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How to protect PDF with password using C#

I’m using Aspose.Words and I convert a Word document to a PDF which I then save to an online file storage.

Later on, I need to add a password to the PDF so the customer receives a protected PDF. Is this possible? If so, how would I go about this?

Kind regards,

Can someone help?


Following code example shows how to set password to PDF file. Hope this helps you.

Document doc = new Document(MyDir + "Rendering.docx");

PdfSaveOptions saveOptions = new PdfSaveOptions();

// Create encryption details and set owner password
PdfEncryptionDetails encryptionDetails =
    new PdfEncryptionDetails("password1", "password2", PdfEncryptionAlgorithm.RC4_128);

// Start by disallowing all permissions
encryptionDetails.Permissions = PdfPermissions.DisallowAll;

// Extend permissions to allow editing or modifying annotations
encryptionDetails.Permissions = PdfPermissions.ModifyAnnotations | PdfPermissions.DocumentAssembly;
saveOptions.EncryptionDetails = encryptionDetails;

// Render the document to PDF format with the specified permissions
doc.Save(ArtifactsDir + "Rendering.EncryptionPermissions.pdf", saveOptions);

Here you use a .docx file as input. Is it also possible to password protect an already converted pdf file?

Nevermind I’ll just generate the pdf again… unconvenient but it works.


You can import PDF document into Aspose.Words’ DOM and use same PdfEncryptionDetails properties to get the desired output.

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