Bouncy Castle Cryptography 1.11 API Specification: Class PaddedBufferedBlockCipher
org.bouncycastle.crypto.paddings
Class PaddedBufferedBlockCipher
java.lang.Object
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+--org.bouncycastle.crypto.BufferedBlockCipher
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+--org.bouncycastle.crypto.paddings.PaddedBufferedBlockCipher
public class PaddedBufferedBlockCipher extends BufferedBlockCipher
A wrapper class that allows block ciphers to be used to process data in
a piecemeal fashion with padding. The PaddedBufferedBlockCipher
outputs a block only when the buffer is full and more data is being added,
or on a doFinal (unless the current block in the buffer is a pad block).
The default padding mechanism used is the one outlined in PKCS5/PKCS7.
Method Summary
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.
void
init (boolean forEncryption,
CipherParameters params)
initialise the cipher.
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.
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
PaddedBufferedBlockCipher
public PaddedBufferedBlockCipher (BlockCipher cipher,
BlockCipherPadding padding)
Create a buffered block cipher with the desired padding.
Parameters: cipher
- the underlying block cipher this buffering object wraps.padding
- the padding type.
PaddedBufferedBlockCipher
public PaddedBufferedBlockCipher (BlockCipher cipher)
Create a buffered block cipher PKCS7 padding
Parameters: cipher
- the underlying block cipher this buffering object wraps.
init
public void init (boolean forEncryption,
CipherParameters params)
throws java.lang.IllegalArgumentException
initialise the cipher.
Overrides: init
in class BufferedBlockCipher
Parameters: forEncryption
- if true the cipher is initialised for
encryption, if false for decryption.param
- the key and other data required by the cipher.Throws: java.lang.IllegalArgumentException
- if the params argument is
inappropriate.
getOutputSize
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.
Overrides: getOutputSize
in class BufferedBlockCipher
Parameters: len
- the length of the input.Returns: the space required to accommodate a call to update and doFinal
with len bytes of input.
getUpdateOutputSize
public int getUpdateOutputSize (int len)
return the size of the output buffer required for an update
an input of len bytes.
Overrides: getUpdateOutputSize
in class BufferedBlockCipher
Parameters: len
- the length of the input.Returns: the space required to accommodate a call to update
with len bytes of input.
processByte
public int processByte (byte in,
byte[] out,
int outOff)
throws DataLengthException ,
java.lang.IllegalStateException
process a single byte, producing an output block if neccessary.
Overrides: processByte
in class BufferedBlockCipher
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.Throws: DataLengthException
- if there isn't enough space in out.java.lang.IllegalStateException
- if the cipher isn't initialised.
processBytes
public int processBytes (byte[] in,
int inOff,
int len,
byte[] out,
int outOff)
throws DataLengthException ,
java.lang.IllegalStateException
process an array of bytes, producing output if necessary.
Overrides: processBytes
in class BufferedBlockCipher
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.Throws: DataLengthException
- if there isn't enough space in out.java.lang.IllegalStateException
- if the cipher isn't initialised.
doFinal
public int doFinal (byte[] out,
int outOff)
throws DataLengthException ,
java.lang.IllegalStateException,
InvalidCipherTextException
Process the last block in the buffer. If the buffer is currently
full and padding needs to be added a call to doFinal will produce
2 * getBlockSize() bytes.
Overrides: doFinal
in class BufferedBlockCipher
Parameters: out
- the array the block currently being held is copied into.outOff
- the offset at which the copying starts.Throws: DataLengthException
- if there is insufficient space in out for
the output or we are decrypting and the input is not block size aligned.java.lang.IllegalStateException
- if the underlying cipher is not
initialised.InvalidCipherTextException
- if padding is expected and not found.