Class CryptoInputStream

java.lang.Object

java.io.InputStream

org.apache.commons.crypto.stream.CryptoInputStream

All Implemented Interfaces:

Closeable, AutoCloseable, Channel, ReadableByteChannel

Direct Known Subclasses:

CtrCryptoInputStream

public class CryptoInputStream
extends InputStream
implements ReadableByteChannel

CryptoInputStream reads input data and decrypts data in stream manner. It supports any mode of operations such as AES CBC/CTR/GCM mode in concept.It is not thread-safe.

Field Summary

Fields

Modifier and Type	Field	Description
static final int	EOS	The index value when the end of the stream has been reached -1.
static final String	STREAM_BUFFER_SIZE_KEY	The configuration key of the buffer size for stream.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	CryptoInputStream(InputStream inputStream, CryptoCipher cipher, int bufferSize, Key key, AlgorithmParameterSpec params)	Constructs a CryptoInputStream.
	CryptoInputStream(String transformation, Properties properties, InputStream inputStream, Key key, AlgorithmParameterSpec params)	Constructs a CryptoInputStream.
	CryptoInputStream(String transformation, Properties properties, ReadableByteChannel channel, Key key, AlgorithmParameterSpec params)	Constructs a CryptoInputStream.
protected	CryptoInputStream(ReadableByteChannel channel, CryptoCipher cipher, int bufferSize, Key key, AlgorithmParameterSpec params)	Constructs a CryptoInputStream.
protected	CryptoInputStream(Input input, CryptoCipher cipher, int bufferSize, Key key, AlgorithmParameterSpec params)	Constructs a CryptoInputStream.

Method Summary

Modifier and Type	Method	Description
int	available()	Overrides the InputStream.available().
protected void	checkStream()	Checks whether the stream is closed.
void	close()	Overrides the InputStream.close().
protected void	decrypt()	Does the decryption using inBuffer as input and outBuffer as output.
protected void	decryptFinal()	Does final of the cipher to end the decrypting stream.
protected int	decryptMore()	Decrypts more data by reading the under layer stream.
protected void	freeBuffers()	Forcibly free the direct buffers.
protected int	getBufferSize()	Gets the buffer size.
protected CryptoCipher	getCipher()	Gets the internal CryptoCipher.
protected Input	getInput()	Gets the input.
protected Key	getKey()	Gets the key.
protected AlgorithmParameterSpec	getParams()	Gets the specification of cryptographic parameters.
protected void	initCipher()	Initializes the cipher.
boolean	isOpen()	Overrides the Channel.isOpen().
boolean	markSupported()	Overrides the InputStream.markSupported().
int	read()	Overrides the InputStream.read().
int	read(byte[] array, int off, int len)	Overrides the InputStream.read(byte[], int, int).
int	read(ByteBuffer dst)	Overrides the ReadableByteChannel.read(ByteBuffer).
long	skip(long n)	Overrides the InputStream.skip(long).

Methods inherited from class InputStream

mark, read, reset

Methods inherited from class Object

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

Field Details

STREAM_BUFFER_SIZE_KEY

public static final String STREAM_BUFFER_SIZE_KEY

The configuration key of the buffer size for stream.

See Also:

• Constant Field Values

EOS

public static final int EOS

The index value when the end of the stream has been reached -1.

Since:

1.1

See Also:

• Constant Field Values

Constructor Details

CryptoInputStream

protected CryptoInputStream(Input input,
 CryptoCipher cipher,
 int bufferSize,
 Key key,
 AlgorithmParameterSpec params)
                     throws IOException

Constructs a CryptoInputStream.

Parameters:

input - the input data.

cipher - the cipher instance.

bufferSize - the bufferSize.

key - crypto key for the cipher.

params - the algorithm parameters.

Throws:

IOException - if an I/O error occurs.

CryptoInputStream

protected CryptoInputStream(InputStream inputStream,
 CryptoCipher cipher,
 int bufferSize,
 Key key,
 AlgorithmParameterSpec params)
                     throws IOException

Constructs a CryptoInputStream.

Parameters:

inputStream - the input stream.

cipher - the cipher instance.

bufferSize - the bufferSize.

key - crypto key for the cipher.

params - the algorithm parameters.

Throws:

IOException - if an I/O error occurs.

CryptoInputStream

protected CryptoInputStream(ReadableByteChannel channel,
 CryptoCipher cipher,
 int bufferSize,
 Key key,
 AlgorithmParameterSpec params)
                     throws IOException

Constructs a CryptoInputStream.

Parameters:

channel - the ReadableByteChannel instance.

cipher - the cipher instance.

bufferSize - the bufferSize.

key - crypto key for the cipher.

params - the algorithm parameters.

Throws:

IOException - if an I/O error occurs.

CryptoInputStream

public CryptoInputStream(String transformation,
 Properties properties,
 InputStream inputStream,
 Key key,
 AlgorithmParameterSpec params)
                  throws IOException

Constructs a CryptoInputStream.

Parameters:

transformation - the name of the transformation, e.g., AES/CBC/PKCS5Padding. See the Java Cryptography Architecture Standard Algorithm Name Documentation for information about standard transformation names.

properties - The Properties class represents a set of properties.

inputStream - the input stream.

key - crypto key for the cipher.

params - the algorithm parameters.

Throws:

IOException - if an I/O error occurs.

CryptoInputStream

public CryptoInputStream(String transformation,
 Properties properties,
 ReadableByteChannel channel,
 Key key,
 AlgorithmParameterSpec params)
                  throws IOException

Constructs a CryptoInputStream.

Parameters:

transformation - the name of the transformation, e.g., AES/CBC/PKCS5Padding. See the Java Cryptography Architecture Standard Algorithm Name Documentation for information about standard transformation names.

properties - The Properties class represents a set of properties.

channel - the ReadableByteChannel object.

key - crypto key for the cipher.

params - the algorithm parameters.

Throws:

IOException - if an I/O error occurs.

Method Details

available

public int available()
              throws IOException

Overrides the InputStream.available(). Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking by the next invocation of a method for this input stream.

Overrides:

available in class InputStream

Returns:

an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking or 0 when it reaches the end of the input stream.

Throws:

IOException - if an I/O error occurs.

checkStream

protected void checkStream()
                    throws IOException

Checks whether the stream is closed.

Throws:

IOException - if an I/O error occurs.

close

public void close()
           throws IOException

Overrides the InputStream.close(). Closes this input stream and releases any system resources associated with the stream.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Channel

Specified by:

close in interface Closeable

Overrides:

close in class InputStream

Throws:

IOException - if an I/O error occurs.

decrypt

protected void decrypt()
                throws IOException

Does the decryption using inBuffer as input and outBuffer as output. Upon return, inBuffer is cleared; the decrypted data starts at outBuffer.position() and ends at outBuffer.limit().

Throws:

IOException - if an I/O error occurs.

decryptFinal

protected void decryptFinal()
                     throws IOException

Does final of the cipher to end the decrypting stream.

Throws:

IOException - if an I/O error occurs.

decryptMore

protected int decryptMore()
                   throws IOException

Decrypts more data by reading the under layer stream. The decrypted data will be put in the output buffer. If the end of the under stream reached, we will do final of the cipher to finish all the decrypting of data.

Returns:

The number of decrypted data. return -1 (if end of the decrypted stream) return 0 (no data now, but could have more later)

Throws:

IOException - if an I/O error occurs.

freeBuffers

protected void freeBuffers()

Forcibly free the direct buffers.

getBufferSize

protected int getBufferSize()

Gets the buffer size.

Returns:

the bufferSize.

getCipher

protected CryptoCipher getCipher()

Gets the internal CryptoCipher.

Returns:

the cipher instance.

getInput

protected Input getInput()

Gets the input.

Returns:

the input.

getKey

protected Key getKey()

Gets the key.

Returns:

the key.

getParams

protected AlgorithmParameterSpec getParams()

Gets the specification of cryptographic parameters.

Returns:

the params.

initCipher

protected void initCipher()
                   throws IOException

Initializes the cipher.

Throws:

IOException - if an I/O error occurs.

isOpen

public boolean isOpen()

Overrides the Channel.isOpen().

Specified by:

isOpen in interface Channel

Returns:

true if, and only if, this channel is open.

markSupported

public boolean markSupported()

Overrides the InputStream.markSupported().

Overrides:

markSupported in class InputStream

Returns:

false,the CtrCryptoInputStream don't support the mark method.

read

public int read()
         throws IOException

Overrides the InputStream.read(). Reads the next byte of data from the input stream.

Specified by:

read in class InputStream

Returns:

the next byte of data, or EOS (-1) if the end of the stream is reached.

Throws:

IOException - if an I/O error occurs.

read

public int read(byte[] array,
 int off,
 int len)
         throws IOException

Overrides the InputStream.read(byte[], int, int). Decryption is buffer based. If there is data in outBuffer, then read it out of this buffer. If there is no data in outBuffer, then read more from the underlying stream and do the decryption.

Overrides:

read in class InputStream

Parameters:

array - the buffer into which the decrypted data is read.

off - the buffer offset.

len - the maximum number of decrypted data bytes to read.

Returns:

int the total number of decrypted data bytes read into the buffer.

Throws:

IOException - if an I/O error occurs.

read

public int read(ByteBuffer dst)
         throws IOException

Overrides the ReadableByteChannel.read(ByteBuffer). Reads a sequence of bytes from this channel into the given buffer.

Specified by:

read in interface ReadableByteChannel

Parameters:

dst - The buffer into which bytes are to be transferred.

Returns:

The number of bytes read, possibly zero, or EOS (-1) if the channel has reached end-of-stream.

Throws:

IOException - if an I/O error occurs.

skip

public long skip(long n)
          throws IOException

Overrides the InputStream.skip(long). Skips over and discards n bytes of data from this input stream.

Overrides:

skip in class InputStream

Parameters:

n - the number of bytes to be skipped.

Returns:

the actual number of bytes skipped.

Throws:

IOException - if an I/O error occurs.