The best way to handle AWS IoT Greengrass core system 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 units to assist functions that demand native information processing and low latency. The rising variety of edge units in client, enterprise, and industrial segments, raises questions on the right way to deal with safety dangers posed by IoT edge units and system communication to and from the cloud. In Operational Expertise (OT) environments with a long time outdated Industrial Management Techniques (ICS), which weren’t constructed with cybersecurity in thoughts, the sting system usually performs the position of a gateway, guarding and interfacing with these less-capable techniques.

AWS recommends a multilayered safety strategy to safe IoT options. To guard and encrypt information in transit from an IoT edge system to the cloud, AWS IoT Core helps Transport Layer Safety (TLS)-based mutual authentication utilizing X.509 certificates. Prospects should provision a novel id, together with a novel non-public key and X.509 certificates, for every IoT edge system. Certificates are long-lived credentials, however you might must renew the certificates in the course of the lifetime of the system. Managing the system certificates lifecycle, together with periodic rotation of the system certificates and personal key, is likely 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 providers to rotate AWS IoT Greengrass core system certificates and personal keys. This resolution is deployable as is, however is delivered as an open-source reference implementation which you could tailor to your wants.


AWS IoT Greengrass is an IoT edge runtime and cloud service that lets you construct, deploy, and handle clever IoT system software program. It gives you with pre-built elements 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 providers, and native information aggregation, filtering, and transmission to cloud targets. As soon as growth is full, you possibly can seamlessly deploy and remotely handle system software program on thousands and thousands of units.

An AWS IoT Greengrass core system makes use of its system certificates and personal key to authenticate and hook up with AWS IoT Core. An AWS IoT coverage authorizes entry to the AWS IoT Core and AWS IoT Greengrass information planes. When the core system is permitted, AWS IoT Greengrass elements can ship and obtain MQTT messages to and from AWS IoT Core utilizing inter-process communication, with no need further or unbiased authentication or authorization with AWS IoT Core. To acquire licensed entry to non-IoT AWS providers, AWS IoT Greengrass makes use of the Token Alternate Service and the AWS IoT Core credential supplier to change the X.509 system certificates for time-limited AWS credentials. These time-limited credentials are licensed to carry out the actions outlined within the AWS IoT Greengrass core system position (often known as the token change position).

Figure 1: AWS IoT Greengrass security model

Determine 1: AWS IoT Greengrass safety mannequin

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

For a lot of AWS IoT system varieties, it’s difficult to supply a full end-to-end system certificates rotation reference implementation as a result of the system software program is closely depending on the system {hardware}. Particularly, certificates and personal key storage and APIs are strongly influenced by the {hardware} and the {Hardware} Abstraction Layer (HAL). Nevertheless, 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 might 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 system a part of the contract and an AWS Cloud Growth Package (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 resolution 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 units. 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 client or software developer. In different phrases, this resolution gives the technique of rotating a tool certificates and personal key with out dictating when or why it ought to be carried out. Instance invocation circumstances embrace AWS IoT Gadget Defender Audit checks or Detect anomalies, an everyday cadence, or a brand new compliance requirement that calls for a unique non-public key algorithm.

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

Main traits of the answer embrace:

  1. It might probably rotate credentials which might be both saved as information on disk or as PKCS#11 objects in a {Hardware} Safety Module (HSM). It’s your duty to decide on the storage sort, applicable in your safety posture. AWS recommends utilizing an HSM to guard these credentials.
  2. The cloud backend can challenge system certificates utilizing both AWS IoT Core or AWS Non-public CA, chosen by CDK context variables throughout resolution deployment. Deciding on AWS Non-public CA means that you can use your individual CA and to manage certificates expiry dates.
  3. The certificates rotation course of is encapsulated in an AWS IoT Job, created from the provided job template. This implies you possibly can reap the benefits of the superior capabilities of jobs, resembling job configurations and dealing with of units with intermittent connectivity, to handle the credentials of your system fleet at scale.
  4. The element might be deployed to core units which might be 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’ve the flexibleness to determine when to rotate certificates based mostly in your use case, danger evaluation and safety technique, and the renewal might be computerized to scale back any potential entry disruption because of handbook rotation.
  6. The answer is resilient to perturbation and gives notifications to customers utilizing SNS.

Answer deployment

Detailed deployment directions and stipulations are contained within the Certificates Rotator repository and within the “Certificates Rotator for AWS IoT Greengrass” video. You might 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 system certificates

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

  1. The AWS IoT Console
  2. The AWS CLI
  3. Fleet Hub for AWS IoT Gadget 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, you might want to modify it, tailoring it in your use case. The element and cloud backend are delivered with:

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


AWS recommends a multilayered safety strategy to safe IoT options, together with using robust identities, least privileged entry, monitoring of system well being and anomalies, safe connections to units to repair points, and making use of updates to maintain units updated and wholesome. Once you use X.509 certificates for digital id and authentication, you might must rotate the certificates and personal key based mostly on system well being and enterprise context.

You should use AWS IoT Gadget Defender to audit when system certificates are expiring, test system 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 durations require extra involvement, with this AWS IoT Greengrass Certificates Rotator element, AWS IoT makes rotation of IoT edge system certificates and personal keys simpler to carry out and furthermore, helps you enhance your IoT system’s safety posture.

Study extra

In regards to the Authors

Greg BreenGreg Breen is a Senior IoT Specialist Options Architect at Amazon Internet Providers. Based mostly in Australia, he helps clients all through Asia Pacific to construct their IoT options. With deep expertise in embedded techniques, he has a selected curiosity in helping product growth groups to convey their units to market.
Jen O'HehirRyan Dsouza is a Principal Options Architect for IoT at AWS. Based mostly in New York Metropolis, Ryan helps clients design, develop, and function safer, scalable, and modern options utilizing the breadth and depth of AWS capabilities to ship measurable enterprise outcomes. Ryan has over 25 years of expertise in digital platforms, good 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, Common Electrical, IBM, and AECOM, serving clients for his or her digital transformation initiatives.

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