Package org.apache.pdfbox.examples.signature

Class CreateEmbeddedTimeStamp

java.lang.Object

org.apache.pdfbox.examples.signature.CreateEmbeddedTimeStamp

public class CreateEmbeddedTimeStamp
extends Object

An example for timestamp-signing a PDF for PADeS-Specification. The document will only be changed in its existing signature by a signed timestamp (A timestamp and the Hash-Value of the document are signed by a Time Stamp Authority (TSA)). This method only changes the unsigned parameters of a signature, so that it is kept valid. Use case: sign offline to avoid zero-day attacks against the signing machine. Once the signature is there and the pdf is transferred to a network connected machine, one is likely to want to add a timestamp. (Ralf Hauser)

Field Summary

Fields

Modifier and Type	Field	Description
private byte[]	changedEncodedSignature
private PDDocument	document
private PDSignature	signature
private final String	tsaUrl

Constructor Summary

Constructors

Constructor	Description
CreateEmbeddedTimeStamp(String tsaUrl)

Method Summary

Modifier and Type	Method	Description
private void	embedNewSignatureIntoDocument(byte[] docBytes, OutputStream output)	Embeds the new signature into the document, by copying the rest of the document
void	embedTimeStamp(File file)	Embeds the given PDF file with signed timestamp(s).
void	embedTimeStamp(File inFile, File outFile)	Embeds signed timestamp(s) into existing signatures of the given document
static void	main(String[] args)
private void	processRelevantSignatures(byte[] documentBytes)	Create changed Signature with embedded TimeStamp from TSA
private void	processTimeStamping(File inFile, File outFile)	Processes the time-stamping of the signature.
private static void	usage()

Methods inherited from class java.lang.Object

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

Field Details

tsaUrl

private final String tsaUrl

document

private PDDocument document

signature

private PDSignature signature

changedEncodedSignature

private byte[] changedEncodedSignature

Constructor Details

CreateEmbeddedTimeStamp

public CreateEmbeddedTimeStamp(String tsaUrl)

Method Details

embedTimeStamp

public void embedTimeStamp(File file)
                    throws IOException,
URISyntaxException

Embeds the given PDF file with signed timestamp(s). Alters the original file on disk.

Parameters:

file - the PDF file to sign and to overwrite

Throws:

IOException

URISyntaxException

embedTimeStamp

public void embedTimeStamp(File inFile,
 File outFile)
                    throws IOException,
URISyntaxException

Embeds signed timestamp(s) into existing signatures of the given document

Parameters:

inFile - The pdf file possibly containing signatures

outFile - Where the changed document will be saved

Throws:

IOException

URISyntaxException

processTimeStamping

private void processTimeStamping(File inFile,
 File outFile)
                          throws IOException,
URISyntaxException

Processes the time-stamping of the signature.

Parameters:

inFile - The existing PDF file

outFile - Where the new file will be written to

Throws:

IOException

URISyntaxException

processRelevantSignatures

private void processRelevantSignatures(byte[] documentBytes)
                                throws IOException,
org.bouncycastle.cms.CMSException,
NoSuchAlgorithmException,
URISyntaxException

Create changed Signature with embedded TimeStamp from TSA

Parameters:

documentBytes - byte[] of the input file

Throws:

IOException

org.bouncycastle.cms.CMSException

NoSuchAlgorithmException

URISyntaxException

embedNewSignatureIntoDocument

private void embedNewSignatureIntoDocument(byte[] docBytes,
 OutputStream output)
                                    throws IOException

Embeds the new signature into the document, by copying the rest of the document

Parameters:

docBytes - byte array of the document

output - target, where the file will be written

Throws:

IOException

main

public static void main(String[] args)
                 throws IOException,
URISyntaxException

Throws:

IOException

URISyntaxException

usage

private static void usage()