#Itext pdf signature example how to#
#Itext pdf signature example full#
#Itext pdf signature example code#

I’m not going to try to tell you how to validate PDF signatures-that’d be hard to do in a blog post anyhow. This.Validating digital signatures in PDF documents is a tricky business, and contrary to popular belief, there’s no one true validation algorithm. Public AwsKmsSignatureFactory(string keyId, string signingAlgorithm) Private AlgorithmIdentifier signatureAlgorithm IX509Store collectionStore = X509StoreFactory.Create('CERTIFICATE/COLLECTION', collectionStoreParameters) ĬmsSignedData sigData = gen.Generate(msg, false) Ĭlass AwsKmsSignatureFactory : ISignatureFactory Public class AwsKmsContentSigner implements ContentSigner )

#Itext pdf signature example code#

So, the differences in the code are not just in its method name capitalization.ĭon’t worry though, as we’ll be pointing out these differences where they occur throughout the article NET classes were used for the creation of the self-signed certificate and there are some differences between the Bounc圜astle Java and. For example, the latter API uses the async pattern for. While the Java and C# iText 7 Core APIs are largely the same, there are a number of differences in the code examples here, in part due to certain differences in the Java and. Different strokes for different folksĪ quick note before we continue.

#Itext pdf signature example full#

Each code snippet included in this article has a link leading to the full Java/C# example on our Knowledge Base. Once again, we’ve worked with independent PDF expert and top StackOverflow contributor Michael Klink ( who kindly provided C# versions of his Java code examples from his original answer for our. While we won’t be covering them in this article, the process of signing a PDF using these services should be largely the same. Google has its Cloud Key Management and Microsoft Azure offers their Key Vault, both of which lower the cost of entry to using HSMs for cryptographic key management. Of course, Amazon is not the only big player in cloud services, and so it should not be surprising that Google and Microsoft also provide similar functionality. In addition, we’ll also point out some things you’ll need to consider if you plan to do mass-signing operations with AWS KMS. We’ll walk through the whole process of accessing the AWS KMS API to generate a digital signature, and then applying that signature to a PDF with iText 7. This topic came up in a recent Stack Overflow question, and the comprehensive answer provided by Michael Klink led to this article which we hope many of you will benefit from.

Since AWS KMS doesn’t store or associate digital certificates with asymmetric CMKs it creates, it’s not directly possible to use the asymmetric CMK for signing PDFs, as you would first have to generate a certificate for the public key of your AWS KMS signing key pair. Since it’s a scalable service with no upfront charges, AWS KMS can be an attractive option for digitally signing PDFs. Similar to the symmetric key features that were previously available, asymmetric keys can be generated as customer master keys (CMKs) where the private portion never leaves the service, or as a data key where the private portion is returned to your calling application encrypted under a CMK. However, Amazon Web Services now offers the generation of asymmetric keys as part of its Key Management Service (KMS) which makes it easy to create and manage cryptographic keys and control their use across a range of AWS services and in your applications. This is a physical computing device and is usually very expensive. There are a number of ways to generate such a key pair, but one of the most secure is the use of a hardware security module (or HSM). We’ve also kept pace with advances in the field, supporting the PAdES framework and PDF 2.0, and updating our Java and C# (.NET) code examples to apply to the latest versions of iText 7.Īn essential component in creating a secure digital signature is the generation of an asymmetric key pair, consisting of both a public and a private key. Since then, we’ve continued to promote the technology for secure PDF documents, as it provides integrity, authenticity, non-repudiation, and assurance of when a document was signed. We first published our digital signatures eBook back in 2013, which provided a comprehensive overview of PDF features, industry standards and technology options relating to secure digital signatures, together with in-depth best practices, real-life examples, and code samples for PDF development. Here at iText we’ve long been involved with PDF digital signatures.