public class

CTSBlockCipher

extends BufferedBlockCipher
java.lang.Object
   ↳ org.bouncycastle.crypto.BufferedBlockCipher
     ↳ org.bouncycastle.crypto.modes.CTSBlockCipher

Class Overview

A Cipher Text Stealing (CTS) mode cipher. CTS allows block ciphers to be used to produce cipher text which is the same length as the plain text.

Summary

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Inherited Fields
From class org.bouncycastle.crypto.BufferedBlockCipher
Public Constructors
CTSBlockCipher(BlockCipher cipher)
Create a buffered block cipher that uses Cipher Text Stealing
Public Methods
int doFinal(byte[] out, int outOff)
Process the last block in the buffer.
int getOutputSize(int len)
return the size of the output buffer required for an update plus a doFinal with an input of len bytes.
int getUpdateOutputSize(int len)
return the size of the output buffer required for an update an input of len bytes.
int processByte(byte in, byte[] out, int outOff)
process a single byte, producing an output block if neccessary.
int processBytes(byte[] in, int inOff, int len, byte[] out, int outOff)
process an array of bytes, producing output if necessary.
[Expand]
Inherited Methods
From class org.bouncycastle.crypto.BufferedBlockCipher
From class java.lang.Object

Public Constructors

public CTSBlockCipher (BlockCipher cipher)

Create a buffered block cipher that uses Cipher Text Stealing

Parameters
cipher the underlying block cipher this buffering object wraps.

Public Methods

public int doFinal (byte[] out, int outOff)

Process the last block in the buffer.

Parameters
out the array the block currently being held is copied into.
outOff the offset at which the copying starts.
Returns
  • the number of output bytes copied to out.
Throws
DataLengthException if there is insufficient space in out for the output.
IllegalStateException if the underlying cipher is not initialised.
InvalidCipherTextException if cipher text decrypts wrongly (in case the exception will never get thrown).

public int getOutputSize (int len)

return the size of the output buffer required for an update plus a doFinal with an input of len bytes.

Parameters
len the length of the input.
Returns
  • the space required to accommodate a call to update and doFinal with len bytes of input.

public int getUpdateOutputSize (int len)

return the size of the output buffer required for an update an input of len bytes.

Parameters
len the length of the input.
Returns
  • the space required to accommodate a call to update with len bytes of input.

public int processByte (byte in, byte[] out, int outOff)

process a single byte, producing an output block if neccessary.

Parameters
in the input byte.
out the space for any output that might be produced.
outOff the offset from which the output will be copied.
Returns
  • the number of output bytes copied to out.
Throws
DataLengthException if there isn't enough space in out.
IllegalStateException if the cipher isn't initialised.

public int processBytes (byte[] in, int inOff, int len, byte[] out, int outOff)

process an array of bytes, producing output if necessary.

Parameters
in the input byte array.
inOff the offset at which the input data starts.
len the number of bytes to be copied out of the input array.
out the space for any output that might be produced.
outOff the offset from which the output will be copied.
Returns
  • the number of output bytes copied to out.
Throws
DataLengthException if there isn't enough space in out.
IllegalStateException if the cipher isn't initialised.