Securing Service Meshes with Authorization Policies and Non-Human Identities

Understanding the Need for Service Mesh Authorization

So, service meshes are kinda becoming a big deal for keeping microservices safe, right? But why is authorization, like, so important in these setups? Let's get into why we really need solid authorization policies in our service meshes.

Traditional security models? They kinda struggle with how complicated distributed microservices are. Unlike those old monolithic apps, microservices talk to each other across a bunch of network boundaries, which just opens up way more ways for bad actors to get in. Plus, with Kubernetes, those pod IPs are always changing, making regular firewall rules pretty useless. As the Authorization policy overview points out, globally-distributed microservices apps make calls across network boundaries, which means more points of entry into your applications, and more opportunities for malicious attacks.

Service meshes give us this one-stop shop for securing microservices by being this dedicated infrastructure layer. They let us do security policies at both the app level (L7) and the transport level (L3/4), with stuff like mutual TLS (mTLS), authentication, and, you guessed it, authorization. With a service mesh, you can actually have the same security policies everywhere in your app, no matter what's going on under the hood.

In microservices architectures, Non-Human Identities (NHIs) are super important. NHIs, or machine identities or workload identities, are basically for services and apps, not people. Authorization policies gotta think about NHIs to actually control who can talk to who.

Like, imagine a healthcare app where a "patient-data" service needs to get info from a "records" service. The authorization policy should make sure only the "patient-data" service, identified by its NHI, can hit certain spots on the "records" service. This stops people from snooping on data they shouldn't see.

So, now that we get why service mesh authorization is a thing, we can look at how authorization policies and Non-Human Identities team up to keep service meshes safe. Next up, we'll get into the nitty-gritty of authorization policies.

Authorization Policies: The Building Blocks of Service Mesh Security

Authorization policies are basically the bouncers for your service mesh, deciding who gets in where. Think of them as the super-detailed instructions that tell your security system exactly how to manage traffic.

Authorization policies let you set up really specific permissions for your workloads. They decide what a service or a Non-Human Identity (NHI) is allowed to do inside the mesh. These policies are pretty flexible and can be applied to different scopes, so you can put security exactly where you need it.

• Granular Permissions: Authorization policies tell you precisely what actions a service can take. For example, a policy might only let a "payment-service" hit the "charge" endpoint of a "billing-service."
• NHI Access Control: Like we talked about, authorization policies consider Non-Human Identities, making sure only authorized services or apps can get to certain resources. This is a big deal for service-to-service communication.
• Flexible Scope: Policies can be applied mesh-wide for general rules, at the namespace level for broader control, or to individual workloads for really specific permissions. As the Authorization policy overview mentions, you can apply a policy to the entire service mesh, to a namespace, or to an individual workload.

Every authorization policy has three main parts that decide how it works. These pieces all work together to make sure only legit requests get through, based on the rules you set.

• Policy Scope (Selector): This is what the policy targets, basically saying which workloads it applies to. If you don't have a selector, the policy applies to everything in its scope.
• Action: This is whether to ALLOW or DENY requests. It's a good idea to always be clear and specify the action.
• Rules: These are what trigger the action, based on who's making the request, what they're trying to do, and any other conditions that need to be met.

Authorization policies can be applied at different levels in your service mesh. Each level gives you a different kind of control, letting you tweak your security to fit what you need.

• Mesh-wide Policies: These apply to the whole service mesh, setting a basic security standard for all services. Mesh-wide policies are good for making sure everyone follows company rules.
• Namespace Policies: These apply to all workloads in a specific namespace. If you have a bunch of services in the same namespace that need the same policies, this is handy.
• Workload-Specific Policies: These policies use selectors to target specific workloads based on their labels.

To lock down a policy to a specific workload, you gotta include a selector field, like the Authorization policy overview says.

Knowing these scopes and how to use selectors is key to writing good authorization policies. Next, we'll dig into how these policies work with Non-Human Identities to build a solid security setup.

Implementing Authorization Policies for NHIs

Keeping service meshes safe with authorization policies is crucial, but how do you actually do it for Non-Human Identities (NHIs)? Let's look at ways to control access based on who's authenticated and other matching stuff.

One really effective way is to limit access based on the authenticated identity of the workload or namespace. You can do this using the principals and namespaces fields in your authorization policies.

• Using principals and namespaces: These fields let you say which workloads or namespaces are allowed to access a service. For instance, you could let only workloads with a specific service account hit a sensitive API endpoint.
• Requires mutual TLS (mTLS): This method relies on mutual TLS (mTLS) being turned on in STRICT mode. With mTLS, each service shows a certificate to prove its identity, making communication secure.
• Example: To let only the frontend service talk to the currencyservice, you'd put the frontend service's principal in the principals field of the authorization policy.

Authorization policies also support different matching schemas to give you flexibility when defining rules. You can use exact matches, prefix matches, suffix matches, or presence matches for various fields in the policy.

• Matching Schemas: Most fields let you use a bunch of matching options. For example, you could use a prefix match to allow access from any service in a particular domain.
• Wildcard Characters: Wildcards like "*" can be used for prefix and suffix matching. For instance, "*.example.com" would match "eng.example.com" or "test.eng.example.com".
• Exceptions: Some fields, like the key under the when section, only work with exact matches. So, you gotta put in the exact value for these.

Exclusion matching lets you set conditions where access should be denied. The notValues, notIpBlocks, and notPorts fields let you specify negative conditions.

• Negative Conditions: These fields let you exclude certain values, IP blocks, or ports from the policy. For example, you could exclude requests to the /healthz path from needing JWT authentication.
• Example: You could combine exclusion matching with JWT validation to make sure all requests, except those to a specific health check endpoint, need a valid JWT.
• JWT Validation: This makes sure only authenticated requests are processed, while still letting unauthenticated access to important endpoints like health checks.

By setting up authorization policies the right way, you can secure your service mesh and keep your microservices safe from people trying to get in without permission.

Next, we'll look at how to configure advanced features in authorization policies to boost your service mesh security.

Advanced Authorization Policy Configuration

Can you actually block all unencrypted traffic in your service mesh? With advanced authorization policy setup, you can really dial in your security measures to make sure only authenticated and encrypted traffic gets through. Let's see how to amp up your service mesh security with advanced features in authorization policies.

You can use authorization policies to enforce mutual TLS (mTLS) and reject traffic that's not encrypted. This is super important if you can't enable STRICT mTLS mode for a workload or namespace.

• Enforce mTLS: Create policies that specifically allow traffic with non-empty namespaces or principals.
• Deny Plaintext: Reject traffic with empty namespaces or principals, which basically blocks any unencrypted traffic, as mentioned in the Authorization policy overview.
• Example: The following policy denies requests if the principal is empty, which is pretty typical for unencrypted requests.

apiVersion: security.istio.io/v1beta1
kind: AuthorizationPolicy
metadata:
  name: require-mtls
  namespace: NAMESPACE
spec:
  action: DENY
  rules:
  - from:
    - source:
        notPrincipals: ["*"]

When you're setting up ALLOW and DENY policies, understanding how they take precedence is key. DENY policies are checked before ALLOW policies, making sure that really important restrictions are enforced.

• allow-nothing Policy: An ALLOW policy that doesn't match anything means requests get denied by default if there aren't any other ALLOW policies.
• deny-all Policy: A DENY policy that matches everything denies all requests, even if there's an ALLOW policy.
• allow-all Policy: An ALLOW policy that matches everything lets all traffic through, making other ALLOW policies kinda pointless; however, DENY policies still win.

The when section in authorization policies lets you add more conditions for authorization. This gives you really fine-grained control based on different attributes.

• Istio Attributes: Use Istio attributes to set conditions. For example, you can allow access based on specific request headers or JWT claims.
• Request Headers: You can create custom conditions based on request headers. This lets you control access based on whether certain headers are present or what their values are.
• JWT Claims: You can also create conditions based on JWT claims. This is useful for enforcing access control based on user roles or permissions that are encoded in the JWT.

With these advanced configurations, you can seriously boost the security and flexibility of your service mesh.

Next, we'll cover some best practices for securing Non-Human Identities (NHIs) within the service mesh.

Best Practices for Implementing Service Mesh Authorization

Is your service mesh strategy as strong as it could be? Let's look at some important steps to make your implementation solid and secure.

A really crucial first step in securing your service mesh is managing your service accounts properly. A Kubernetes service account gives an identity to processes running in a Pod.

• Create a Kubernetes service account for each service. This gives every service in your cluster a unique identity.
• Specify the service account in the Deployment configuration. This links the service account to the workload, tying the workload to its unique identity.
• This practice makes identity better and makes setting up authorization policies easier. Like we said before, Non-Human Identities are super important for good authorization, so using service accounts makes managing these identities simpler.

Following the principle of least privilege is a basic security thing. This means giving each service only the minimum permissions it needs to do its job.

• Start with an allow-nothing policy and slowly add more ALLOW policies. This makes sure no unintended access is granted by default.
• Give only the necessary permissions to each workload. For example, a payment service should only be allowed to access the billing service's charge endpoint.
• Sticking to the principle of least privilege cuts down the risk of unauthorized access and attackers moving around. If a service gets compromised, the attacker's access is limited to only what was explicitly allowed.

If your services use JSON Web Tokens (JWT) for authentication, there are specific steps you can take to secure them. JWTs are a standard way to securely pass information between parties as a JSON object.

• Create a DENY policy to block requests that aren't authenticated.
• Apply an allow-nothing policy. This is a baseline that denies all requests that don't meet specific criteria.
• Define ALLOW policies for each workload based on JWT claims. Set up your authorization policies to check the JWT's issuer, audience, and other important claims.

By following these best practices, you can really improve the security of your service mesh. These steps make sure access is controlled, authenticated, and authorized based on clear policies.

Next, we'll look at how to monitor and audit your service mesh to keep improving its security.

Leveraging Non-Human Identity Management Group for Enhanced Security

Is managing Non-Human Identities (NHIs) keeping you up at night? Securing service meshes needs special skills, and that's where a dedicated partner can really make a difference.

NHIMG is the main independent authority in NHI Research and Advisory. We help organizations deal with the critical risks of Non-Human Identities (NHIs). Our main goal is to help you understand and secure your service mesh.

Stay up-to-date on the always-changing world of Non-Human Identities with NHIMG's research. Our advisory services can help you put in place solid authorization policies and secure your service mesh.

NHIMG focuses on giving complete non-human identity management solutions. Our offerings include:

• NHI Strategy Development: We help you create a custom strategy for securing service meshes. This includes figuring out important NHIs and mapping out your authorization policies.
• Expert Guidance: NHIMG gives expert advice on putting authorization policies into practice within service meshes. We make sure your policies line up with industry best practices.
• Security Posture Assessment: NHIMG checks your current security setup and gives recommendations for making it better. We help you find weaknesses related to NHIs.

Ready to take the next step in securing your service mesh? Here's how NHIMG can help:

• Contact NHIMG for a chat about your specific service mesh security needs. We'll look at what you have now and find areas to improve.
• Use NHIMG's know-how to design and implement strong authorization policies. Our team will help you create policies that effectively manage NHI access.
• Improve your overall security setup with NHIMG's complete NHI management solutions. We give ongoing support and advice to keep your service mesh secure.

By working with NHIMG, you can make sure your service mesh is protected from unauthorized access and potential threats. In the next section, we'll look at how to monitor and audit your service mesh.

Conclusion: Securing Your Service Mesh with Confidence

Securing your service mesh might seem tough, but with the right approach, you can get a really solid security setup. Let's go over the main ideas and figure out a way forward.

• Service mesh authorization policies are super important for controlling who can talk to who between microservices. This makes sure only authenticated and authorized Non-Human Identities (NHIs) can communicate.

• NHIs play a big role in service-to-service access control, like we said before. Managing these identities properly is key to keeping things secure.

• Well-set-up authorization policies help against both people inside your company messing things up and outside threats. This protects sensitive data and stops unauthorized access to important resources.

• Expect service mesh security features to keep changing. The need to protect workloads is always there, and these features will adapt.

• We'll also see closer integration with other security tools and platforms. This will give a more complete security picture.

• It's important to stay in the loop about the latest security best practices. Always learning will make sure you're ready for the next threats.

• Check your current service mesh security setup. Find any holes or areas that need improvement.

• Put in authorization policies based on the principle of least privilege. Give only the necessary permissions to each workload.

• Keep an eye on and update your security policies. Adapt to changing threats and vulnerabilities.

With these steps, you can confidently secure your service mesh and protect your microservices.