Package org.loboevolution.pdfview.decrypt

Class PDFDecrypterFactory

java.lang.Object

org.loboevolution.pdfview.decrypt.PDFDecrypterFactory

public class PDFDecrypterFactory
extends Object

Produces a PDFDecrypter for documents given a (possibly non-existent) Encrypt dictionary. Supports decryption of versions 1, 2 and 4 of the password-based encryption mechanisms as described in PDF Reference version 1.7. This means that it supports RC4 and AES encryption with keys of 40-128 bits; esentially, password-protected documents with compatibility up to Acrobat 8.

See "PDF Reference version 1.7, section 3.5: Encryption" Author Luke Kirby

Field Summary

Fields

Modifier and Type	Field	Description
static final String	CF_IDENTITY	The name of the standard Identity CryptFilter

Constructor Summary

Constructors

Constructor	Description
PDFDecrypterFactory()

Method Summary

Modifier and Type	Method	Description
static PDFDecrypter	createDecryptor(PDFObject encryptDict, PDFObject documentId, PDFPassword password)	Create a decryptor for a given encryption dictionary.
static boolean	isFilterExist(PDFObject encryptDict)	isFilterExist.

Methods inherited from class java.lang.Object

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

Field Details

CF_IDENTITY

public static final String CF_IDENTITY

The name of the standard Identity CryptFilter

See Also:

• Constant Field Values

Constructor Details

PDFDecrypterFactory

public PDFDecrypterFactory()

Method Details

createDecryptor

public static PDFDecrypter createDecryptor(PDFObject encryptDict,
 PDFObject documentId,
 PDFPassword password)
                                    throws IOException,
EncryptionUnsupportedByPlatformException,
EncryptionUnsupportedByProductException,
PDFAuthenticationFailureException

Create a decryptor for a given encryption dictionary. A check is immediately performed that the supplied password decrypts content described by the encryption specification.

Parameters:

encryptDict - the Encrypt dict as found in the document's trailer. May be null, in which case the IdentityDecrypter will be returned.

documentId - the object with key "ID" in the trailer's dictionary. Should always be present if Encrypt is.

password - the password to use; may be null

Returns:

The decryptor that should be used for all encrypted data in the PDF

Throws:

IOException - if any.

EncryptionUnsupportedByPlatformException - if any.

EncryptionUnsupportedByProductException - if any.

PDFAuthenticationFailureException - if any.

isFilterExist

public static boolean isFilterExist(PDFObject encryptDict)

isFilterExist.

Parameters:

encryptDict - the Encrypt dict as found in the document's trailer.

Returns:

true if the Filter exist in the current dictionary