Tips on how to handle AWS IoT Greengrass core gadget certificates


We’re very happy to introduce the Certificates Rotator element for AWS IoT Greengrass, a brand new element within the Greengrass Software program Catalog.

AWS IoT Greengrass brings the AWS cloud nearer to edge gadgets to assist purposes that demand native knowledge processing and low latency. The rising variety of edge gadgets in client, enterprise, and industrial segments, raises questions on the right way to tackle safety dangers posed by IoT edge gadgets and gadget communication to and from the cloud. In Operational Know-how (OT) environments with a long time previous Industrial Management Methods (ICS), which weren’t constructed with cybersecurity in thoughts, the sting gadget usually performs the position of a gateway, guarding and interfacing with these less-capable techniques.

AWS recommends a multilayered safety method to safe IoT options. To guard and encrypt knowledge in transit from an IoT edge gadget to the cloud, AWS IoT Core helps Transport Layer Safety (TLS)-based mutual authentication utilizing X.509 certificates. Clients should provision a novel id, together with a novel personal key and X.509 certificates, for every IoT edge gadget. Certificates are long-lived credentials, however chances are you’ll have to renew the certificates through the lifetime of the gadget. Managing the gadget certificates lifecycle, together with periodic rotation of the gadget certificates and personal key, is without doubt one of the safety greatest practices within the IoT Lens for the AWS Effectively-Architected Framework.

On this weblog submit, you’ll learn to use the Certificates Rotator element and the right way to use AWS companies to rotate AWS IoT Greengrass core gadget certificates and personal keys. This answer is deployable as is, however is delivered as an open-source reference implementation that you would be able to tailor to your wants.


AWS IoT Greengrass is an IoT edge runtime and cloud service that lets you construct, deploy, and handle clever IoT gadget software program. It supplies you with pre-built parts for frequent capabilities, resembling native/cloud MQTT messaging, assist for native edge processing together with Machine Studying (ML) inference, logging and monitoring, out-of-the-box integration with AWS companies, and native knowledge aggregation, filtering, and transmission to cloud targets. As soon as improvement is full, you’ll be able to seamlessly deploy and remotely handle gadget software program on hundreds of thousands of gadgets.

An AWS IoT Greengrass core gadget makes use of its gadget certificates and personal key to authenticate and connect with AWS IoT Core. An AWS IoT coverage authorizes entry to the AWS IoT Core and AWS IoT Greengrass knowledge planes. When the core gadget is allowed, AWS IoT Greengrass parts can ship and obtain MQTT messages to and from AWS IoT Core utilizing inter-process communication, while not having extra or impartial authentication or authorization with AWS IoT Core. To acquire licensed entry to non-IoT AWS companies, AWS IoT Greengrass makes use of the Token Alternate Service and the AWS IoT Core credential supplier to alternate the X.509 gadget certificates for time-limited AWS credentials. These time-limited credentials are licensed to carry out the actions outlined within the AWS IoT Greengrass core gadget position (also called the token alternate position).

Figure 1: AWS IoT Greengrass security model

Determine 1: AWS IoT Greengrass safety mannequin

Due to this fact, the X.509 gadget certificates and personal key are the muse of an AWS IoT Greengrass core gadget’s id and authentication. It’s your duty to rotate the gadget certificates and personal key primarily based in your operational wants. To information you on this implementation, AWS provides a tool certificates rotation weblog, an IoT Jumpstart workshop and the Linked System Framework (CDF) Certificates Vendor module. These are documented rotation procedures and supply a partial implementation reference.

For a lot of AWS IoT gadget varieties, it’s difficult to supply a full end-to-end gadget certificates rotation reference implementation as a result of the gadget software program is closely depending on the gadget {hardware}. Specifically, certificates and personal key storage and APIs are strongly influenced by the {hardware} and the {Hardware} Abstraction Layer (HAL). Nonetheless, AWS IoT Greengrass standardizes the certificates and personal key storage by the AWS IoT Greengrass Core software program set up configuration. The situation of the certificates and personal key are outlined by the certificateFilePath and privateKeyPath configuration parameters. Accordingly, a deployable end-to-end certificates rotation reference implementation will be delivered.

Answer overview

The Certificates Rotator element is an answer consisting of two components: an AWS IoT Greengrass element named aws.greengrass.labs.CertificateRotator that delivers the gadget a part of the contract and an AWS Cloud Growth Equipment (CDK) stack that delivers the companion cloud backend. The cloud backend is principally comprised of three Lambda capabilities, three AWS IoT Core guidelines, an AWS IoT customized job template named AWSLabsCertificateRotator, and an Amazon Easy Notification Service (SNS) subject. Certificates are issued by both AWS IoT Core or by AWS Non-public Certificates Authority (CA).

Figure 2: Certificate Rotator solution architecture

Determine 2: Certificates Rotator answer structure

As indicated, the Certificates Rotator element and cloud backend talk utilizing MQTT. An AWS IoT Job defines a set of distant operations that may be despatched to and run on a number of gadgets. The cloud software initiates a certificates and personal key rotation by creating an AWS IoT Job utilizing the customized job template. Invocation circumstances and enterprise logic for the job creation are left to the shopper or software developer. In different phrases, this answer supplies the technique of rotating a tool certificates and personal key with out dictating when or why it needs to be accomplished. Instance invocation circumstances embody AWS IoT System Defender Audit checks or Detect anomalies, an everyday cadence, or a brand new compliance requirement that calls for a unique personal key algorithm.

The SNS subject is used to inform customers of any certificates rotation failures. Clients can benefit from the flexibleness of SNS subscriptions to implement failure dealing with and restoration that’s acceptable for his or her enterprise.

Main traits of the answer embody:

  1. It might probably rotate credentials which are both saved as recordsdata on disk or as PKCS#11 objects in a {Hardware} Safety Module (HSM). It’s your duty to decide on the storage sort, acceptable in your safety posture. AWS recommends utilizing an HSM to guard these credentials.
  2. The cloud backend can problem gadget certificates utilizing both AWS IoT Core or AWS Non-public CA, chosen by CDK context variables throughout answer deployment. Deciding on AWS Non-public CA permits you to use your personal CA and to manage certificates expiry dates.
  3. The certificates rotation course of is encapsulated in an AWS IoT Job, created from the equipped job template. This implies you’ll be able to benefit from the superior capabilities of jobs, resembling job configurations and dealing with of gadgets with intermittent connectivity, to handle the credentials of your gadget fleet at scale.
  4. The element will be deployed to core gadgets which are both Linux or Home windows. The one limitation is that the element assumes that AWS IoT Greengrass is put in as a system service.
  5. You have got the flexibleness to resolve when to rotate certificates primarily based in your use case, threat evaluation and safety technique, and the renewal will be automated to cut back any potential entry disruption resulting from guide rotation.
  6. The answer is resilient to perturbation and supplies notifications to customers utilizing SNS.

Answer deployment

Detailed deployment directions and conditions are contained within the Certificates Rotator repository and within the “Certificates Rotator for AWS IoT Greengrass” video. You want to deploy the answer in every AWS account and/or area the place you might be working an IoT/IIoT workload. Deployment has two components: deploying the cloud backend CDK software, and constructing, publishing and deploying the AWS IoT Greengrass element.

Rotating gadget certificates

With the element and cloud backend deployed, a certificates rotation will be carried out just by making a job utilizing the AWSLabsCertificateRotator job template. This job creation will be achieved in a number of methods, together with:

  1. The AWS IoT Console
  2. The AWS CLI
  3. Fleet Hub for AWS IoT System Administration
Figure 3: Creating a certificate rotation job in the AWS IoT console

Determine 3: Making a certificates rotation job within the AWS IoT console

Answer customization and testability

Though the answer is delivered in deployable kind, chances are you’ll want to modify it, tailoring it in your use case. The element and cloud backend are delivered with:

  1. An in depth unit check suite, with 100% line and department protection.
  2. An in depth automated integration check suite, that checks certificates rotation towards a user-defined factor group of AWS IoT Greengrass core gadgets.
  3. A CI/CD pipeline for improvement environments, that automates the construct, publish and deployment of each the element and the cloud backend, and in addition runs the total suite of unit and integration checks for automated regression testing.


AWS recommends a multilayered safety method to safe IoT options, together with using robust identities, least privileged entry, monitoring of gadget well being and anomalies, safe connections to gadgets to repair points, and making use of updates to maintain gadgets updated and wholesome. If you use X.509 certificates for digital id and authentication, chances are you’ll have to rotate the certificates and personal key primarily based on gadget well being and enterprise context.

You need to use AWS IoT System Defender to audit when gadget certificates are expiring, examine gadget certificates key high quality and different certificates greatest practices which may act as an invocation situation on when to rotate IoT edge certificates and personal keys. Though shorter certificates validity intervals require extra involvement, with this AWS IoT Greengrass Certificates Rotator element, AWS IoT makes rotation of IoT edge gadget certificates and personal keys simpler to carry out and furthermore, helps you enhance your IoT system’s safety posture.

Be taught extra

In regards to the Authors

Greg BreenGreg Breen is a Senior IoT Specialist Options Architect at Amazon Net Companies. Primarily based in Australia, he helps prospects all through Asia Pacific to construct their IoT options. With deep expertise in embedded techniques, he has a specific curiosity in aiding product improvement groups to carry their gadgets to market.
Jen O'HehirRyan Dsouza is a Principal Options Architect for IoT at AWS. Primarily based in New York Metropolis, Ryan helps prospects design, develop, and function safer, scalable, and progressive options utilizing the breadth and depth of AWS capabilities to ship measurable enterprise outcomes. Ryan has over 25 years of expertise in digital platforms, sensible manufacturing, power administration, constructing and industrial automation, and OT/IIoT safety throughout a various vary of industries. Earlier than AWS, Ryan labored for Accenture, SIEMENS, Normal Electrical, IBM, and AECOM, serving prospects for his or her digital transformation initiatives.

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