Intel Trust Authority Client Tutorial - AMD SEV-SNP Attestation on GCP

· 12/19/2024 ·

This tutorial provides steps to deploy a demo application that uses the Intel® Trust Authority client for securing an application using AMD* SEV-SNP on Google Cloud Platform***** (GCP).

The demo application, built for AMD* SEV-SNP, uses the Intel Trust Authority client to retrieve evidence from the platform and request an attestation from Intel Trust Authority. This demonstrates a simple passport attestation model (stopping before involving a relying party). The application's output is the resulting attestation token. The demo application can be used as a workflow reference for your applications.

Creating a CVM with AMD SEV-SNP on GCP

To create a Confidential virtual machine (CVM) with AMD SEVSNP on GCP, sign in to GCP and create a CVM using the terminal. When creating an instance using GCP web UI, all AMD CVMs default to SEV instead of SEV-SNP. These instructions use the Cloud Shell terminal to create an AMD SEV-SNP CVM.

Create a CVM that supports AMD SEV-SNP on GCP, with the following attributes:

Virtual machine name - Give your virtual machine a name
Machine type: n2d-standard-2
Minimum CPU platform: AMD Milan
Zone: us-central1-a
Confidential compute type: SEV_SNP
Maintenance policy: TERMINATE
Image family: ubuntu-2204-lts
Image project: ubuntu-os-cloud

Note

The availability of specific CVM images in specific regions and availability zones is dynamic and may change. This tutorial uses us-central-a as an example. If you're outside North America, you may need to select a different region and availability zone. Check the Google Regions and zones page to find the regions and availability zones with available Confidential VMs with AMD SEV-SNP support.

To get a list of compute images for AMD SEV-SNP, use the following command in Google Cloud Shell.

gcloud compute images list --filter="guestOsFeatures[].type:SEV_SNP_CAPABLE"

Use the following steps to create a GCP CVM in Cloud Shell.

Sign in to GCP here.
Select the option to Create a VM.
Open the Cloud Shell by selecting the terminal icon in the upper right of the screen. Cloud Shell terminal displays.

Create the CVM in Cloud Shell.

The following is an example of creating a CVM using Ubuntu* 22.04 LTS with AMD SEV-SNP in Cloud Shell.

   gcloud compute instances create sev-snp-vm \
      --machine-type=n2d-standard-2 \
      --min-cpu-platform="AMD  Milan" \
      --zone=us-central1-a \
      --confidential-compute-type=SEV_SNP \
      --maintenance-policy=TERMINATE \
      --image-family=ubuntu-2204-lts \
      --image-project=ubuntu-os-cloud

Once the CVM is created, you should have information display details such as name, zone, machine type, IP addresses, and status.

Connect to the CVM via SSH

After the CVM is created, exit the Cloud Shell terminal and connect to the CVM with SSH. You can connect in the browser with the following steps.

Select the drop-down arrow for SSH in the Connect category for your CVM.
Select Open in browser window.

After this selection, you will have a SSH in browser window display. In this step, another window displays with a button for you to Authorize.
Select the Authorize button. After authorization you will have a terminal display, in the browser, connected via SSH to your CVM.

GCP CVM AMD SEV-SNP prerequisites

To verify that the CVM is AMD SEV-SNP is enabled, use the following command. This should print Memory Encryption Features active: SEV-SNP. If this is missing, SEV-SNP is not enabled. In that case, check to see that the parameters are correct.

   sudo dmesg | grep -i sev-snp

To run the initial setup, you will need the following dependencies.

- git
- Go*
- make
- gcc 
- gh

Install the required packages.

Use the GitHub* CLI to connect to GitHub.

Use the following commands to check the version, login, and check the status.

To check the version, use --version.

      gh --version

Login with GitHub CLI with the following command.
```
      gh auth login
```
Follow the on-screen prompts. You will be prompted to select Github.com or Github Enterprise server.

Select your account.

   What account do you want to login to? 
   Github.com or GitHub Enterprise Server

Select HTTPS or SSH.

   What is your preferred protocol for Git operationa? HTTPS or SSH

You will be prompted to authenticate with GitHub credentials. Press Enter for Yes or type n for no then Enter.
```
   HTTPS > Authenticate Git with your Github credentials (Y/n)
```

You will be prompted to authenticate with a web browser or authentication token.

   How would you like to authenticate GitHub CLI?
   Login with a web browser or Paste an authentication token?

Select the option for web browser and use the Enter key. A one-time code displays.
Copy the one-time code. The following text displays to open the browser.
```
   Press **Enter** to open github.com in your browser...
```
Press Enter. If the browser does not open, try entering the URL https://github.com/login/device in your browser manually to authorize your gh login in a browser. The URL takes you to Device Activation.
1. Select Continue.
2. Enter the one-time code. An authorize cli screen displays.
3. Select Authorize github. A confirm access screen displays.
4. Enter the password.
5. Select confirm. A screen displays with the following message: Congratulations, you're all set! Your device is now connected.
6. Return to the SSH connect window. The terminal displays that the authentication is complete.
Press Enter to continue. Information displays that you are logged in.
Check the status of GitHub CLI by running the command below. The output will confirm you are logged into github.com.
```
   gh auth status 
```

Install Intel Trust Authority client for Go

The Intel Trust Authority CLI client provides a command-line wrapper for Golang client libraries. The following steps will get and build Intel Trust Authority client for Go client.

Note

Note that the preview branch is being checked out for the GCP AMD SEV-SNP feature, because this feature is not supported on the main branch of the client CLI.

Build the Intel Trust Authority client.
```
   git clone https://github.com/intel/trustauthority-client -b sevsnp-preview \
   cd trustauthority-client/sevsnp-cli \
   make cli
```
Configure your API key and any desired policy to evaluate. Set the attestation API key and attestation endpoint.
Create config.json.
```
touch config.json
```
You must configure certain properties before using the token and verify commands. The properties and values are saved as JSON in config.json. The config.json requires the following properties:
```
   cat <<EOF> config.json
      {
         "trustauthority_api_url": "https://api.trustauthority.intel.com",
         "trustauthority_api_key": "<attestation api key>"
      }
   EOF
```
Note

If you are in the European Union (EU) region, use the following Intel Trust Authority URL:
"trustauthority_api_url": "https://api.eu.trustauthority.intel.com"
Run the sample application. Use the trustauthority-cli utility to request an attestation. The token command automatically collects evidence from SEV-SNP and requests an attestation token from Intel Trust Authority. Full usage details for the trustauthority-cli utility can be found at Intel Trust Authority Attestation Client CLI documentation.
```
   sudo ./trustauthority-sevsnp-cli token --config config.json
```

* Other names and brands may be claimed as the property of others.