org.bouncycastle.jcajce.io
Class CipherInputStream

java.lang.Object
  java.io.InputStream
      java.io.FilterInputStream
          org.bouncycastle.jcajce.io.CipherInputStream

public class CipherInputStream

extends java.io.FilterInputStream

A CipherInputStream is composed of an InputStream and a cipher so that read() methods return data that are read in from the underlying InputStream but have been additionally processed by the Cipher. The cipher must be fully initialized before being used by a CipherInputStream.

For example, if the Cipher is initialized for decryption, the CipherInputStream will attempt to read in data and decrypt them, before returning the decrypted data.

This is a reimplementation of CipherInputStream that is safe for use with AEAD block ciphers, and does not silently catch BadPaddingException and IllegalBlockSizeException errors. Any errors that occur during finalisation are rethrown wrapped in an InvalidCipherTextIOException.

Field Summary

Fields inherited from class java.io.FilterInputStream

in

Constructor Summary

CipherInputStream(java.io.InputStream input, javax.crypto.Cipher cipher)
Constructs a CipherInputStream from an InputStream and an initialised Cipher.

Method Summary

int	available()
void	close() Closes the underlying input stream, and then finalises the processing of the data by the cipher.
void	mark(int readlimit)
boolean	markSupported()
int	read() Reads data from the underlying stream and processes it with the cipher until the cipher outputs data, and returns the next available byte.
int	read(byte[] b, int off, int len) Reads data from the underlying stream and processes it with the cipher until the cipher outputs data, and then returns up to len bytes in the provided array.
void	reset()
long	skip(long n)

Methods inherited from class java.io.FilterInputStream

read

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CipherInputStream

public CipherInputStream(java.io.InputStream input,
                         javax.crypto.Cipher cipher)

Constructs a CipherInputStream from an InputStream and an initialised Cipher.

Method Detail

read

public int read()
         throws java.io.IOException

Reads data from the underlying stream and processes it with the cipher until the cipher outputs data, and returns the next available byte.

If the underlying stream is exhausted by this call, the cipher will be finalised.

Throws:

java.io.IOException - if there was an error closing the input stream.

InvalidCipherTextIOException - if the data read from the stream was invalid ciphertext (e.g. the cipher is an AEAD cipher and the ciphertext tag check fails).

read

public int read(byte[] b,
                int off,
                int len)
         throws java.io.IOException

Reads data from the underlying stream and processes it with the cipher until the cipher outputs data, and then returns up to len bytes in the provided array.

If the underlying stream is exhausted by this call, the cipher will be finalised.

Parameters:

b - the buffer into which the data is read.

off - the start offset in the destination array b

len - the maximum number of bytes read.

Returns:

the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached.

Throws:

java.io.IOException - if there was an error closing the input stream.

InvalidCipherTextIOException - if the data read from the stream was invalid ciphertext (e.g. the cipher is an AEAD cipher and the ciphertext tag check fails).

skip

public long skip(long n)
          throws java.io.IOException

Throws:

java.io.IOException

available

public int available()
              throws java.io.IOException

Throws:

java.io.IOException

close

public void close()
           throws java.io.IOException

Closes the underlying input stream, and then finalises the processing of the data by the cipher.

Throws:

java.io.IOException - if there was an error closing the input stream.

InvalidCipherTextIOException - if the data read from the stream was invalid ciphertext (e.g. the cipher is an AEAD cipher and the ciphertext tag check fails).

mark

public void mark(int readlimit)

reset

public void reset()
           throws java.io.IOException

Throws:

java.io.IOException

markSupported

public boolean markSupported()