PCypher Class Reference

#include <cypher.h>

Inheritance diagram for PCypher:

List of all members.

Public Types
enum	BlockChainMode {   ElectronicCodebook, ECB = ElectronicCodebook, CypherBlockChaining, CBC = CypherBlockChaining,   OutputFeedback, OFB = OutputFeedback, CypherFeedback, CFB = CypherFeedback,   NumBlockChainModes }
	Mechanism by which sequential blocks are linked. More...
Public Member Functions
PString	Encode (const PString &str)
PString	Encode (const PBYTEArray &clear)
PString	Encode (const void *data, PINDEX length)
void	Encode (const PBYTEArray &clear, PBYTEArray &coded)
void	Encode (const void *data, PINDEX length, PBYTEArray &coded)
PString	Decode (const PString &cypher)
PBoolean	Decode (const PString &cypher, PString &clear)
PBoolean	Decode (const PString &cypher, PBYTEArray &clear)
PINDEX	Decode (const PString &cypher, void *data, PINDEX length)
PINDEX	Decode (const PBYTEArray &coded, void *data, PINDEX length)
PBoolean	Decode (const PBYTEArray &coded, PBYTEArray &clear)
Protected Member Functions
	PCypher (PINDEX blockSize, BlockChainMode chainMode)
	PCypher (const void *keyData, PINDEX keyLength, PINDEX blockSize, BlockChainMode chainMode)
virtual void	Initialise (PBoolean encoding)=0
virtual void	EncodeBlock (const void *in, void *out)=0
virtual void	DecodeBlock (const void *in, void *out)=0
Protected Attributes
PBYTEArray	key
	Key for the encryption/decryption.
PINDEX	blockSize
	Size of each encryption block in bytes.
BlockChainMode	chainMode
	Mode for sequential encryption each block.

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Detailed Description

This abstract class defines an encryption/decryption algortihm. A specific algorithm is implemented in a descendent class.

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Member Enumeration Documentation

enum PCypher::BlockChainMode

Mechanism by which sequential blocks are linked.

Enumerator:

ElectronicCodebook
ECB
CypherBlockChaining
CBC
OutputFeedback
OFB
CypherFeedback
CFB
NumBlockChainModes

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Constructor & Destructor Documentation

PCypher::PCypher	(	PINDEX	blockSize,
		BlockChainMode	chainMode
	)			[protected]

Create a new encryption object instance.

Parameters:

blockSize	Size of encryption blocks (in bits)
chainMode	Block chain mode

PCypher::PCypher	(	const void *	keyData,
		PINDEX	keyLength,
		PINDEX	blockSize,
		BlockChainMode	chainMode
	)			[protected]

Parameters:

keyData	Key for the encryption/decryption algorithm.
keyLength	Length of the key.
blockSize	Size of encryption blocks (in bits)
chainMode	Block chain mode

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Member Function Documentation

PString PCypher::Encode

(

const PString &

str

)

Encode the data.

Parameters:

str	Clear text string to be encoded.

PString PCypher::Encode

(

const PBYTEArray &

clear

)

Encode the data.

Parameters:

clear

Clear text binary data to be encoded.

PString PCypher::Encode	(	const void *	data,
		PINDEX	length
	)

Encode the data.

Parameters:

data	Clear text binary data to be encoded.
length	Number of bytes of data to be encoded.

void PCypher::Encode	(	const PBYTEArray &	clear,
		PBYTEArray &	coded
	)

Encode the data.

Parameters:

clear	Clear text binary data to be encoded.
coded	Encoded data.

void PCypher::Encode	(	const void *	data,
		PINDEX	length,
		PBYTEArray &	coded
	)

Encode the data. The data is encoded using the algorithm embodied by the descendent class and the key specifed in the construction of the objects instance.

The first form takes a string and returns an encoded string. The second form takes arbitrary binary data bytes and returns an encoded string. In both cases the encoded string is always 7 bit printable ASCII suitable for use in mail systems etc.

The final form takes and arbitrary block of bytes and encodes them into another block of binary data.

Returns:

encoded string.

PString PCypher::Decode

(

const PString &

cypher

)

Decode the data.

Parameters:

cypher

Base64 Cypher text string to be decoded.

PBoolean PCypher::Decode	(	const PString &	cypher,
		PString &	clear
	)

Decode the data.

Parameters:

cypher	Base64 Cypher text string to be decoded.
clear	Clear text string decoded.

PBoolean PCypher::Decode	(	const PString &	cypher,
		PBYTEArray &	clear
	)

Decode the data.

Parameters:

cypher	Base64 Cypher text string to be decoded.
clear	Clear text binary data decoded.

PINDEX PCypher::Decode	(	const PString &	cypher,
		void *	data,
		PINDEX	length
	)

Decode the data.

Parameters:

cypher	Base64 Cypher text string to be decoded.
data	Clear text binary data decoded.
length	Maximum number of bytes of data decoded.

PINDEX PCypher::Decode	(	const PBYTEArray &	coded,
		void *	data,
		PINDEX	length
	)

Decode the data.

Parameters:

coded	Encoded data (cyphertext).
data	Clear text binary data decoded.
length	Maximum number of bytes of data decoded.

PBoolean PCypher::Decode	(	const PBYTEArray &	coded,
		PBYTEArray &	clear
	)

Decode the data. Decode the data using the algorithm embodied by the descendent class and the key specifed in the construction of the objects instance.

The first form takes a string and returns a decoded string. The second form takes an encoded string and returns arbitrary binary data bytes. In both cases the encoded string is always 7 bit printable ASCII suitable for use in mail systems etc.

The final form takes and arbitrary block of bytes and decodes them into another block of binary data.

Returns:

decoded string.

Parameters:

coded	Encoded data (cyphertext).
clear	Clear text binary data decoded.

virtual void PCypher::Initialise

(

PBoolean

encoding

)

[protected, pure virtual]

Initialise the encoding/decoding sequence.

Parameters:

encoding

Flag for encoding/decoding sequence about to start.

Implemented in PTEACypher.

virtual void PCypher::EncodeBlock	(	const void *	in,
		void *	out
	)			[protected, pure virtual]

Encode an n bit block of memory according to the encryption algorithm.

Parameters:

in	Pointer to clear n bit block.
out	Pointer to coded n bit block.

Implemented in PTEACypher.

virtual void PCypher::DecodeBlock	(	const void *	in,
		void *	out
	)			[protected, pure virtual]

Dencode an n bit block of memory according to the encryption algorithm.

Parameters:

in	Pointer to coded n bit block.
out	Pointer to clear n bit block.

Implemented in PTEACypher.

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Member Data Documentation

PBYTEArray PCypher::key [protected]

Key for the encryption/decryption.

PINDEX PCypher::blockSize [protected]

Size of each encryption block in bytes.

BlockChainMode PCypher::chainMode [protected]

Mode for sequential encryption each block.

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

• cypher.h

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