Change Password of PDF File

Change Password of a PDF File

In order to change password of a PDF file, you need to create PdfFileSecurity object and then call the ChangePassword method. You need to pass existing owner password and new user and owner passwords to the ChangePassword method.

• The User password, if set, is what you need to provide in order to open a PDF. Acrobat/Reader will prompt a user to enter the user password. If it’s not correct, the document will not open.
• The Owner password, if set, controls permissions, such as printing, editing, extracting, commenting, etc. Acrobat/Reader will disallow these things based on the permission settings. Acrobat will require this password if you want to set/change permissions.

The following code snippet shows you how to change passwords of a PDF file.

public static void ChangePassword()
{
    PdfFileInfo pdfFileInfo = new PdfFileInfo(dataDir + "sample_encrypted.pdf");
    // Create PdfFileSecurity object
    if (pdfFileInfo.IsEncrypted)
    {
        PdfFileSecurity fileSecurity = new PdfFileSecurity();
        fileSecurity.BindPdf(dataDir + "sample_encrypted.pdf");
        fileSecurity.ChangePassword("OwnerP@ssw0rd", "Pa$$w0rd1", "Pa$$w0rd2", DocumentPrivilege.Print, KeySize.x256);
        fileSecurity.Save(dataDir + "sample_encrtypted1.pdf");
    }
}