org.verapdf.tools

Class EncryptionToolsRevision6

java.lang.Object

org.verapdf.tools.EncryptionToolsRevision6

public class EncryptionToolsRevision6
extends Object

Author:

Sergey Shemyakov

Constructor Summary

Constructors

Constructor and Description
EncryptionToolsRevision6()

Method Summary

Modifier and Type	Method and Description
static byte[]	computeHashRevision6(byte[] password, byte[] string, byte[] u, boolean isCheckingOwnerPassword) Implements algorithm 2.B: Computing a hash (revision 6 and later), introduced in PDF-2.0.
static void	enableAES256()
static byte[]	getFileEncryptionKey(byte[] password, byte[] o, byte[] u, byte[] oe, byte[] ue) Implementation of algorithm 2.A: Retrieving the file encryption key from an encrypted document in order to decrypt it (revision 6 and later) as described in PDF-2.0 specification.

Methods inherited from class java.lang.Object

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

Constructor Detail

EncryptionToolsRevision6

public EncryptionToolsRevision6()

Method Detail

getFileEncryptionKey

public static byte[] getFileEncryptionKey(byte[] password,
                                          byte[] o,
                                          byte[] u,
                                          byte[] oe,
                                          byte[] ue)
                                   throws GeneralSecurityException

Implementation of algorithm 2.A: Retrieving the file encryption key from an encrypted document in order to decrypt it (revision 6 and later) as described in PDF-2.0 specification.

Parameters:

password - is UTF-8 representation of password.

o - is value of O key.

u - is value of U key.

oe - is value of OE key. At least one of oe, ue should not be null.

ue - is value of UE key. At least one of oe, ue should not be null.

Returns:

calculated file encryption key.

Throws:

GeneralSecurityException - if password is not valid or error with AES-256 happens.

computeHashRevision6

public static byte[] computeHashRevision6(byte[] password,
                                          byte[] string,
                                          byte[] u,
                                          boolean isCheckingOwnerPassword)
                                   throws GeneralSecurityException

Implements algorithm 2.B: Computing a hash (revision 6 and later), introduced in PDF-2.0.

Parameters:

string - is UTF-8 password hashInput string.

u - is 48 byte user key.

isCheckingOwnerPassword - is true if hash is being calculated for checking the owner password or creating the owner key.

Returns:

computed hash.

Throws:

GeneralSecurityException

enableAES256

public static void enableAES256()
                         throws GeneralSecurityException

Throws:

GeneralSecurityException