com.itdhq.poc.ocrsign.ShowSignature.java Source code

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Here is the source code for com.itdhq.poc.ocrsign.ShowSignature.java

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package com.itdhq.poc.ocrsign;

/*
 * 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.
 */

import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.IOException;
import java.security.cert.Certificate;
import java.security.cert.CertificateException;
import java.security.cert.CertificateFactory;
import java.util.Collection;

import org.apache.pdfbox.cos.COSArray;
import org.apache.pdfbox.cos.COSDictionary;
import org.apache.pdfbox.cos.COSName;
import org.apache.pdfbox.cos.COSString;
import org.apache.pdfbox.pdmodel.PDDocument;

/**
 * This will read a document from the filesystem, decrypt it and do something with the signature.
 *
 * @author Ben Litchfield
 */
public final class ShowSignature {
    private ShowSignature() {
    }

    /**
     * This is the entry point for the application.
     *
     * @param args The command-line arguments.
     *
     * @throws IOException If there is an error reading the file.
     * @throws CertificateException
     */
    public static void main(String[] args) throws IOException, CertificateException {
        ShowSignature show = new ShowSignature();
        show.showSignature(args);
    }

    private void showSignature(String[] args) throws IOException, CertificateException {
        if (args.length != 2) {
            usage();
        } else {
            String password = args[0];
            String infile = args[1];
            PDDocument document = null;
            try {
                document = PDDocument.load(new File(infile));
                if (!document.isEncrypted()) {
                    System.err.println("Warning: Document is not encrypted.");
                }

                COSDictionary trailer = document.getDocument().getTrailer();
                COSDictionary root = (COSDictionary) trailer.getDictionaryObject(COSName.ROOT);
                COSDictionary acroForm = (COSDictionary) root.getDictionaryObject(COSName.ACRO_FORM);
                COSArray fields = (COSArray) acroForm.getDictionaryObject(COSName.FIELDS);
                for (int i = 0; i < fields.size(); i++) {
                    COSDictionary field = (COSDictionary) fields.getObject(i);
                    // FIXME
                    /*
                    COSName type = field.getCOSName( COSName.FT );
                    if( COSName.SIG.equals( type ) )
                    {
                    COSDictionary cert = (COSDictionary)field.getDictionaryObject( COSName.V );
                    if( cert != null )
                    {
                        System.out.println( "Certificate found" );
                        System.out.println( "Name=" + cert.getDictionaryObject( COSName.NAME ) );
                        System.out.println( "Modified=" + cert.getDictionaryObject( COSName.M ) );
                        COSName subFilter = (COSName)cert.getDictionaryObject( COSName.SUB_FILTER );
                        if( subFilter != null )
                        {
                            if( subFilter.getName().equals( "adbe.x509.rsa_sha1" ) )
                            {
                                COSString certString = (COSString)cert.getDictionaryObject(
                                        COSName.getPDFName( "Cert" ) );
                                byte[] certData = certString.getBytes();
                                CertificateFactory factory = CertificateFactory.getInstance( "X.509" );
                                ByteArrayInputStream certStream = new ByteArrayInputStream( certData );
                                Collection<? extends Certificate> certs = factory.generateCertificates( certStream );
                                System.out.println( "certs=" + certs );
                            }
                            else if( subFilter.getName().equals( "adbe.pkcs7.sha1" ) )
                            {
                                COSString certString = (COSString)cert.getDictionaryObject(
                                        COSName.CONTENTS );
                                byte[] certData = certString.getBytes();
                                CertificateFactory factory = CertificateFactory.getInstance( "X.509" );
                                ByteArrayInputStream certStream = new ByteArrayInputStream( certData );
                                Collection<? extends Certificate> certs = factory.generateCertificates( certStream );
                                System.out.println( "certs=" + certs );
                            }
                            else
                            {
                                System.err.println( "Unknown certificate type:" + subFilter );
                            }
                        }
                        else
                        {
                            throw new IOException( "Missing subfilter for cert dictionary" );
                        }
                    }
                    else
                    {
                        System.out.println( "Signature found, but no certificate" );
                    }
                    }
                    */
                }
            } finally {
                if (document != null) {
                    document.close();
                }
            }
        }
    }

    /**
     * This will print a usage message.
     */
    private static void usage() {
        System.err.println("usage: java " + ShowSignature.class.getName() + "<password> <inputfile>");
    }
}