org.xwiki.crypto.cipher

Interface Cipher

All Known Subinterfaces:

AsymmetricCipher, SymmetricCipher

public interface Cipher

Interface on a Block cipher engines ready to process data for encryption and decryption.

Since:

5.4M1

Version:

$Id: 84ec9ab2bd6f01c857350a7ca4864deeb6c8d09a $

Method Summary

Modifier and Type	Method and Description
byte[]	doFinal() Finishes a multiple-part encryption or decryption operation.
byte[]	doFinal(byte[] input) Encrypts or decrypts data in a one shot operation, or finishes a multiple-part operation.
byte[]	doFinal(byte[] input, int inputOffset, int inputLen) Encrypts or decrypts data in a one shot operation, or finishes a multiple-part operation.
String	getAlgorithmName()
int	getInputBlockSize()
FilterInputStream	getInputStream(InputStream is) Return a filtered input stream based on this cipher.
int	getOutputBlockSize()
FilterOutputStream	getOutputStream(OutputStream os) Return a filtered output stream based on this cipher.
boolean	isForEncryption()
byte[]	update(byte[] input) Continues a multiple-part encryption or decryption operation, processing another data chunk.
byte[]	update(byte[] input, int inputOffset, int inputLen) Continues a multiple-part encryption or decryption operation processing another data chunk.

Method Detail

getAlgorithmName

String getAlgorithmName()

Returns:

the algorithm name of the underlying cipher. The returned string has in the form algorithm/mode/padding, like in "DES/CBC/PKCS5Padding".

getInputBlockSize

int getInputBlockSize()

Returns:

the size of input data process as a block by this cipher (in bytes).

getOutputBlockSize

int getOutputBlockSize()

Returns:

the size of encrypted data returned for a block of input data (in bytes).

isForEncryption

boolean isForEncryption()

Returns:

true if the cipher is initialised for encryption, and false for decryption.

getInputStream

FilterInputStream getInputStream(InputStream is)

Return a filtered input stream based on this cipher. The cipher is reset each time this function is called. Any previously retrieved input stream or in progress operation get discarded.

Parameters:

is - an input stream to filter.

Returns:

a filtered input stream based on this cipher.

getOutputStream

FilterOutputStream getOutputStream(OutputStream os)

Return a filtered output stream based on this cipher. The cipher is reset each time this function is called. Any previously retrieved input stream or in progress operation get discarded.

Parameters:

os - an output stream to filter.

Returns:

a filtered output stream based on this cipher.

update

byte[] update(byte[] input)

Continues a multiple-part encryption or decryption operation, processing another data chunk.

Parameters:

input - the input buffer.

Returns:

the new buffer with the result, or null if the underlying cipher is a block cipher and the input data is too short to result in a new block.

update

byte[] update(byte[] input,
              int inputOffset,
              int inputLen)

Continues a multiple-part encryption or decryption operation processing another data chunk.

Parameters:

input - the input buffer.

inputOffset - the offset in input where the input starts.

inputLen - the input length.

Returns:

the new buffer with the result, or null if the underlying cipher is a block cipher and the input data is too short to result in a new block.

doFinal

byte[] doFinal()
        throws GeneralSecurityException

Finishes a multiple-part encryption or decryption operation. Input data that may have been buffered during a previous update operation is processed, with padding being applied. The result is stored in a new buffer. Upon finish, this method resets this cipher.

Returns:

the new buffer with the result.

Throws:

GeneralSecurityException - if this encryption algorithm is unable to proceed properly.

doFinal

byte[] doFinal(byte[] input)
        throws GeneralSecurityException

Encrypts or decrypts data in a one shot operation, or finishes a multiple-part operation. The bytes in the input buffer, and any input bytes that may have been buffered during a previous update operation, are processed, with padding being applied. The result is stored in a new buffer. Upon finish, this method resets this cipher.

Parameters:

input - the input buffer.

Returns:

the new buffer with the result.

Throws:

GeneralSecurityException - if this encryption algorithm is unable to proceed properly.

doFinal

byte[] doFinal(byte[] input,
               int inputOffset,
               int inputLen)
        throws GeneralSecurityException

Encrypts or decrypts data in a one shot operation, or finishes a multiple-part operation. The first inputLen bytes in the input buffer, starting at inputOffset inclusive, and any input bytes that may have been buffered during a previous update operation, are processed, with padding being applied. The result is stored in a new buffer. Upon finish, this method resets this cipher.

Parameters:

input - the input buffer.

inputOffset - the offset in input where the input starts.

inputLen - the input length.

Returns:

the new buffer with the result.

Throws:

GeneralSecurityException - if this encryption algorithm is unable to proceed properly.