digital-signature

I am adding a visual signature to a pdf using this as reference - https://stackoverflow.com/a/27940667/7103795 I am able to print the details properly. But the pdf does not display a green tick when opened in Acrobat though it is written "Signed and all signatures are valid." in the signature panel. This is an example of what I need: How can I ensure that the validity sign show up? I am using pdfBox version 2.0.1 In-document visualisations of the signature validity have been deprecated nearly a decade ago. Adobe Reader supports them for backward compatibility reasons only but they have never

The following command generates a signature for an input file: openssl dgst -sha1 -sign privateKey.pem -out signature1 someInputFile The following commands also generates a signature for an input file: openssl dgst -binary -sha1 someInputFile > digest openssl rsautl -sign -in digest -inkey privateKey.pem -out signature2 As far as I know, they should both create the RSA signature of a SHA1 digest of the file. But they don't generate the same signature. As a result, the signature generated with method 2 can also not be verified by an openssl dgst -verify call. Does somebody know what the

I'm trying to understand what the Java java.security.Signature class does. If I compute an SHA1 message digest, and then encrypt that digest using RSA, I get a different result to asking the Signature class to sign the same thing: // Generate new key KeyPair keyPair = KeyPairGenerator.getInstance("RSA").generateKeyPair(); PrivateKey privateKey = keyPair.getPrivate(); String plaintext = "This is the message being signed"; // Compute signature Signature instance = Signature.getInstance("SHA1withRSA"); instance.initSign(privateKey); instance.update((plaintext).getBytes()); byte[] signature =

I have a digital certificate that identifies an user. I need to use it to Digitally sign pdf files. Does anyone have an example that does not uses a third party component? I need to get this done but it would be nice to fully understand how things are done. C# Examples please :) Darin Dimitrov The open source iTextSharp library will allow you to do this. Here's a post explaining how to digitally sign a pdf file. If you don't want to use a third party library then you can implement it yourself but it could be a tough task -> you can start by reading the pdf specification (8.6MB) Proper PDF