Package org.verapdf.cos.filters

Class COSFilterRC4DecryptionDefault

java.lang.Object

java.io.InputStream

org.verapdf.as.io.ASInputStream

org.verapdf.as.filters.ASInFilter

org.verapdf.as.filters.io.ASBufferedInFilter

org.verapdf.cos.filters.COSFilterRC4DecryptionDefault

All Implemented Interfaces:

Closeable, AutoCloseable

public class COSFilterRC4DecryptionDefault
extends ASBufferedInFilter

Filter that decrypts data using RC4 cipher decryption according to Algorithm 1 of 7.6.2 of ISO 32000:2008.

Author:

Sergey Shemyakov

Field Summary

Fields

Modifier and Type	Field	Description
static final int	MAXIMAL_KEY_LENGTH

Fields inherited from class org.verapdf.as.filters.io.ASBufferedInFilter

BF_BUFFER_SIZE, buffer, START_BUFFER_SIZE

Fields inherited from class org.verapdf.as.io.ASInputStream

isClosed, isSourceClosed, resourceUsers

Constructor Summary

Constructors

Constructor	Description
COSFilterRC4DecryptionDefault(ASInputStream stream, COSKey objectKey, byte[] encryptionKey)	Constructor.

Method Summary

Modifier and Type	Method	Description
static byte[]	getObjectKeyDigest(COSKey objectKey)	Gets a byte string consisting of object number and object generation concatenated.
int	read(byte[] buffer, int size)
int	read(byte[] buffer, int off, int size)
void	reset()

Methods inherited from class org.verapdf.as.filters.io.ASBufferedInFilter

addToBuffer, bufferPop, bufferPopArray, bufferSize, closeResource, concatenate, feedBuffer, getBufferBegin, getBufferCapacity, getBufferEnd, getReadCounter, getStream, getStreamUntilToken, initialize, isEOF, peek, peek, processBuffer, read, readByte, resetReadCounter, skip, unread, unread

Methods inherited from class org.verapdf.as.filters.ASInFilter

close, decrementResourceUsers, getInputStream, incrementResourceUsers, read, setInputStream

Methods inherited from class org.verapdf.as.io.ASInputStream

createStreamFromStream

Methods inherited from class java.io.InputStream

available, mark, markSupported, nullInputStream, readAllBytes, readNBytes, readNBytes, skip, skipNBytes, transferTo

Methods inherited from class java.lang.Object

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

Field Details

MAXIMAL_KEY_LENGTH

public static final int MAXIMAL_KEY_LENGTH

See Also:

• Constant Field Values

Constructor Details

COSFilterRC4DecryptionDefault

public COSFilterRC4DecryptionDefault(ASInputStream stream,
 COSKey objectKey,
 byte[] encryptionKey)
                              throws IOException,
NoSuchAlgorithmException

Constructor.

Parameters:

stream - is stream with encrypted data.

objectKey - contains object and generation numbers from object identifier for object that is being decrypted. If it is direct object, objectKey is taken from indirect object that contains it.

encryptionKey - is encryption key that is calculated from user password and encryption dictionary.

Throws:

IOException

NoSuchAlgorithmException

Method Details

read

public int read(byte[] buffer,
 int size)
         throws IOException

Overrides:

read in class ASBufferedInFilter

Throws:

IOException

read

public int read(byte[] buffer,
 int off,
 int size)
         throws IOException

Overrides:

read in class InputStream

Throws:

IOException

reset

public void reset()
           throws IOException

Overrides:

reset in class ASBufferedInFilter

Throws:

IOException

getObjectKeyDigest

public static byte[] getObjectKeyDigest(COSKey objectKey)

Gets a byte string consisting of object number and object generation concatenated.

Parameters:

objectKey - is key of object.

Returns:

byte string consisting of object number and object generation concatenated.