PAdES PDF Avanced Electronic Signatures Support in Qoppa PDF SDK

Does Qoppa’s PDF API support signing using “Advanced Electronic Signatures (AdES)”, as recognized by eIDAS regulation? Qoppa’s PDF library and components currently support the following digital signature types: • PKCS7 Signatures • B-B PAdES signatures • B-T PAdES signatures Qoppa’s PDF library and components currently do not support the following types of signatures (which are […]

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Can a digital signature in a PDF document have multiple linked widgets?

Q: We know that standard interactive form fields can have multiple widgets associated with them. In this case, all “linked” widgets in the document will contain the same form field data & have the same appearance stream. But how about digital signature fields? Do they allow multiple widgets to be associated with them? Answer: The […]

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How to lock a PDF document when applying a digital signature in Java

Below is sample Java code showing how to lock a PDF document when applying a digital signature to it using jPDFSecure, Qoppa’s Java PDF Security SDK.   // load PDF document into jPDFSecure PDFSecure pdf = new PDFSecure("c:/test/test01.pdf", null);   // add a signature field SignatureField signField = pdf.addSignatureField(0, "sign here", new Rectangle(72, 72, 144, […]

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Resolve Error “JCE Provider does not support SHA hash algorithm”

Q: I am building a web application to sign a PDF document with a given .pfx key store. I am running Spring Boot and using Qoppa’s PDF library jPDFSecure. I am getting an exception which states “JCE Provider does not support SHA hash algorithm”. How can I resolve this error? com.qoppa.pdf.PDFException: JCE Provider does not […]

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Retrieving signature information from a signed PDF

This java sample program shows how to open a signed PDF and retrieve signature information from it such as signer’s name, sign reason, location, date, etc…. This sample uses Qoppa’s Java PDF Library jPDFSecure but can be easily changed to use jPDFProcess. // Load the signed document PDFSecure pdfDoc = new PDFSecure ("C:\\test\\output.pdf", null); if(pdfDoc.getSignatureFields() […]

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Signing a PDF with a p12 file in Java

This is a sample java program showing how to sign a PDF document using a certificate loaded from a p12 file. The signature appearance is customized with an image, signer’s name and date. A signature field is added to the PDF document and then signed. This code uses jPDFSecure library but could very easily be adapted […]

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Digital signatures and PDF/A compliance

Converting to PDF/A an existing Signed Document It is not possible to convert an existing PDF document that is already signed to PDF/A. This is because any changes that you make to a PDF even if it’s only adding PDF/A tags information in the metadata would invalidate the signature. If your PDF is already signed, […]

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Clear and delete signature fields in a PDF document using Java

This is sample Java program showing how to clear and delete signature fields in a PDF using Qoppa’s PDF library jPDFProcess. The jPDFProcess’ public API does not give a direct access to deleting fields in a PDF, but when deleting widgets which are the annotation associated with a field on a PDF page, it will […]

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Support for PDF Digital Signatures in HTML5 Viewer

Q: Do you support validating and applying digital signatures in your HTML5 PDF Markup Module? We need to add the ability to view and sign PDF documents from any browser and platform within our web-based application. A: The current version of Qoppa’s HTML PDF Viewer and Markup Module supports the validation and display of exiting […]

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