Confidencial Official Documentation Site

ℹ️

This page describes how to use the Confidencial SDK, which lets developers perform Confidencial actions such as decryption within their applications. Please contact us if you would like to get access to it.

ℹ️

The SDK is currently available in JavaScript and consists of one function, which supports the decryption of files. Support for encryption and other languages is coming soon. Have a language you’d like to see supported? Contact us.

ℹ️

While the SDK does not currently support encryption, the Confidencial

Command-Line Interface (CLI) can be used to encrypt files and can be invoked from JavaScript code running in a Node environment (using the child_process module)

Set up

Referencing the library

To use the Confidencial SDK in your JavaScript code, include a reference to the main SDK file, c11-sdk-js.min.js. For example, if the SDK is being used within a web page, include the following line within the <head> element of the HTML


<script src="sdk-location/c11-sdk-js.min.js"></script>

where sdk-location is the path to the main SDK file.

Namespace

All SDK functions are contained within the C11 namespace (e.g. C11.removeEncryption)

Private (decryption) keys

To use decryption functions within the SDK, valid private (decryption) keys are required for all files to be decrypted. Private keys can be obtained by following the instructions in

🔑

Obtaining public-private key pairs for use with the Confidencial SDK.

Functions

`removeEncryption(file, privateKeyPemMap)`

Removes encryption from (decrypts) a file

Input arguments

file is a File object referencing the file to be decrypted

privateKeyPemMap is a dictionary object that maps public key hashes (stored as string) to private keys in PEM format (also stored as string)

The keys in this dictionary object are strings that represent the hashes of public keys
The values in this dictionary object are strings that represent the corresponding private keys in PEM format
Both public key hashes and private key PEMs can be obtained using the Confidencial
🖥️
Desktop App or
🌐
Web App; see
🔑
Obtaining public-private key pairs for use with the Confidencial SDK
See the partial code example below for how a private key map can be assembled once public key hashes and private key PEMs are obtained

Return value

Upon success removeEncryption returns a File object representing the decrypted file

Partial example

The example below assumes privateKeyfileElement and encryptedPdfFileElement are HTML file inputs and publicKeyHashElement is an HTML text input.


const privateKeyFile = privateKeyfileElement.files[0];
const encryptedPdfFile = encryptedPdfFileElement.files[0];
const publicKeyHash = publicKeyHashElement.value;
const privateKeyMap = {};
privateKeyMap[publicKeyHash] = await privateKeyFile.text();
const decryptedFile = await C11.removeEncryption(encryptedPdfFile, privateKeyMap);

Full example

The example below contains a complete HTML page that allows a user to decrypt a file. The HTML page contains file inputs for the user to upload a file to be decrypted and a file representing the private (decryption) key in PEM format. The page also contains a text input for the user to supply the hash of the public (encryption) key that corresponds to the uploaded private key.

⚠️

To avoid CORS errors, the HTML page below should be accessed through a web server (running either locally or in the cloud). Viewing this page directly in a web browser will not work if your browser is enforcing CORS restrictions (as most browsers do by default).

ℹ️

NOTE: The script below assumes the main SDK file, c11-sdk-js.min.js, is being served by a local web server running on port 8080. Adjust the <script src="..."> line in the code below accordingly if you are hosting the SDK file in a different location.

⚠️

To avoid invalid character errors, make sure the web server serving the SDK file is sending the appropriate content type header (Content-Type: application/javascript; charset=UTF-8)


<!DOCTYPE html>
<html>
  <head>
    <title>C11-SDK-Encryption-Removal</title>
    <script src="http://127.0.0.1:8080/c11-sdk-js.min.js"></script>
    <script>
      async function removeEncryption() {
        console.log("removeEncryption started");
        let publicKeyHashElement = document.getElementById("PublicKeyHash");
        if (publicKeyHashElement.value.length === 0) {
          alert("Please enter your Public Key Hash");
          return;
        }
        let privateKeyfileElement = document.getElementById("privateKey");
        if (privateKeyfileElement.files.length === 0) {
          alert("Please upload your private Key");
          return;
        }
        let encryptedPdfFileElement = document.getElementById("encryptedPdfFile");
        if (encryptedPdfFileElement.files.length === 0) {
          alert("Please upload encrypted Pdf File");
          return;
        }
        let privateKeyFile = privateKeyfileElement.files[0];
        let encryptedPdfFile = encryptedPdfFileElement.files[0];
        let publicKeyHash = publicKeyHashElement.value;
        const privateKeyMap = {};
        privateKeyMap[publicKeyHash] = await privateKeyFile.text();
        const decryptedFile = await C11.removeEncryption(encryptedPdfFile, privateKeyMap);
        if (window.navigator.msSaveOrOpenBlob)
          // IE10+
          window.navigator.msSaveOrOpenBlob(decryptedFile, filename);
        else {
          // Others
          var a = document.createElement("a"),
            url = URL.createObjectURL(decryptedFile);
          a.href = url;
          a.download = encryptedPdfFile.name;
          document.body.appendChild(a);
          a.click();
          setTimeout(function () {
            document.body.removeChild(a);
            window.URL.revokeObjectURL(url);
          }, 0);
        }
      }
    </script>
    <style>
      form {
        margin: 20px auto;
        max-width: 600px;
        padding: 20px;
        border: 1px solid #ccc;
        border-radius: 5px;
      }

      label {
        display: block;
        margin-bottom: 10px;
        font-weight: bold;
      }

      input[type="text"],
      input[type="file"] {
        display: block;
        margin-bottom: 20px;
        width: 100%;
        padding: 10px;
        border-radius: 5px;
        border: 1px solid #ccc;
        box-sizing: border-box;
      }

      input[type="button"] {
        background-color: #08329d;
        color: white;
        padding: 10px 20px;
        border: none;
        border-radius: 5px;
        cursor: pointer;
      }

      input[type="button"]:hover {
        background-color: #3e558e;
      }
    </style>
  </head>
  <body>
    <form>
      <label for="PublicKeyHash">Your Public Key Hash:</label>
      <input type="text" id="PublicKeyHash" name="PublicKeyHash" placeholder="Enter Your Public Key Hash" />

      <label for="privateKey">Your Private Key:</label>
      <input type="file" accept=".key" id="privateKey" name="privateKey" />

      <label for="encryptedPdfFile">Encrypted Pdf File:</label>
      <input type="file" accept=".pdf" id="encryptedPdfFile" name="encryptedPdfFile" />

      <input type="button" value="Decrypt" onclick="removeEncryption()" />
    </form>
  </body>
</html>

Software Development Kit (SDK)