Fortanix Data Security Manager with Google Cloud EKM Interface Using Virtual Private Cloud

1.0 Introduction

This article describes how to integrate Fortanix Data Security Manager (DSM) with Google Cloud Platform (GCP) services using a Virtual Private Cloud (VPC) network. It also contains the information that a User needs to:

• Enable the Cloud Key Management Service (KMS) API in your GCP project
• Obtain GCP service account email address
• Configure a GCP External Key Manager (EKM) connection
• Import/Create the Google Advanced Encryption Standard (AES) Key in Fortanix DSM
• Create a manually managed Cloud EKM connection using VPC
• Complete the GCP key setup

Fortanix DSM supports the following customer-managed encryption keys (CMEK) integration services on the Google cloud:

• Artifact Registry
• BigQuery
• Compute Engine
• Cloud Logging: Log Router
• Cloud Spanner
• Cloud SQL
• Cloud Storage
• Dataflow Appliance and Dataflow shuffle
• Dataproc
• Google Kubernetes Engine: Data on VM disks or Application-layer Secrets
• Pub/Sub
• Secret Manager

Refer to the Cloud EKM documentation for the complete list.

1.1 Why Use Fortanix Data Security Manager With Google Cloud EKM Using VPC

Google Cloud’s External Key Manager allows services running in the Google Cloud Platform (GCP), namely Big Query and Google Compute Engine (GCE) to use an encryption key managed in an external key management service and controlled entirely by the customer. A Cloud Deployment Architect for GCP can access an EKM through a Virtual Private Cloud (VPC) network to satisfy their data sovereignty requirements.

Fortanix DSM protects all your data on-premises as well as in the cloud. It provides end-to-end security for keys and data (at-rest, in-transit, and in-use) protected with layers of defense including Fortanix Runtime Encryption®, Intel® SGX , and FIPS-validated hardware; Only authorized users can access keys.

2.0 Terminology References

Fortanix Data Security Manager (DSM)

Fortanix DSM is the cloud solution secured with Intel® SGX. With Fortanix DSM, you can securely generate, store, and use cryptographic keys and certificates, as well as secrets, such as passwords, API keys, tokens, or any blob of data.

GCP - Google Cloud Platform

Google Cloud Platform is a suite of public cloud computing services offered by Google. The platform includes a range of hosted services for compute, storage, and application development that run on Google hardware. Google Cloud Platform services can be accessed by software developers, cloud administrators, and other enterprises IT professionals over the public internet or through a dedicated network connection.

Google KMS - Google Key Management Service

Google Cloud Key Management Service (KMS) is a cloud service for managing encryption keys for other Google cloud services that enterprises can use to implement cryptographic functions. For more information, see Google Cloud Key Management Service.

VPC – Virtual Private Cloud

A Virtual Private Cloud (VPC) network is a virtual version of a physical network that is implemented inside of Google's production network. For more information on what a VPC network does, refer to the Google documentation here.

AES - Advanced Encryption Standard

Google uses the Advanced Encryption Standard (AES) algorithm to encrypt data at rest. AES is widely used because:

1. Both AES256 and AES128 are recommended by the National Institute of Standards and Technology (NIST) for long-term storage use (as of November 2015).
2. AES is often included as part of customer compliance requirements. For more information please see Advanced Encryption Standard.

SGX - Software Guard Extensions

Intel’s Software Guard Extensions (SGX) is a set of extensions to the Intel architecture that aims to provide integrity and confidentiality guarantees to security-sensitive computation performed on a computer where all the privileged software (kernel, hypervisor, and so on) is potentially malicious.

FIPS - Federal Information Processing Standards

FIPS is a set of standards that describe document processing, encryption algorithms, and other information technology standards for use within non-military government agencies and by government contractors and vendors who work with the agencies.

3.0 Prerequisites

• Fortanix Data Security Manager
• GCP Services
• Google Cloud Project
• AES key
• The GCP Project Owner must enable the Cloud Key Management Service (KMS) API in your GCP Project. Refer to the Google documentation for steps to enable the Cloud KMS API in your GCP project.
• The user trying to add the EKM Key in the GCP keyring must have a Cloud KMS Admin role.
• The GCP Project Owner must enable BigQuery API access in your GCP Project.
• The user using BigQuery must have permission to use BigQuery and permission to access the EKM key that Fortanix creates.

4.0 Fortanix Data Security Manager with GCP Service Using VPC

4.1 Overview

With Google Cloud Platform (GCP) External Key Manager, administrators use Fortanix DSM to store cryptographic keys for the purpose of encrypting/decrypting GCP workloads including BigQuery and Google Compute Engine (GCE). An Administrator for GCP can deploy a VPC network to reverse proxy the EKM requests and can access an EKM through this Virtual Private Cloud (VPC) network to satisfy their data sovereignty requirements

4.2 Enable KMS API in Your GCP Project

See Google documentation for steps on how to enable Google External Key Manager API in your GCP project.

4.3 Obtain Your Google Service Account Email Address

Fortanix DSM requires the identity of the GCP service account in your Google cloud project. This service account is automatically created by GCP once the KMS API is enabled. This service account exists by default and has the appropriate permissions, which cannot be modified. This service account will also not be viewable from your IAM; it is a backend service account controlled by GCP. This is in the format of the following email address, using your own project-number, where specified:

service-[PROJECT-NUMBER]@gcp-sa-ekms.iam.gserviceaccount.com

In the example above, PROJECT-NUMBER is the project number of your Google Cloud Platform project.

You can look up your project number using the following instructions:

Creating and managing projects  |  Resource Manager Documentation  |  Google Cloud

4.4 Configure GCP External Key Manager Connection

Set up Cloud External Key Manager (Cloud EKM) to connect to your external key management (EKM) provider over a Virtual Private Cloud (VPC) network. See Google documentation for steps to Create an EKM Connection.

4.5 Obtaining Access in Fortanix Data Security Manager

Create an account in Fortanix DSM if you do not have one already. See the Fortanix DSM Getting Started.

4.6 Create/Import an AES Key

In your Fortanix DSM console, follow the process below to create/import an AES encryption key:

1. Click the Security Objects tab.
2. Click  to create a new security object.
   In the Add New Security Object form, you can create or import an AES key. See the example below to import an AES key:
3. Enter a name for the security object (key).
4. Click Import to set the option to import an AES key.
5. Click AES for the type of key to import.
6. Select an option for the key-value format.
7. Click UPLOAD A FILE to upload your AES key.
   NOTE

   Make sure the new key has “encrypt” and “decrypt” key operations allowed.

To generate a new AES key, follow the instruction below:

1. Type a name for the security object (key).
2. Click Generate to set the option to generate an AES key.
3. Click AES for the type of key to import.
4. Type a value for the key size, in the Key size field.
5. Select the permitted key operations for this key.
6. Assign a group for the key.
7. Select Audit log to enable audit logging. This will inform you about all the audit logging for this security object. it is an optional field.
8. Click Generate to generate the AES key.
   NOTE

   Make sure the new key has “encrypt” and “decrypt” key operations allowed.

4.7 Create an App in Fortanix Data Security Manager

To create an application in Fortanix DSM, specify the Google service account email as the application name and the Google Service Account as the authentication method.

1. In the Fortanix DSM account, click the Apps tab.
2. Create a new Fortanix DSM app using the button .
3. In the Adding new app form, do the following:
   1. In the App name field, type the name of the service account email you acquired before.
      NOTE

      The app name must match the email address of an existing Google Service Account.
   2. In the Authentication method, click Google Service Account.

The user can allow access to wrap/unwrap keys for the following types of key access justifications options:

• Accept All: Select Accept All to allow access for all the justification reasons provided below. You can also customize your selection and select specific justification criteria for access.
  • Customer-initiated support – Support initiated from the customer, for example, Case Number: ####.
  • Customer-initiated access – Customer or a third-party authorized by customer's IAM policy perform any access to the customer's data.
  • Google-initiated service – Google-initiated access, for example, to perform system management and troubleshooting which includes:
    • Backup and recovery from outages and system failures
    • Investigation to confirm that the customer is not affected by suspected service issues
    • Remediation of technical issues, such as storage failure or data corruption
  • Google-initiated review – Google-initiated access for security, fraud, abuse, or compliance purposes including:
    • Ensuring the safety and security of customer accounts and content
    • Confirming whether the content is affected by an event that may impact account security (for example, malware infections)
    • Confirming whether the customer is using Google services in compliance with Google Terms of Service
    • Investigating complaints by other users and customers, or other signals of abusive activity
    • Checking that Google services are being used consistently with relevant compliance regimes (for example, anti-money laundering regulations)
  • Google-initiated system operation – Google-initiated access for security, fraud, abuse, or compliance purposes.
  • Third-party data request – Customer-initiated access by Google to respond to a legal request or legal process, including when responding to legal process from the customer that requires Google to access the customer's own content. Note that Access Transparency logs, in this case, may not be available if Google cannot legally inform the customer of such a request or process.
  • Unspecified reason – Indicates the actor accessing the data provided no access reason for the request. This may have been due to a transient error, a bug, or some other unexpected circumstance.
  • No justification reason expected – Indicates no reason is expected for this key request as the service in question has never integrated with Key Access Justification or is still in the pre-GA state and therefore may still have residual methods that call the External Key Manager but does not provide a justification.
  • Modified customer-initiated access – A customer uses their account to perform any access which is authorized by their own IAM policy; however, a Google administrator has reset the superuser account associated with the user’s organization within the last 7 days.
  • Modified Google-initiated system operation – Google initiated access of customer data to perform indexing, structuring, precomputation, hashing, sharding and caching to optimize the structure and quality of data for future uses by the customer.
  • Google responses to production alert – indicates Google-initiated access to main system reliability.
• Allow missing justification: Select this option to allow access even if a justification reason is not provided.

4.8 Enable GCP Service to Access AES Key in Fortanix DSM Using VPC

GCP services need a URL to access a key stored in Fortanix DSM through the VPC network. This is known as the external_key_uri.

1. The following is the format of the Google EKM URI using a VPC network.
   /v0/key/path/<key_id>
   Where
   
   • <key_id> is the UUID of the AES key.
2. To obtain the external_key_uri of the AES key using a VPC network from the DSM Security Objects table:
3. From the Fortanix DSM Security Objects table, click the AES key created earlier.
4. In the detailed view of the AES key, click COPY KEY PATH FOR EKM VPC in the COPY ID drop down menu.
   
   Figure 1: Get the Google EKM VPC URI
5. Use the above resource URL to create a manually managed cloud EKM using the VPC key created above.

4.9 Create a Manually Managed Cloud EKM Using VPC Key

1. Refer to Google documentation for steps to create a manually managed cloud EKM using the VPC key.
2. In Step 9 from the link above, for the Key Path field, enter the key path for EKM VPC copied in the previous section (Section 4.8).

5.0 Edit Authentication Method for an Existing App

To change the authentication method for an existing app to Google Service Account from the detailed view of an app.

1. In the detailed view of an app, click the INFO tab and in the API Key section click the Change authentication method drop-down menu.
   Figure 2: Change Authentication Method
2. Select Google Service Account and click SAVE to save the setting.
   Figure 3: Select Authentication Method
3. In the Configure authentication method window, select the key justification reasons, and click UPDATE. Refer to Section 4.7 to learn about the justification policies.
   
   NOTE

   The app name must match the email address of an existing Google Service Account.
   Figure 4: Select Key Justification Reason
   The application is updated with the new authentication method.
   Figure 5: Authentication Method Updated

6.0 Edit Key Access Justification Reason for an Existing App

You also have the option to edit the key justification reason for an existing app.

1. In the detailed view of an app, click the INFO tab and in the Google Service Account section, click the SHOW INSTRUCTIONS button.
   Figure 6: Edit Existing Key Justification Reason
2. In the Google Service Account window, click the EDIT button.
   Figure 7: Edit Key Justification Reason
3. Edit the allowed justification reason and click SAVE AND CLOSE to save the new updates.

7.0 Add Key Access Justification Policy for an Existing Key (Optional) 

You can also change the authentication method for an existing key from the Security Objects page. 

1. On the Security Objects page, select the key for which you want to change the key justification policy.
   
   Figure 8: Select the Key
2. In the detailed view of the key, click the KEY ACCESS JUSTIFICATION tab, and then click ADD POLICY to add a new key access justification policy.  
   
   Figure 9: Change Key Authentication Method
3. By default, the Accept All option is selected. Click Save to apply all the defined access justification policies to the key. 
   
   Figure 10: Change Key Authentication Method (Default Settings)
4. To change the applicable policies, clear the Accept All option, select the access justification policies that you want to apply to the key, and then click Save. Refer to Section 4.7 to learn about the justification policies.
   
   Figure 11: Update Key Policies The key is updated with the new justification policy. 

8.0 Edit Key Level Justification Policy for an Existing Key

You can also edit and change the authentication method for an existing key from the detailed view of a security object. After you have applied the policies to a key, you will see the EDIT POLICY button.

1. On the Security Objects page, select the key for which you want to edit the key access justification reason. In the detailed view of the key, the KEY ACCESS JUSTIFICATION tab, and then click EDIT POLICY.
   Figure 12: Edit Key Authentication Method
2. Clear the default policies you want to remove, select the policies you want to add, and then click SAVE.
   Figure 13: Update Key Policies

         The key is updated with the new access justification policy.

9.0 References

1. Google Cloud Key Management Service

https://cloud.google.com/kms/ekm/docs/

2. GCP Key Manager Service API

https://cloud.google.com/kms/docs/reference/rest/

3. Fortanix DSM Getting started

https://support.fortanix.com/hc/en-us/articles/360015809372-Getting-Started-with-Fortanix-Data-Security-Manager 

4. Advanced Encryption Standard

https://www.researchgate.net/publication/317615794_Advanced_Encryption_Standard_AES_Algorithm_to_Encrypt_and_Decrypt_Data

5. Enable Billing in GCP

https://cloud.google.com/billing/docs/how-to/modify-project