AWS Greengrass Parsec Provider

Welcome to the Parsec Provider plug-in for AWS IoT Greengrass v2. This community component allows AWS IoT Greengrass devices to integrate hardware security solutions using the open-source Parsec project from Cloud Native Computing Foundation (CNCF). Starting from the Greengrass v2.8 release, Parsec can be used as an alternative to the PKCS#11 Provider to manage the creation and storage of private keys within hardware-enforced security boundaries on a variety of platforms, including devices that use a Hardware Security Module (HSM) or a Trusted Platform Module (TPM). With ongoing investment from the open-source community, Parsec is making it easier and more portable to integrate cloud-native applications with an increasing number of diverse hardware security solutions.

Description

The Parsec Provider is a plug-in component (aws.greengrass.plugin). It is implemented with Java and is supplied as a single Java Archive (JAR) file that can be downloaded from this GitHub repository. The Greengrass Nucleus runs this plug-in in the same Java Virtual Machine (JVM) as the nucleus itself. When it is used, it takes care of security operations that require the use of private keys that are protected in hardware. These operations are routed to the Parsec service on the core device. The Parsec service is then responsible for using the available platform hardware and software interfaces to perform those operations with the private key. It is conceptually very similar to how the PKCS#11 Provider component works, except that the Parsec project aims to handle the various interoperability issues that are often found when using PKCS#11 libraries on different devices.

Dependencies

To use this component, you will first need to have the Parsec service and the Parsec command-line tool (parsec-tool) installed and configured on your core device. Parsec is a local service on any given device, so you will need to have it running and available on the same core device where the Greengrass Nucleus is running. If you are setting up multiple Greengrass core devices, then you will need to have Parsec installed and configured on all of them.

The method for installing and configuring Parsec depends on the Operating System image that you are using on your core device. Some customized distributions might contain Parsec already, in which case no additional steps are needed. If Parsec is not already installed and running, you may be able to install it using your system's package manager. In other cases, it can be downloaded as a binary or built from source code. If you are trying out Parsec for the first time, refer to the Parsec Getting Started guide to learn the steps needed to get Parsec installed and running.

Check for the availability of Parsec on your system using the following command:

parsec-tool ping

If Parsec is installed and running, this command will produce output similar to the following:

[INFO ] Service wire protocol version
1.0

If the command fails or is not found, this indicates that Parsec is not fully or correctly installed. Please refer back to the guidelines above and proceed only when you can successfully execute the ping command.

Limitations

Currently, the Parsec Provider plug-in for AWS IoT Greenrass v2 is only supported on Linux devices.

Installation and Usage

The AWS IoT Greengrass Core software includes an installer that sets up your device as a Greengrass core device. To successfully provision your device and register it with the AWS IoT service, you need a private key and a corresponding certificate in order to establish trust and a secure connection between your device and the service. There are also various additional resources that need to exist within the cloud to represent and manage your device once it is connected. The process of creating all of these assets is collectively known as provisioning.

AWS IoT Greengrass v2 supports a variety of provisioning methods, summarised as follows:

• Automatic provisioning. The private key, device certificate, and all other resources are created automatically within the AWS IoT service at the point where the AWS IoT Greengrass Core software is installed on the core device.
• Manual provisioning. All resources are created manually. The private key can either be created locally on the device hardware, or it can be downloaded from the AWS IoT service.
• Fleet provisioning. This is a variant of automatic provisioning where private keys and certificates are created on-demand when a device connects to the AWS IoT service for the first time.
• Custom provisioning. This is also a variant of automatic provisioning, where additional Java components are plugged into the AWS IoT Greengrass core installer to run custom actions that implement the provisioning process.

When you use the Parsec Provider component, the private key is created and managed inside Parsec, which means that it is created on your Greengrass core device and never leaves the device. It is not downloaded from the AWS IoT service. Once you have created the key, you use Parsec tools to create a Certificate Signing Request (CSR) based on that key. The AWS IoT service can then use this CSR to create the certificate for your device.

The provisioning method that best supports this workflow is the manual provisioning method. So you will need to use manual provisioning if you wish to use AWS IoT Greengrass with the Parsec Provider component.

The steps for manual provisioning are provided as part of the AWS IoT Greengrass v2 Documentation.

You will need to follow these steps in order to install and provision your device. The steps vary depending on whether you wish to create the private key locally on the device, or download a key from the AWS IoT service. When you are using Parsec, you will always be creating the private key locally on the device using Parsec tools. The steps to do this are documented below. Please refer to these steps instead of the "HSM" instructions given in the AWS IoT Greengrass documentation, because those assume that you are using the PKCS#11 interface rather than Parsec.

The guinelines below will show you how to follow the AWS IoT Greengrass documentation while substituting the steps where Parsec tooling is required.

Retrieve the AWS IoT endpoints

Follow this step exactly according to the AWS IoT Greengrass documentation.

Create an AWS IoT thing

Follow this step exactly according to the AWS IoT Greengrass documentation.

Create the thing certificate

To create the thing certificate, you will begin by creating a suitable private key using the parsec-tool. Choose a name for your private key. You may wish to give the key the same name as the AWS thing. However, please note that the current version of the software requires the key name to be all in lower case, so you may need to convert the AWS thing name. Or, you can choose another name. Whatever naming scheme you choose for the key, you will need to remember it later on when you configure the Greengrass Nucleus component on your core device.

Set the environment variable KEY_NAME to be your chosen key name, and then run this commmand:

parsec-tool create-rsa-key -s --key-name ${KEY_NAME}

This will create a 2048-bit RSA signing key, which is suitable for use as a private key on which to base your device certificate.

The next step is to create the CSR. The following example creates a CSR whose Common Name is the same as the AWS thing that you have provisioned. This assumes that the environment variable GG_THING_NAME has been set to the name of the AWS thing. Run the following command:

parsec-tool create-csr --key-name ${KEY_NAME} --cn "${GG_THING_NAME}" >iotdevicekey.csr

In the above example, the CSR will have a Common Name (CN) that is the same as the name of the AWS thing that you have provisioned. Should you wish to structure your CSR with different properties, please refer to the help text for the CSR command as follows:

parsec-tool create-csr --help

Once you have created the private key and the CSR, the remaining steps to create the thing certificate are the same as in the AWS IoT Greengrass documentation.

Configure the thing certificate

Follow this step exactly according to the AWS IoT Greengrass documentation.

Create a token exchange role

Follow this step exactly according to the AWS IoT Greengrass documentation.

Download the certificates to the device

You will mostly follow this step according to the AWS IoT Greengrass documentation. Follow the steps that describe how to download the certificates onto the device using an HSM. The steps to do this with Parsec are the same, except that Parsec does not yet support importing certificates. The device.pem.crt file simply needs to be copied into the greengrass root folder of the core device.

Set up the device environment

Follow this step exactly according to the AWS IoT Greengrass documentation.

Download the AWS IoT Greengrass Core software

Follow this step exactly according to the AWS IoT Greengrass documentation.

Install the AWS IoT Greengrass Core software

Begin by following the steps in the AWS IoT Greengrass documentation.

Download the Parsec Provider component. This is a single Java JAR file called aws.greengrass.crypto.ParsecProvider.jar. You can download the latest version from TODO - URL. You should copy this file into the same folder where you placed the installer in the step above.

Ensure that thw following environment variables are set in the shell on your core device:

• GG_USER_HOME should be set to the root folder for the Greengrass user on your core device, such as /greengrass/v2.
• KEY_NAME should be set to the name of the private key that you created earlier.
• GG_THING_NAME should be set to the name of the AWS thing that you are provisioning.
• AWS_REGION should be set to the name of the AWS region that you are using, such as us-west-2.
• iot_role_alias should be set to the name of the token exchange role alias from above, such as GreengrassCoreTokenExchangeRoleAlias.
• iot_endpoint should be set to your AWS IoT data endpoint, such as device-data-prefix-ats.iot.us-west-2.amazonaws.com.
• cred_endpoint should be set to your AWS IoT credentials endpoint, such as device-credentials-prefix.credentials.iot.us-west-2.amazonaws.com.

Now run the following command to create the partial config.yaml file from these inputs:

cat <<EOF >${GG_USER_HOME}/config.yaml
system:
  certificateFilePath: "parsec:import=${GG_USER_HOME}/device.pem.crt;object=${KEY_NAME};type=cert"
  privateKeyPath: "parsec:object=${KEY_NAME};type=private"
  rootCaPath: "${GG_USER_HOME}/AmazonRootCA1.pem"
  rootpath: ""
  thingName: "${GG_THING_NAME}"
services:
  aws.greengrass.Nucleus:
    componentType: "NUCLEUS"
    configuration:
      awsRegion: "${AWS_REGION}"
      iotRoleAlias: "${iot_role_alias}"
      iotDataEndpoint: "${iot_endpoint}"
      iotCredEndpoint: "${cred_endpoint}"
  aws.greengrass.crypto.ParsecProvider:
    configuration:
      name: "greengrass-parsec-plugin"
      parsecSocket: "/run/parsec/parsec.sock"
EOF

Now run the installer, and specify --init-config to provide the configuration file that you just created.

sudo -E java -Droot="{GG_USER_HOME}" -Dlog.store=FILE \
  -jar ./GreengrassInstaller/lib/Greengrass.jar \
  --trusted-plugin ./GreengrassInstaller/aws.greengrass.crypto.ParsecProvider.jar \
  --init-config ./GreengrassInstaller/config.yaml \
  --component-default-user ggc_user:ggc_group \
  --setup-system-service true

(If you used a folder other than GreengrassInstaller when you downloaded the installer, then substitute the name of your folder in the above command).

Follow the final verification steps from the AWS IoT Greengrass documentation.

Congratulations! You have now provisioned and installed your AWS IoT Greengrass core device using Parsec.

License

This project is licensed under the Apache-2.0 License.