/*
* Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright
* ownership. The ASF licenses this file to You under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the
* License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
* implied. See the License for the specific language governing permissions and limitations under the License.
*/
package org.apache.pdfbox.pdmodel.encryption;
import java.io.IOException;
import org.apache.pdfbox.cos.COSArray;
import org.apache.pdfbox.cos.COSBase;
import org.apache.pdfbox.cos.COSBoolean;
import org.apache.pdfbox.cos.COSDictionary;
import org.apache.pdfbox.cos.COSName;
import org.apache.pdfbox.cos.COSString;
/**
* This class is a specialized view of the encryption dictionary of a PDF document. It contains a low level dictionary (COSDictionary) and provides the methods to manage its fields.
*
* The available fields are the ones who are involved by standard security handler and public key security handler.
*
* @author <a href="mailto:ben@benlitchfield.com">Ben Litchfield</a>
* @author Benoit Guillon (benoit.guillon@snv.jussieu.fr)
*
* @version $Revision: 1.7 $
*/
public class PDEncryptionDictionary {
/**
* See PDF Reference 1.4 Table 3.13.
*/
public static final int VERSION0_UNDOCUMENTED_UNSUPPORTED = 0;
/**
* See PDF Reference 1.4 Table 3.13.
*/
public static final int VERSION1_40_BIT_ALGORITHM = 1;
/**
* See PDF Reference 1.4 Table 3.13.
*/
public static final int VERSION2_VARIABLE_LENGTH_ALGORITHM = 2;
/**
* See PDF Reference 1.4 Table 3.13.
*/
public static final int VERSION3_UNPUBLISHED_ALGORITHM = 3;
/**
* See PDF Reference 1.4 Table 3.13.
*/
public static final int VERSION4_SECURITY_HANDLER = 4;
public static final int VERSION5_SECURITY_HANDLER = 5;
/**
* The default length for the encryption key.
*/
public static final int DEFAULT_LENGTH = 40;
/**
* The default version, according to the PDF Reference.
*/
public static final int DEFAULT_VERSION = VERSION0_UNDOCUMENTED_UNSUPPORTED;
/**
* COS encryption dictionary.
*/
protected COSDictionary encryptionDictionary = null;
/**
* creates a new empty encryption dictionary.
*/
public PDEncryptionDictionary() {
encryptionDictionary = new COSDictionary();
}
/**
* creates a new encryption dictionary from the low level dictionary provided.
*
* @param d
* the low level dictionary that will be managed by the newly created object
*/
public PDEncryptionDictionary(final COSDictionary d) {
encryptionDictionary = d;
}
public COSArray findRecipients() {
final COSArray recipients = (COSArray) encryptionDictionary.getItem(COSName.RECIPIENTS);
if (recipients != null) {
return recipients;
}
final COSName streamFilterName = getStreamFilterName();
final PDCryptFilterDictionary cryptFilterDictionary = getCryptFilterDictionary(streamFilterName);
if (cryptFilterDictionary == null) {
return null;
}
final COSArray recipientsInCryptFilter = (COSArray) cryptFilterDictionary.cryptFilterDictionary.getItem(COSName.RECIPIENTS);
return recipientsInCryptFilter;
}
/**
* This will get the dictionary associated with this encryption dictionary.
*
* @return The COS dictionary that this object wraps.
*/
public COSDictionary getCOSDictionary() {
return encryptionDictionary;
}
/**
* Returns the crypt filter with the given name.
*
* @param cryptFilterName
* the name of the crypt filter
*
* @return the crypt filter with the given name if available
*/
public PDCryptFilterDictionary getCryptFilterDictionary(final COSName cryptFilterName) {
final COSDictionary cryptFilterDictionary = (COSDictionary) encryptionDictionary.getDictionaryObject(COSName.CF);
if (cryptFilterDictionary != null) {
final COSDictionary stdCryptFilterDictionary = (COSDictionary) cryptFilterDictionary.getDictionaryObject(cryptFilterName);
if (stdCryptFilterDictionary != null) {
return new PDCryptFilterDictionary(stdCryptFilterDictionary);
}
}
return null;
}
/**
* Get the name of the filter.
*
* @return The filter name contained in this encryption dictionary.
*/
public String getFilter() {
return encryptionDictionary.getNameAsString(COSName.FILTER);
}
/**
* This will return the Length entry of the encryption dictionary.<br />
* <br />
* The length in <b>bits</b> for the encryption algorithm. This will return a multiple of 8.
*
* @return The length in bits for the encryption algorithm
*/
public int getLength() {
return encryptionDictionary.getInt(COSName.LENGTH, 40);
}
/**
* This will get the O entry in the standard encryption dictionary.
*
* @return A 32 byte array or null if there is no owner key.
*
* @throws IOException
* If there is an error accessing the data.
*/
public byte[] getOwnerKey() throws IOException {
byte[] o = null;
final COSString owner = (COSString) encryptionDictionary.getDictionaryObject(COSName.O);
if (owner != null) {
o = owner.getBytes();
}
return o;
}
/**
* This will get the permissions bit mask.
*
* @return The permissions bit mask.
*/
public int getPermissions() {
return encryptionDictionary.getInt(COSName.P, 0);
}
/**
* Returns the number of recipients contained in the Recipients field of the dictionary.
*
* @return the number of recipients contained in the Recipients field.
*/
public int getRecipientsLength() {
final COSArray recipients = findRecipients();
if (recipients == null) {
return 0;
}
return recipients.size();
}
/**
* returns the COSString contained in the Recipients field at position i.
*
* @param i
* the position in the Recipients field array.
*
* @return a COSString object containing information about the recipient number i.
*/
public COSString getRecipientStringAt(final int i) {
final COSArray recipients = findRecipients();
if (recipients == null) {
return null;
}
return (COSString) recipients.get(i);
}
/**
* This will return the R entry of the encryption dictionary.<br />
* <br />
* See PDF Reference 1.4 Table 3.14.
*
* @return The encryption revision to use.
*/
public int getRevision() {
return encryptionDictionary.getInt(COSName.R, DEFAULT_VERSION);
}
/**
* Returns the standard crypt filter.
*
* @return the standard crypt filter if available.
*/
public PDCryptFilterDictionary getStdCryptFilterDictionary() {
return getCryptFilterDictionary(COSName.STD_CF);
}
/**
* Returns the name of the filter which is used for de/encrypting streams. Default value is "Identity".
*
* @return the name of the filter
*/
public COSName getStreamFilterName() {
COSName stmF = (COSName) encryptionDictionary.getDictionaryObject(COSName.STM_F);
if (stmF == null) {
stmF = COSName.IDENTITY;
}
return stmF;
}
/**
* Returns the name of the filter which is used for de/encrypting strings. Default value is "Identity".
*
* @return the name of the filter
*/
public COSName getStringFilterName() {
COSName strF = (COSName) encryptionDictionary.getDictionaryObject(COSName.STR_F);
if (strF == null) {
strF = COSName.IDENTITY;
}
return strF;
}
/**
* Get the name of the subfilter.
*
* @return The subfilter name contained in this encryption dictionary.
*/
public String getSubFilter() {
return encryptionDictionary.getNameAsString(COSName.SUB_FILTER);
}
/**
* This will get the U entry in the standard encryption dictionary.
*
* @return A 32 byte array or null if there is no user key.
*
* @throws IOException
* If there is an error accessing the data.
*/
public byte[] getUserKey() throws IOException {
byte[] u = null;
final COSString user = (COSString) encryptionDictionary.getDictionaryObject(COSName.U);
if (user != null) {
u = user.getBytes();
}
return u;
}
/**
* This will return the V entry of the encryption dictionary.<br />
* <br />
* See PDF Reference 1.4 Table 3.13.
*
* @return The encryption version to use.
*/
public int getVersion() {
return encryptionDictionary.getInt(COSName.V, 0);
}
/**
* Will get the EncryptMetaData dictionary info.
*
* @return true if EncryptMetaData is explicitly set to false (the default is true)
*/
public boolean isEncryptMetaData() {
// default is true (see 7.6.3.2 Standard Encryption Dictionary PDF 32000-1:2008)
boolean encryptMetaData = true;
final COSBase value = encryptionDictionary.getDictionaryObject(COSName.ENCRYPT_META_DATA);
if (value instanceof COSBoolean) {
encryptMetaData = ((COSBoolean) value).getValue();
}
return encryptMetaData;
}
public void setCryptFilterDictionary(final COSName cryptFilterName, final PDCryptFilterDictionary cryptFilterDictionary) {
encryptionDictionary.setItem(cryptFilterName, cryptFilterDictionary.getCOSDictionary());
}
/**
* Sets the filter entry of the encryption dictionary.
*
* @param filter
* The filter name.
*/
public void setFilter(final String filter) {
encryptionDictionary.setItem(COSName.FILTER, COSName.getPDFName(filter));
}
/**
* This will set the number of bits to use for the encryption algorithm.
*
* @param length
* The new key length.
*/
public void setLength(final int length) {
encryptionDictionary.setInt(COSName.LENGTH, length);
}
/**
* This will set the O entry in the standard encryption dictionary.
*
* @param o
* A 32 byte array or null if there is no owner key.
*
* @throws IOException
* If there is an error setting the data.
*/
public void setOwnerKey(final byte[] o) throws IOException {
final COSString owner = new COSString();
owner.append(o);
encryptionDictionary.setItem(COSName.O, owner);
}
/**
* This will set the permissions bit mask.
*
* @param permissions
* The new permissions bit mask
*/
public void setPermissions(final int permissions) {
encryptionDictionary.setInt(COSName.P, permissions);
}
/**
* This will set the Recipients field of the dictionary. This field contains an array of string.
*
* @param recipients
* the array of bytes arrays to put in the Recipients field.
* @throws IOException
* If there is an error setting the data.
*/
public void setRecipients(final byte[][] recipients) throws IOException {
final COSArray array = new COSArray();
for (int i = 0; i < recipients.length; i++) {
final COSString recip = new COSString();
recip.append(recipients[i]);
recip.setForceLiteralForm(true);
array.add(recip);
}
encryptionDictionary.setItem(COSName.RECIPIENTS, array);
}
/**
* This will set the R entry of the encryption dictionary.<br />
* <br />
* See PDF Reference 1.4 Table 3.14. <br />
* <br/>
*
* <b>Note: This value is used to decrypt the pdf document. If you change this when the document is encrypted then decryption will fail!.</b>
*
* @param revision
* The new encryption version.
*/
public void setRevision(final int revision) {
encryptionDictionary.setInt(COSName.R, revision);
}
public void setStdCryptFilterDictionary(final PDCryptFilterDictionary cryptFilterDictionary) {
encryptionDictionary.setItem(COSName.STD_CF, cryptFilterDictionary.getCOSDictionary());
}
public void setStreamFilterName(final String streamFilterName) {
encryptionDictionary.setName(COSName.STM_F, streamFilterName);
}
public void setStringFilterName(final String stringFilterName) {
encryptionDictionary.setName(COSName.STR_F, stringFilterName);
}
/**
* Set the subfilter entry of the encryption dictionary.
*
* @param subfilter
* The value of the subfilter field.
*/
public void setSubFilter(final String subfilter) {
encryptionDictionary.setName(COSName.SUB_FILTER, subfilter);
}
/**
* This will set the U entry in the standard encryption dictionary.
*
* @param u
* A 32 byte array.
*
* @throws IOException
* If there is an error setting the data.
*/
public void setUserKey(final byte[] u) throws IOException {
final COSString user = new COSString();
user.append(u);
encryptionDictionary.setItem(COSName.U, user);
}
/**
* This will set the V entry of the encryption dictionary.<br />
* <br />
* See PDF Reference 1.4 Table 3.13. <br />
* <br/>
* <b>Note: This value is used to decrypt the pdf document. If you change this when the document is encrypted then decryption will fail!.</b>
*
* @param version
* The new encryption version.
*/
public void setVersion(final int version) {
encryptionDictionary.setInt(COSName.V, version);
}
}