To access your destinations in the service mesh, you can require specific JWT claims or scopes for authorization. These rules can match values extracted from the JWT for allowed issuers, expiries, audiences, scopes, or other valid JSON claims from the JWT payload.

About claim-based JWT policies

You can restrict a request’s access based on the claims and scopes in a JWT. For more information about JWTs, see the JWT overview and API docs.

Claims

Claims are key-value pairs that provide identity details, such as the subject’s user ID, the entity that issued the token, and expiration time. RFC 7519 spec reserves seven claims, and the IANA JSON Web Token Claims outline many more registered claims to encourage interoperability across providers. Further, your OIDC provider might have custom claims, such as described in the Auth0 docs.

For Gloo JWT policies, claims have the following features:

  • When you require multiple claims, the JWT must have all of the specified claims to be allowed. Claims are logically AND’d together.
  • You can optionally specify required values or notValues for a claim’s key, which are logically OR’d together.
    • For values, the claim can have any of the specified values to be allowed.
    • For notValues, the claim cannot have any of the specified values to be allowed.

The claims field does not support the following features:

  • Multiple list entries with the same key.
  • Requiring each scope in the claim. For the following example policy, a JWT with is:developer or read:secrets scopes would be allowed. To require the JWT to have both scopes, use the requiredScopes field instead.
      claims:
  - key: scope
    values:
    - is:developer
    - read:secrets
  • Nested claims are not supported. In the following JWT payload example, you can create a rule for the email claim, but not the location claim.
  {
  "email": "user2@solo.io",
  "location": {
    "city": "Cambridge",
    "state": "MA",
    "country": "USA"
  }
}

Scopes

Scopes are a special type of claim that represent specific permissions that a client has. These scopes might be returned from an Identity and Access Management (IAM) provider, and are typically formatted similar to is:developer or read:profile.

For Gloo JWT policies, scopes have the following features:

  • Scopes are specified as a list, not key-value pairs.
  • When you require multiple scopes, the JWT must have all of the specified scopes to be allowed. Scopes are logically AND’d together.

Scopes do not support the following features:

  • Listing scopes that, if present in the claim, are not allowed. Instead, you can use the claims field with the notValue setting.
  • Requiring that only one of the listed scopes is present (logical OR). Instead, you can use claims.

More considerations for JWT policies

As you develop your JWT authorization policies, keep in mind the following considerations about how claims, scopes, and other policy features work together.

  • The main difference between requiredScopes and claims for configuring scopes is that the requiredScopes value sets a list of scopes that must all be included in the request (logical AND). On the other hand, claims lets you set several scopes that can be accepted (logical OR), or scopes that will be denied (notValue).
  • You can use claims and scopes together. A request must meet all of the claim and scope conditions that you specify.
  • If your policy has multiple providers, the claims and scopes apply to all the providers. If one of your providers does not return a claim or scope value, consider using a separate policy for that provider.
  • Because you use the JWT policy for authorization, you cannot set the policy’s phase to postAuthz.
  • You cannot apply multiple JWT policies to the same route in a route table, so make sure to keep all your rules for a route in the same policy.
  • If you import or export resources across workspaces, your policies might not apply. For more information, see Import and export policies.

Before you begin

  1. Complete the multicluster getting started guide to set up the following testing environment.

    • Three clusters along with environment variables for the clusters and their Kubernetes contexts.
    • The Gloo meshctl CLI, along with other CLI tools such as kubectl and istioctl.
    • The Gloo management server in the management cluster, and the Gloo agents in the workload clusters.
    • Istio installed in the workload clusters.
    • A simple Gloo workspace setup.
  2. Install Bookinfo and other sample apps.

Example JWT policies configurations

Review the following examples for claim- and scope-based JWT authorization. You can apply a JWT policy at the destination or route level, but you cannot apply multiple JWT policies to the same destination or to the same route in a route table. If you try to apply multiple policies, only the policy that you created first takes effect. In general, you apply policies to routes to protect ingress traffic through the gateway, and to destinations to protect traffic within the service mesh. For more information, see Applying policies and the API docs.

You can configure key-value pairs of claims. The following example:

  • Requires that a request meets the conditions for all of the name, email, and org claims.
  • Requires that the name claim equals the value glooy.
  • Requires that the email claim equals the value user2@solo.io.
  • Requires that the org claim equals either internal or partner.
  apiVersion: security.policy.gloo.solo.io/v2
kind: JWTPolicy
  ...
  config:
    claims:
    - key: "name"
      values:
      - "glooy"
    - key: "email"
      values:
      - "user2@solo.io"
    - key: "org"
      values:
      - "internal"
      - "partner"

You can configure a list of scopes. The following example:

  • Requires that a request has all of the listed scopes.
  • Requires the ec2:DescribeInstances scope.
  • Requires the s3:ListBuckets scope.

JWT payloads with the specific listed scopes, as well as broader scopes such as ec2:* or s3:*, would meet the scope requirement.

  apiVersion: security.policy.gloo.solo.io/v2
kind: JWTPolicy
  ...
  config:
    requiredScopes:
    - "ec2:DescribeInstances"
    - "s3:ListBuckets"

You can use notValues for claims to deny requests that have a certain value. The following example:

  • Requires that a request meets the conditions for the name and aud claims.
  • Denies a request that has the name claim.
  • Denies a request that has either product.solo.io or marketing.solo.io as a value in the aud claim. Claims with other aud values are allowed.
  apiVersion: security.policy.gloo.solo.io/v2
kind: JWTPolicy
  ...
  config:
    claims:
    - key: "name"
      notValues:
      - "*"
    - key: "aud"
      notValues:
      - "product.solo.io"
      - "marketing.solo.io"

You can use wildcards to allow or deny a wide range of possible claim values. The following example:

  • Requires that a request meets the conditions for all of the name, email, and aud claims.
  • Denies a request that has the name claim.
  • Requires that the email claim has a value of any @solo.io email address.
  • Requires that a request has a value for the aud claim.
  apiVersion: security.policy.gloo.solo.io/v2
kind: JWTPolicy
  ...
  config:
    claims:
    - key: "name"
      notValues:
      - "*"
    - key: "email"
      values:
      - "*@solo.io"
    - key: "aud"
      values:
      - "*"

Try out JWT policies with claims

To test claims-based JWT authorization, you can create a JWT policy that requires certain claims and scopes. Then, you can create two JWT tokens. One token has the required claims and scope, while the other token does not.

  1. Save the example JWT policy for the httpbin route. For more information about this policy, see the configuration example.

      cat << EOF > jwt-policy_authz.yaml
apiVersion: security.policy.gloo.solo.io/v2
kind: JWTPolicy
metadata:
  annotations:
    cluster.solo.io/cluster: ""
  name: jwt-policy
  namespace: httpbin
spec:
  applyToDestinations:
  - selector:
      labels:
        route: httpbin
  config:
    claims:
    - key: "email"
      values:
      - "*@solo.io"
    - key: "org"
      values:
      - "internal"
      - "partner"
    requiredScopes:
    - "is:developer"
    providers:
      provider1:
        issuer: https://localhost
        local:
          inline: |-
            -----BEGIN PUBLIC KEY-----
            MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAnknfKiIDREaE/vxu8rtz
            oMaPop6rsiX7GANCRcqFks0j96Gb+UssKD8zJs2JBvEe4n0wNKVeLRbOctII+ZEO
            G8b+Dqig/1ubq3xiGbDBbZqHiFKjFQVUnII3Un9VRtDcJdgaaPGHnhlPs79sJNgQ
            e6AWJmfAasdT7i3MVEW7/dXcROiMRGapmxv+nQbKdoeiCJDULRdMSodhg/WJw2sH
            LLVxh4fPSF7cRxj36Y9FKWcGUH+YKe7n4gufAeEsHk+tPBndymYpmcMjb6W9HrJO
            39vvyMTjLAUyElCEfeMqCpFBCElhaGbF8ZncbV6vvDEkOxMX/m1TYhoJr1E2U8y/
            NwIDAQAB
            -----END PUBLIC KEY-----
        tokenSource:                    
          headers:  
          - name: X-Auth
            prefix: 'Bearer '
          queryParams:       
          - auth_token
EOF

  2. Create a private-public key pair by using OpenSSL. You use this pair to create your own JWT token.

    1. Create a private key to sign the JWT.
        openssl genrsa 2048 > private-key.pem
    2. Extract the public key from the private key.
        openssl rsa -in private-key.pem -pubout

  3. Open the downloaded JWT policy.

      open jwt-policy_authz.yaml

  4. Run the following command to copy the public key value again.

      openssl rsa -in private-key.pem -pubout | pbcopy

  5. Paste the public key value in the inline section of the YAML configuration file. Make sure the indentation is kept.

  6. Create the JWT policy with your new public key value, which is used to verify the JWT token in subsequent requests.

      kubectl apply -f jwt-policy_authz.yaml

  7. Create a JWT that uses your private key. Refer to the following image to help understand the UI location of the steps.

    JWT token
    JWT token

    1. In your browser, go to https://jwt.io/. For the subsequent steps, you can refer to the following image.
    2. From the Algorithm dropdown, select RS256.
    3. From the Decoded section, scroll to the Payload: Data pane. Replace the content by pasting the following JWT payload information.
        {
  "iss": "https://localhost",
  "exp": 4804324736,
  "iat": 1648651136,
  "org": "internal",
  "email": "user2@solo.io",
  "scope": "is:developer"
}
    4. From the Decoded section, scroll to the Verify Signature pane. In the first input box for -----BEGIN PUBLIC KEY-----, replace the content by pasting the value of your public key from the previous output of your terminal.
    5. In your terminal, copy the contents of your private key.
        cat private-key.pem | pbcopy
    6. Return to your browser and go to the Verify Signature pane in the Decoded section. In the second input box for -----BEGIN PRIVATE KEY-----, replace the content by pasting the value of your private key.
    7. Optional: Click Share JWT and paste the JWT values into a file to refer to later.
    8. From the Encoded section, copy the token value to your clipboard, such as eyJhbG.....
    9. Add the token value to an environment variable on your local machine.
        export TOKEN_DEV="Bearer <token_value>"

  8. Repeat the previous step to create another JWT that does not include the correct claim and scope data.

    1. For the Payload: Data section, use the following details. Note that the org, email, and scope details differ from the required claims in your JWT policy.
        {
  "iss": "https://localhost",
  "exp": 4804324736,
  "iat": 1648651136,
  "org": "external",
  "email": "user1@example.com",
  "scope": "is:user"
}
    2. After filling out the rest of the details and getting the encoded token, set the token as a different environment variable.
        export TOKEN_USER="Bearer <token_value>"

  9. Try the request to the httpbin app without any authentication. Notice that your request is denied with a 401 error. Create a temporary curl pod in the bookinfo namespace, so that you can test the app setup. You can also use this method in Kubernetes 1.23 or later, but an ephemeral container might be simpler.

    1. Create the curl pod.
        kubectl run -it -n httpbin --context ${REMOTE_CONTEXT1} curl --image=curlimages/curl:7.73.0 --rm  -- sh
    2. Send a request to the httpbin app.
        http://httpbin:8000/get

    Example output:

      HTTP/1.1 401 Unauthorized
www-authenticate: Bearer realm="http://httpbin.httpbin:8000/get"
...
Jwt is missing

    Example output:

      HTTP/1.1 401 Unauthorized
www-authenticate: Bearer realm="http://httpbin.httpbin:8000/get"
...
Jwt is missing

  10. Try the request to the httpbin app again, this time with your developer token (${TOKEN_DEV}). Notice that your request is now accepted!

      curl -H "X-Auth: Bearer ${TOKEN_DEV}" -v http://httpbin:8000/get

    In the example output you get back a 200 response.

      HTTP/1.1 200 OK 
...

  11. Try the request to the httpbin app again, this time with your user token (${TOKEN_USER}). Notice that your request is denied as expected, because this token does not have the required claim data.

    1. Send a request to the app.
        curl -H "X-Auth: Bearer ${TOKEN_USER}" -v http://httpbin:8000/get
    2. Exit the temporary pod. The pod deletes itself.
        exit

    In the example output you get back a 403 response.

      HTTP/1.1 403 Forbidden
...
RBAC: access denied%

Cleanup

You can optionally remove the resources that you set up as part of this guide.
  kubectl -n httpbin delete jwtpolicy jwt-policy