| java.lang.Object
 org.bouncycastle.crypto.modes.CFBBlockCipher
| CFBBlockCipher | | public class CFBBlockCipher implements BlockCipher(Code) | | implements a Cipher-FeedBack (CFB) mode on top of a simple cipher.
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| Method Summary | |
| public int | decryptBlock(byte[] in, int inOff, byte[] out, int outOff)
Do the appropriate processing for CFB mode decryption.
Parameters:
in - the array containing the data to be decrypted.
Parameters:
inOff - offset into the in array the data starts at.
Parameters:
out - the array the encrypted data will be copied into.
Parameters:
outOff - the offset into the out array the output will start at.
exception:
DataLengthException - if there isn't enough data in in, orspace in out.
exception:
IllegalStateException - if the cipher isn't initialised. | | public int | encryptBlock(byte[] in, int inOff, byte[] out, int outOff)
Do the appropriate processing for CFB mode encryption.
Parameters:
in - the array containing the data to be encrypted.
Parameters:
inOff - offset into the in array the data starts at.
Parameters:
out - the array the encrypted data will be copied into.
Parameters:
outOff - the offset into the out array the output will start at.
exception:
DataLengthException - if there isn't enough data in in, orspace in out.
exception:
IllegalStateException - if the cipher isn't initialised. | | public String | getAlgorithmName()
return the algorithm name and mode. | | public int | getBlockSize()
return the block size we are operating at. | | public BlockCipher | getUnderlyingCipher()
return the underlying block cipher that we are wrapping. | | public void | init(boolean encrypting, CipherParameters params)
Initialise the cipher and, possibly, the initialisation vector (IV). | | public 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.
Parameters:
in - the array containing the input data.
Parameters:
inOff - offset into the in array the data starts at.
Parameters:
out - the array the output data will be copied into.
Parameters:
outOff - the offset into the out array the output will start at.
exception:
DataLengthException - if there isn't enough data in in, orspace in out.
exception:
IllegalStateException - if the cipher isn't initialised. | | public void | reset()
reset the chaining vector back to the IV and reset the underlying
cipher. |
| CFBBlockCipher | | public CFBBlockCipher(BlockCipher cipher, int bitBlockSize)(Code) | | Basic constructor.
Parameters:
cipher - the block cipher to be used as the basis of thefeedback mode.
Parameters:
bitBlockSize - the block size in bits (note: a multiple of 8) |
| decryptBlock | | public int decryptBlock(byte[] in, int inOff, byte[] out, int outOff) throws DataLengthException, IllegalStateException(Code) | | Do the appropriate processing for CFB mode decryption.
Parameters:
in - the array containing the data to be decrypted.
Parameters:
inOff - offset into the in array the data starts at.
Parameters:
out - the array the encrypted data will be copied into.
Parameters:
outOff - the offset into the out array the output will start at.
exception:
DataLengthException - if there isn't enough data in in, orspace in out.
exception:
IllegalStateException - if the cipher isn't initialised. the number of bytes processed and produced. |
| encryptBlock | | public int encryptBlock(byte[] in, int inOff, byte[] out, int outOff) throws DataLengthException, IllegalStateException(Code) | | Do the appropriate processing for CFB mode encryption.
Parameters:
in - the array containing the data to be encrypted.
Parameters:
inOff - offset into the in array the data starts at.
Parameters:
out - the array the encrypted data will be copied into.
Parameters:
outOff - the offset into the out array the output will start at.
exception:
DataLengthException - if there isn't enough data in in, orspace in out.
exception:
IllegalStateException - if the cipher isn't initialised. the number of bytes processed and produced. |
| getAlgorithmName | | public String getAlgorithmName()(Code) | | return the algorithm name and mode.
the name of the underlying algorithm followed by "/CFB"and the block size in bits. |
| getBlockSize | | public int getBlockSize()(Code) | | return the block size we are operating at.
the block size we are operating at (in bytes). |
| getUnderlyingCipher | | public BlockCipher getUnderlyingCipher()(Code) | | return the underlying block cipher that we are wrapping.
the underlying block cipher that we are wrapping. |
| init | | public void init(boolean encrypting, CipherParameters params) throws IllegalArgumentException(Code) | | 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 - if true the cipher is initialised forencryption, if false for decryption.
Parameters:
params - the key and other data required by the cipher.
exception:
IllegalArgumentException - if the params argument isinappropriate. |
| processBlock | | public int processBlock(byte[] in, int inOff, byte[] out, int outOff) throws DataLengthException, IllegalStateException(Code) | | Process one block of input from the array in and write it to
the out array.
Parameters:
in - the array containing the input data.
Parameters:
inOff - offset into the in array the data starts at.
Parameters:
out - the array the output data will be copied into.
Parameters:
outOff - the offset into the out array the output will start at.
exception:
DataLengthException - if there isn't enough data in in, orspace in out.
exception:
IllegalStateException - if the cipher isn't initialised. the number of bytes processed and produced. |
| reset | | public void reset()(Code) | | reset the chaining vector back to the IV and reset the underlying
cipher.
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