How to Set Password and Permissions on a PDF

IronPDF supports everything you need for Password and Permissions for your existing and new PDF files. Granular meta-data and security settings can be applied, this includes the ability to limit PDF documents to be unprintable, read only, and encrypted, 128 bit encryption, decryption, and password protection are all supported.

How to Protect your PDF with Password and Permissions in C#

  1. Download the C# IronPDF Library
  2. Set a password for the PDF file
  3. 128 Bit Encryption for the PDF
  4. Make the PDF read-only
  5. Save the protected PDF

C# NuGet Library for PDF

Install with NuGet

Install-Package IronPdf
nuget.org/packages/IronPdf/
or
C# PDF DLL

Download DLL

Download DLL

Manually install into your project

Set a Password for a PDF

Here we have an example of a PDF which we want to protect with IronPDF:

Let's run the following code to add a password to the PDF. We will use the password password123 as an example:

:path=/static-assets/pdf/content-code-examples/how-to/pdf-permissions-passwords-add-password.cs
using IronPdf;

var renderer = new ChromePdfRenderer();

var pdf = renderer.RenderHtmlAsPdf("<h1>Secret Information:</h1> Hello World");

pdf.SecuritySettings.OwnerPassword = "123password"; // password to edit the pdf

pdf.SecuritySettings.UserPassword = "password123"; // password to open the pdf

pdf.SaveAs("protected.pdf");
Imports IronPdf

Private renderer = New ChromePdfRenderer()

Private pdf = renderer.RenderHtmlAsPdf("<h1>Secret Information:</h1> Hello World")

pdf.SecuritySettings.OwnerPassword = "123password" ' password to edit the pdf

pdf.SecuritySettings.UserPassword = "password123" ' password to open the pdf

pdf.SaveAs("protected.pdf")
VB   C#

The result is the following PDF which you can view by typing the password password123.

Open a PDF that has a Password

This is how we can open a PDF that has a password. The PdfDocument.FromFile method has a second optional parameter which is the password:

:path=/static-assets/pdf/content-code-examples/how-to/pdf-permissions-passwords-open-password.cs
using IronPdf;

var pdf = PdfDocument.FromFile("protected.pdf", "password123");

//... perform PDF-tasks

pdf.SaveAs("protected_2.pdf"); // Saved as another file
Imports IronPdf

Private pdf = PdfDocument.FromFile("protected.pdf", "password123")

'... perform PDF-tasks

pdf.SaveAs("protected_2.pdf") ' Saved as another file
VB   C#

Advanced Security and Permissions Settings

The PdfDocument object also has MetaData fields you may set such as Author and ModifiedDate. You can also disable User Annotations, User Printing, and many more as shown below:

:path=/static-assets/pdf/content-code-examples/how-to/pdf-permissions-passwords-advanced.cs
using IronPdf;

// Open an Encrypted File, alternatively create a new PDF from HTML
var pdf = PdfDocument.FromFile("protected.pdf", "password");

// Edit file metadata
pdf.MetaData.Author = "Satoshi Nakamoto";
pdf.MetaData.Keywords = "SEO, Friendly";
pdf.MetaData.ModifiedDate = System.DateTime.Now;

// Edit file security settings

// The following code makes a PDF read only and will disallow copy & paste and printing
pdf.SecuritySettings.RemovePasswordsAndEncryption();
pdf.SecuritySettings.MakePdfDocumentReadOnly("secret-key");
pdf.SecuritySettings.AllowUserAnnotations = false;
pdf.SecuritySettings.AllowUserCopyPasteContent = false;
pdf.SecuritySettings.AllowUserFormData = false;
pdf.SecuritySettings.AllowUserPrinting = IronPdf.Security.PdfPrintSecurity.FullPrintRights;

// Change or set the document encryption password
pdf.SecuritySettings.OwnerPassword = "top-secret"; // password to edit the pdf
pdf.SecuritySettings.UserPassword = "sharable"; // password to open the pdf

// Save the secure PDF
pdf.SaveAs("secured.pdf");
Imports System
Imports IronPdf

' Open an Encrypted File, alternatively create a new PDF from HTML
Private pdf = PdfDocument.FromFile("protected.pdf", "password")

' Edit file metadata
pdf.MetaData.Author = "Satoshi Nakamoto"
pdf.MetaData.Keywords = "SEO, Friendly"
pdf.MetaData.ModifiedDate = DateTime.Now

' Edit file security settings

' The following code makes a PDF read only and will disallow copy & paste and printing
pdf.SecuritySettings.RemovePasswordsAndEncryption()
pdf.SecuritySettings.MakePdfDocumentReadOnly("secret-key")
pdf.SecuritySettings.AllowUserAnnotations = False
pdf.SecuritySettings.AllowUserCopyPasteContent = False
pdf.SecuritySettings.AllowUserFormData = False
pdf.SecuritySettings.AllowUserPrinting = IronPdf.Security.PdfPrintSecurity.FullPrintRights

' Change or set the document encryption password
pdf.SecuritySettings.OwnerPassword = "top-secret" ' password to edit the pdf
pdf.SecuritySettings.UserPassword = "sharable" ' password to open the pdf

' Save the secure PDF
pdf.SaveAs("secured.pdf")
VB   C#