public class

CCMBlockCipher

extends Object
implements AEADBlockCipher
java.lang.Object
   ↳ org.bouncycastle.crypto.modes.CCMBlockCipher

Class Overview

Implements the Counter with Cipher Block Chaining mode (CCM) detailed in NIST Special Publication 800-38C.

Note: this mode is a packet mode - it needs all the data up front.

Summary

Public Constructors
CCMBlockCipher(BlockCipher c)
Basic constructor.
Public Methods
int doFinal(byte[] out, int outOff)
Finish the operation either appending or verifying the MAC at the end of the data.
String getAlgorithmName()
Return the name of the algorithm.
byte[] getMac()
Returns a byte array containing the mac calculated as part of the last encrypt or decrypt operation.
int getOutputSize(int len)
return the size of the output buffer required for a processBytes plus a doFinal with an input of len bytes.
BlockCipher getUnderlyingCipher()
return the underlying block cipher that we are wrapping.
int getUpdateOutputSize(int len)
return the size of the output buffer required for a processBytes an input of len bytes.
void init(boolean forEncryption, CipherParameters params)
initialise the underlying cipher.
int processByte(byte in, byte[] out, int outOff)
encrypt/decrypt a single byte.
int processBytes(byte[] in, int inOff, int inLen, byte[] out, int outOff)
process a block of bytes from in putting the result into out.
byte[] processPacket(byte[] in, int inOff, int inLen)
void reset()
Reset the cipher.
[Expand]
Inherited Methods
From class java.lang.Object
From interface org.bouncycastle.crypto.modes.AEADBlockCipher

Public Constructors

public CCMBlockCipher (BlockCipher c)

Basic constructor.

Parameters
c the block cipher to be used.

Public Methods

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

Finish the operation either appending or verifying the MAC at the end of the data.

Parameters
out space for any resulting output data.
outOff offset into out to start copying the data at.
Returns
  • number of bytes written into out.
Throws
IllegalStateException
InvalidCipherTextException

public String getAlgorithmName ()

Return the name of the algorithm.

Returns
  • the algorithm name.

public byte[] getMac ()

Returns a byte array containing the mac calculated as part of the last encrypt or decrypt operation.

Returns
  • the last mac calculated.

public int getOutputSize (int len)

return the size of the output buffer required for a processBytes 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 processBytes and doFinal with len bytes of input.

public BlockCipher getUnderlyingCipher ()

return the underlying block cipher that we are wrapping.

Returns
  • the underlying block cipher that we are wrapping.

public int getUpdateOutputSize (int len)

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

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

public void init (boolean forEncryption, CipherParameters params)

initialise the underlying cipher. Parameter can either be an AEADParameters or a ParametersWithIV object.

Parameters
forEncryption true if we are setting up for encryption, false otherwise.
params the necessary parameters for the underlying cipher to be initialised.
Throws
IllegalArgumentException

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

encrypt/decrypt a single byte.

Parameters
in the byte to be processed.
out the output buffer the processed byte goes into.
outOff the offset into the output byte array the processed data starts at.
Returns
  • the number of bytes written to out.
Throws
DataLengthException
IllegalStateException

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

process a block of bytes from in putting the result into out.

Parameters
in the input byte array.
inOff the offset into the in array where the data to be processed starts.
inLen the number of bytes to be processed.
out the output buffer the processed bytes go into.
outOff the offset into the output byte array the processed data starts at.
Returns
  • the number of bytes written to out.
Throws
DataLengthException
IllegalStateException

public byte[] processPacket (byte[] in, int inOff, int inLen)

Throws
IllegalStateException
InvalidCipherTextException

public void reset ()

Reset the cipher. After resetting the cipher is in the same state as it was after the last init (if there was one).