Digitally Sign PDF Document From Web Portal Using C#

Question

How to Digitally sign PDF file from Web Portal (Browser Based Application) using DSC Token in C#

Aymen Amri · Answer

Generally, this kind of task depends on several components and your application should be a part of several other items that are based on PKI (Public Key Infrastructure) : Your token should be provided by a security Provider, this provider has already put a certificate on it using a certificate autority. This certificate has a key pair (public and private Key that are mathematically linked). This provider should indicate you the way of access to the certificates of your token (for example some gives a driver that extracts the certificates to windows trust store and they are protected with a PIN that only the holder of the token knows). Once you installed your certificate in your trust store (you can check that it's there using mmc.exe, that go to add snap-In, then certificates. The installed certificate is linked to your token using the provided driver by the Token Provider. And it can be used only when to token is plugged in. Using the code, you can parse your trust store and then use the private key of the certificate to sign your document. This link may help : https://www.pkisolutions.com/accessing-and-using-certificate-private-keys-in-net-framework-net-core/