Fortanix Data Security Manager using Zoho

1.0 Introduction

This article describes how to integrate Fortanix-Data-Security-Manager (DSM) with Zoho Bring Your Own Key (BYOK) feature to use a key from Fortanix DSM as the Key Encryption Key (KEK) in place of Zoho's default KEK.

Zoho offers a suite of cloud-based applications for managing various business functions such as Customer Relationship Management (CRM), finance, and human resources. By integrating Zoho with Fortanix DSM, you maintain full control over your encryption keys, which ensures that your data remains secure and complies with regulatory requirements.

2.0 Prerequisites

Ensure the following:

• Fortanix DSM is accessible. For more information, refer to Section 5.1: Signing Up and Section 5.2: Creating an Account.

3.0 Product Tested Version

• Fortanix DSM version 4.23 and above.

4.0 Architecture Diagram

You can configure Fortanix DSM as your external key manager to manage KEKs for encrypting and decrypting the Data Encryption Keys (DEKs) used by Zoho. By integrating with Fortanix DSM, you maintain full control over your encryption operations, enhancing the security of your data.

After you configure the key in Zoho Directory, Zoho sends a request to Fortanix DSM to encrypt its DEKs using the KEK. Fortanix DSM processes this request, encrypts the DEK, and securely returns the encrypted DEK to Zoho. Zoho then stores the encrypted DEK in its internal Key Management Service (KMS).

When Zoho requires the plaintext DEK for operations, it sends a decryption request to Fortanix DSM along with the encrypted DEK. Fortanix DSM decrypts the DEK and securely provides the plaintext DEK to Zoho. Zoho temporarily caches the plaintext DEK for the duration specified by you. Once this caching period ends, Zoho sends a fresh request to Fortanix DSM for encrypting or decrypting the DEK, repeating the process as needed.

5.0 Configure Fortanix DSM

A Fortanix DSM service must be configured, and the URL must be accessible. To create a Fortanix DSM account and group, refer to the following sections:

5.1 Signing Up

5.2 Creating an Account

Access <Your_DSM_Service_URL> in a web browser and enter your credentials to log in to Fortanix DSM.

5.3 Creating a Group

Perform the following steps to create a group in the Fortanix DSM:

1. In the DSM left navigation panel, click the Groups menu item, and then click the + button to create a new group.

   

2. On the Adding new group page, do the following:

   1. Title: Enter a name for your group.

   2. Description (optional): Enter a short description of the group.

3. Click SAVE to create the new group.

The new group is added to the Fortanix DSM successfully.

5.4 Creating an Application

Perform the following steps to create an application (app) in the Fortanix DSM:

1. In the DSM left navigation panel, click the Apps menu item, and then click the + button to create a new app.

   

2. On the Adding new app page, do the following:

   1. App name: Enter the name for your application.

   2. ADD DESCRIPTION (optional): Enter a short description of the application.

   3. Authentication method: Select the default API Key as the authentication method from the drop down menu. For more information on these authentication methods, refer to the User's Guide: Authentication.

   4. Assigning the new app to groups: Select the group created in Section 5.3: Creating a Group from the list.

3. Click SAVE to add the new application.

The new application is added to the Fortanix DSM successfully.

5.5 Copying the API Key

Perform the following steps to copy the API key from the Fortanix DSM:

1. In the DSM left navigation panel, click the Apps menu item, and then click the app created in Section 5.4: Creating an Application to go to the detailed view of the app.

2. On the INFO tab, click VIEW API KEY DETAILS.

3. From the API Key Details dialog box, copy the API Key of the app to use in Section 6.1: Adding a Key from an EKM Provider.

6.0 Configuring Zoho

In this section, you will configure Zoho to work with Fortanix DSM as the EKM for securing your DEKs. This process includes adding keys from Fortanix DSM and optionally uploading a key through Zoho Directory.

6.1 Adding a Key from an EKM Provider

Perform the following steps:

1. Log in to the Zoho directory with your administrative credentials.

2. Click the Admin Panel menu item from the left navigation panel and navigate to the Security option.

3. Select BYOK→ Setup.

4. If you already have a key added, click Add Key from the top-right of the screen.

   

5. On the Add Key page, enter the following:

   • Key Name: Enter a name for the key.

   • Available Applications: Select the applications you want to secure with this key.

   • Key Type: Select the Fortanix DSM radio button, then enter the following key details:

     • Key provider: Select the Google KMS option from the drop down menu.

     • API key: Enter the API Key as copied in Section 5.5: Copying the API Key.

     • Key ID: Provide the Key ID.

     • Domain: Specify the Domain.

       NOTE

       You can retrieve the necessary details such as the API Key, Key ID, and Domain, from the Fortanix DSM user interface (UI).

       

   • Cache Duration: Select the required duration from the drop-down menu. This setting determines how long the decrypted DEK will be cached before the system needs to send encrypt/decrypt requests to the EKM again.

     

6. Click Add to finish the setup process.

NOTE

When configuring BYOK for a specific service, the application is removed from the default key. If the BYOK key is deleted, the application will be added back to the default key.

6.2 Uploading a Key Through Zoho Directory

If you prefer to upload your own key instead of using an external key manager (EKM), follow these steps:

6.2.1 Prerequisites

Ensure you have the following:

• A BYOK certificate.

• An encrypted KEK.

• A Hashed KEK.

6.2.2 Adding a BYOK Certificate

Perform the following steps to add and download a certificate in the Zoho directory:

1. Click the Admin Panel menu item from the left navigation panel and then navigate to the Security option.

2. Click the BYOK menu item, then select View Certificates from the top-right corner of the screen.

3. Click Add Certificates and provide a unique name for your certificate.

4. Click Add.

   NOTE

   You can add up to two certificates.

5. Hover over the added certificate and click the download icon to download it for key generation.

6.2.3 Generating an Encrypted KEK

This section outlines the steps to generate an encrypted KEK by extracting a public key from a certificate, encrypting the AES key with it, and generating a hash for the AES key.

Perform the following steps in a local environment:

1. Run the following command to extract the public key from the downloaded certificate file:

   public static String getPublicKeyFromFile(String fileName) 
   throws IOException, CertificateException { 
   PemReader reader = new PemReader(new FileReader(new 
   File(fileName))); 
   PemObject pemObject = reader.readPemObject(); 
   byte[] content = pemObject.getContent(); 
   reader.close(); 
   InputStream fin = new ByteArrayInputStream(content); 
   CertificateFactory f = 
   CertificateFactory.getInstance("X.509"); 
   X509Certificate certificate = 
   (X509Certificate)f.generateCertificate(fin); 
   PublicKey pk = certificate.getPublicKey(); 
   return 
   Base64.getEncoder().encodeToString(pk.getEncoded()); 
   }

2. Run the following command to encrypt the AES key using the RSA public key you extracted from the certificate:

   public static String encryptKeyWithPublicKey(String 
   publicKey, byte[] plainKeyBytes) throws Exception{ 
   byte[] publicKeyBytes = 
   Base64.getDecoder().decode(publicKey);  
   X509EncodedKeySpec keySpec = new 
   X509EncodedKeySpec(publicKeyBytes); 
   KeyFactory keyFactory = KeyFactory.getInstance("RSA"); 
   PublicKey publicKey = keyFactory.generatePublic(keySpec); 
   Cipher encryptCipher = Cipher.getInstance("RSA/ECB/OAEPWITHSHA-
   256ANDMGF1PADDING"); 
   OAEPParameterSpec oaepParams = new OAEPParameterSpec("SHA-
   256", "MGF1", new MGF1ParameterSpec("SHA-256"), 
   PSource.PSpecified.DEFAULT); 
   encryptCipher.init(Cipher.ENCRYPT_MODE, publicKey, oaepParams); 
   byte[] encryptedBytes = encryptCipher.doFinal(plainKeyBytes); 
   return Base64.getEncoder().encodeToString(encryptedBytes); 
   } 

3. Run the following command to generate the AES key hash value:

   public static String getHashValue(byte[] plainKeyBytes) 
   throws NoSuchAlgorithmException { 
       MessageDigest digest = MessageDigest.getInstance("SHA-
   256"); 
       byte[] hashed = digest.digest(plainKeyBytes); 
       return Base64.getEncoder().encodeToString(hashed); 
   }

6.2.4 Uploading a Key

Perform the following steps to add a key:

1. Click the Admin Panel menu item from the left navigation panel and then navigate to the Security option.

2. Click the BYOK → Setup option.

3. If you already have a key added, click Add Key from the top-right of the screen.

4. On the Add Key page, enter the following details:

   • Key Name: Enter a name for the key.

   • Available Applications: Select the applications you want to secure with this key.

   • Key Type: Choose the appropriate key type, such as External Key Manager, Upload Key.

   • BYOK Certificates: Select the BYOK certificates you have uploaded.

   • Hashed KEK: Browse and upload the generated hashed KEK.

   • Encrypted KEK: Browse and upload the generated encrypted KEK.

   

5. Click Add to finalize the key upload process.

6.2.5 Managing the Keys

For more information on how to edit, change, or delete a key, refer to the Zoho’s official documentation.