DigitalSignature.Core 1.0.0

DigitalSignature.NetCore

A robust digital signature library for .NET Core applications, providing comprehensive functionality for PDF signing and certificate management.

Features

• Create and manage X.509 certificates with both RSA and ECDSA keys
• Sign PDF documents with digital certificates
• Verify PDF signatures and detect modifications
• Create certificate hierarchies (Root CA, Intermediate CA, Leaf certificates)
• Export certificates and keys to PEM format
• Handle PKCS#12 (.pfx) certificate stores

Installation

dotnet add package DigitalSignature.NetCore

Quick Start

Create a Certificate and Sign a PDF

using DigitalSignature.Core.Helpers;

// Create a self-signed certificate
var certificateStore = Pkcs12Helper.CreateRsaRootCertificate(
    "Signer Certificate", 
    "password123", 
    keySize: 2048, 
    validityYears: 1);

// Sign a PDF document
PdfSignerHelper.SignPdf(
    "input.pdf",
    "signed.pdf",
    certificateStore,
    "Signer Certificate", 
    reason: "Document Approval",
    location: "New York");

Verify a Signed PDF

using DigitalSignature.Core.Helpers;

// Validate all signatures in the PDF
var validation = PdfSignerHelper.ValidateAllSignatures("signed.pdf");
if (validation.IsValid)
{
    Console.WriteLine("The document is valid and has not been modified since signing.");
}
else
{
    Console.WriteLine($"Signature validation failed: {validation.ErrorMessage}");
}

Create a Certificate Hierarchy

using DigitalSignature.Core.Helpers;
using System.Collections.Generic;

// Create a certificate hierarchy (root CA, intermediate, leaf)
var hierarchy = new List<Pkcs12Helper.CertificateSpec>
{
    new Pkcs12Helper.CertificateSpec
    {
        FriendlyName = "root",
        CommonName = "Root CA",
        Password = "password123",
        IsCA = true,
        IsRsa = true,
        KeySize = 4096,
        ValidityYears = 10
    },
    new Pkcs12Helper.CertificateSpec
    {
        FriendlyName = "intermediate",
        CommonName = "Intermediate CA",
        Password = "password123",
        IsCA = true,
        IsRsa = true,
        KeySize = 3072,
        ValidityYears = 5
    },
    new Pkcs12Helper.CertificateSpec
    {
        FriendlyName = "leaf",
        CommonName = "End Entity Certificate",
        Password = "password123",
        IsCA = false,
        IsRsa = true,
        KeySize = 2048,
        ValidityYears = 1
    }
};

var certificates = Pkcs12Helper.BuildCertificateHierarchy(hierarchy);

License

This project is licensed under the MIT License - see the LICENSE file for details.