Bouncy Castle Cryptography Library 1.80 · org.bouncycastle.crypto.modes.CFBBlockCipher

Modifier and Type	Field and Description
private int	blockSize
private int	byteCount
private byte[]	cfbOutV
private byte[]	cfbV
private BlockCipher	cipher Hides org.bouncycastle.crypto.StreamBlockCipher.cipher.
private boolean	encrypting
private byte[]	inBuf
private byte[]	IV

Access	Constructor and Description
public	CFBBlockCipher(BlockCipher the block cipher to be used as the basis of the feedback mode. cipher, int the block size in bits (note: a multiple of 8) bitBlockSize) Deprecated use the equivalent CFBBlockCipher.newInstance() static method. Basic constructor.

Method Summary

Modifier and Type	Method and Description
protected byte	calculateByte(byte in) Implements abstract org.bouncycastle.crypto.StreamBlockCipher.calculateByte.
public int	Returns: the number of bytes processed and produced. decryptBlock(byte[] the array containing the data to be decrypted. in, int offset into the in array the data starts at. inOff, byte[] the array the encrypted data will be copied into. out, int the offset into the out array the output will start at. outOff) Do the appropriate processing for CFB mode decryption.
private byte	decryptByte(byte in)
public int	Returns: the number of bytes processed and produced. encryptBlock(byte[] the array containing the data to be encrypted. in, int offset into the in array the data starts at. inOff, byte[] the array the encrypted data will be copied into. out, int the offset into the out array the output will start at. outOff) Do the appropriate processing for CFB mode encryption.
private byte	encryptByte(byte in)
public String	Returns: the name of the underlying algorithm followed by "/CFB" and the block size in bits. getAlgorithmName() Implements org.bouncycastle.crypto.BlockCipher.getAlgorithmName, org.bouncycastle.crypto.StreamCipher.getAlgorithmName. return the algorithm name and mode.
public int	Returns: the block size we are operating at (in bytes). getBlockSize() Implements org.bouncycastle.crypto.BlockCipher.getBlockSize. return the block size we are operating at.
public byte[]	Returns: current IV getCurrentIV() Return the current state of the initialisation vector.
public void	init(boolean if true the cipher is initialised for encryption, if false for decryption. encrypting, CipherParameters the key and other data required by the cipher. params) Implements org.bouncycastle.crypto.BlockCipher.init, org.bouncycastle.crypto.StreamCipher.init. Initialise the cipher and, possibly, the initialisation vector (IV).
public static CFBModeCipher	newInstance(BlockCipher the base cipher for the CFB mode. cipher, int the block size (in bits) used for the CFB mode. blockSize) Return a new CFB mode cipher based on the passed in base cipher
public int	Returns: the number of bytes processed and produced. processBlock(byte[] the array containing the input data. in, int offset into the in array the data starts at. inOff, byte[] the array the output data will be copied into. out, int the offset into the out array the output will start at. outOff) Implements org.bouncycastle.crypto.BlockCipher.processBlock. Process one block of input from the array in and write it to the out array.
public void	reset() Implements org.bouncycastle.crypto.BlockCipher.reset, org.bouncycastle.crypto.StreamCipher.reset. reset the chaining vector back to the IV and reset the underlying cipher.

Inherited from org.bouncycastle.crypto.StreamBlockCipher:: getUnderlyingCipher processBytes returnByte

blockSize	back to summary
private int blockSize

byteCount	back to summary
private int byteCount

cfbOutV	back to summary
private byte[] cfbOutV

cfbV	back to summary
private byte[] cfbV

cipher	back to summary
private BlockCipher cipher Hides org.bouncycastle.crypto.StreamBlockCipher.cipher.

encrypting	back to summary
private boolean encrypting

inBuf	back to summary
private byte[] inBuf

IV	back to summary
private byte[] IV

CFBBlockCipher	back to summary
public CFBBlockCipher(BlockCipher cipher, int bitBlockSize) Deprecated use the equivalent CFBBlockCipher.newInstance() static method. Basic constructor. Parameters cipher:BlockCipher the block cipher to be used as the basis of the feedback mode. bitBlockSize:int the block size in bits (note: a multiple of 8)

Method Detail

calculateByte	back to summary
protected byte calculateByte(byte in) throws DataLengthException, IllegalStateException Implements abstract org.bouncycastle.crypto.StreamBlockCipher.calculateByte.

decryptBlock	back to summary
public int decryptBlock(byte[] in, int inOff, byte[] out, int outOff) throws DataLengthException, IllegalStateException Do the appropriate processing for CFB mode decryption. Parameters in:byte[] the array containing the data to be decrypted. inOff:int offset into the in array the data starts at. out:byte[] the array the encrypted data will be copied into. outOff:int the offset into the out array the output will start at. Returns:int the number of bytes processed and produced. Exceptions DataLengthException: if there isn't enough data in in, or space in out. IllegalStateException: if the cipher isn't initialised.

decryptBlock

back to summary

public int decryptBlock(byte[] in, int inOff, byte[] out, int outOff) throws DataLengthException, IllegalStateException

Do the appropriate processing for CFB mode decryption.

Parameters

in:byte[]: the array containing the data to be decrypted.
inOff:int: offset into the in array the data starts at.
out:byte[]: the array the encrypted data will be copied into.
outOff:int: the offset into the out array the output will start at.

Returns:int

the number of bytes processed and produced.

Exceptions

DataLengthException:: if there isn't enough data in in, or space in out.
IllegalStateException:: if the cipher isn't initialised.

decryptByte	back to summary
private byte decryptByte(byte in)

encryptBlock	back to summary
public int encryptBlock(byte[] in, int inOff, byte[] out, int outOff) throws DataLengthException, IllegalStateException Do the appropriate processing for CFB mode encryption. Parameters in:byte[] the array containing the data to be encrypted. inOff:int offset into the in array the data starts at. out:byte[] the array the encrypted data will be copied into. outOff:int the offset into the out array the output will start at. Returns:int the number of bytes processed and produced. Exceptions DataLengthException: if there isn't enough data in in, or space in out. IllegalStateException: if the cipher isn't initialised.

encryptBlock

back to summary

public int encryptBlock(byte[] in, int inOff, byte[] out, int outOff) throws DataLengthException, IllegalStateException

Do the appropriate processing for CFB mode encryption.

Parameters

in:byte[]: the array containing the data to be encrypted.
inOff:int: offset into the in array the data starts at.
out:byte[]: the array the encrypted data will be copied into.
outOff:int: the offset into the out array the output will start at.

Returns:int

the number of bytes processed and produced.

Exceptions

DataLengthException:: if there isn't enough data in in, or space in out.
IllegalStateException:: if the cipher isn't initialised.

encryptByte	back to summary
private byte encryptByte(byte in)

getAlgorithmName	back to summary
public String getAlgorithmName() Implements org.bouncycastle.crypto.BlockCipher.getAlgorithmName, org.bouncycastle.crypto.StreamCipher.getAlgorithmName. return the algorithm name and mode. Returns:String the name of the underlying algorithm followed by "/CFB" and the block size in bits.

getAlgorithmName

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public String getAlgorithmName()

Implements org.bouncycastle.crypto.BlockCipher.getAlgorithmName, org.bouncycastle.crypto.StreamCipher.getAlgorithmName.

return the algorithm name and mode.

Returns:String: the name of the underlying algorithm followed by "/CFB" and the block size in bits.

getBlockSize	back to summary
public int getBlockSize() Implements org.bouncycastle.crypto.BlockCipher.getBlockSize. return the block size we are operating at. Returns:int the block size we are operating at (in bytes).

getBlockSize

back to summary

public int getBlockSize()

Implements org.bouncycastle.crypto.BlockCipher.getBlockSize.

return the block size we are operating at.

Returns:int: the block size we are operating at (in bytes).

getCurrentIV	back to summary
public byte[] getCurrentIV() Return the current state of the initialisation vector. Returns:byte[] current IV

getCurrentIV

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public byte[] getCurrentIV()

Return the current state of the initialisation vector.

Returns:byte[]: current IV

init	back to summary
public void init(boolean encrypting, CipherParameters params) throws IllegalArgumentException Implements org.bouncycastle.crypto.BlockCipher.init, org.bouncycastle.crypto.StreamCipher.init. Initialise the cipher and, possibly, the initialisation vector (IV). If an IV isn't passed as part of the parameter, the IV will be all zeros. An IV which is too short is handled in FIPS compliant fashion. Parameters encrypting:boolean if true the cipher is initialised for encryption, if false for decryption. params:CipherParameters the key and other data required by the cipher. Exceptions IllegalArgumentException: if the params argument is inappropriate.

init

back to summary

public void init(boolean encrypting, CipherParameters params) throws IllegalArgumentException

Implements org.bouncycastle.crypto.BlockCipher.init, org.bouncycastle.crypto.StreamCipher.init.

Initialise the cipher and, possibly, the initialisation vector (IV). If an IV isn't passed as part of the parameter, the IV will be all zeros. An IV which is too short is handled in FIPS compliant fashion.

Parameters

encrypting:boolean: if true the cipher is initialised for encryption, if false for decryption.
params:CipherParameters: the key and other data required by the cipher.

Exceptions

IllegalArgumentException:: if the params argument is inappropriate.

newInstance	back to summary
public static CFBModeCipher newInstance(BlockCipher cipher, int blockSize) Return a new CFB mode cipher based on the passed in base cipher Parameters cipher:BlockCipher the base cipher for the CFB mode. blockSize:int the block size (in bits) used for the CFB mode.

newInstance

back to summary

public static CFBModeCipher newInstance(BlockCipher cipher, int blockSize)

Return a new CFB mode cipher based on the passed in base cipher

Parameters

cipher:BlockCipher: the base cipher for the CFB mode.
blockSize:int: the block size (in bits) used for the CFB mode.

processBlock	back to summary
public int processBlock(byte[] in, int inOff, byte[] out, int outOff) throws DataLengthException, IllegalStateException Implements org.bouncycastle.crypto.BlockCipher.processBlock. Process one block of input from the array in and write it to the out array. Parameters in:byte[] the array containing the input data. inOff:int offset into the in array the data starts at. out:byte[] the array the output data will be copied into. outOff:int the offset into the out array the output will start at. Returns:int the number of bytes processed and produced. Exceptions DataLengthException: if there isn't enough data in in, or space in out. IllegalStateException: if the cipher isn't initialised.

processBlock

back to summary

public int processBlock(byte[] in, int inOff, byte[] out, int outOff) throws DataLengthException, IllegalStateException

Implements org.bouncycastle.crypto.BlockCipher.processBlock.

Process one block of input from the array in and write it to the out array.

Parameters

in:byte[]: the array containing the input data.
inOff:int: offset into the in array the data starts at.
out:byte[]: the array the output data will be copied into.
outOff:int: the offset into the out array the output will start at.

Returns:int

the number of bytes processed and produced.

Exceptions

DataLengthException:: if there isn't enough data in in, or space in out.
IllegalStateException:: if the cipher isn't initialised.

reset	back to summary
public void reset() Implements org.bouncycastle.crypto.BlockCipher.reset, org.bouncycastle.crypto.StreamCipher.reset. reset the chaining vector back to the IV and reset the underlying cipher.

reset

back to summary

public void reset()

Implements org.bouncycastle.crypto.BlockCipher.reset, org.bouncycastle.crypto.StreamCipher.reset.

reset the chaining vector back to the IV and reset the underlying cipher.

public Class CFBBlockCipher

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Field Detail

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