Section:

Apryse Custom Security Handler using JavaScript

The Apryse Custom Security Handler provides a means to encrypt files in a way that cannot be decrypted by other applications. This makes it especially suitable for Digital Rights Management (DRM) use cases. This is an alternative to defining your own custom encryption method. In particular using the Apryse Custom Security Handler is much simpler as it comes built-in with Apryse SDK.

Like other encryption methods a password is required to encrypt and decrypt the document. This custom security handler also requires the application choose a unique unsigned integer custom id (typically one per application) of their choice to encrypt and decrypt the document. Using this unique id provides an extra level of security as even other applications based on Apryse SDK will not typically be configured to open files secured with that particular id.

Encrypting an Apryse Custom secured document using the password and application custom id

The first step before encrypting is to choose an application custom id. A typical way to create this is to use a random generator to create a 32-bit number. This number would then be used throughout your document workflow.

Note that when using WebViewer you would generally perform the encryption on the server side, but the code is shown below for reference and will look similar on the server.

Once that is done, the document can be encrypted:

1<html>
2  <script src="../lib/core/webviewer-core.min.js"></script>
3  <script src="../lib/core/pdf/PDFNet.js"></script>
4  <script>
5    (async function() {
6      Core.setWorkerPath('../lib/core');
7      const PDFNet = Core.PDFNet;
8      const doc = await PDFNet.PDFDoc.createFromURL(fileURL);
9      // Create Apryse custom security handler with a custom id. Replace this with your own integer
10      const customHandler = await PDFNet.PDFTronCustomSecurityHandler.create(myCustomId);
11      // Set a new password required to open a document
12      customHandler.changeUserPasswordUString(myPassword);
13      // Note: document takes the ownership of customHandler.
14      doc.setSecurityHandler(customHandler);
15      // Save the encrypted document
16      const docArrayBuffer = await doc.saveMemoryBuffer(PDFNet.SDFDoc.SaveOptions.e_remove_unused);
17    })()
18  </script>
19</html>

Related Links

Encrypt and Decrypt PDF Files
Full sample code which illustrates some of our encryption support.

Decrypting an Apryse Custom secured document using the password and application custom id

The same application custom id and password using during encryption are required for decryption. Failing to provide the correct password or application custom id will prevent opening the encrypted document.

To decrypt a PDF with Apryse Custom security:

If you're opening the file through the WebViewer UI or WebViewer Core then you can use the customHandlerId option in loadDocument.

With the WebViewer UI:

JavaScript

1WebViewer({
2  // options
3}, viewerElement)
4.then(instance => {
5  instance.UI.loadDocument('secure.pdf', {
6    password: 'password',
7    customHandlerId: 42
8  });
9});

With the WebViewer Core:

JavaScript

1myDocumentViewerInstance.loadDocument('secure.pdf', {
2  password: (callback) => {
3    return callback('password');
4  },
5  customHandlerId: 42
6});

If you would like to use the full API to do this with a PDFDoc in memory:

1<html>
2  <script src="../lib/core/webviewer-core.min.js"></script>
3  <script src="../lib/core/pdf/PDFNet.js"></script>
4  <script>
5    (async function() {
6      Core.setWorkerPath('../lib/core');
7      // Register the Apryse Custom Security handler with the same custom id used in encryption.
8      // Calling this function is a requirement to load files encrypted with PDFTronCustomSecurityHandler.
9      await PDFNet.addPDFTronCustomHandler(myCustomId);
10      const doc_enc = await PDFNet.PDFDoc.createFromURL(filename);
11      if ((await doc_enc.initStdSecurityHandlerUString(myPassword))) {
12        // The password is correct! Document can now be used for reading and editing
13      }
14    })()
15  </script>
16</html>

Related Links

Encrypt and Decrypt PDF Files
Full sample code which illustrates some of our encryption support.

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