EvoPdf Classic · PDF Security

EVO PDF Security Library

EVO PDF Security library allows you to set the permissions, encrypt and password protect PDF documents. It can be integrated into any .NET application, both ASP.NET web sites and desktop applications, to add pdf security capabilities to your application.

Download for .NET Documentation

Classic v14.0 · Windows, .NET Framework 4.0+ and .NET 6–10 · Evaluate without registration — demo mode by default (watermarked) · Licensed with the EVO PDF Toolkit

$dotnet add package EvoPdf.PdfSecurity

Windows · .NET Framework 4.0+ and .NET 6–10 (.NET Standard 2.0)

Program.csC#

using EvoPdf.PdfSecurity;

var options = new PdfSecurityOptions();
options.CanPrint = false;
options.OpenPassword = "secret";
var manager = new PdfSecurityManager(options);
manager.SaveSecuredPdfToFile("in.pdf", "secured.pdf");

Classic API: EvoPdf.PdfSecurity namespace, one converter class, synchronous calls. API reference →

Windows 10 / 11 / Server 2016–2025
.NET Framework 4.0 – 4.8.1
.NET 6 → 10, .NET Standard 2.0
Azure Cloud Services & Virtual Machines
Web, console and desktop applications

Features

What the PDF Security component does

Easy integration, no installation or setup is necessary on the server
Delivered as a single strong named .NET assembly (can be installed in GAC)
Can be deployed on the server by simple copy (xcopy deployment support)
Can be used from ASP.NET, Windows Forms, WPF, Web Service or Console applications
The same assembly can be used both on 32-bit and 64-bit Windows servers
Secure PDF documents from files and streams
Save secured document in memory or in file
Command line sample with full C# source code
Set user and owner passwords
Encrypt PDF document content
40 and 128 bit encryption keys
Set PDF document permissions (print, edit, copy)
Remove PDF document security settings based on user or owner password

In detail

EVO PDF Security Library — how it works

The EVO PDF security for .NET can be used in any type of application to manage the security settings of the PDF documents. You can encrypt the PDF content, add user and owner passwords, control the PDF document permissions for printing, copying, assembling, filling forms, editing content, editing annotations, etc or you can specify the length of the encryption key to 40 or 128 bits, remove all the security settings by providing the user or owner password.

If you need a simple ready to use tool for combining your PDF documents and images we offer you a command line utility. The integration is extremely easy and no additional installation is necessary in order to get started. It's just a .NET assembly that you have to reference in your application.

Samples are available in the downloaded archive.

At a glance

Component: EvoPdf Classic · PDF Security
NuGet package: EvoPdf.PdfSecurity
Namespace: EvoPdf.PdfSecurity
Main class: PdfSecurityManager
Runs on: Windows · .NET Framework 4.0+ · .NET 6–10 (.NET Standard 2.0)
Version: Classic v14.0
License: EVO PDF Toolkit; evaluation without registration

Documentation →

Sample.csC#

PdfSecurityOptions securityOptions = new PdfSecurityOptions();

securityOptions.CanAssembleDocument = canAssembleDocument;
securityOptions.CanCopyContent = canCopyContent;
securityOptions.CanEditAnnotations = canEditAnnotations;
securityOptions.CanEditContent = canEditContent;
securityOptions.CanFillFormFields = canFillFormFields;
securityOptions.CanPrint = canPrint;
securityOptions.KeySize = keySize;
securityOptions.UserPassword = userPassword;
securityOptions.OwnerPassword = ownerPassword;

PdfSecurityManager securityManager = new PdfSecurityManager(securityOptions);

if (removeSecurity)
    securityManager.SaveUnSecuredPdfToFile(srcPdfFile, outFile, removeSecurityPswd);
else
    securityManager.SaveSecuredPdfToFile(srcPdfFile, outFile);

Installation

Install and run on Windows

The Classic library is a managed .NET assembly plus a Windows rendering engine shipped inside the NuGet package — nothing to install on the server, xcopy deployment, works in Azure Cloud Services and Virtual Machines. It targets Windows only; for Linux and macOS use EvoPdf Next.

Documentation

API reference and usage notes for the PDF Security component.

Open the docs →

Getting started

The user guide chapters of the Classic documentation, with the C# code for each feature: options, merging, bookmarks, forms, security, deployment.

Read the guide →

Moving to Next?

EvoPdf Classic is the original engine, fully supported and licensed alongside EvoPdf Next. New projects should start with Next: Chromium rendering, Windows, Linux and macOS.

Migration guide →

Licensing

Perpetual licenses, updates and support included for a year

The HTML to PDF Converter license (450 USD Deployment / 1200 USD Company) covers the Classic and the Next converter; the EVO PDF Toolkit (650 / 1400 USD) covers every component on this site, Classic tools included. The Company License includes redistribution.

Pricing & licensing Next equivalent All downloads