abstract public  void decryptDocument(PDDocument doc,
    DecryptionMaterial mat) throws CryptographyException, IOException
Prepare the document for decryption.

 public  void decryptStream(COSStream stream,
    long objNum,
    long genNum) throws CryptographyException, IOException 
{
        decryptDictionary( stream, objNum, genNum );
        InputStream encryptedStream = stream.getFilteredStream();
        encryptData( objNum,
                                genNum,
                                encryptedStream,
                                stream.createFilteredStream() );
}

This will decrypt a stream.

 public  void decryptString(COSString string,
    long objNum,
    long genNum) throws CryptographyException, IOException 
{
        ByteArrayInputStream data = new ByteArrayInputStream( string.getBytes() );
        ByteArrayOutputStream buffer = new ByteArrayOutputStream();
        encryptData( objNum, genNum, data, buffer );
        string.reset();
        string.append( buffer.toByteArray() );
}

This will decrypt a string.

 public  void encryptData(long objectNumber,
    long genNumber,
    InputStream data,
    OutputStream output) throws CryptographyException, IOException 
{
        byte[] newKey = new byte[ encryptionKey.length + 5 ];
        System.arraycopy( encryptionKey, 0, newKey, 0, encryptionKey.length );
        //PDF 1.4 reference pg 73
        //step 1
        //we have the reference
        //step 2
        newKey[newKey.length -5] = (byte)(objectNumber & 0xff);
        newKey[newKey.length -4] = (byte)((objectNumber  > > 8) & 0xff);
        newKey[newKey.length -3] = (byte)((objectNumber  > > 16) & 0xff);
        newKey[newKey.length -2] = (byte)(genNumber & 0xff);
        newKey[newKey.length -1] = (byte)((genNumber  > > 8) & 0xff);
        //step 3
        byte[] digestedKey = null;
        try
        {
            MessageDigest md = MessageDigest.getInstance( "MD5" );
            digestedKey = md.digest( newKey );
        }
        catch( NoSuchAlgorithmException e )
        {
            throw new CryptographyException( e );
        }
        //step 4
        int length = Math.min( newKey.length, 16 );
        byte[] finalKey = new byte[ length ];
        System.arraycopy( digestedKey, 0, finalKey, 0, length );
        rc4.setKey( finalKey );
        rc4.write( data, output );
        output.flush();
}

Encrypt a set of data.

 public AccessPermission getCurrentAccessPermission() 
{
        return currentAccessPermission;
}

Returns the access permissions that were computed during document decryption. The returned object is in read only mode.

 public int getKeyLength() 
{
        return keyLength;
}

Getter of the property keyLength.

 abstract public  void prepareDocumentForEncryption(PDDocument doc) throws CryptographyException, IOException
Prepare the document for encryption.

 protected  void proceedDecryption() throws IOException, CryptographyException 
{
        COSDictionary trailer = document.getDocument().getTrailer();
        COSArray fields = (COSArray)trailer.getObjectFromPath( "Root/AcroForm/Fields" );
        //We need to collect all the signature dictionaries, for some
        //reason the 'Contents' entry of signatures is not really encrypted
        if( fields != null )
        {
            for( int i=0; i< fields.size(); i++ )
            {
                COSDictionary field = (COSDictionary)fields.getObject( i );
                addDictionaryAndSubDictionary( potentialSignatures, field );
            }
        }
        List allObjects = document.getDocument().getObjects();
        Iterator objectIter = allObjects.iterator();
        while( objectIter.hasNext() )
        {
            decryptObject( (COSObject)objectIter.next() );
        }
        document.setEncryptionDictionary( null );
}

This method must be called by an implementation of this class to really proceed to decryption.

 public  void setKeyLength(int keyLen) 
{
        this.keyLength = keyLen;
}

Setter of the property keyLength.