# SigningSupport.java

    /*
     * 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.interactive.digitalsignature;

    import org.apache.pdfbox.pdfwriter.COSWriter;

    import java.io.Closeable;
    import java.io.IOException;
    import java.io.InputStream;

    /**
     * Class to be used when creating PDF signatures externally. COSWriter is used to obtain data to be
     * signed and set the resulted CMS signature.
     *
     */
    public class SigningSupport implements ExternalSigningSupport, Closeable
    {
        private COSWriter cosWriter;

        public SigningSupport(COSWriter cosWriter)
        {
            this.cosWriter = cosWriter;
        }

        @Override
        public InputStream getContent() throws IOException
        {
            return cosWriter.getDataToSign();
        }

        @Override
        public void setSignature(byte[] signature) throws IOException
        {
            cosWriter.writeExternalSignature(signature);
        }

        @Override
        public void close() throws IOException
        {
            cosWriter = null;
        }
    }