com.sun.pdfview.decrypt

Class IdentityDecrypter

java.lang.Object

com.sun.pdfview.decrypt.IdentityDecrypter

All Implemented Interfaces:

PDFDecrypter

public class IdentityDecrypter
extends Object
implements PDFDecrypter

Performs identity decryption; that is, inputs aren't encrypted and are returned right back.

Constructor Summary

Constructors

Constructor and Description
IdentityDecrypter()

Method Summary

Modifier and Type	Method and Description
ByteBuffer	decryptBuffer(String cryptFilterName, PDFObject streamObj, ByteBuffer streamBuf) Decrypt a buffer of data
String	decryptString(int objNum, int objGen, String inputBasicString) Decrypt a basic string.
static IdentityDecrypter	getInstance()
boolean	isEncryptionPresent() Determine whether this actually applies a decryption other than identity decryption.
boolean	isOwnerAuthorised() Determine whether the password known by the decrypter indicates that the user is the owner of the document.

Methods inherited from class java.lang.Object

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

Constructor Detail

IdentityDecrypter

public IdentityDecrypter()

Method Detail

decryptBuffer

public ByteBuffer decryptBuffer(String cryptFilterName,
                                PDFObject streamObj,
                                ByteBuffer streamBuf)
                         throws PDFParseException

Description copied from interface: PDFDecrypter

Decrypt a buffer of data

Specified by:

decryptBuffer in interface PDFDecrypter

Parameters:

cryptFilterName - the name of the crypt filter, if V4 encryption is being used, where individual crypt filters may be specified for individual streams. If encryption is not using V4 encryption (indicated by V=4 in the Encrypt dictionary) then this must be null. Null may also be specified with V4 encryption to indicate that the default filter should be used.

streamObj - the object whose stream is being decrypted. The containing object's number and generation contribute to the key used for stream encrypted with the document's default encryption, so this is typically required. Should be null only if a cryptFilterName is specified, as objects with specific stream filters use the general document key, rather than a stream-specific key.

streamBuf - the buffer to decrypt

Returns:

a buffer containing the decrypted stream, positioned at its beginning; will only be the same buffer as streamBuf if the identity decrypter is being used

Throws:

PDFParseException - if the named crypt filter does not exist, or if a crypt filter is named when named crypt filters are not supported. Problems due to incorrect passwords are revealed prior to this point.

decryptString

public String decryptString(int objNum,
                            int objGen,
                            String inputBasicString)

Description copied from interface: PDFDecrypter

Decrypt a basic string.

Specified by:

decryptString in interface PDFDecrypter

Parameters:

objNum - the object number of the containing object

objGen - the generation number of the containing object

inputBasicString - the string to be decrypted

Returns:

the decrypted string

getInstance

public static IdentityDecrypter getInstance()

isEncryptionPresent

public boolean isEncryptionPresent()

Description copied from interface: PDFDecrypter

Determine whether this actually applies a decryption other than identity decryption.

Specified by:

isEncryptionPresent in interface PDFDecrypter

Returns:

whether encryption is present

isOwnerAuthorised

public boolean isOwnerAuthorised()

Description copied from interface: PDFDecrypter

Determine whether the password known by the decrypter indicates that the user is the owner of the document. Can be used, in conjunction with PDFDecrypter.isEncryptionPresent() to determine whether any permissions apply.

Specified by:

isOwnerAuthorised in interface PDFDecrypter

Returns:

whether owner authentication is being used to decrypt the document