alexbartlow · October 15, 2014 18:16 · Oct 15, 2014
diff --git a/gistfile1.java b/gistfile1.java
@@ -0,0 +1,33 @@
+The signing implementation
+The SignImp class isn’t much different from all the examples we’ve written before. When I write 
+Servlets that involve the use of iText, I always start by writing a short standalone application with a 
+main() method. This way I can test the code before integrating it into a web application.
+In code sample 4.11, I’ve removed the main() method for brevity.
+Code sample 4.11: the SignImp class
+public class SignImp {
+ private PrivateKey pk;
+ private Certificate[] chain;
+ public SignImp(PrivateKey pk, Certificate[] chain) {
+ this.pk = pk;
+ this.chain = chain;
+ }
+ public byte[] signDoc(InputStream pdf, String reason, String location)
+ throws GeneralSecurityException, IOException, DocumentException {
+ // Creating the reader and the stamper
+ PdfReader reader = new PdfReader(pdf, null);
+ ByteArrayOutputStream baos = new ByteArrayOutputStream();
+ PdfStamper stamper =
+ PdfStamper.createSignature(reader, baos, '\0', null, true);
+ // Creating the appearance
+ PdfSignatureAppearance appearance = stamper.getSignatureAppearance();
+ appearance.setReason(reason);
+ appearance.setLocation(location);
+ // Creating the signature
+ ExternalSignature pks =
+ new PrivateKeySignature(pk, DigestAlgorithms.SHA256, null);
+ ExternalDigest digest = new BouncyCastleDigest();
+ MakeSignature.signDetached(appearance, digest, pks, chain,
+ null, null, null, 0, CryptoStandard.CMS);
+ return baos.toByteArray();
+ }
+}