Package org.bouncycastle.crypto.modes
Class CBCBlockCipher
java.lang.Object
org.bouncycastle.crypto.modes.CBCBlockCipher
- All Implemented Interfaces:
BlockCipher
implements Cipher-Block-Chaining (CBC) mode on top of a simple cipher.
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionreturn the algorithm name and mode.int
return the block size of the underlying cipher.return the underlying block cipher that we are wrapping.void
init
(boolean encrypting, CipherParameters params) Initialise the cipher and, possibly, the initialisation vector (IV).int
processBlock
(byte[] in, int inOff, byte[] out, int outOff) Process one block of input from the array in and write it to the out array.void
reset()
reset the chaining vector back to the IV and reset the underlying cipher.
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Constructor Details
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CBCBlockCipher
Basic constructor.- Parameters:
cipher
- the block cipher to be used as the basis of chaining.
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Method Details
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getUnderlyingCipher
return the underlying block cipher that we are wrapping.- Returns:
- the underlying block cipher that we are wrapping.
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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.- Specified by:
init
in interfaceBlockCipher
- Parameters:
encrypting
- if true the cipher is initialised for encryption, if false for decryption.params
- the key and other data required by the cipher.- Throws:
IllegalArgumentException
- if the params argument is inappropriate.
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getAlgorithmName
return the algorithm name and mode.- Specified by:
getAlgorithmName
in interfaceBlockCipher
- Returns:
- the name of the underlying algorithm followed by "/CBC".
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getBlockSize
public int getBlockSize()return the block size of the underlying cipher.- Specified by:
getBlockSize
in interfaceBlockCipher
- Returns:
- the block size of the underlying cipher.
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processBlock
public int processBlock(byte[] in, int inOff, byte[] out, int outOff) throws DataLengthException, IllegalStateException Process one block of input from the array in and write it to the out array.- Specified by:
processBlock
in interfaceBlockCipher
- Parameters:
in
- the array containing the input data.inOff
- offset into the in array the data starts at.out
- the array the output data will be copied into.outOff
- the offset into the out array the output will start at.- Returns:
- the number of bytes processed and produced.
- Throws:
DataLengthException
- if there isn't enough data in in, or space in out.IllegalStateException
- if the cipher isn't initialised.
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reset
public void reset()reset the chaining vector back to the IV and reset the underlying cipher.- Specified by:
reset
in interfaceBlockCipher
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