fix: pkcs12 signing

TODO: add PEM support and use page number

src/main/java/org/apache/pdfbox/examples/signature/CMSProcessableInputStream.java

@@ -0,0 +1,64 @@
+/*
+ * 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.examples.signature;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+
+import org.bouncycastle.asn1.ASN1ObjectIdentifier;
+import org.bouncycastle.asn1.cms.CMSObjectIdentifiers;
+import org.bouncycastle.cms.CMSException;
+import org.bouncycastle.cms.CMSTypedData;
+
+/**
+ * Wraps a InputStream into a CMSProcessable object for bouncy castle. It's a memory saving
+ * alternative to the {@link org.bouncycastle.cms.CMSProcessableByteArray CMSProcessableByteArray}
+ * class.
+ *
+ * @author Thomas Chojecki
+ */
+class CMSProcessableInputStream implements CMSTypedData {
+    private final InputStream in;
+    private final ASN1ObjectIdentifier contentType;
+
+    CMSProcessableInputStream(InputStream is) {
+        this(new ASN1ObjectIdentifier(CMSObjectIdentifiers.data.getId()), is);
+    }
+
+    CMSProcessableInputStream(ASN1ObjectIdentifier type, InputStream is) {
+        contentType = type;
+        in = is;
+    }
+
+    @Override
+    public Object getContent() {
+        return in;
+    }
+
+    @Override
+    public void write(OutputStream out) throws IOException, CMSException {
+        // read the content only one time
+        in.transferTo(out);
+        in.close();
+    }
+
+    @Override
+    public ASN1ObjectIdentifier getContentType() {
+        return contentType;
+    }
+}

src/main/java/org/apache/pdfbox/examples/signature/CreateSignatureBase.java

@@ -0,0 +1,170 @@
+/*
+ * Copyright 2015 The Apache Software Foundation.
+ *
+ * Licensed 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.examples.signature;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.URISyntaxException;
+import java.security.GeneralSecurityException;
+import java.security.KeyStore;
+import java.security.KeyStoreException;
+import java.security.NoSuchAlgorithmException;
+import java.security.PrivateKey;
+import java.security.UnrecoverableKeyException;
+import java.security.cert.Certificate;
+import java.security.cert.CertificateException;
+import java.security.cert.X509Certificate;
+import java.util.Arrays;
+import java.util.Enumeration;
+
+import org.apache.pdfbox.pdmodel.interactive.digitalsignature.SignatureInterface;
+import org.bouncycastle.cert.jcajce.JcaCertStore;
+import org.bouncycastle.cms.CMSException;
+import org.bouncycastle.cms.CMSSignedData;
+import org.bouncycastle.cms.CMSSignedDataGenerator;
+import org.bouncycastle.cms.jcajce.JcaSignerInfoGeneratorBuilder;
+import org.bouncycastle.operator.ContentSigner;
+import org.bouncycastle.operator.OperatorCreationException;
+import org.bouncycastle.operator.jcajce.JcaContentSignerBuilder;
+import org.bouncycastle.operator.jcajce.JcaDigestCalculatorProviderBuilder;
+
+public abstract class CreateSignatureBase implements SignatureInterface {
+    private PrivateKey privateKey;
+    private Certificate[] certificateChain;
+    private String tsaUrl;
+    private boolean externalSigning;
+
+    /**
+     * Initialize the signature creator with a keystore (pkcs12) and pin that should be used for the
+     * signature.
+     *
+     * @param keystore is a pkcs12 keystore.
+     * @param pin is the pin for the keystore / private key
+     * @throws KeyStoreException if the keystore has not been initialized (loaded)
+     * @throws NoSuchAlgorithmException if the algorithm for recovering the key cannot be found
+     * @throws UnrecoverableKeyException if the given password is wrong
+     * @throws CertificateException if the certificate is not valid as signing time
+     * @throws IOException if no certificate could be found
+     */
+    public CreateSignatureBase(KeyStore keystore, char[] pin)
+            throws KeyStoreException,
+                    UnrecoverableKeyException,
+                    NoSuchAlgorithmException,
+                    IOException,
+                    CertificateException {
+        // grabs the first alias from the keystore and get the private key. An
+        // alternative method or constructor could be used for setting a specific
+        // alias that should be used.
+        Enumeration<String> aliases = keystore.aliases();
+        String alias;
+        Certificate cert = null;
+        while (cert == null && aliases.hasMoreElements()) {
+            alias = aliases.nextElement();
+            setPrivateKey((PrivateKey) keystore.getKey(alias, pin));
+            Certificate[] certChain = keystore.getCertificateChain(alias);
+            if (certChain != null) {
+                setCertificateChain(certChain);
+                cert = certChain[0];
+                if (cert instanceof X509Certificate) {
+                    // avoid expired certificate
+                    ((X509Certificate) cert).checkValidity();
+
+                    //// SigUtils.checkCertificateUsage((X509Certificate) cert);
+                }
+            }
+        }
+
+        if (cert == null) {
+            throw new IOException("Could not find certificate");
+        }
+    }
+
+    public final void setPrivateKey(PrivateKey privateKey) {
+        this.privateKey = privateKey;
+    }
+
+    public final void setCertificateChain(final Certificate[] certificateChain) {
+        this.certificateChain = certificateChain;
+    }
+
+    public Certificate[] getCertificateChain() {
+        return certificateChain;
+    }
+
+    public void setTsaUrl(String tsaUrl) {
+        this.tsaUrl = tsaUrl;
+    }
+
+    /**
+     * SignatureInterface sample implementation.
+     *
+     * <p>This method will be called from inside of the pdfbox and create the PKCS #7 signature. The
+     * given InputStream contains the bytes that are given by the byte range.
+     *
+     * <p>This method is for internal use only.
+     *
+     * <p>Use your favorite cryptographic library to implement PKCS #7 signature creation. If you
+     * want to create the hash and the signature separately (e.g. to transfer only the hash to an
+     * external application), read <a href="https://stackoverflow.com/questions/41767351">this
+     * answer</a> or <a href="https://stackoverflow.com/questions/56867465">this answer</a>.
+     *
+     * @throws IOException
+     */
+    @Override
+    public byte[] sign(InputStream content) throws IOException {
+        // cannot be done private (interface)
+        try {
+            CMSSignedDataGenerator gen = new CMSSignedDataGenerator();
+            X509Certificate cert = (X509Certificate) certificateChain[0];
+            ContentSigner sha1Signer =
+                    new JcaContentSignerBuilder("SHA256WithRSA").build(privateKey);
+            gen.addSignerInfoGenerator(
+                    new JcaSignerInfoGeneratorBuilder(
+                                    new JcaDigestCalculatorProviderBuilder().build())
+                            .build(sha1Signer, cert));
+            gen.addCertificates(new JcaCertStore(Arrays.asList(certificateChain)));
+            CMSProcessableInputStream msg = new CMSProcessableInputStream(content);
+            CMSSignedData signedData = gen.generate(msg, false);
+            if (tsaUrl != null && !tsaUrl.isEmpty()) {
+                ValidationTimeStamp validation = new ValidationTimeStamp(tsaUrl);
+                signedData = validation.addSignedTimeStamp(signedData);
+            }
+            return signedData.getEncoded();
+        } catch (GeneralSecurityException
+                | CMSException
+                | OperatorCreationException
+                | URISyntaxException e) {
+            throw new IOException(e);
+        }
+    }
+
+    /**
+     * Set if external signing scenario should be used. If {@code false}, SignatureInterface would
+     * be used for signing.
+     *
+     * <p>Default: {@code false}
+     *
+     * @param externalSigning {@code true} if external signing should be performed
+     */
+    public void setExternalSigning(boolean externalSigning) {
+        this.externalSigning = externalSigning;
+    }
+
+    public boolean isExternalSigning() {
+        return externalSigning;
+    }
+}

src/main/java/org/apache/pdfbox/examples/signature/TSAClient.java

@@ -0,0 +1,176 @@
+/*
+ * 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.examples.signature;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.math.BigInteger;
+import java.net.URL;
+import java.net.URLConnection;
+import java.nio.charset.StandardCharsets;
+import java.security.DigestInputStream;
+import java.security.MessageDigest;
+import java.security.SecureRandom;
+import java.util.Base64;
+import java.util.Random;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.bouncycastle.asn1.ASN1ObjectIdentifier;
+import org.bouncycastle.operator.DefaultDigestAlgorithmIdentifierFinder;
+import org.bouncycastle.operator.DigestAlgorithmIdentifierFinder;
+import org.bouncycastle.tsp.TSPException;
+import org.bouncycastle.tsp.TimeStampRequest;
+import org.bouncycastle.tsp.TimeStampRequestGenerator;
+import org.bouncycastle.tsp.TimeStampResponse;
+import org.bouncycastle.tsp.TimeStampToken;
+
+/**
+ * Time Stamping Authority (TSA) Client [RFC 3161].
+ *
+ * @author Vakhtang Koroghlishvili
+ * @author John Hewson
+ */
+public class TSAClient {
+    private static final Logger LOG = LogManager.getLogger(TSAClient.class);
+
+    private static final DigestAlgorithmIdentifierFinder ALGORITHM_OID_FINDER =
+            new DefaultDigestAlgorithmIdentifierFinder();
+
+    private final URL url;
+    private final String username;
+    private final String password;
+    private final MessageDigest digest;
+
+    // SecureRandom.getInstanceStrong() would be better, but sometimes blocks on Linux
+    private static final Random RANDOM = new SecureRandom();
+
+    /**
+     * @param url the URL of the TSA service
+     * @param username user name of TSA
+     * @param password password of TSA
+     * @param digest the message digest to use
+     */
+    public TSAClient(URL url, String username, String password, MessageDigest digest) {
+        this.url = url;
+        this.username = username;
+        this.password = password;
+        this.digest = digest;
+    }
+
+    /**
+     * @param content
+     * @return the time stamp token
+     * @throws IOException if there was an error with the connection or data from the TSA server, or
+     *     if the time stamp response could not be validated
+     */
+    public TimeStampToken getTimeStampToken(InputStream content) throws IOException {
+        digest.reset();
+        DigestInputStream dis = new DigestInputStream(content, digest);
+        while (dis.read() != -1) {
+            // do nothing
+        }
+        byte[] hash = digest.digest();
+
+        // 32-bit cryptographic nonce
+        int nonce = RANDOM.nextInt();
+
+        // generate TSA request
+        TimeStampRequestGenerator tsaGenerator = new TimeStampRequestGenerator();
+        tsaGenerator.setCertReq(true);
+        ASN1ObjectIdentifier oid = ALGORITHM_OID_FINDER.find(digest.getAlgorithm()).getAlgorithm();
+        TimeStampRequest request = tsaGenerator.generate(oid, hash, BigInteger.valueOf(nonce));
+
+        // get TSA response
+        byte[] tsaResponse = getTSAResponse(request.getEncoded());
+
+        TimeStampResponse response;
+        try {
+            response = new TimeStampResponse(tsaResponse);
+            response.validate(request);
+        } catch (TSPException e) {
+            throw new IOException(e);
+        }
+
+        TimeStampToken timeStampToken = response.getTimeStampToken();
+        if (timeStampToken == null) {
+            // https://www.ietf.org/rfc/rfc3161.html#section-2.4.2
+            throw new IOException(
+                    "Response from "
+                            + url
+                            + " does not have a time stamp token, status: "
+                            + response.getStatus()
+                            + " ("
+                            + response.getStatusString()
+                            + ")");
+        }
+
+        return timeStampToken;
+    }
+
+    // gets response data for the given encoded TimeStampRequest data
+    // throws IOException if a connection to the TSA cannot be established
+    private byte[] getTSAResponse(byte[] request) throws IOException {
+        LOG.debug("Opening connection to TSA server");
+
+        // todo: support proxy servers
+        URLConnection connection = url.openConnection();
+        connection.setDoOutput(true);
+        connection.setDoInput(true);
+        connection.setRequestProperty("Content-Type", "application/timestamp-query");
+
+        LOG.debug("Established connection to TSA server");
+
+        if (username != null && password != null && !username.isEmpty() && !password.isEmpty()) {
+            String contentEncoding = connection.getContentEncoding();
+            if (contentEncoding == null) {
+                contentEncoding = StandardCharsets.UTF_8.name();
+            }
+            connection.setRequestProperty(
+                    "Authorization",
+                    "Basic "
+                            + new String(
+                                    Base64.getEncoder()
+                                            .encode(
+                                                    (username + ":" + password)
+                                                            .getBytes(contentEncoding))));
+        }
+
+        // read response
+        try (OutputStream output = connection.getOutputStream()) {
+            output.write(request);
+        } catch (IOException ex) {
+            LOG.error("Exception when writing to {}", this.url, ex);
+            throw ex;
+        }
+
+        LOG.debug("Waiting for response from TSA server");
+
+        byte[] response;
+        try (InputStream input = connection.getInputStream()) {
+            response = input.readAllBytes();
+        } catch (IOException ex) {
+            LOG.error("Exception when reading from {}", this.url, ex);
+            throw ex;
+        }
+
+        LOG.debug("Received response from TSA server");
+
+        return response;
+    }
+}

src/main/java/org/apache/pdfbox/examples/signature/ValidationTimeStamp.java

@@ -0,0 +1,134 @@
+/*
+ * 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.examples.signature;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.MalformedURLException;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.bouncycastle.asn1.ASN1Encodable;
+import org.bouncycastle.asn1.ASN1EncodableVector;
+import org.bouncycastle.asn1.ASN1ObjectIdentifier;
+import org.bouncycastle.asn1.ASN1Primitive;
+import org.bouncycastle.asn1.DERSet;
+import org.bouncycastle.asn1.cms.Attribute;
+import org.bouncycastle.asn1.cms.AttributeTable;
+import org.bouncycastle.asn1.cms.Attributes;
+import org.bouncycastle.asn1.pkcs.PKCSObjectIdentifiers;
+import org.bouncycastle.cms.CMSSignedData;
+import org.bouncycastle.cms.SignerInformation;
+import org.bouncycastle.cms.SignerInformationStore;
+import org.bouncycastle.tsp.TimeStampToken;
+
+/**
+ * This class wraps the TSAClient and the work that has to be done with it. Like Adding Signed
+ * TimeStamps to a signature, or creating a CMS timestamp attribute (with a signed timestamp)
+ *
+ * @author Others
+ * @author Alexis Suter
+ */
+public class ValidationTimeStamp {
+    private TSAClient tsaClient;
+
+    /**
+     * @param tsaUrl The url where TS-Request will be done.
+     * @throws NoSuchAlgorithmException
+     * @throws MalformedURLException
+     * @throws java.net.URISyntaxException
+     */
+    public ValidationTimeStamp(String tsaUrl)
+            throws NoSuchAlgorithmException, MalformedURLException, URISyntaxException {
+        if (tsaUrl != null) {
+            MessageDigest digest = MessageDigest.getInstance("SHA-256");
+            this.tsaClient = new TSAClient(new URI(tsaUrl).toURL(), null, null, digest);
+        }
+    }
+
+    /**
+     * Creates a signed timestamp token by the given input stream.
+     *
+     * @param content InputStream of the content to sign
+     * @return the byte[] of the timestamp token
+     * @throws IOException
+     */
+    public byte[] getTimeStampToken(InputStream content) throws IOException {
+        TimeStampToken timeStampToken = tsaClient.getTimeStampToken(content);
+        return timeStampToken.getEncoded();
+    }
+
+    /**
+     * Extend cms signed data with TimeStamp first or to all signers
+     *
+     * @param signedData Generated CMS signed data
+     * @return CMSSignedData Extended CMS signed data
+     * @throws IOException
+     */
+    public CMSSignedData addSignedTimeStamp(CMSSignedData signedData) throws IOException {
+        SignerInformationStore signerStore = signedData.getSignerInfos();
+        List<SignerInformation> newSigners = new ArrayList<>();
+
+        for (SignerInformation signer : signerStore.getSigners()) {
+            // This adds a timestamp to every signer (into his unsigned attributes) in the
+            // signature.
+            newSigners.add(signTimeStamp(signer));
+        }
+
+        // Because new SignerInformation is created, new SignerInfoStore has to be created
+        // and also be replaced in signedData. Which creates a new signedData object.
+        return CMSSignedData.replaceSigners(signedData, new SignerInformationStore(newSigners));
+    }
+
+    /**
+     * Extend CMS Signer Information with the TimeStampToken into the unsigned Attributes.
+     *
+     * @param signer information about signer
+     * @return information about SignerInformation
+     * @throws IOException
+     */
+    private SignerInformation signTimeStamp(SignerInformation signer) throws IOException {
+        AttributeTable unsignedAttributes = signer.getUnsignedAttributes();
+
+        ASN1EncodableVector vector = new ASN1EncodableVector();
+        if (unsignedAttributes != null) {
+            vector = unsignedAttributes.toASN1EncodableVector();
+        }
+
+        TimeStampToken timeStampToken =
+                tsaClient.getTimeStampToken(new ByteArrayInputStream(signer.getSignature()));
+        byte[] token = timeStampToken.getEncoded();
+        ASN1ObjectIdentifier oid = PKCSObjectIdentifiers.id_aa_signatureTimeStampToken;
+        ASN1Encodable signatureTimeStamp =
+                new Attribute(oid, new DERSet(ASN1Primitive.fromByteArray(token)));
+
+        vector.add(signatureTimeStamp);
+        Attributes signedAttributes = new Attributes(vector);
+
+        // There is no other way changing the unsigned attributes of the signer information.
+        // result is never null, new SignerInformation always returned,
+        // see source code of replaceUnsignedAttributes
+        return SignerInformation.replaceUnsignedAttributes(
+                signer, new AttributeTable(signedAttributes));
+    }
+}

src/main/java/org/apache/pdfbox/examples/util/ConnectedInputStream.java

@@ -0,0 +1,82 @@
+/*
+ * 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.examples.util;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.HttpURLConnection;
+
+/**
+ * Delegate class to close the connection when the class gets closed.
+ *
+ * @author Tilman Hausherr
+ */
+public class ConnectedInputStream extends InputStream {
+    HttpURLConnection con;
+    InputStream is;
+
+    public ConnectedInputStream(HttpURLConnection con, InputStream is) {
+        this.con = con;
+        this.is = is;
+    }
+
+    @Override
+    public int read() throws IOException {
+        return is.read();
+    }
+
+    @Override
+    public int read(byte[] b) throws IOException {
+        return is.read(b);
+    }
+
+    @Override
+    public int read(byte[] b, int off, int len) throws IOException {
+        return is.read(b, off, len);
+    }
+
+    @Override
+    public long skip(long n) throws IOException {
+        return is.skip(n);
+    }
+
+    @Override
+    public int available() throws IOException {
+        return is.available();
+    }
+
+    @Override
+    public synchronized void mark(int readlimit) {
+        is.mark(readlimit);
+    }
+
+    @Override
+    public synchronized void reset() throws IOException {
+        is.reset();
+    }
+
+    @Override
+    public boolean markSupported() {
+        return is.markSupported();
+    }
+
+    @Override
+    public void close() throws IOException {
+        is.close();
+        con.disconnect();
+    }
+}

src/main/java/stirling/software/SPDF/controller/api/security/CertSignController.java

@@ -1,47 +1,21 @@
 package stirling.software.SPDF.controller.api.security;
 
-import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
-import java.io.InputStreamReader;
+import java.io.InputStream;
-import java.security.KeyFactory;
+import java.io.OutputStream;
 import java.security.KeyStore;
-import java.security.PrivateKey;
+import java.security.KeyStoreException;
+import java.security.NoSuchAlgorithmException;
 import java.security.Security;
-import java.security.cert.CertificateFactory;
+import java.security.UnrecoverableKeyException;
-import java.security.cert.X509Certificate;
+import java.security.cert.CertificateException;
-import java.security.spec.PKCS8EncodedKeySpec;
-import java.text.SimpleDateFormat;
 import java.util.Calendar;
-import java.util.Collections;
-import java.util.Date;
 
-import org.apache.commons.io.IOUtils;
+import org.apache.pdfbox.examples.signature.CreateSignatureBase;
 import org.apache.pdfbox.pdmodel.PDDocument;
-import org.apache.pdfbox.pdmodel.PDPage;
-import org.apache.pdfbox.pdmodel.PDPageContentStream;
-import org.apache.pdfbox.pdmodel.PDResources;
-import org.apache.pdfbox.pdmodel.common.PDRectangle;
-import org.apache.pdfbox.pdmodel.font.PDType1Font;
-import org.apache.pdfbox.pdmodel.interactive.annotation.PDAnnotationWidget;
-import org.apache.pdfbox.pdmodel.interactive.annotation.PDAppearanceDictionary;
-import org.apache.pdfbox.pdmodel.interactive.annotation.PDAppearanceStream;
-import org.apache.pdfbox.pdmodel.interactive.digitalsignature.ExternalSigningSupport;
 import org.apache.pdfbox.pdmodel.interactive.digitalsignature.PDSignature;
-import org.apache.pdfbox.pdmodel.interactive.digitalsignature.SignatureOptions;
-import org.apache.pdfbox.pdmodel.interactive.form.PDAcroForm;
-import org.apache.pdfbox.pdmodel.interactive.form.PDSignatureField;
-import org.bouncycastle.cert.jcajce.JcaCertStore;
-import org.bouncycastle.cms.CMSProcessableByteArray;
-import org.bouncycastle.cms.CMSSignedData;
-import org.bouncycastle.cms.CMSSignedDataGenerator;
-import org.bouncycastle.cms.CMSTypedData;
-import org.bouncycastle.cms.jcajce.JcaSignerInfoGeneratorBuilder;
 import org.bouncycastle.jce.provider.BouncyCastleProvider;
-import org.bouncycastle.operator.ContentSigner;
-import org.bouncycastle.operator.jcajce.JcaContentSignerBuilder;
-import org.bouncycastle.operator.jcajce.JcaDigestCalculatorProviderBuilder;
-import org.bouncycastle.util.io.pem.PemReader;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.http.ResponseEntity;
@@ -68,6 +42,17 @@ public class CertSignController {
         Security.addProvider(new BouncyCastleProvider());
     }
 
+    class CreateSignature extends CreateSignatureBase {
+        public CreateSignature(KeyStore keystore, char[] pin)
+                throws KeyStoreException,
+                        UnrecoverableKeyException,
+                        NoSuchAlgorithmException,
+                        IOException,
+                        CertificateException {
+            super(keystore, pin);
+        }
+    }
+
     @PostMapping(consumes = "multipart/form-data", value = "/cert-sign")
     @Operation(
             summary = "Sign PDF with a Digital Certificate",
@@ -87,203 +72,71 @@ public class CertSignController {
         String name = request.getName();
         Integer pageNumber = request.getPageNumber();
 
-        PrivateKey privateKey = null;
+        if (certType == null) {
-        X509Certificate cert = null;
+            throw new IllegalArgumentException("Cert type must be provided");
-
-        if (certType != null) {
-            logger.info("Cert type provided: {}", certType);
-            switch (certType) {
-                case "PKCS12":
-                    if (p12File != null) {
-                        KeyStore ks = KeyStore.getInstance("PKCS12");
-                        ks.load(
-                                new ByteArrayInputStream(p12File.getBytes()),
-                                password.toCharArray());
-                        String alias = ks.aliases().nextElement();
-                        if (!ks.isKeyEntry(alias)) {
-                            throw new IllegalArgumentException(
-                                    "The provided PKCS12 file does not contain a private key.");
-                        }
-                        privateKey = (PrivateKey) ks.getKey(alias, password.toCharArray());
-                        cert = (X509Certificate) ks.getCertificate(alias);
-                    }
-                    break;
-                case "PEM":
-                    if (privateKeyFile != null && certFile != null) {
-                        // Load private key
-                        KeyFactory keyFactory =
-                                KeyFactory.getInstance("RSA", BouncyCastleProvider.PROVIDER_NAME);
-                        if (isPEM(privateKeyFile.getBytes())) {
-                            privateKey =
-                                    keyFactory.generatePrivate(
-                                            new PKCS8EncodedKeySpec(
-                                                    parsePEM(privateKeyFile.getBytes())));
-                        } else {
-                            privateKey =
-                                    keyFactory.generatePrivate(
-                                            new PKCS8EncodedKeySpec(privateKeyFile.getBytes()));
-                        }
-
-                        // Load certificate
-                        CertificateFactory certFactory =
-                                CertificateFactory.getInstance(
-                                        "X.509", BouncyCastleProvider.PROVIDER_NAME);
-                        if (isPEM(certFile.getBytes())) {
-                            cert =
-                                    (X509Certificate)
-                                            certFactory.generateCertificate(
-                                                    new ByteArrayInputStream(
-                                                            parsePEM(certFile.getBytes())));
-                        } else {
-                            cert =
-                                    (X509Certificate)
-                                            certFactory.generateCertificate(
-                                                    new ByteArrayInputStream(certFile.getBytes()));
-                        }
-                    }
-                    break;
-            }
         }
-        PDSignature signature = new PDSignature();
-        signature.setFilter(PDSignature.FILTER_ADOBE_PPKLITE); // default filter
-        signature.setSubFilter(PDSignature.SUBFILTER_ADBE_PKCS7_SHA1);
-        signature.setName(name);
-        signature.setLocation(location);
-        signature.setReason(reason);
-        signature.setSignDate(Calendar.getInstance());
 
-        // Load the PDF
+        InputStream ksInputStream = null;
-        try (PDDocument document = PDDocument.load(pdf.getBytes())) {
-            logger.info("Successfully loaded the provided PDF");
-            SignatureOptions signatureOptions = new SignatureOptions();
 
-            // If you want to show the signature
+        switch (certType) {
+            case "PKCS12":
+                ksInputStream = p12File.getInputStream();
+                break;
+            case "PEM":
+                throw new IllegalArgumentException("TODO: PEM not supported yet");
+                // ksInputStream = privateKeyFile.getInputStream();
+                // break;
+            default:
+                throw new IllegalArgumentException("Invalid cert type: " + certType);
+        }
 
-            // ATTEMPT 2
+        // TODO: page number
-            if (showSignature != null && showSignature) {
-                PDPage page = document.getPage(pageNumber - 1);
 
-                PDAcroForm acroForm = document.getDocumentCatalog().getAcroForm();
+        KeyStore ks = getKeyStore(ksInputStream, password);
-                if (acroForm == null) {
+        CreateSignature createSignature = new CreateSignature(ks, password.toCharArray());
-                    acroForm = new PDAcroForm(document);
+        ByteArrayOutputStream baos = new ByteArrayOutputStream();
-                    document.getDocumentCatalog().setAcroForm(acroForm);
+        sign(pdf.getBytes(), baos, createSignature, name, location, reason);
-                }
+        return WebResponseUtils.boasToWebResponse(
+                baos, pdf.getOriginalFilename().replaceFirst("[.][^.]+$", "") + "_signed.pdf");
+    }
 
-                // Create a new signature field and widget
+    private static KeyStore getKeyStore(InputStream is, String password) throws Exception {
+        KeyStore ks = KeyStore.getInstance("PKCS12");
+        ks.load(is, password.toCharArray());
+        return ks;
+    }
 
-                PDSignatureField signatureField = new PDSignatureField(acroForm);
+    private static void sign(
-                PDAnnotationWidget widget = signatureField.getWidgets().get(0);
+            byte[] input,
-                PDRectangle rect =
+            OutputStream output,
-                        new PDRectangle(100, 100, 200, 50); // Define the rectangle size here
+            CreateSignature instance,
-                widget.setRectangle(rect);
+            String name,
-                page.getAnnotations().add(widget);
+            String location,
+            String reason) {
+        try (PDDocument doc = PDDocument.load(input)) {
+            PDSignature signature = new PDSignature();
+            signature.setFilter(PDSignature.FILTER_ADOBE_PPKLITE);
+            signature.setSubFilter(PDSignature.SUBFILTER_ADBE_PKCS7_DETACHED);
+            signature.setName(name);
+            signature.setLocation(location);
+            signature.setReason(reason);
+            signature.setSignDate(Calendar.getInstance());
 
-                // Set the appearance for the signature field
+            doc.addSignature(signature, instance);
-                PDAppearanceDictionary appearanceDict = new PDAppearanceDictionary();
+            doc.saveIncremental(output);
-                PDAppearanceStream appearanceStream = new PDAppearanceStream(document);
-                appearanceStream.setResources(new PDResources());
-                appearanceStream.setBBox(rect);
-                appearanceDict.setNormalAppearance(appearanceStream);
-                widget.setAppearance(appearanceDict);
-
-                try (PDPageContentStream contentStream =
-                        new PDPageContentStream(document, appearanceStream)) {
-                    contentStream.beginText();
-                    contentStream.setFont(PDType1Font.HELVETICA_BOLD, 12);
-                    contentStream.newLineAtOffset(110, 130);
-                    contentStream.showText(
-                            "Digitally signed by: " + (name != null ? name : "Unknown"));
-                    contentStream.newLineAtOffset(0, -15);
-                    contentStream.showText(
-                            "Date: "
-                                    + new SimpleDateFormat("yyyy.MM.dd HH:mm:ss z")
-                                            .format(new Date()));
-                    contentStream.newLineAtOffset(0, -15);
-                    if (reason != null && !reason.isEmpty()) {
-                        contentStream.showText("Reason: " + reason);
-                        contentStream.newLineAtOffset(0, -15);
-                    }
-                    if (location != null && !location.isEmpty()) {
-                        contentStream.showText("Location: " + location);
-                        contentStream.newLineAtOffset(0, -15);
-                    }
-                    contentStream.endText();
-                }
-
-                // Add the widget annotation to the page
-                page.getAnnotations().add(widget);
-
-                // Add the signature field to the acroform
-                acroForm.getFields().add(signatureField);
-
-                // Handle multiple signatures by ensuring a unique field name
-                String baseFieldName = "Signature";
-                String signatureFieldName = baseFieldName;
-                int suffix = 1;
-                while (acroForm.getField(signatureFieldName) != null) {
-                    suffix++;
-                    signatureFieldName = baseFieldName + suffix;
-                }
-                signatureField.setPartialName(signatureFieldName);
-            }
-
-            document.addSignature(signature, signatureOptions);
-            logger.info("Signature added to the PDF document");
-            // External signing
-            ExternalSigningSupport externalSigning =
-                    document.saveIncrementalForExternalSigning(new ByteArrayOutputStream());
-
-            byte[] content = IOUtils.toByteArray(externalSigning.getContent());
-
-            // Using BouncyCastle to sign
-            CMSTypedData cmsData = new CMSProcessableByteArray(content);
-
-            CMSSignedDataGenerator gen = new CMSSignedDataGenerator();
-            ContentSigner signer =
-                    new JcaContentSignerBuilder("SHA256withRSA")
-                            .setProvider(BouncyCastleProvider.PROVIDER_NAME)
-                            .build(privateKey);
-
-            gen.addSignerInfoGenerator(
-                    new JcaSignerInfoGeneratorBuilder(
-                                    new JcaDigestCalculatorProviderBuilder()
-                                            .setProvider(BouncyCastleProvider.PROVIDER_NAME)
-                                            .build())
-                            .build(signer, cert));
-
-            gen.addCertificates(new JcaCertStore(Collections.singletonList(cert)));
-            CMSSignedData signedData = gen.generate(cmsData, false);
-
-            byte[] cmsSignature = signedData.getEncoded();
-            logger.info("About to sign content using BouncyCastle");
-            externalSigning.setSignature(cmsSignature);
-            logger.info("Signature set successfully");
-
-            // After setting the signature, return the resultant PDF
-            try (ByteArrayOutputStream signedPdfOutput = new ByteArrayOutputStream()) {
-                document.save(signedPdfOutput);
-                return WebResponseUtils.boasToWebResponse(
-                        signedPdfOutput,
-                        pdf.getOriginalFilename().replaceFirst("[.][^.]+$", "") + "_signed.pdf");
-
-            } catch (Exception e) {
-                e.printStackTrace();
-            }
         } catch (Exception e) {
             e.printStackTrace();
         }
-
-        return null;
     }
 
-    private byte[] parsePEM(byte[] content) throws IOException {
+    // private byte[] parsePEM(byte[] content) throws IOException {
-        PemReader pemReader =
+    //     PemReader pemReader =
-                new PemReader(new InputStreamReader(new ByteArrayInputStream(content)));
+    //             new PemReader(new InputStreamReader(new ByteArrayInputStream(content)));
-        return pemReader.readPemObject().getContent();
+    //     return pemReader.readPemObject().getContent();
-    }
+    // }
 
-    private boolean isPEM(byte[] content) {
+    // private boolean isPEM(byte[] content) {
-        String contentStr = new String(content);
+    //     String contentStr = new String(content);
-        return contentStr.contains("-----BEGIN") && contentStr.contains("-----END");
+    //     return contentStr.contains("-----BEGIN") && contentStr.contains("-----END");
-    }
+    // }
 }