com.itextpdf.kernel.pdf

Class PdfEncryption

java.lang.Object

com.itextpdf.kernel.pdf.PdfObjectWrapper<PdfDictionary>

com.itextpdf.kernel.pdf.PdfEncryption

All Implemented Interfaces:

Serializable

public class PdfEncryption
extends PdfObjectWrapper<PdfDictionary>

Author:

Paulo Soares, Kazuya Ujihara

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
PdfEncryption(byte[] userPassword, byte[] ownerPassword, int permissions, int encryptionType, byte[] documentId) Creates the encryption.
PdfEncryption(Certificate[] certs, int[] permissions, int encryptionType) Creates the certificate encryption.
PdfEncryption(PdfDictionary pdfDict, byte[] password, byte[] documentId)
PdfEncryption(PdfDictionary pdfDict, Key certificateKey, Certificate certificate, String certificateKeyProvider, IExternalDecryptionProcess externalDecryptionProcess)

Method Summary

Modifier and Type	Method and Description
byte[]	computeUserPassword(byte[] ownerPassword) Computes user password if standard encryption handler is used with Standard40, Standard128 or AES128 algorithm.
static PdfObject	createInfoId(byte[] id, boolean modified) Creates a PdfLiteral that contains an array of two id entries.
static PdfObject	createInfoId(byte[] firstId, byte[] secondId) Creates a PdfLiteral that contains an array of two id entries.
byte[]	decryptByteArray(byte[] b)
byte[]	encryptByteArray(byte[] b)
void	flush() To manually flush a PdfObject behind this wrapper, you have to ensure that this object is added to the document, i.e.
static byte[]	generateNewDocumentId()
int	getCryptoMode() Gets encryption algorithm and access permissions.
byte[]	getDocumentId()
OutputStreamEncryption	getEncryptionStream(OutputStream os)
Long	getPermissions() Gets the encryption permissions.
boolean	isEmbeddedFilesOnly()
boolean	isMetadataEncrypted()
boolean	isOpenedWithFullPermission()
protected boolean	isWrappedObjectMustBeIndirect() Defines if the object behind this wrapper must be an indirect object in the resultant document.
void	setHashKeyForNextObject(int objNumber, int objGeneration)

Methods inherited from class com.itextpdf.kernel.pdf.PdfObjectWrapper

ensureObjectIsAddedToDocument, ensureUnderlyingObjectHasIndirectReference, getPdfObject, isFlushed, makeIndirect, makeIndirect, markObjectAsIndirect, setForbidRelease, setModified, setPdfObject, unsetForbidRelease

Methods inherited from class java.lang.Object

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

Constructor Detail

PdfEncryption

public PdfEncryption(byte[] userPassword,
                     byte[] ownerPassword,
                     int permissions,
                     int encryptionType,
                     byte[] documentId)

Creates the encryption. The userPassword and the ownerPassword can be null or have zero length. In this case the ownerPassword is replaced by a random string. The open permissions for the document can be AllowPrinting, AllowModifyContents, AllowCopy, AllowModifyAnnotations, AllowFillIn, AllowScreenReaders, AllowAssembly and AllowDegradedPrinting. The permissions can be combined by ORing them.

Parameters:

userPassword - the user password. Can be null or empty

ownerPassword - the owner password. Can be null or empty

permissions - the user permissions

encryptionType - the type of encryption. It can be one of STANDARD_ENCRYPTION_40, STANDARD_ENCRYPTION_128 or ENCRYPTION_AES128. Optionally DO_NOT_ENCRYPT_METADATA can be ored to output the metadata in cleartext

Throws:

PdfException - if the document is already open

PdfEncryption

public PdfEncryption(Certificate[] certs,
                     int[] permissions,
                     int encryptionType)

Creates the certificate encryption. An array of one or more public certificates must be provided together with an array of the same size for the permissions for each certificate. The open permissions for the document can be AllowPrinting, AllowModifyContents, AllowCopy, AllowModifyAnnotations, AllowFillIn, AllowScreenReaders, AllowAssembly and AllowDegradedPrinting. The permissions can be combined by ORing them. Optionally DO_NOT_ENCRYPT_METADATA can be ored to output the metadata in cleartext

Parameters:

certs - the public certificates to be used for the encryption

permissions - the user permissions for each of the certificates

encryptionType - the type of encryption. It can be one of STANDARD_ENCRYPTION_40, STANDARD_ENCRYPTION_128 or ENCRYPTION_AES128.

Throws:

PdfException - if the document is already open

PdfEncryption

public PdfEncryption(PdfDictionary pdfDict,
                     byte[] password,
                     byte[] documentId)

PdfEncryption

public PdfEncryption(PdfDictionary pdfDict,
                     Key certificateKey,
                     Certificate certificate,
                     String certificateKeyProvider,
                     IExternalDecryptionProcess externalDecryptionProcess)

Method Detail

generateNewDocumentId

public static byte[] generateNewDocumentId()

createInfoId

public static PdfObject createInfoId(byte[] id,
                                     boolean modified)

Creates a PdfLiteral that contains an array of two id entries. These entries are both hexadecimal strings containing 16 hex characters. The first entry is the original id, the second entry should be different from the first one if the document has changed.

Parameters:

id - the first id

modified - whether the document has been changed or not

Returns:

PdfObject containing the two entries.

createInfoId

public static PdfObject createInfoId(byte[] firstId,
                                     byte[] secondId)

Creates a PdfLiteral that contains an array of two id entries. These entries are both hexadecimal strings containing 16 hex characters. The first entry is the original id, the second entry should be different from the first one if the document has changed.

Parameters:

firstId - the first id

secondId - the second id

Returns:

PdfObject containing the two entries.

getPermissions

public Long getPermissions()

Gets the encryption permissions. It can be used directly in WriterProperties.setStandardEncryption(byte[], byte[], int, int). See ISO 32000-1, Table 22 for more details.

Returns:

the encryption permissions, an unsigned 32-bit quantity.

getCryptoMode

public int getCryptoMode()

Gets encryption algorithm and access permissions.

See Also:

EncryptionConstants

isMetadataEncrypted

public boolean isMetadataEncrypted()

isEmbeddedFilesOnly

public boolean isEmbeddedFilesOnly()

getDocumentId

public byte[] getDocumentId()

Returns:

document id which was used for encryption. Could be null, if encryption doesn't rely on document id.

setHashKeyForNextObject

public void setHashKeyForNextObject(int objNumber,
                                    int objGeneration)

getEncryptionStream

public OutputStreamEncryption getEncryptionStream(OutputStream os)

encryptByteArray

public byte[] encryptByteArray(byte[] b)

decryptByteArray

public byte[] decryptByteArray(byte[] b)

isOpenedWithFullPermission

public boolean isOpenedWithFullPermission()

computeUserPassword

public byte[] computeUserPassword(byte[] ownerPassword)

Computes user password if standard encryption handler is used with Standard40, Standard128 or AES128 algorithm.

Parameters:

ownerPassword - owner password of the encrypted document.

Returns:

user password, or null if not a standard encryption handler was used.

flush

public void flush()

To manually flush a PdfObject behind this wrapper, you have to ensure that this object is added to the document, i.e. it has an indirect reference. Basically this means that before flushing you need to explicitly call PdfObjectWrapper.makeIndirect(PdfDocument). For example: wrapperInstance.makeIndirect(document).flush(); Note that not every wrapper require this, only those that have such warning in documentation.

Overrides:

flush in class PdfObjectWrapper<PdfDictionary>

isWrappedObjectMustBeIndirect

protected boolean isWrappedObjectMustBeIndirect()

Description copied from class: PdfObjectWrapper

Defines if the object behind this wrapper must be an indirect object in the resultant document.

If this method returns true it doesn't necessarily mean that object must be in the indirect state at any moment, but rather defines that when the object will be written to the document it will be transformed into indirect object if it's not indirect yet.

Return value of this method shouldn't depend on any logic, it should return always true or false.

Specified by:

isWrappedObjectMustBeIndirect in class PdfObjectWrapper<PdfDictionary>

Returns:

true if in the resultant document the object behind the wrapper must be indirect, otherwise false.