject this actually returns the sum of the size of all parts of the KLV other than the decrypted value - in other words total KLVE length - Source Length

Reimplemented from KLVObject.

GCElementKind GetGCElementKind

(

void

)

[virtual]

Get a GCElementKind structure.

Reimplemented from KLVObject.

UInt32 GetGCTrackNumber

(

void

)

[virtual]

Get the track number of this KLVObject (if it is a GC KLV, else 0).

Reimplemented from KLVObject.

std::string GetSource

(

void

)

[virtual]

Get text that describes where this item came from.

Reimplemented from KLVObject.

Int32 ReadKL

(

void

)

[virtual]

Read the key and length for this KLVObject from the current source.

Returns:

The number of bytes read (i.e. KLSize)

Reimplemented from KLVObject.

virtual size_t ReadData

(

size_t

Size = static_cast<size_t>(-1)

)

[inline, virtual]

Read data from the start of the KLV value into the current DataChunk.

Parameters:

Size

Number of bytes to read, if -1 all available bytes will be read (which could be billions!)

Returns:

The number of bytes read

Reimplemented from KLVObject.

size_t ReadDataFrom	(	Position	Offset,
		size_t	Size = static_cast< size_t >(-1)
	)			[virtual]

Read data from a specified position in the KLV value field into the DataChunk.

Parameters:

	Offset	Offset from the start of the KLV value from which to start reading
	Size	Number of bytes to read, if -1 all available bytes will be read (which could be billions!)

Returns:

The number of bytes read

Reimplemented from KLVObject.

Int32 WriteKL

(

Int32

LenSize = 0

)

[virtual]

Write the key and length of the current DataChunk to the destination file.

The key and length will be written to the source file as set by SetSource. If LenSize is zero the length will be formatted to match KLSize (if possible!)

Note:

If the length will not fit in KLSize then KLSize will be updated

Write Out the Header

Reimplemented from KLVObject.

virtual size_t WriteData

(

size_t

Size = static_cast<size_t>(-1)

)

[inline, virtual]

Write (some of) the current data to the same location in the destination file.

Parameters:

Size

The number of bytes to write, if -1 all available bytes will be written

Returns:

The number of bytes written

Reimplemented from KLVObject.

virtual size_t WriteDataFrom	(	Position	Start,
		size_t	Size = static_cast<size_t>(-1)
	)			[inline, virtual]

Write (some of) the current data to the same location in the destination file.

Parameters:

	Start	The offset within the current DataChunk of the first byte to write
	Size	The number of bytes to write, if -1 all available bytes will be written

Returns:

The number of bytes written

Reimplemented from KLVObject.

virtual size_t WriteDataTo	(	Position	Offset,
		size_t	Size = static_cast<size_t>(-1)
	)			[inline, virtual]

Write (some of) the current data to a different location in the destination file.

Parameters:

	Offset	The offset within the KLV value field of the first byte to write
	Size	The number of bytes to write, if -1 all available bytes will be written

Returns:

The number of bytes written

Reimplemented from KLVObject.

virtual size_t WriteDataFromTo	(	Position	Offset,
		Position	Start,
		size_t	Size = static_cast<size_t>(-1)
	)			[inline, virtual]

Write (some of) the current data to the same location in the destination file.

Parameters:

	Offset	The offset within the KLV value field of the first byte to write
	Start	The offset within the current DataChunk of the first byte to write
	Size	The number of bytes to write, if -1 all available bytes will be written

Returns:

The number of bytes written

Reimplemented from KLVObject.

size_t WriteDataTo	(	const UInt8 *	Buffer,
		Position	Offset,
		size_t	Size
	)			[virtual]

Write data from a given buffer to a given location in the destination file.

Parameters:

	Buffer	Pointer to data to be written
	Offset	The offset within the KLV value field of the first byte to write
	Size	The number of bytes to write

Returns:

The number of bytes written

Note:

As there may be a need for the implementation to know where within the value field this data lives, there is no WriteData(Buffer, Size) function.

Reimplemented from KLVObject.

virtual Length GetLength

(

void

)

[inline, virtual]

Get the length of the value field.

Reimplemented from KLVObject.

virtual void SetLength

(

Length

NewLength

)

[inline, virtual]

Set the length of the value field.

Reimplemented from KLVObject.

void SetContextID

(

UUIDPtr &

Context

)

[inline]

Set the context ID.

UUIDPtr& GetContextID

(

void

)

[inline]

Get the context ID.

bool LoadData

(

void

)

[protected]

Load the AS-DCP set data.

Sets DataLoaded on success

Returns:

true if all loaded OK, false on error

bool ReadFooter

(

void

)

[protected]

Read the AS-DCP footer (if any).

Returns:

false on error, else true

UInt32 CalcFooterLength

(

void

)

[protected]

Calculate the size of the AS-DCP footer for this KLVEObject.

The size it returned and also written to property FooterLength

bool WriteFooter

(

void

)

[protected]

Write the AS-DCP footer (if fequired).

Returns:

false on error, else true

size_t ReadCryptoDataFrom	(	Position	Offset,
		size_t	Size = static_cast< size_t >(-1)
	)			[protected]

Read data from a specified position in the encrypted portion of the KLV value field into the DataChunk.

Parameters:

	Offset	Offset from the start of the KLV value from which to start reading
	Size	Number of bytes to read, if -1 all available bytes will be read (which could be billions!)

Returns:

The number of bytes read The IV must have already been set. Only encrypted parts of the value may be read using this function (i.e. Offset >= PlaintextOffset)

size_t ReadChunkedCryptoDataFrom	(	Position	Offset,
		size_t	Size
	)			[protected]

Read an integer set of chunks from a specified position in the encrypted portion of the KLV value field into the DataChunk.

Parameters:

	Offset	Offset from the start of the KLV value from which to start reading
	Size	Number of bytes to read, if -1 all available bytes will be read (which could be billions!)

Returns:

The number of bytes read The IV must have already been set, Size must be a multiple of 16 as must (Offset - PlaintextOffset). Only encrypted parts of the value may be read using this function (i.e. Offset >= PlaintextOffset)

size_t WriteCryptoDataTo	(	const UInt8 *	Buffer,
		Position	Offset,
		size_t	Size
	)			[protected]

Write encrypted data from a given buffer to a given location in the destination file.

Parameters:

	Buffer	Pointer to data to be written
	Offset	The offset within the KLV value field of the first byte to write
	Size	The number of bytes to write

Returns:

Size if all OK, else != Size. This may not equal the actual number of bytes written. The IV must have already been set. Only encrypted parts of the value may be written using this function (i.e. Offset >= PlaintextOffset)

---

Member Data Documentation

EncryptPtr Encrypt [protected]

Pointer to the encryption wrapper.

DecryptPtr Decrypt [protected]

Pointer to the decryption wrapper.

HashPtr WriteHasher [protected]

Pointer to a hasher being used for hashing data being written.

HashPtr ReadHasher [protected]

Pointer to a hasher being used for hashing data being read.

bool DataLoaded [protected]

True once the AS-DCP header data has been read.

UUIDPtr ContextID [protected]

The context ID used to link to encryption metadata.

Length PlaintextOffset [protected]

Number of unencrypted bytes at start of source data.

DRAGONS: ValueLength is a standard MXF length (signed 64-bit), however the AS-DCP spec uses an unsigned 64-bit for PlaintextOffset. We use a Length for PlaintextOffset to keep comparison signs the same

ULPtr SourceKey [protected]

Key for the plaintext KLV.

Length EncryptedLength [protected]

Length of the encrypted KLV Value.

int SourceLengthFormat [protected]

Number of bytes used to encode SourceLength in the KLVE (allows us to faithfully recreate if required).

UInt8 IV[16] [protected]

The Initialization Vector for this KLVE.

UInt8 Check[16] [protected]

The check value for this KLVE.

UUIDPtr TrackFileID [protected]

The optional TrackFile ID or NULL.

UInt64 SequenceNumber [protected]

The optional Sequence Number of this KLVE within the TrackFile.

bool HasSequenceNumber [protected]

True if SequenceNumber has been set or read.

DataChunkPtr MIC [protected]

The optional MIC (if loaded or computed when reading or computed when writing) else NULL.

size_t DataOffset [protected]

Offset of the start of the encrypted value from the start of the KLV value.

DataChunkPtr EncryptionIV [protected]

Encryption IV if one has been specified.

Position CurrentReadOffset [protected]

The location of the next read (if reading in sequence) - used to detect random access attempts.

Position CurrentWriteOffset [protected]

The location of the next write (if writing in sequence) - used to detect random access attempts.

int PreDecrypted [protected]

Number of extra bytes decrypted last time that are buffer for the next read.

UInt8 PreDecryptBuffer[EncryptionGranularity] [protected]

Left over bytes from decrypting the last chunk - these will be returned first with the next read call.

int AwaitingEncryption [protected]

Number of left over bytes not encrypted last time that are buffer for the next write.

UInt8 AwaitingEncryptionBuffer[EncryptionGranularity] [protected]

Left over bytes from encrypting the last chunk - these will be written first at the next write call.

UInt32 FooterLength [protected]

The size of the AS-DCP footer to be written for this KLVEObject.

---

The documentation for this class was generated from the following files:

• crypto.h
• crypto.cpp

---