Release G: Coordinated Service Exposure

JIRA Ticket


NONRTRIC-634 - Getting issue details... STATUS

ISTIO

Istio is a service mesh which provides a dedicated infrastructure layer that you can add to your applications. It adds capabilities like observability, traffic management, and security, without adding them to your own code. 

To populate its own service registry, Istio connects to a service discovery system. For example, if you’ve installed Istio on a Kubernetes cluster, then Istio automatically detects the services and endpoints in that cluster. Using this service registry, the Envoy proxies can then direct traffic to the relevant services.

Istio Ingress Gateway can be used as a API-Gateway to securely expose the APIs of your micro services. It can be easily configured to provide access control for the APIs i.e. allowing you to apply policies defining who can access the APIs, what operations they are allowed to perform and much more conditions.

The Istio API traffic management features available are: Virtual services: Configure request routing to services within the service mesh. Each virtual service can contain a series of routing rules, that are evaluated in order. Destination rules: Configures the destination of routing rules within a virtual service.

Destination Rule
apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: bookinfo-ratings
spec:
  host: ratings.prod.svc.cluster.local
  trafficPolicy:
    loadBalancer:
      simple: LEAST_CONN
  subsets:
  - name: testversion
    labels:
      version: v3
    trafficPolicy:
      loadBalancer:
        simple: ROUND_ROBIN


Istio provisions the DNS names and secret names for the DNS certificates based on configuration you provide. The DNS certificates provisioned are signed by the Kubernetes CA and stored in the secrets following your configuration. Istio also manages the lifecycle of the DNS certificates, including their rotations and regenerations.


With Mutual TLS (mTLS)  the client and server both verify each other’s certificates and use them to encrypt traffic using TLS.. With Istio, you can enforce mutual TLS automatically.

PeerAuthentication
apiVersion: "security.istio.io/v1beta1"
kind: "PeerAuthentication"
metadata:
  name: "default"
  namespace: "istio-system"
spec:
  mtls:
    mode: STRICT


JWT

JSON Web Token (JWT) is an open standard (RFC 7519) that defines a compact and self-contained way for securely transmitting information between parties as a JSON object. 

JWT is mostly used for Authorization. Once the user is logged in, each subsequent request will include the JWT, allowing the user to access routes, services, and resources that are permitted with that token (User context).  You can pass the original jwt as an embedded jwt or pass original jwt in the http header (Istio / JWTRule).

JWT can also contain information about the client that sent the request (client context).

We can use Istio's RequestAuthentication resource to configure JWT policies for your services.


Request Authentication
apiVersion: security.istio.io/v1beta1
kind: RequestAuthentication
metadata:
  name: httpbin
  namespace: foo
spec:
  selector:
    matchLabels:
      app: httpbin
  jwtRules:
  - issuer: "issuer-foo"
    jwksUri: https://example.com/.well-known/jwks.json
---
apiVersion: security.istio.io/v1beta1
kind: AuthorizationPolicy
metadata:
  name: httpbin
  namespace: foo
spec:
  selector:
    matchLabels:
      app: httpbin
  rules:
  - from:
    - source:
        requestPrincipals: ["*"]


JWT can also be used for service level authorization (SLA)

Authorization Policy
apiVersion: security.istio.io/v1beta1
kind: AuthorizationPolicy
metadata:
  name: httpbin
  namespace: foo
spec:
  selector:
    matchLabels:
      app: httpbin
  rules:
  - from:
    - source:
        requestPrincipals: ["*"]
  - to:
    - operation:
        paths: ["/healthz"]


Use Case


KUBERNETES

K8S RBAC (Role Based Access Control) - supported by default in kubernetes.

K8S Service Account

  • Kube use service account (sa) to validate api access
  • SAs can be lined to a role via a binding
  • A default sa, with no permissions (no bindings), is created in each namespace – pods uses this namespace unless otherwise specified
  • Pods can be specified to run with a specific sa
  • The helm manger needs a SA with cluster wide permission (to be able to list installed charts etc)
    However, during installation the pod running the helm install/upgrade/delete should run with a sa with only namespace permission to ensure not other modification is made to kube objects outside the namespace

K8S RBAC  - controlling access to kubernetes resources

  • Role and and rolebinding objects defines who (sa, user or group) is allowed to do what in the kubernetes api
  • Role object
    • Sets permissions on resources in a specific namespace
  • ClusterRole object
    • Sets permission on non-namespaced resources  or across namespaces
  • RoleBinding object
    • Binds one or more Role or a ClusterRole object(s) to a user, group or service account
  • ClusterRoleBinding object
    • Binds one or more ClusterRole object(s) to a user, group or service account
  • No installation requried – RBAC enabled by default

Network Policies

  • K8S supports Network Policy objects but a provider need to be install for the polcies to take effect, e.g. Calico
  • Network policies can control ingress and/or egress traffic by selecting applicable pods  - bacially controlling traffic between pods and/or network endpoints
  • Several providers: Calico, Cillium etc


  • Allow traffic from ns: kong (the gateway), nonrtric and onap
  • Deny traffic from any other ns


KONG

Kong is Orchestration Microservice API Gateway. Kong provides a flexible abstraction layer that securely manages communication between clients and microservices via API. Also known as an API Gateway, API middleware or in some cases Service Mesh.

  • Kong can be used as an API gateway:
  • Hiding internal microservice structure
  • Could be used as R1 API front-end

Kong acts as the service registry, keeping a record of the available target instances for the upstream services. When a target comes online, it must register itself with Kong by sending a request to the Admin API. Each upstream service has its own ring balancer to distribute requests to the available targets.

With client-side discovery, the client or API gateway making the request is responsible for identifying the location of the service instance and routing the request to it. The client begins by querying the service registry to identify the location of the available instances of the service and then determines which instance to use. See https://konghq.com/learning-center/microservices/service-discovery-in-a-microservices-architecture/

Kong datastore

Kong uses an external datastore to store its configuration such as registered APIs, Consumers and Plugins. Plugins themselves can store every bit of information they need to be persisted, for example rate-limiting data or Consumer credentials. See https://konghq.com/faqs/#:~:text=PostgreSQL%20is%20an%20established%20SQL%20database%20for%20use,Cassandra%20or%20PostgreSQL%2C%20Kong%20maintains%20its%20own%20cache.







Kong Demo

Demo of Kong gateway access control already available.

JWT tokens are used to grant access to particular services for different users.

See also https://konghq.com/blog/jwt-kong-gateway


Network Policy
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: networkpolicy-nr
  namespace: nonrtric
spec:
  podSelector: {}
  policyTypes:
  - Ingress
  ingress:
  - from:
    - namespaceSelector:
        matchLabels:
          kubernetes.io/metadata.name: kong
    - namespaceSelector:
        matchLabels:
          kubernetes.io/metadata.name: onap
    - namespaceSelector:
        matchLabels:
          kubernetes.io/metadata.name: nonrtric    



Kong Gateway JWT
apiVersion: configuration.konghq.com/v1
kind: KongPlugin
metadata:
  name: app-jwt-kp
  namespace: nonrtric
plugin: jwt
---
apiVersion: v1
kind: Secret
metadata:
  name: pms-jwt-sec
  namespace: nonrtric
type: Opaque
stringData:
  kongCredType: jwt
  key: pms-issuer
  algorithm: RS256
  rsa_public_key: |
    -----BEGIN PUBLIC KEY-----
    MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAwetu4+suoz6c7e1kQz7I
    Jmujci8zHpp4qh3nsmEL8e3QOKzMVsLuQPcF8lO1bBoChSA+KMNJ5rEixGWSxClp
    9XroBSgrvjDsKtpPIlBQMnyOUYRSXWnIodmN+7wA72pTxo7JtAypPzRscSgi0OZt
    9dtmv50RLr9Wph5cI+IE9OtgW58OKtdFRGigGHfdUEwrT/MPw2rOU85YRFaEgT/i
    wcuQCe+Zmf2S2gVgK62u51ZFFn2VycJT1LcOt9cdqrSXYZAPfVKnQ/EgYvDdzFL1
    x73JkrrSEP3pfrN4bXOnc7cS/S9Y2qk/I+QCR6a6XKmqk5SnWJSyXvKdYQJrgxJp
    lQIDAQAB
    -----END PUBLIC KEY-----
---
apiVersion: v1
kind: Secret
metadata:
  name: ecs-jwt-sec
  namespace: nonrtric
type: Opaque
stringData:
  kongCredType: jwt
  key: ecs-issuer
  algorithm: RS256
  rsa_public_key: |
    -----BEGIN PUBLIC KEY-----
    MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAtminzTtNs5oqPCbg4uC1
    L7MfR3B+uyYvkSKr3NFieRCxp6VhrgodJJXYc3SqXbaTVBkTwU24wG4UvJCnoRQd
    0VhSawtLkN8XNAdCiD831dKUYMJPs43ZY/gO5CHVqUMdSHlp8dn7jNren59dvRRS
    3xC1D3etXuEU01XGuLi/5qJLAKqDbYs3bH1vslTjndg1WTsrkU8GEIT1NphSYg25
    s6rSLTIBfk8FjKquYHw3wYVSQK9rg2mqddJpRWkfZnazMHTmSNjOJpiNb77VLGSx
    9qDbbLjurCl2mAG5Z+w76uKfKGgOo68SU0TL1sPybsKhAoZZg1gF06mvMln5eq5C
    RQIDAQAB
    -----END PUBLIC KEY-----
---
apiVersion: configuration.konghq.com/v1
kind: KongPlugin
metadata:
  name: pms-group-acl-kp
  namespace: nonrtric
plugin: acl
config:
  whitelist: ['pms-group']
---
apiVersion: v1
kind: Secret
metadata:
  name: pms-group-acl-sec
  namespace: nonrtric
type: Opaque
stringData:
  kongCredType: acl
  group: pms-group
---
apiVersion: configuration.konghq.com/v1
kind: KongPlugin
metadata:
  name: ecs-group-acl-kp
  namespace: nonrtric
plugin: acl
config:
  whitelist: ['ecs-group']
---
apiVersion: v1
kind: Secret
metadata:
  name: ecs-group-acl-sec
  namespace: nonrtric
type: Opaque
stringData:
  kongCredType: acl
  group: ecs-group
---
apiVersion: configuration.konghq.com/v1
kind: KongPlugin
metadata:
  name: all-group-acl-kp
  namespace: nonrtric
plugin: acl
config:
  whitelist: ['ecs-group', 'pms-group']
---
apiVersion: configuration.konghq.com/v1
kind: KongConsumer
metadata:
  name: pms-user-kc
  namespace: nonrtric
  annotations:
    kubernetes.io/ingress.class: kong
username: pms-user
credentials:
  - pms-jwt-sec
  - pms-group-acl-sec
---
apiVersion: configuration.konghq.com/v1
kind: KongConsumer
metadata:
  name: ecs-user-kc
  namespace: nonrtric
  annotations:
    kubernetes.io/ingress.class: kong
username: ecs-user
credentials:
  - ecs-jwt-sec
  - ecs-group-acl-sec
---
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: r1-pms-ing
  namespace: nonrtric
  annotations:
    konghq.com/plugins: app-jwt-kp,pms-group-acl-kp
    konghq.com/strip-path: "false"
spec:
  ingressClassName: kong
  rules:
  - http:
      paths:
      - path: /a1-policy
        pathType: ImplementationSpecific
        backend:
          service:
            name: policymanagementservice
            port:
              number: 8081
---
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: r1-ecs-ing
  namespace: nonrtric
  annotations:
    konghq.com/plugins: app-jwt-kp,ecs-group-acl-kp
    konghq.com/strip-path: "false"
spec:
  ingressClassName: kong
  rules:
  - http:
      paths:
      - path: /data-consumer
        pathType: ImplementationSpecific
        backend:
          service:
            name: enrichmentservice
            port:
              number: 8083
      - path: /data-producer
        pathType: ImplementationSpecific
        backend:
          service:
            name: enrichmentservice
            port:
              number: 8083
---
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: r1-echo-ing
  namespace: nonrtric
  annotations:
    konghq.com/plugins: app-jwt-kp,all-group-acl-kp
    konghq.com/strip-path: "true"
spec:
  ingressClassName: kong
  rules:
  - http:
      paths:
      - path: /echo
        pathType: ImplementationSpecific
        backend:
          service:
            name: httpecho
            port:
              number: 80


Kong-Gateway-JWT.zip


ISTIO Demo


  1. Install ISTIO on minikube using instruction here: Istio Installation - Simplified Learning (waytoeasylearn.com)
  2. cd to the istio directory and install the demo application

    1. kubectl create ns foo
    2. kubectl apply -f <(istioctl kube-inject -f samples/httpbin/httpbin.yaml) -n foo
  3. Create a python script to generate a JWT token using the code from here: https://medium.com/intelligentmachines/istio-jwt-step-by-step-guide-for-micro-services-authentication-690b170348fc . Install python_jwt using pip if it's not already installed.

  4. Create jwt-example.yaml using the public key generated by the python script:
    kubectl create -f  jwt-example.yaml
    jwt-example.yaml
    apiVersion: "security.istio.io/v1beta1"
    kind: "RequestAuthentication"
    metadata:
      name: "jwt-example"
      namespace: istio-system
    spec:
      selector:
        matchLabels:
          istio: ingressgateway
      jwtRules:
      - issuer: "ISSUER"
        jwks: |
          { "keys":[{"e":"AQAB","kty":"RSA","n":"x_yYl4uW5c6NHOA-bDDh0MThFggBWl-vYJr77b9F1LmAtTlJVM0rL5klTfv2DmlAmD9eZPrWeUOoOGhSpe58XiSAvxyeaOrZhtyUjT3aglrSys0YBsB19ItNGMuoIuzPpWOrdtKwHa9rPbrdc6q7vb93qu2UVaIz-3FJmGFtSA5t8FK_5bZKF-oOzRLwqeVQ3n0Bu_dFDuGeZjQWMZF32QupyA-GF-tDGGriPLy9sutlB1NQyZ4qiSZx5UMxcfLwsWfQxHemdwLeZXWKWNBov8RmbZy2Jz-dwg6XjHBWAjTnCGG9p-bp63nUlnELI3LcEGhGOugZBqcpNT5dEAQ0fQ"}]}
  5. Export the JWT token generated by the python script as an environment variable:
    export TOKEN="eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJhdWQiOiJBVURJRU5DRSIsImV4cCI6MTYzNzI1NDkxNSwiaWF0IjoxNjM3MjUxOTE1LCJpc3MiOiJJU1NVRVIiLCJqdGkiOiJCcmhDdEstcC00ZTF0RlBrZmpuSmhRIiwibmJmIjoxNjM3MjUxOTE1LCJwZXJtaXNzaW9uIjoicmVhZCIsInJvbGUiOiJ1c2VyIiwic3ViIjoiU1VCSkVDVCJ9.HrQCLPZXf0VkFe7JUVGXq-sHJQhVibqhToG4r63py-iwHWlUL02_WfoWRoxapgqGwImDdSlt1uG8RR-6VMqzWwGlcqBIRhFTG0nmzmtQjnOUs6QAKSUpA3PyWBIYHV0BwZbpo8Zq1Bo-sELy400fU-MCQ_054fSsG7JMBMmrnj8NyJmD2lNN0VSFGO53SPl2tQSVlc9OwAr8Uu0jfLPfUmh6yq43qFuxnVRfBGLLPNOt29aOfAetKLc72qlphtnbDx2a9teP5AIbkIWyIlhTytEnQRCwU4x8gDrEdkrHui4qCtzpl_uoITSwPe3AFsi7gQHB6rJoDj-j2zPc4rUTAA"

  6. export INGRESS_HOST=$(minikube ip)

  7. export INGRESS_PORT=$(kubectl -n istio-system get service istio-ingressgateway -o jsonpath='{.spec.ports[?(@.name=="http2")].nodePort}')

  8. Test the service:
    curl --header "Authorization: Bearer $TOKEN" $INGRESS_HOST:$INGRESS_PORT/headers -s -o /dev/null -w "%{http_code}\n"

  9. You should get a response code of 200

  10. Update the token to something invalid

  11. The response will be 401


Istio Service JWT Test

istio-test.yaml (uses the default namespace)


export TOKEN="eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJhdWQiOiJBVURJRU5DRSIsImV4cCI6MTYzODA4ODYzOSwiaWF0IjoxNjM3NjU2NjM5LCJpc3MiOiJJU1NVRVIiLCJqdGkiOiJXMW1ldEJISTlQWnJLZGZuTG54V0ZBIiwibmJmIjoxNjM3NjU2NjM5LCJwZXJtaXNzaW9uIjoicmVhZCIsInJvbGUiOiJ1c2VyIiwic3ViIjoiU1VCSkVDVCJ9.C8zVi4XpqaK-VVhDviCGO5SChNsUWe_WmP2Z-JXkM3VzMVQnc2w7ResUI-g8DxXQLXojc7BZiDA74VCRRzdSXtDrBbikd9riCN1D9UVXWaCdIv0gU9b23mOp2jUP7G8FgdKTjtcyx3pPmliHH1OnDhrsQUeTMezRurBa96sRf_9XF5B_SBXiTy65UhqzL-kKmbaTCXWO6F5d4mJ8gPJQ4BGQdl1CMfytg0RB1Tuyj72dDTetfWMStqRw0nEh76oAC5bDZAUhwpAUMbXTG0Iba9MSAhImha6grthU1_VY39LbmbZ7W7OfRV1mAI9PrDl0nwWWobvJ-iIg93luqvGrlA"


kubectl label namespace default istio-injection=enabled --overwrite

export INGRESS_HOST=$(minikube ip)

export INGRESS_PORT=$(kubectl -n istio-system get service istio-ingressgateway -o jsonpath='{.spec.ports[?(@.name=="http2")].nodePort}')

curl --header "Authorization: Bearer $TOKEN" $INGRESS_HOST:$INGRESS_PORT/data-producer

curl --header "Authorization: Bearer $TOKEN" $INGRESS_HOST:$INGRESS_PORT/a1-policy

curl --header "Authorization: Bearer $TOKEN" $INGRESS_HOST:$INGRESS_PORT/data-consumer


You can use different tokens for different deployments.

Currently we use the same token for both jwt-ecs and jwt-pms. They match on the deployment labels nonrtric-ecs and nonrtric-pms.

You can also change the token issuer to one for your particular service(s).

You can also change the expiry time.

Please refer to the python script in the link above. 


You can move these objects to their own namespace if you prefer:

e.g.

kubectl create ns istio-nonrtric
namespace/istio-nonrtric created

 kubectl label namespace istio-nonrtric istio-injection=enabled --overwrite
namespace/istio-nonrtric labeled


replace the default name space in the yaml above with the new ns name.


You can also update the AuthorizationPolicy to check the JWT issuer/subject

e.g.

rules:
- from:
- source:
requestPrincipals: ["ECSISSUER/SUBJECT"]


See the latest version here: istio-test-latest.yaml


Istio with Keycloak

If you are using minikube on Ubuntu WSL you need to run "minikube service keycloak" to see keycloak ui.


Run the following command to get the keycloak URLs:

KEYCLOAK_URL=http://$(minikube ip):$(kubectl get services/keycloak -o go-template='{{(index .spec.ports 0).nodePort}}')/auth &&
o "" &

echo "" &&
echo "Keycloak: $KEYCLOAK_URL" &&

echo "Keycloak Admin Console: $KEYCLOAK_URL/admin" &&

echo "Keycloak Account Console: $KEYCLOAK_URL/realms/myrealm/account" &&
 echo ""


Retrieve public key using : http(s)://<hostname>/auth/realms/<realm name>


Enable keycloak with Istio

Setup a new realm, user and client as shown here : https://www.keycloak.org/getting-started/getting-started-kube

Note the id of the new user, this will be used as the sub field in the token e.g. 81b2051b-52d9-4e4e-88a6-00ca04b7b73d"

The iss field is url of the realm e.g. http://192.168.49.2:30869/auth/realms/myrealm

Edit the jwt-pms RequestAuthentication definition above, replace the issuer with the keycloak iss and remove the jwks field and replace it with the jwksUri pointing to your keycloak certs


RequestAuthentication
apiVersion: security.istio.io/v1beta1
kind: RequestAuthentication
metadata:
  name: "jwt-pms"
  namespace: istio-nonrtric
spec:
  selector:
    matchLabels:
      apptype: nonrtric-pms
  jwtRules:
  - issuer: "http://192.168.49.2:30869/auth/realms/myrealm"
    jwksUri: "http://192.168.49.2:30869/auth/realms/myrealm/protocol/openid-connect/certs"


Modify the AuthorizationPolicy named pms-policy, change the issuer and subject to the keycloak iss/sub

AuthorizationPolicy
apiVersion: "security.istio.io/v1beta1"
kind: "AuthorizationPolicy"
metadata:
  name: "pms-policy"
  namespace: istio-nonrtric
spec:
  selector:
    matchLabels:
      apptype: nonrtric-pms
  action: ALLOW
  rules:
  - from:
    - source:
       requestPrincipals: ["http://192.168.49.2:30869/auth/realms/myrealm/81b2051b-52d9-4e4e-88a6-00ca04b7b73d"]


Reapply the yaml file

to generate a token use the following command:

curl -X POST "$KEYCLOAK_URL" \
-H "Content-Type: application/x-www-form-urlencoded" \
-d "username=$USERNAME" \
-d "password=$PASSWORD" \
-d 'grant_type=password' \
-d "client_id=$CLIENT_ID" | jq -r '.access_token'

e.g.

curl -X POST http://192.168.49.2:30869/auth/realms/myrealm/protocol/openid-connect/token \
-H "Content-Type: application/x-www-form-urlencoded" \
-d "username=user" \
-d "password=secret" \
-d 'grant_type=password' \
-d "client_id=myclient" | jq -r '.access_token'


Note: you may need to install the jq utility on your system for this to work - sudo apt-get install jq

Test the a1-policy service with your new token


TOKEN=$(curl -X POST http://192.168.49.2:30869/auth/realms/myrealm/protocol/openid-connect/token -H "Content-Type: application/x-www-form-urlencoded" -d username=user -d password=secret -d 'grant_type=password' -d client_id=myclient | jq -r '.access_token')

curl --header "Authorization: Bearer $TOKEN" $INGRESS_HOST:$INGRESS_PORT/a1-policy
Hello a1-policy


Note: The iss of the token will differ depending on how you retrieve it. If it's retrieved from within the cluster for URL will start with http://keycloak.default:8080/ otherwise it will be something like : http://192.168.49.2:31560/ (http://(minikube ip): (keycloak service nodePort))


Keycloak database

Keycloak uses the H2 database by default.

To configure keycloak to use a different database follow these steps.

  1. Install either postgres or mariadb using these yaml files: postgres.yaml or mariadb.yaml. These will setup the keycloak db along with the username and password. You just need to change the directory for your persistent storage to an appropiate directory on your host.
  2. Update the keycloak installation script https://raw.githubusercontent.com/keycloak/keycloak-quickstarts/latest/kubernetes-examples/keycloak.yaml

    Keycloak Environment
            env:
            - name: KEYCLOAK_USER
              value: "admin"
            - name: KEYCLOAK_PASSWORD
              value: "admin"
            - name: PROXY_ADDRESS_FORWARDING
              value: "true"
            - name: DB_VENDOR
              value: "postgres"
            - name: DB_ADDR
              value: "postgres"
            - name: DB_PORT
              value: "5432"
            - name: DB_DATABASE
              value: "keycloak"
            - name: DB_USER
              value: "keycloak"
            - name : DB_PASSWORD
              value: "keycloak"

You can also add the following code block to make sure keycloak only start once the database is up and running

Wait For Database
      initContainers:
      - name: init-postgres
        image: busybox
        command: ['sh', '-c', 'until nc -vz postgres 5432; do echo waiting for postgres db; sleep 2; done;']


Note: you may also want to update the keycloak service to specify a value for nodePort.

Keycloak Service
apiVersion: v1
kind: Service
metadata:
  name: keycloak
  labels:
    app: keycloak
spec:
  ports:
  - name: http
    port: 8080
    targetPort: 8080
    nodePort: 31560
  selector:
    app: keycloak
  type: LoadBalancer


You can also add a wait for keycloak to your deployment containers

Wait for Keycloak
    spec:
      initContainers:
      - name: init-keycloak
        image: busybox
        command: ['sh', '-c', 'until nc -vz keycloak.default 8080; do echo waiting for keycloak; sleep 2; done;']
      containers:
      - name: a1-policy
        image: hashicorp/http-echo
        ports:
        - containerPort: 5678
        args:
        - -text
        - "Hello a1-policy"

See also: keycloak.yaml


Keycloak Operator

Keycloak Operator Installation

Keycloak Operator

Istio mTLS

Test:  Istio / Mutual TLS Migration

To see mTLS in kiali go to the display menu and check the security check box.

Running curl --header "Authorization: Bearer $TOKEN" ai-policy from the httpbin pod.

The padlock icon indicates mTLS is being used for communication between the pods.


Policy to enforce mTLS between PODs in the istio-nonrtric namespace in STRICT mode:

PeerAuthentication
apiVersion: security.istio.io/v1beta1
kind: PeerAuthentication
metadata:
  name: "default"
  namespace: istio-nonrtric
spec:
  mtls:
    mode: STRICT


Change the mode to PERMISSIVE to allow communication from pods without istio sidecar.

Change namespace to istio-system to apply mTLS for the entire cluster. 

Istio cert manager

https://istio.io/latest/docs/ops/integrations/certmanager/


Go Http Request Handler for Testing

nonrtric-server-go


nonrtric-server-go
package main

import (
	"fmt"
	"log"
	"github.com/gorilla/mux"
	"net/http"
	"encoding/json"
	"io/ioutil" 
	"strings"
)

func requestHandler(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "application/json")
	params := mux.Vars(r)
	var id = params["id"]
	var data = params["data"]
	var prefix = strings.Split(r.URL.Path, "/")[1]

    switch r.Method {
                case "GET":
                    if id == "" {
                                fmt.Println( "Received get request for "+ prefix +", params: nil\n")
                                fmt.Fprintf(w, "Response to get request for "+ prefix +", params: nil\n")
                        }else {
                                fmt.Println("Received get request for "+ prefix +", params: id=" + id + "\n")
                                fmt.Fprintf(w, "Response to get request for "+ prefix +", params: id=" + id + "\n")
                        }
                case "POST":
                        body, err := ioutil.ReadAll(r.Body)
                        if err != nil {
                        panic(err.Error())
                        }
                        keyVal := make(map[string]string)
                        json.Unmarshal(body, &keyVal)
                        id := keyVal["id"]
                        data := keyVal["data"]
                        fmt.Println("Received post request for "+ prefix +", params: id=" + id +", data=" + data + "\n")
                        fmt.Fprintf(w, "Response to post request for "+ prefix +", params: id=" + id +", data=" + data + "\n")
                case "PUT":
                        fmt.Println("Received put request for "+ prefix +", params: id=" + id +", data=" + data + "\n")
                        fmt.Fprintf(w, "Response to put request for "+ prefix +", params: id=" + id +", data=" + data + "\n")
                case "DELETE":
                        fmt.Println("Received delete request for "+ prefix +", params: id=" + id + "\n")
                        fmt.Fprintf(w, "Response to delete request for "+ prefix +", params: id=" + id + "\n")
                default:
                        fmt.Println("Received request for unsupported method, only GET, POST, PUT and DELETE methods are supported.")
                        fmt.Fprintf(w, "Error, only GET, POST, PUT and DELETE methods are supported.")
	}
}

func main() {
	router := mux.NewRouter()

	var prefixArray [3]string = [3]string{"/a1-policy", "/data-consumer", "/data-producer"}

	for _, prefix := range prefixArray {
		router.HandleFunc(prefix, requestHandler) 
		router.HandleFunc(prefix+"/{id}", requestHandler)
		router.HandleFunc(prefix+"/{id}/{data}", requestHandler)
	}

	log.Fatal(http.ListenAndServe(":8080", router))
}


Dockerfile
FROM golang:1.15.2-alpine3.12 as build
RUN apk add git
RUN mkdir /build
ADD . /build
WORKDIR /build
RUN go get github.com/gorilla/mux
RUN go build -o nonrtric-server-go .

FROM alpine:latest
RUN mkdir /app
WORKDIR /app/

# Copy the Pre-built binary file from the previous stage
COPY --from=build /build .

# Expose port 8080
EXPOSE 8080

# Run Executable
CMD ["/app/nonrtric-server-go"]


Testing

Update AuthorizationPolicy to only allow certain operations:

AuthorizationPolicy
apiVersion: "security.istio.io/v1beta1"
kind: "AuthorizationPolicy"
metadata:
  name: "pms-policy"
  namespace: istio-nonrtric
spec:
  selector:
    matchLabels:
      apptype: nonrtric-pms
  action: ALLOW
  rules:
  - from:
    - source:
        requestPrincipals: ["http://192.168.49.2:31560/auth/realms/pmsrealm/fab53fd0-3315-4e2f-bd17-6984fb7745f2"]
    to:
    - operation:
        methods: ["GET", "POST", "PUT"]
        paths: ["/a1-policy*"]


AuthorizationPolicy
apiVersion: "security.istio.io/v1beta1"
kind: "AuthorizationPolicy"
metadata:
  name: "ics-policy"
  namespace: istio-nonrtric
spec:
  selector:
    matchLabels:
      apptype: nonrtric-ics
  action: ALLOW
  rules:
  - from:
    - source:
        requestPrincipals: ["http://192.168.49.2:31560/auth/realms/icsrealm/ad83e4ea-c114-4549-be29-b3aaf92148a5"]
    to:
    - operation:
        methods: ["GET", "PUT", "DELETE"]
        paths: ["/data-*"]


Shell script to test AuthorizationPolicy

service_exposure_tests.sh
#!/bin/bash
INGRESS_HOST=$(minikube ip)
INGRESS_PORT=$(kubectl -n istio-system get service istio-ingressgateway -o jsonpath='{.spec.ports[?(@.name=="http2")].nodePort}')
TESTS=0
PASSED=0
FAILED=0
TEST_TS=$(date +%F-%T)
TOKEN=""

function get_token
{
    local prefix="${1}"
    url="http://192.168.49.2:31560/auth/realms"
    if [[ "$prefix"  =~ ^a1-policy* ]]; then
         TOKEN=$(curl -s -X POST ${url}/pmsrealm/protocol/openid-connect/token -H \
                 "Content-Type: application/x-www-form-urlencoded" -d username=pmsuser -d password=secret \
                 -d 'grant_type=password' -d client_id=pmsclient | jq -r '.access_token')
   else
         TOKEN=$(curl -s -X POST $url/icsrealm/protocol/openid-connect/token -H \
                 "Content-Type: application/x-www-form-urlencoded" -d username=icsuser -d password=secret \
                 -d 'grant_type=password' -d client_id=icsclient | jq -r '.access_token')
    fi
}

function run_test
{
    local prefix="${1}" type=${2} msg="${3}" data=${4}
    TESTS=$((TESTS+1))
    echo "Test ${TESTS}: Testing $type /${prefix}"
    get_token $prefix
    url=$INGRESS_HOST:$INGRESS_PORT"/"$prefix
    if [ "$data" != "" ]; then
      result=$(curl -s -X ${type} -H "Content-type: application/json" -H "Authorization: Bearer $TOKEN" -d ${data} $url)
    else
      result=$(curl -s -X ${type} -H "Content-type: application/json" -H "Authorization: Bearer $TOKEN" $url)
    fi
    echo $result
    if [ "$result" != "$msg" ]; then
            echo "FAIL"
            FAILED=$((FAILED+1))
    else
            echo "PASS"
            PASSED=$((PASSED+1))
    fi
    echo ""
}


run_test "a1-policy" "GET" "Received get request for a1-policy, params: nil" ""
run_test "a1-policy/1001" "GET" "Received get request for a1-policy, params: id=1001" ""
run_test "a1-policy/1002/xyz" "PUT" "Received put request for a1-policy, params: id=1002, data=xyz" ""
run_test "a1-policy/1001" "DELETE" "RBAC: access denied" ""
run_test "a1-policy" "POST" "Received post request for a1-policy, params: id=1003, data=abc" '{"id":"1003","data":"abc"}'
run_test "data-consumer" "GET" "Received get request for data-consumer, params: nil" ""
run_test "data-consumer/3001" "DELETE" "Received delete request for data-consumer, params: id=3001" ""
run_test "data-producer/2001/xyz" "PUT" "Received put request for data-producer, params: id=2001, data=xyz" ""
run_test "data-consumer" "POST" "RBAC: access denied" '{"id":"1004","data":"abc"}'
run_test "data-producer" "POST" "RBAC: access denied" '{"id":"1005","data":"abc"}'

echo
echo "-----------------------------------------------------------------------"
echo "Number of Tests: $TESTS, Tests Passed: $PASSED, Tests Failed: $FAILED"
echo "Date: $TEST_TS"
echo "-----------------------------------------------------------------------"


Results:

./service_exposure_tests.sh
Test 1: Testing /a1-policy GET
Received get request for a1-policy, params: nil
PASS

Test 2: Testing /a1-policy/1001 GET
Received get request for a1-policy, params: id=1001
PASS

Test 3: Testing /a1-policy/1002/xyz PUT
Received put request for a1-policy, params: id=1002, data=xyz
PASS

Test 4: Testing /a1-policy/1001 DELETE
RBAC: access denied
PASS

Test 5: Testing /a1-policy POST
Received post request for a1-policy, params: id=1003, data=abc
PASS

Test 6: Testing /data-consumer GET
Received get request for data-consumer, params: nil
PASS

Test 7: Testing /data-consumer/3001 DELETE
Received delete request for data-consumer, params: id=3001
PASS

Test 8: Testing /data-producer/2001/xyz PUT
Received put request for data-producer, params: id=2001, data=xyz
PASS

Test 9: Testing /data-consumer POST
RBAC: access denied
PASS

Test 10: Testing /data-producer POST
RBAC: access denied
PASS


-----------------------------------------------------------------------
Number of Tests: 10, Tests Passed: 10, Tests Failed: 0
Date: 2021-12-06-14:48:33
-----------------------------------------------------------------------


Go Http Client for running inside cluster

nonrtric-client-go

nonrtric-client-go
package main

import (
	"fmt"
	"net/http"
	"net/url"
	"encoding/json"
	"time"
	"io/ioutil"
	"math/rand"
	"strings"
	"bytes"
	"strconv"
	"flag"
)

type Jwttoken struct {
	Access_token string
	Expires_in int
	Refresh_expires_in int
	Refresh_token string
	Token_type string
    Not_before_policy int
    Session_state string
    Scope string
  }

var gatewayHost string
var gatewayPort string
var keycloakHost string
var keycloakPort string 
var useGateway string 
var letters = []rune("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")

func randSeq(n int) string {
    b := make([]rune, n)
    for i := range b {
        b[i] = letters[rand.Intn(len(letters))]
    }
    return string(b)
}


func getToken(user string, password string, clientId string, realmName string) string {
    keycloakUrl := "http://"+keycloakHost+":"+keycloakPort+"/auth/realms/"+realmName+"/protocol/openid-connect/token"
	resp, err := http.PostForm(keycloakUrl,
	url.Values{"username": {user}, "password": {password}, "grant_type": {"password"}, "client_id": {clientId}})
	if err != nil {
		fmt.Println(err)
		panic("Something wrong with the credentials or url ")
	}
	defer resp.Body.Close()
	body, err := ioutil.ReadAll(resp.Body)
	var jwt Jwttoken	
     json.Unmarshal([]byte(body), &jwt)
	 return jwt.Access_token;
}


func MakeRequest(client *http.Client, prefix string, method string, ch chan<-string) {
	var id = rand.Intn(1000)
	var data = randSeq(10)
	var service = strings.Split(prefix, "/")[1]
	var gatewayUrl = "http://"+gatewayHost+":"+gatewayPort
	var token = ""
	var jsonValue []byte = []byte{}
	var restUrl string = ""
	if strings.ToUpper(useGateway) != "Y" {
		gatewayUrl = "http://"+service+".istio-nonrtric:80"
		//fmt.Println(gatewayUrl)
	}

	if service == "a1-policy" {
		token = getToken("pmsuser", "secret","pmsclient", "pmsrealm")
	 }else{
		token = getToken("icsuser", "secret","icsclient", "icsrealm")
	 }


	       
	if method == "POST" {
		values := map[string]string{"id": strconv.Itoa(id), "data": data}
		jsonValue, _  = json.Marshal(values)
		restUrl = gatewayUrl+prefix
	} else if method == "PUT"  {
		restUrl = gatewayUrl+prefix+"/"+strconv.Itoa(id)+"/"+data
	} else {
		restUrl = gatewayUrl+prefix+"/"+strconv.Itoa(id)
	}

	req, err := http.NewRequest(method, restUrl, bytes.NewBuffer(jsonValue))
	if err != nil {
		fmt.Printf("Got error %s", err.Error())
	}		
	req.Header.Set("Content-type", "application/json")
	req.Header.Set("Authorization", "Bearer "+token)

	resp, err := client.Do(req)
	if err != nil {
		fmt.Printf("Got error %s", err.Error())
	}
	defer resp.Body.Close()
	body, _ := ioutil.ReadAll(resp.Body)
	respString := string(body[:])
	if respString == "RBAC: access denied"{
		respString += " for "+service+" "+strings.ToLower(method)+" request\n"
	}
	ch <- fmt.Sprintf("%s", respString)
  }

func main() {
	flag.StringVar(&gatewayHost, "gatewayHost", "192.168.49.2", "Gateway Host")
	flag.StringVar(&gatewayPort, "gatewayPort" , "32162", "Gateway Port")  
	flag.StringVar(&keycloakHost, "keycloakHost", "192.168.49.2", "Keycloak Host")
	flag.StringVar(&keycloakPort, "keycloakPort" , "31560", "Keycloak Port")  
	flag.StringVar(&useGateway, "useGateway" , "Y", "Connect to services hrough API gateway") 
	flag.Parse()	

    client := &http.Client{
        Timeout: time.Second * 10,
    }


	ch := make(chan string)
	var prefixArray [3]string = [3]string{"/a1-policy", "/data-consumer", "/data-producer"}
	var methodArray [4]string = [4]string{"GET", "POST", "PUT", "DELETE"}	
	for true {	
		for _,prefix := range prefixArray{
			for _,method := range methodArray{
				go MakeRequest(client, prefix, method, ch)
			}
		}

		for i := 0; i < len(prefixArray); i++ {
			for j := 0; j < len(methodArray); j++ {
				fmt.Println(<-ch)
			}
		}
		time.Sleep(30 * time.Second)
    }
}


Dockerfile
FROM golang:1.15.2-alpine3.12 as build
RUN apk add git
RUN mkdir /build
ADD . /build
WORKDIR /build
RUN go build -o nonrtric-client-go .

FROM alpine:latest
RUN mkdir /app
WORKDIR /app/
 
# Copy the Pre-built binary file from the previous stage
COPY --from=build /build .

# Expose port 8080
EXPOSE 8080

# Run Executable
ENTRYPOINT  [ "/app/nonrtric-client-go", \ 
              "-gatewayHost", "istio-ingressgateway.istio-system", \
              "-gatewayPort", "80", \
              "-keycloakHost", "keycloak.default", \
              "-keycloakPort", "8080", \
              "-useGateway", "N" ]


Update AuthorizationPolicy

AuthorizationPolicy
apiVersion: "security.istio.io/v1beta1"
kind: "AuthorizationPolicy"
metadata:
  name: "ics-policy"
  namespace: istio-nonrtric
spec:
  selector:
    matchLabels:
      apptype: nonrtric-ics
  action: ALLOW
  rules:
  - from:
    - source:
        namespaces: ["default"]
    to:
    - operation:
        methods: ["GET", "POST", "PUT", "DELETE"]
        paths: ["/data-*"]
        hosts: ["data-consumer*", "data-producer*"]
        ports: ["8080"]
---
apiVersion: "security.istio.io/v1beta1"
kind: "AuthorizationPolicy"
metadata:
  name: "pms-policy"
  namespace: istio-nonrtric
spec:
  selector:
    matchLabels:
      apptype: nonrtric-pms
  action: ALLOW
  rules:
  - from:
    - source:
        principals: ["cluster.local/ns/default/sa/goclient"]
    to:
    - operation:
        methods: ["GET", "POST", "PUT", "DELETE"]
        paths: ["/a1-policy*"]
        hosts: ["a1-policy*"]
        ports: ["8080"]
    when:
    - key: request.auth.claims[preferred_username]
      values: ["pmsuser"]

Request are sent from the nonrtric-client-go pod to the services directly from within the cluster.

In the above example I'm using principals and namespaces for authorization.

Both of these require MTLS to be enabled.

If istio is not enabled for the client you can inject the individual pod with the istio proxy : istioctl kube-inject -f client.yaml | kubectl apply -f -

I have also included a "when" condition which checks one of the JWT fields, in this case "preferred_username": "icsuser".

The hosts and ports fields refer to the destination host(s) and post(s).

To use JWT inside the cluster you need to update the RequestAuthentication policy to include the internal address for the jwksUri


jwtRules
  jwtRules:
  - issuer: "http://192.168.49.2:31560/auth/realms/pmsrealm"
    jwksUri: "http://192.168.49.2:31560/auth/realms/pmsrealm/protocol/openid-connect/certs"
  - issuer: "http://keycloak.default:8080/auth/realms/pmsrealm"
    jwksUri: "http://keycloak.default:8080/auth/realms/pmsrealm/protocol/openid-connect/certs"


You also need to update the AuthorizationPolicy to include the internal source


Rules
  rules:
  - from:
    - source:
        requestPrincipals: ["http://192.168.49.2:31560/auth/realms/pmsrealm/fab53fd0-3315-4e2f-bd17-6984fb7745f2"]
    - source:
        requestPrincipals: ["http://keycloak.default:8080/auth/realms/pmsrealm/fab53fd0-3315-4e2f-bd17-6984fb7745f2"]
    to:
    - operation:
        methods: ["GET", "POST", "PUT", "DELETE"]
        paths: ["/a1-policy*"]


You can change the contents (fields) of your JWT token by using client mappers.

Create a new roles pms_admin

The assign the role to your user: role mapping(tab) →available roles →add selected

Then in you client select mappers → create → Mapper Type: User Realm Role, Token claim name : role 

The following field will be added to your JWT:

"role": [
"pms_admin"
],

you can then use this in you when clause to alow/block access to cetain endpoints:

- key: request.auth.claims[role]
values: ["pms_admin"]

Create another role pms_viewer and assign it to a second user pmsuser2

We can then configure the AuthorizationPolicy to grant differnt access to different roles

AuthorizationPolicy
apiVersion: "security.istio.io/v1beta1"
kind: "AuthorizationPolicy"
metadata:
  name: "pms-policy"
  namespace: istio-nonrtric
spec:
  selector:
    matchLabels:
      apptype: nonrtric-pms
  action: ALLOW
  rules:
  - from:
    - source:
        requestPrincipals: ["http://192.168.49.2:31560/auth/realms/pmsrealm/fab53fd0-3315-4e2f-bd17-6984fb7745f2"]
    - source:
        requestPrincipals: ["http://keycloak.default:8080/auth/realms/pmsrealm/fab53fd0-3315-4e2f-bd17-6984fb7745f2"]
    to:
    - operation:
        methods: ["GET", "POST", "PUT", "DELETE"]
        paths: ["/a1-policy*"]
    when:
    - key: request.auth.claims[role]
      values: ["pms_admin"]
  - from:
    - source:
        requestPrincipals: ["http://192.168.49.2:31560/auth/realms/pmsrealm/f96255ec-d553-4c2e-b106-0ed586ccab70"]
    - source:
        requestPrincipals: ["http://keycloak.default:8080/auth/realms/pmsrealm/f96255ec-d553-4c2e-b106-0ed586ccab70"]
    to:
    - operation:
        methods: ["GET"]
        paths: ["/a1-policy*"]
    when:
    - key: request.auth.claims[role]
      values: ["pms_viewer"]
pms_admin role:

Test 1: Testing GET /a1-policy
Received get request for a1-policy, params: nil

Test 2: Testing GET /a1-policy/1001
Received get request for a1-policy, params: id=1001

Test 3: Testing PUT /a1-policy/1002/xyz
Received put request for a1-policy, params: id=1002, data=xyz

Test 4: Testing DELETE /a1-policy/1001
Received delete request for a1-policy, params: id=1001

Test 5: Testing POST /a1-policy
Received post request for a1-policy, params: id=1003, data=abc


pms_viewer role:

Test 1: Testing GET /a1-policy
Received get request for a1-policy, params: nil

Test 2: Testing GET /a1-policy/1001
Received get request for a1-policy, params: id=1001

Test 3: Testing PUT /a1-policy/1002/xyz
RBAC: access denied

Test 4: Testing DELETE /a1-policy/1001
RBAC: access denied

Test 5: Testing POST /a1-policy
RBAC: access denied


You can also leave out the from clause and just use to and when in the rules:

Rules
  rules:
  - to:
    - operation:
        methods: ["GET", "POST", "PUT", "DELETE"]
        paths: ["/a1-policy*"]
    when:
    - key: request.auth.claims[role]
      values: ["pms_admin"]
  - to:
    - operation:
        methods: ["GET"]
        paths: ["/a1-policy*"]
    when:
    - key: request.auth.claims[role]
      values: ["pms_viewer"]

Further details on authorization policies are avaiable here



Istio network policy is enforced at the pod level (in the Envoy proxy), in user-space, (layer 7), as opposed to Kubernetes network policy, which is in kernel-space (layer 4), and is enforced on the host. By operating at application layer, Istio has a richer set of attributes to express and enforce policy in the protocols it understands (e.g. HTTP headers).

Istio Network Policy

Grafana

Istio also comes with grafana, to start it run : istioctl dashboard grafana

This will bring up the grafana home page

From the side menu select dashboards →Manage

The istio dashboards are installed by default

Select the Istio Service dashboard → service workloads to see the incoming requests

You can elasticsearch as a datasource to grafana.

Add the URL for your elasticsearch instance.

Set basic auth to on.

Add your elasticsearch username and password.

Add your index name (e.g. logstash-*)

Set the version to 7.10+

Set Max concurrent shard requests to 1

Save and test.

You data source is now setup.

To view the data being collected, download the grafana elasticseach dashboard and import it.

This does not really work for a single shard instance like the one we are using.

See also: Grafana playground

Prometheus

Start the prometheus dashboard by running:  istioctl dashboard prometheus

See the following link on Querying Metrics from Prometheus for more information.

You can setup your own dashboard in grafana to view these metrics if the default dashboards don't meet your needs.

You can also insert your own customer metrics into your code: INSTRUMENTING A GO APPLICATION FOR PROMETHEUS

Code Snippet
import (
        "github.com/prometheus/client_golang/prometheus"
        "github.com/prometheus/client_golang/prometheus/promhttp"
)
var (
        reqDuration = prometheus.NewHistogramVec(prometheus.HistogramOpts{
                Name:    "rapp_http_request_duration_seconds",
                Help:    "Duration of the last request call.",
                Buckets: []float64{0.05, 0.1, 0.25, 0.5, 1, 2.5, 5, 10},
        }, []string{"app", "func", "handler", "method", "code"})
        reqBytes = prometheus.NewSummaryVec(prometheus.SummaryOpts{
                Name: "rapp_bytes_summary",
                Help: "Summary of bytes transferred over http",
        }, []string{"app", "func", "handler", "method", "code"})
)

func getToken() string {
               resp := &http.Response{}
        ...
                timer := prometheus.NewTimer(prometheus.ObserverFunc(func(v float64) {
                        reqDuration.WithLabelValues("rapp-jwt-invoker", "getToken", resp.Request.URL.Path, resp.Request.Method,
                                resp.Status).Observe(v)
                }))
                defer timer.ObserveDuration()
                resp, err = http.PostForm(keycloakUrl, url.Values{"client_assertion_type": {client_assertion_type},
                                                                  "client_assertion": {client_assertion}, "grant_type": {"client_credentials"},
                                                                  "client_id": {clientId}, "scope": {scope}})
 
                if err != nil {
                        fmt.Println(err)
                        panic("Something wrong with the credentials or url ")
                }

                defer resp.Body.Close()
                body, err := ioutil.ReadAll(resp.Body)
                json.Unmarshal([]byte(body), &jwt)
                reqBytes.WithLabelValues("rapp-jwt-invoker", "getToken", resp.Request.URL.Path, resp.Request.Method,
                        resp.Status).Observe(float64(resp.ContentLength))
        ....        
} 
       ....
func main() {
        prometheus.Register(reqDuration)
        prometheus.Register(reqBytes)
        http.Handle("/metrics", promhttp.Handler())
        go func() {
                http.ListenAndServe(":9000", nil)
        }()
       ....
}

Lastly you need to update the scrape_configs section in prometheus.yaml

scrape_configs:
- job_name: rapp
scrape_interval: 10s
metrics_path: /metrics
static_configs:
- targets:
- rapp-jwt-invoker.istio-nonrtric:80

You can then create your own dashboard in grafana using these metrics: rapps-requests.json

OAuth2 Proxy

Welcome to OAuth2 Proxy | OAuth2 Proxy (oauth2-proxy.github.io)

Calico network policy

https://docs.projectcalico.org/security/calico-network-policy

Calico can be used with Istio to enforce network policies :  Enforce Calico network policy using Istio

For example we can limit connections to the keycloak database to only pods using the keycloak service account

GlobalNetworkPolicy
apiVersion: projectcalico.org/v3
kind: GlobalNetworkPolicy
metadata:
  name: postgres
spec:
  selector: app == 'postgres'
  ingress:
    - action: Allow
      source:
        serviceAccounts:
          names: ["keycloak"]
  egress:
    - action: Allow


Following the example in the link above I installed the test application in a separate namespace (calico-test). Using curl I was able to access the database prior to applying the GlobalNetworkPolicy. After applying the policy the request timed out rather than return a 403 forbidden message.


Logging

Elasticsearch

We can use elasticsearch, kibana and fluentd to aggregate and visualize the kubernetes logs.

You can use the following files to setup a single node ELK stack on minikube

elastic.yaml

kibana.yaml

fluentd-rbac.yaml

fluentd-daemonset.yaml

Latest version of files (8.1.2)

elastic-8.1.2.yaml

kibana-8.1.2.yaml

fluentd.yaml


  • elastic.yaml includes a persistence volume that mounts the /usr/share/elasticsearch/data directory to a host path. This prevents loss of data when the pod is restarted. (You may ned to change the hostPath path value to a directory on your own host)
  • Both elastic.yaml and kibana.yaml contain a config map for configuring the component on start up.
  • xpack.security.enabled is set to true to enable security.
  • This is a single-node minkube setup, you may want to alter this for your own installation.
  • elastic-8.1.2.yaml and kibana-8.1.2.yaml use the most up to date images.
  • fluentd.yaml combines fluentd-rbac.yaml and fluentd-daemonset.yaml into 1 file and includes certificte configuration for version 8.1.2.
  • They all add additional persistent volumes for storing the keys/certificates - please modify these values to suit your own requirements. 


Please ensure to create the logging namespace before applying these files.

Once elasticsearch is up and running, log into kibana and create a new index for the logstash-* pipeline.

Once this is done use the discover tab to create a query against your logs:

Select the timeStamp, kubernetes.container_image, log and kuberentes.label.app for you fields

Use the filters input textbox to only show the logs you want → log : Received and kubernetes.container_image : nonrtric-server-go

Change the date field to the last 15 minutes.

Save your query.

This will produce a report like the following:


This shows the number of requests made to the nonrtric-server-go.

Go to the visualize tab.

Here you can create different charts to display your data and then add them to a dashboard.



Here you can see 3 graphs, the first one shows the number of requests received by each NONRTRIC componet in he last 60 minutes.

The second one is a histogram showing the total number of requests broken down by timeStamp.

The last one is a pie chart showing the distribution of requests across components.


Click the Dev tools tab to use the elasticsearch console

Run GET /_cat/indices?v  to see the list of indices currently in use


You can delete indices that are no longer required by running the following command:

DELETE /<index name> e.g. DELETE /logstash-2022.01.18


You can create a policy to remove logstash indices older than 1 day

Delete logstash indices policy
PUT /_ilm/policy/cleanup_policy
{
      "policy": {                       
        "phases": {
          "hot": {                      
            "actions": {}
          },
          "delete": {
            "min_age": "1d",           
            "actions": { "delete": {} }
          }
        }
      }
}

PUT /logstash-*/_settings
{ "lifecycle.name": "cleanup_policy" }


PUT /_template/logging_policy_template
{
      "index_patterns": ["logstash-*"],               
      "settings": { "index.lifecycle.name": "cleanup_policy" }
}

Elasticsearch SDK

SDK Example
package main

import (
        "bytes"
        "context"
        "encoding/json"
        "fmt"
        "github.com/elastic/go-elasticsearch/esapi"
        "github.com/elastic/go-elasticsearch/v8"
        "io/ioutil"
        "log"
        "os/exec"
        "strings"
)

func main() {
        cmd := exec.Command("minikube", "ip")
        stdout, err := cmd.Output()
        ingressHost := strings.TrimSpace(string(stdout))

        cmd = exec.Command("minikube", "ssh-key")
        stdout, err = cmd.Output()
        ingressKey := strings.TrimSpace(string(stdout))

        // copy ca cert
        cmd = exec.Command("scp", "-i", ingressKey, "docker@"+ingressHost+":/var/elasticsearch/config/certs/ca/ca.crt", "/mnt/c/Users/ktimoney/go/elastic/")
        stdout, err = cmd.Output()

        // get the elasticsearch service nodePort
        cmd = exec.Command("kubectl", "get", "service", "elasticsearch", "-n", "logging",
                "-o", "jsonpath={.spec.ports[?(@.port==9200)].nodePort}")
        stdout, err = cmd.Output()
        secureIngressPort := strings.TrimSpace(string(stdout))

        clusterURLs := []string{"https://" + ingressHost + ":" + secureIngressPort}
        username := "elastic"
        password := "secret"
        cert, _ := ioutil.ReadFile("./ca.crt")

        // client configuration
        cfg := elasticsearch.Config{
                Addresses: clusterURLs,
                Username:  username,
                Password:  password,
                CACert:    cert,
        }
        ctx := context.Background()

        es, err := elasticsearch.NewClient(cfg)
        if err != nil {
                log.Fatalf("Error creating the client: %s", err)
        }
        log.Println(elasticsearch.Version)

        resp, err := es.Info()
        if err != nil {
                log.Fatalf("Error getting response: %s", err)
        }
        defer resp.Body.Close()
        log.Println(resp)

        // Index Query
        indexResp, err := esapi.CatIndicesRequest{Format: "json", Pretty: true}.Do(ctx, es)
        if err != nil {
                return
        }
        indexBody := &indexResp.Body
        defer indexResp.Body.Close()

        fmt.Println(indexResp.String())

        body, err := ioutil.ReadAll(*indexBody)

        var results []map[string]interface{}
        json.Unmarshal(body, &results)
        fmt.Printf("Index: %+v\n", results)
        indexName := fmt.Sprintf("%v", results[len(results)-1]["index"])
        query := `{"query": {"match" : {"log": "token"}},"size": 3}`
        runQuery(es, ctx, indexName, query)
        query = `
                {
                 "query": {
                  "bool": {
                    "must": [
                      { "match": { "kubernetes.container_name": "istio-proxy" }},
                      { "match": { "log": "token" }},
                      { "match": { "kubernetes.labels.app_kubernetes_io/name": "rapp-jwt-invoker" }},
                      { "range": { "@timestamp": { "gte": "now-60m" }}}
                     ]
                   }
                 },"size": 1
                }
        `
        runQuery(es, ctx, indexName, query)
        query = `
                {
                 "query": {
                  "bool": {
                    "must": [
                      { "match": { "kubernetes.container_name": "istio-proxy" }},
                      { "match": { "log": "GET /rapp-jwt-provider" }},
                      { "match": { "kubernetes.labels.app_kubernetes_io/name": "rapp-jwt-provider" }},
                      { "match_phrase": { "tag": "jwt-provider" }},
                      { "range": { "@timestamp": { "gte": "now-60m" }}}
                     ]
                   }
                 },"size": 1
                }
        `
        runQuery(es, ctx, indexName, query)

}

func runQuery(es *elasticsearch.Client, ctx context.Context, indexName string, query string) {
        // Query indexName
        var mapResp map[string]interface{}
        var buf bytes.Buffer
        var b strings.Builder
        b.WriteString(query)
        read := strings.NewReader(b.String())

        // Attempt to encode the JSON query and look for errors
        if err := json.NewEncoder(&buf).Encode(read); err != nil {
                log.Fatalf("Error encoding query: %s", err)

                // Query is a valid JSON object
        } else {
                fmt.Println("\njson.NewEncoder encoded query:", read, "\n")
        }

        // Pass the JSON query to client's Search() method
        searchResp, err := es.Search(
                es.Search.WithContext(ctx),
                es.Search.WithIndex(indexName),
                es.Search.WithBody(read),
                es.Search.WithTrackTotalHits(true),
                es.Search.WithPretty(),
        )

        if err != nil {
                log.Fatalf("Elasticsearch Search() API ERROR:", err)
        }
        defer searchResp.Body.Close()

        // Decode the JSON response and using a pointer
        if err := json.NewDecoder(searchResp.Body).Decode(&mapResp); err != nil {
                log.Fatalf("Error parsing the response body: %s", err)
        }

        // Iterate the document "hits" returned by API call
        for _, hit := range mapResp["hits"].(map[string]interface{})["hits"].([]interface{}) {

                // Parse the attributes/fields of the document
                doc := hit.(map[string]interface{})

                // The "_source" data is another map interface nested inside of doc
                source := doc["_source"]

                // Get the document's _id and print it out along with _source data
                docID := doc["_id"]
                fmt.Println("docID:", docID)
                fmt.Println("_source:", source, "\n")
                // extract the @timestamp field
                timeStamp := fmt.Sprintf("%v", source.(map[string]interface{})["@timestamp"])
                fmt.Println("timeStamp:", timeStamp)
                // extract the tag field
                tag := fmt.Sprintf("%v", source.(map[string]interface{})["tag"])
                fmt.Println("tag:", tag)
                // extract the log field
                k8slog := fmt.Sprintf("%v", source.(map[string]interface{})["log"])
                fmt.Println("log:", k8slog)
        }
        hits := int(mapResp["hits"].(map[string]interface{})["total"].(map[string]interface{})["value"].(float64))
        fmt.Println("Matches:", hits)

}


You can run the same query in elasticsearch dev-tools:

Quick Installation Guide

  1. Download and install istio: istioctl install --set profile=demo
  2. cd to the samples/addons/ directory and install the dashboards e.g. kubectl create -f kiali.yaml
  3. Install postgres: istioctl kube-inject -f postgres.yaml | kubectl apply -f - (change the hostPath path value to a path on your host)
  4. Install keycloak: istioctl kube-inject -f keycloak.yaml | kubectl apply -f -
  5. Open the keycloak admin console and setup the required realms, users and clients
  6. Setup the "pms_admin" and "pms_viewer" roles for pmsuser and pmsuser2 respectively.
  7. Install nonrtric-server-go: docker build -t nonrtric-server-go:latest .
  8. Create the istio-nonrtric namespace: kubectl create namespace istio-nonrtric
  9. Enable istio for the istio-nonrtric namespace: kubectl label namespace istio-nonrtric istio-injection=enabled
  10. Edit the istio-test.yaml so the host ip specified matches yours.
  11. Also change the userid in the requestPrincipals field to match yours
  12. Install istio-test.yaml : kubectl create -f istio-test.yaml
  13. Install nonrtric-client-go: docker build -t nonrtric-client-go:latest .
  14. Install the test client: istioctl kube-inject -f client.yaml | kubectl apply -f -
  15. Open the kiali dashboard to check your services are up and running
  16. Open the grafana to view the istio dashboard
  17. Optionally install elasticsearch

ONAP

ONAP Next Generation Security & Logging Architecture


GO Client

Create kubernetes jobs in golang

Building stuff with the Kubernetes API

There is also a helm sdk you can use:

HELM SDK

Helm Deploy
package main

import (
    "fmt"
    "os"
    "log"
    "k8s.io/cli-runtime/pkg/genericclioptions"
    "k8s.io/client-go/rest"
    "helm.sh/helm/v3/pkg/action"
    "helm.sh/helm/v3/pkg/chart/loader"
)

func main() {
    chartPath := "/tmp/wordpress-12.3.3.tgz"
    chart, err := loader.Load(chartPath)

    releaseName := "wordpress"
    releaseNamespace := "default"

    actionConfig, err := getActionConfig(releaseNamespace)
    if err != nil {
        panic(err)
    }

    listAction := action.NewList(actionConfig)
    releases, err := listAction.Run()
    if err != nil {
        log.Println(err)
    }
    for _, release := range releases {
        log.Println("Release: " + release.Name + " Status: " + release.Info.Status.String())
    }

    iCli := action.NewInstall(actionConfig)
    iCli.Namespace = releaseNamespace
    iCli.ReleaseName = releaseName
    rel, err := iCli.Run(chart, nil)
    if err != nil {

        fmt.Println(err)
    }
   fmt.Println("Successfully installed release: ", rel.Name)
}

func getActionConfig(namespace string) (*action.Configuration, error) {
        actionConfig := new(action.Configuration)
        // Create the rest config instance with ServiceAccount values loaded in them
        config, err := rest.InClusterConfig()
        if err != nil {
        // fallback to kubeconfig
        home, exists := os.LookupEnv("HOME")
        if !exists {
            home = "/root"
        }
        kubeconfigPath := filepath.Join(home, ".kube", "config")
         if envvar := os.Getenv("KUBECONFIG"); len(envvar) >0 {
            kubeconfigPath = envvar
         }
         if err := actionConfig.Init(kube.GetConfig(kubeconfigPath, "", namespace), namespace, os.Getenv("HELM_DRIVER"),
                   func(format string, v ...interface{}) {
                   fmt.Sprintf(format, v)
         }); err != nil {
             panic(err)
         }
        } else {
           // Create the ConfigFlags struct instance with initialized values from ServiceAccount
           var kubeConfig *genericclioptions.ConfigFlags
           kubeConfig = genericclioptions.NewConfigFlags(false)
           kubeConfig.APIServer = &config.Host
           kubeConfig.BearerToken = &config.BearerToken
           kubeConfig.CAFile = &config.CAFile
           kubeConfig.Namespace = &namespace
           if err := actionConfig.Init(kubeConfig, namespace, os.Getenv("HELM_DRIVER"), func(format string, v ...interface{}) {
               fmt.Sprintf(format, v)
           }); err != nil {
               panic(err)
           }
        }
        return actionConfig, nil
}


The method getActionConfig works for both in-cluster deployments and from the localhost. It determines which one to use by calling the rest.InClusterConfig() function.

GO CLIENT SDK

Here are another couple of programs that demonstrate how to use the go client:

hello-world.go

hello-world-del.go

You can also use the client with YAML : job.go


There is also support for istio in client go Istio client-go

ISTIO SDK

AuthorizationPolicy
package main

import (
    "context"
    "bytes"
    "fmt"
    "os"
    "log"
    "path/filepath"
    k8Yaml "k8s.io/apimachinery/pkg/util/yaml"
    metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
    clientcmd "k8s.io/client-go/tools/clientcmd"
    versioned "istio.io/client-go/pkg/clientset/versioned"
    v1beta1 "istio.io/client-go/pkg/apis/security/v1beta1"
    securityv1beta1 "istio.io/api/security/v1beta1"
    typev1beta1 "istio.io/api/type/v1beta1"
)

const (
        NAMESPACE = "default"
)

const authorizationPolicyManifest = `
apiVersion: "security.istio.io/v1beta1"
kind: "AuthorizationPolicy"
metadata:
  name: "pms-policy"
  namespace: default
spec:
  selector:
    matchLabels:
      apptype: nonrtric-pms
  action: ALLOW
  rules:
  - from:
    - source:
        principals: ["cluster.local/ns/default/sa/goclient"]
    to:
    - operation:
        methods: ["GET", "POST", "PUT", "DELETE"]
        paths: ["/a1-policy*"]
        hosts: ["a1-policy*"]
        ports: ["8080"]
    when:
    - key: request.auth.claims[role]
      values: ["pms_admin"]
`

func connectToK8s() *versioned.Clientset {
    home, exists := os.LookupEnv("HOME")
    if !exists {
        home = "/root"
    }

    configPath := filepath.Join(home, ".kube", "config")

    config, err := clientcmd.BuildConfigFromFlags("", configPath)
    if err != nil {
        log.Fatalln("failed to create K8s config")
    }

   ic, err := versioned.NewForConfig(config)
   if err != nil {
        log.Fatalf("Failed to create istio client: %s", err)
                                                                
    return ic
}

func createAuthorizationPolicy(clientset *versioned.Clientset) {
        authClient := clientset.SecurityV1beta1().AuthorizationPolicies(NAMESPACE)

        auth := &v1beta1.AuthorizationPolicy{}
        dec := k8Yaml.NewYAMLOrJSONDecoder(bytes.NewReader([]byte(authorizationPolicyManifest)), 1000)

        if err := dec.Decode(&auth); err != nil {
               fmt.Println(err)
        }

        result, err := authClient.Create(context.TODO(), auth, metav1.CreateOptions{})

        if err!=nil {
                panic(err.Error())
        }

        fmt.Printf("Create Authorization Policy %s \n", result.GetName())
}

func createAuthorizationPolicy2(clientset *versioned.Clientset) {
        authClient := clientset.SecurityV1beta1().AuthorizationPolicies(NAMESPACE)

        auth := &v1beta1.AuthorizationPolicy{
                ObjectMeta: metav1.ObjectMeta{
                        Name: "ics-policy",
                },
                Spec: securityv1beta1.AuthorizationPolicy {
                  Selector: &typev1beta1.WorkloadSelector{
                             MatchLabels: map[string]string{
                             "apptype" : "nonrtric-ics",
                           },
                  },
                  Action: securityv1beta1.AuthorizationPolicy_ALLOW,
                  Rules: []*securityv1beta1.Rule{{
                         From: []*securityv1beta1.Rule_From{{
                              Source: &securityv1beta1.Source{
                                Namespaces : []string{
                                        "default",
                                },
                              },
                         },},
                         To: []*securityv1beta1.Rule_To{{
                              Operation:  &securityv1beta1.Operation{
                                Methods : []string{
                                      "GET", "POST", "PUT", "DELETE",
                                },
                                Paths : []string{
                                      "/data-*",
                                },
                                Hosts : []string{
                                      "data-consumer*", "data-producer*",
                                },
                                Ports : []string{
                                      "8080",
                                },
                              },
                         },},
                  },},
              },
        }

        result, err := authClient.Create(context.TODO(), auth, metav1.CreateOptions{})

        if err!=nil {
                panic(err.Error())
        }

        fmt.Printf("Create Authorization Policy %s \n", result.GetName())
}

func main() {
    clientset := connectToK8s()
    createAuthorizationPolicy(clientset)
    createAuthorizationPolicy2(clientset)
}



keycloak aslo has a client called gocloak

GOCLOAK SDK

gocloak
package main

import (
        "github.com/Nerzal/gocloak/v10"
        "context"
        "fmt"
)

func main(){
 client := gocloak.NewClient("http://192.168.49.2:31560")
 ctx := context.Background()
 token, err := client.LoginAdmin(ctx, "admin", "admin", "master")
 if err != nil {
  fmt.Println(err)
  panic("Something wrong with the credentials or url")
 }

 realmRepresentation := gocloak.RealmRepresentation{
  ID: gocloak.StringP("testRealm"),
  Realm: gocloak.StringP("testRealm"),
  DisplayName: gocloak.StringP("testRealm"),
  Enabled:   gocloak.BoolP(true),
 }

 realm, err := client.CreateRealm(ctx, token.AccessToken, realmRepresentation)
 if err != nil {
  fmt.Println(err)
  panic("Oh no!, failed to create realm :(")
 } else {
  fmt.Println("Created new realm", realm)
 }

 newClient := gocloak.Client{
  ClientID: gocloak.StringP("testClient"),
  Enabled:   gocloak.BoolP(true),
  DirectAccessGrantsEnabled: gocloak.BoolP(true),
  BearerOnly: gocloak.BoolP(false),
  PublicClient: gocloak.BoolP(true),
 }
 clientId, err := client.CreateClient(ctx, token.AccessToken, realm, newClient)
 if err != nil {
  fmt.Println(err)
  panic("Oh no!, failed to create client :(")
 } else {
  fmt.Println("Created new client", clientId)
 }


 newUser := gocloak.User{
  FirstName: gocloak.StringP("Bob"),
  LastName:  gocloak.StringP("Uncle"),
  Email:     gocloak.StringP("something@really.wrong"),
  Enabled:   gocloak.BoolP(true),
  Username:  gocloak.StringP("testUser"),
 }

 userId, err := client.CreateUser(ctx, token.AccessToken, realm, newUser)
 if err != nil {
  fmt.Println(err)
  panic("Oh no!, failed to create user :(")
 } else {
  fmt.Println("Created new user", userId)
}

 err = client.SetPassword(ctx, token.AccessToken, userId, realm, "secret", false)
 if err != nil {
  fmt.Println(err)
  panic("Oh no!, failed to set password :(")
 } else {
  fmt.Println("Set password for user")
 }

 removeRoles := []gocloak.Role{}
 origRoles, err := client.GetRealmRoles(ctx, token.AccessToken, realm, gocloak.GetRoleParams{})
  if err != nil {
  fmt.Println(err)
  panic("Oh no!, failed to retreive roles :(")
 } else {
  fmt.Println("Retrieved roles")
 }
 for _, r := range origRoles {
   removeRoles = append(removeRoles, *r)
 }

 newRole := gocloak.Role{
  Name: gocloak.StringP("testRole"),
 }
 roleName, err := client.CreateRealmRole(ctx, token.AccessToken, realm, newRole)
 if err != nil {
  fmt.Println(err)
  panic("Oh no!, failed to create role :(")
 } else {
  fmt.Println("Created new role", roleName)
 }

 role, err := client.GetRealmRole(ctx, token.AccessToken, realm, roleName)
 if err != nil {
  fmt.Println(err)
  panic("Oh no!, failed to retrieve role :(")
 } else {
  fmt.Println("Retrieved role")
 }

 roles := []gocloak.Role{}
 roles = append(roles, *role)
 err = client.AddRealmRoleToUser(ctx, token.AccessToken, realm, userId, roles)
 if err != nil {
  fmt.Println(err)
  panic("Oh no!, failed to add role to user :(")
 } else {
  fmt.Println("Role added to user")
 }

 err = client.DeleteRealmRoleFromUser(ctx, token.AccessToken, realm, userId, removeRoles)
 if err != nil {
  fmt.Println(err)
  panic("Oh no!, failed to remove roles from user :(")
 } else {
  fmt.Println("Roles removed from user")
 }

 newMapper := gocloak.ProtocolMapperRepresentation{
   ID:             gocloak.StringP("testMapper"),
   Name:           gocloak.StringP("testMapper"),
   Protocol:       gocloak.StringP("openid-connect"),
   ProtocolMapper: gocloak.StringP("oidc-usermodel-realm-role-mapper"),
   Config: &map[string]string{
                                "access.token.claim":   "true",
                                "aggregate.attrs":      "",
                                "claim.name":           "role",
                                "id.token.claim":       "true",
                                "jsonType.label":       "String",
                                "multivalued":          "",
                                "userinfo.token.claim": "true",
                        },
  }
 _, err = client.CreateClientProtocolMapper(ctx, token.AccessToken, realm, clientId, newMapper)
 if err != nil {
  fmt.Println(err)
  panic("Oh no!, failed to add roleampper to client :(")
 } else {
  fmt.Println("Rolemapper added to client")
 }

}


If you want to create a confidential client you can use these settings instead:

newClient := gocloak.Client{
ClientID: gocloak.StringP("testClient"),
Enabled: gocloak.BoolP(true),
DirectAccessGrantsEnabled: gocloak.BoolP(true),
BearerOnly: gocloak.BoolP(false),
PublicClient: gocloak.BoolP(false),
ServiceAccountsEnabled: gocloak.BoolP(true),
ClientAuthenticatorType: gocloak.StringP("client-secret"),
Secret: gocloak.StringP("secret"),
}

You can then access the token with the following URL:  curl -X POST http://<keycloak host ip>:<keycloak port>/auth/realms/testRealm/protocol/openid-connect/token "Content-Type: application/x-www-form-urlencoded" -d client_id=testClient -d client_secret=secret -d 'grant_type=client_credentials'

using client credentials instead of user credentials

You will also need to create a client role and use the "Hardcoded role" mapper to include the client role in the JWT.

This can be done in gocloak like this:

goclock client role
 clientRole := gocloak.Role{
  Name: gocloak.StringP("icsClientRole"),
 }
 clientRoleName, err := client.CreateClientRole(ctx, token.AccessToken, realm, clientId, clientRole)
 if err != nil {
  fmt.Println(err)
  panic("Oh no!, failed to create client role :(")
 } else {
  fmt.Println("Created new client role", clientRoleName)
 }

 clientRole := *newClient.ClientID + "." + clientRoleName
 fmt.Println("clientRole", clientRole)

 hardcodedMapper := gocloak.ProtocolMapperRepresentation{
   ID:             gocloak.StringP("testMapper2"),
   Name:           gocloak.StringP("testMapper2"),
   Protocol:       gocloak.StringP("openid-connect"),
   ProtocolMapper: gocloak.StringP("oidc-hardcoded-role-mapper"),
   Config: &map[string]string{
                                  "role": clientRole,
                        },
  }
 _, err = client.CreateClientProtocolMapper(ctx, token.AccessToken, realm, clientId, hardcodedMapper)
 if err != nil {
  fmt.Println(err)
  panic("Oh no!, failed to add hardcoded roleampper to client :(")
 } else {
  fmt.Println("Hardcoded rolemapper added to client")
 }


This will produce a JWT token with the client role nested inside "resource_access"

JWT snippet
{
  "exp": 1645458971,
  "iat": 1645458671,
  "jti": "54fd719a-bf5b-4638-afd5-828ff10b7537",
  "iss": "http://192.168.49.2:31560/auth/realms/icsrealm",
  "aud": "account",
  "sub": "e9ebe72f-3729-4cd5-88da-79f9bfb23cfb",
  "typ": "Bearer",
  "azp": "icsclient",
  "acr": "1",
  "realm_access": {
    "roles": [
      "offline_access",
      "uma_authorization",
      "default-roles-icsrealm"
    ]
  },
  "resource_access": {
    "icsclient": {
      "roles": [
        "icsclientrole"
      ]
    },


You can then setup your AuthorizationPolicy like this:


AuthorizationPolicy
apiVersion: "security.istio.io/v1beta1"
kind: "AuthorizationPolicy"
metadata:
  name: "ics-policy"
  namespace: istio-nonrtric
spec:
  selector:
    matchLabels:
      apptype: nonrtric-ics
  action: ALLOW
  rules:
  - from:
    - source:
        requestPrincipals: ["http://192.168.49.2:31560/auth/realms/icsrealm/"]
    - source:
        requestPrincipals: ["http://keycloak.default:8080/auth/realms/icsrealm/"]
  - to:
    - operation:
        methods: ["GET", "POST", "PUT", "DELETE"]
        paths: ["/data-*"]
    when:
    - key: request.auth.claims[resource_access][icsclient][roles]
      values: ["icsclientrole"]


You don't ned to include the userId with the requestPrincipals.

keycloak secrets can be (re)generated and retrieved using the following code:


keycloak client secret
 _, err = client.RegenerateClientSecret(ctx, token.AccessToken, realm, clientId)
  if err != nil {
  fmt.Println(err)
  panic("Oh no!, failed to regenerate client secret :(")
 } else {
  fmt.Println("Regenerated Secret")
 }

 cred, err := client.GetClientSecret(ctx, token.AccessToken, realm, clientId)
  if err != nil {
  fmt.Println(err)
  panic("Oh no!, failed to get client secret :(")
 } else {
  fmt.Println("Client Secret", *cred.Value)
 }


Instead of using the hardcoded mapper you can call the GetClientServiceAccount method to get the service a/c user.

You can then add the client role to the service account user with the AddClientRoleToUser method.

Instead of using the hardcoded mapper you can use a client role mapper to include the client role in the JWT.

Finally you can set the default client scpe to "email" to mininmize the size of you token.

JWT
  "iat": 1646152642,
  "jti": "e55fd625-d3e5-476f-aeb7-5a0189380151",
  "iss": "http://192.168.49.2:31560/auth/realms/hwrealm",
  "sub": "d2f705d1-ca27-437d-979f-4d0b80d500d7",
  "typ": "Bearer",
  "azp": "hwclient",
  "acr": "1",
  "scope": "email",
  "email_verified": false,
  "clientHost": "127.0.0.6",
  "clientId": "hwclient",
  "clientRole": [
    "hwclientrole"
  ],
  "clientAddress": "127.0.0.6"
}


In your Istio AuthorizationPolicy use the following when clause : 


Istio
    when:
    - key: request.auth.claims[clientRole]
      values: ["hwclientrole"]


Keycloak Client Authenticator

Using X509 certificates

Create the server side certificates using the following script

server_certs.sh
#!/bin/sh


CA_SUBJECT="/C=IE/ST=/L=/O=/OU=EST/CN=est.tech/emailAddress=ca@mail.com"
SERVER_SUBJECT="/C=IE/ST=/L=/O=/OU=EST/CN=est.tech/emailAddress=server@mail.com"
PW=changeit
IP=$(minikube ip)

echo $PW > secretfile.txt

openssl req -x509 -sha256 -days 3650 -newkey rsa:4096 -keyout rootCA.key -subj "$CA_SUBJECT" -passout file:secretfile.txt -out rootCA.crt

openssl req -new -newkey rsa:4096 -keyout tls.key -subj "$SERVER_SUBJECT" -out tls.csr -nodes

echo "subjectKeyIdentifier   = hash" > x509.ext
echo "authorityKeyIdentifier = keyid:always,issuer:always" >> x509.ext
echo "basicConstraints       = CA:TRUE" >> x509.ext
echo "keyUsage               = digitalSignature, nonRepudiation, keyEncipherment, dataEncipherment, keyAgreement, keyCertSign" >> x509.ext
echo "subjectAltName         = DNS.1:localhost, IP.1:127.0.0.1, DNS.2:minikube, IP.2:${IP}, DNS.3:keycloak.default, DNS.4:keycloak.est.tech" >> x509.ext
echo "issuerAltName          = issuer:copy" >> x509.ext
echo "[ ca ]" >> x509.ext
echo "# X509 extensions for a ca" >> x509.ext
echo "keyUsage                = critical, cRLSign, keyCertSign" >> x509.ext
echo "basicConstraints        = CA:TRUE, pathlen:0" >> x509.ext
echo "subjectKeyIdentifier    = hash" >> x509.ext
echo "authorityKeyIdentifier  = keyid:always,issuer:always" >> x509.ext
echo "" >> x509.ext
echo "[ server ]" >> x509.ext
echo "# X509 extensions for a server" >> x509.ext
echo "keyUsage                = critical,digitalSignature,keyEncipherment" >> x509.ext
echo "extendedKeyUsage        = serverAuth,clientAuth" >> x509.ext
echo "basicConstraints        = critical,CA:FALSE" >> x509.ext
echo "subjectKeyIdentifier    = hash" >> x509.ext
echo "authorityKeyIdentifier  = keyid,issuer:always" >> x509.ext

openssl x509 -req -CA rootCA.crt -CAkey rootCA.key -in tls.csr -passin file:secretfile.txt -out tls.crt -days 365 -CAcreateserial -extfile x509.ext

rm secretfile.txt x509.ext 2>/dev/null


This will produce the following files: tls.key, tls.crt and rootCA.crt.

These need to be copied to a location where keycloak can pick them up when starting.

Add a PersistentVolume and PersistentVolumeClaim to map the hostPath on your localhost to the /etc/x509/https directory  on the keycloak server.

This will automatically pick up the tls.key, tls.crt files and convert them into https-keystore files in the /opt/jboss/keycloak/standalone/configuration/keystores directory.

You will need to map the rootCA.crt file using an environment variable like this:

env:
- name : X509_CA_BUNDLE
value: /etc/x509/https/rootCA.crt

You'll also need to create a port mapping for the keycloak https port in your deployment:

env:
- name: KEYCLOAK_HTTPS_PORT
value: "8443"

ports:
- name: http
containerPort: 8080
- name: https
containerPort: 8443

and include the https port in your service:

ports:
- name: https
port: 8443
targetPort: 8443
nodePort: 31561


keycloak is now ready to accept https connections.

You can generate your client certificates using the following code:


client_certs
#!/bin/sh

CLIENT_SUBJECT="/C=IE/ST=/L=/O=/OU=EST/CN=est.tech/emailAddress=client@mail.com"
PW=changeit
CERTNAME=client
IP=$(minikube ip)

echo $PW > secretfile.txt

echo "subjectKeyIdentifier   = hash" > x509.ext
echo "authorityKeyIdentifier = keyid:always,issuer:always" >> x509.ext
echo "basicConstraints       = CA:TRUE" >> x509.ext
echo "keyUsage               = digitalSignature, nonRepudiation, keyEncipherment, dataEncipherment, keyAgreement, keyCertSign" >> x509.ext
echo "subjectAltName         = DNS.1:localhost, IP.1:127.0.0.1, DNS.2:minikube, IP.2:${IP}, DNS.3:keycloak.default, DNS.4:keycloak.est.tech" >> x509.ext
echo "issuerAltName          = issuer:copy" >> x509.ext

openssl req -new -newkey rsa:4096 -nodes -keyout ${CERTNAME}.key -subj "$CLIENT_SUBJECT" -out ${CERTNAME}.csr

openssl x509 -req -CA rootCA.crt -CAkey rootCA.key -in ${CERTNAME}.csr -passin file:secretfile.txt -out ${CERTNAME}.crt -days 365 -CAcreateserial -extfile x509.ext


openssl pkcs12 -export -clcerts -in ${CERTNAME}.crt -inkey ${CERTNAME}.key -passout file:secretfile.txt -out ${CERTNAME}.p12

openssl pkcs12 -in ${CERTNAME}.p12 -password pass:$PW -passout file:secretfile.txt -out ${CERTNAME}.pem -clcerts -nodes

rm secretfile.txt x509.ext 2>/dev/null

This will generate a client.crt and a client.key which you can use separtley, it also generates client.pem which combined the certificate and key into 1 file.

If you use this as your cert file then you don't need to specifiy a key file parameter.

You now need to setup your realm and add an X.509 Direct Grant Flow.

See this link on how to do that https://wjw465150.gitbooks.io/keycloak-documentation/content/server_admin/topics/authentication/x509.html

Next setup a client with access type of public.

Change Direct Grant Flow in the "Authentication Flow Overrides" section of your client settings to "x509 direct grant".

Last add a new user with an email address which is the same as the one given the the certificate subject i.e. client@mail.com

Note: The subjectAltName contains a list of DNS and IP entries, you must use one of these in your URL when using the cert.

Note: The CN will be used later on when specifying an SNI host name.

You can test your setup using the following script:

test_cert
#!/bin/sh
HOST=$(minikube ip)
KEYCLOAK_PORT=$(kubectl -n default get service keycloak -o jsonpath='{.spec.ports[?(@.name=="https")].nodePort}')
REALM="x509"
CLIENT="x509client"
curl -k -X POST https://$HOST:$KEYCLOAK_PORT/auth/realms/$REALM/protocol/openid-connect/token  \
        --data "grant_type=password&scope=openid profile&username=&password=&client_id=$CLIENT" \
        --cert client.crt --key client.key


echo ""


This will retrieve a JWT token without the need to use a password.

If you are using a confidential client, include the client_secret:

curl -k -X POST https://$HOST:$KEYCLOAK_PORT/auth/realms/$REALM/protocol/openid-connect/token \
--data "grant_type=password&scope=openid profile&client_id=$CLIENT" \
-d client_secret=<client secret> \
--cert client.crt --key client.key


For confidential clients you can also set the Client Authenticator to "X509 certificate" in the credentials tab.

You can then set your subject DN to something like: .*client@mail.com.* and turn on "Allow Regex Pattern Comparison"

The JWT can then be retrieved using a call like the following:

curl -k -X POST https://$HOST:$KEYCLOAK_PORT/auth/realms/$REALM/protocol/openid-connect/token \
--data "grant_type=password&scope=openid profile&client_id=$CLIENT" \
--cert client.pem


Alternatively you can use the -E option to entrypt the pem file

curl -k -X POST https://$HOST:$KEYCLOAK_PORT/auth/realms/$REALM/protocol/openid-connect/token \
--data "grant_type=password&scope=openid profile&client_id=$CLIENT" \
-E client.pem


For more informtion see: X.509 Client Certificate User Authentication

It is not possible to connect to a TLS server with curl using only a client certificate, without the client private key. https://stackoverflow.com/questions/36431179/using-curl-with-cert

Token can also be retrieved using go:

Go X509 Token
package main

import (
        "crypto/tls"
        "crypto/x509"
        "fmt"
        "io/ioutil"
        "net/http"
        "net/url"
)

func main() {
        caCert, _ := ioutil.ReadFile("/mnt/c/Users/ktimoney/keycloak-certs/rootCA.crt")
        caCertPool := x509.NewCertPool()
        caCertPool.AppendCertsFromPEM(caCert)

        cert, _ := tls.LoadX509KeyPair("/mnt/c/Users/ktimoney/keycloak-certs/client.crt", "/mnt/c/Users/ktimoney/keycloak-certs/client.key")

        client := &http.Client{
                Transport: &http.Transport{
                        TLSClientConfig: &tls.Config{
                                RootCAs:      caCertPool,
                                Certificates: []tls.Certificate{cert},
                        },
                },
        }

        keycloakHost := "192.168.49.2"
        keycloakPort := "31561"
        realmName := "x509"
        keycloakUrl := "https://" + keycloakHost + ":" + keycloakPort + "/auth/realms/" + realmName + "/protocol/openid-connect/token"

        clientId := "x509client"
        scope := "openid profile"
        resp, err := client.PostForm(keycloakUrl,
                url.Values{"username": {""}, "password": {""}, "grant_type": {"password"}, "client_id": {clientId}, "scope": {scope}})
        if err != nil {
                panic(err)
        }
        defer resp.Body.Close()

        fmt.Println("response Status:", resp.Status)
        fmt.Println("response Headers:", resp.Header)
        body, _ := ioutil.ReadAll(resp.Body)
        fmt.Println("response Body:", string(body))
}


Java example available here: X.509 Authentication in Spring Security 

Istio CA Certs

To allow istio to work with keycloak you must add your certificate to the istio certs when you're installing.

An istio operator file is used for this: istio.yaml

istioctl install --set profile=demo -f istio.yaml

Further instruction are available here: Custom CA Integration using Kubernetes CSR 

Using istio-gateway to obtain JWT tokens.

You may want to avoid connecting directly to the keycloak server for security reasons.

You can connect to it through the istio ingress gateway instead if you wish.

You will need to setup a gateway in PASSTROUGH mode and virtual service that maps the keycloak host to the keycloak SNI host.

The following file can be used to do this for the CN used when creating certificates above: keycloak-gateway.yaml

You can test this using curl:

Test Gateway
#!/bin/sh
INGRESS_HOST=$(minikube ip)
SECURE_INGRESS_PORT=$(kubectl -n default get service istio-ingressgateway -n istio-system -o jsonpath='{.spec.ports[?(@.name=="https")].nodePort}')

curl -v --resolve "keycloak.est.tech:$SECURE_INGRESS_PORT:$INGRESS_HOST" --cacert rootCA.crt "https://keycloak.est.tech:$SECURE_INGRESS_PORT"

CLIENT="myclient"
REALM="x509"
curl --resolve "keycloak.est.tech:$SECURE_INGRESS_PORT:$INGRESS_HOST" --cacert rootCA.crt \
        -X POST https://keycloak.est.tech:$SECURE_INGRESS_PORT/auth/realms/$REALM/protocol/openid-connect/token  \
        --data "grant_type=password&scope=openid profile&client_id=$CLIENT" \
        -E client.pem
echo ""

The following go code can be used to achieve the same result:


go
package main

import (
        "context"
        "crypto/tls"
        "crypto/x509"
        "fmt"
        "io/ioutil"
        "net"
        "net/http"
        "net/url"
        "os/exec"
        "strings"
        "time"
)

func main() {
        caCert, _ := ioutil.ReadFile("/mnt/c/Users/ktimoney/keycloak-certs/rootCA.crt")
        caCertPool := x509.NewCertPool()
        caCertPool.AppendCertsFromPEM(caCert)

        cert, _ := tls.LoadX509KeyPair("/mnt/c/Users/ktimoney/keycloak-certs/client.crt",
                                       "/mnt/c/Users/ktimoney/keycloak-certs/client.key")

        dialer := &net.Dialer{
                Timeout:   30 * time.Second,
                KeepAlive: 30 * time.Second,
                DualStack: true,
        }

        keycloakAlias := "keycloak.est.tech"
        cmd := exec.Command("minikube", "ip")
        stdout, err := cmd.Output()
        ingressHost := strings.TrimSpace(string(stdout))
        cmd = exec.Command("kubectl", "get", "service", "istio-ingressgateway", "-n", "istio-system",
                           "-o", "jsonpath={.spec.ports[?(@.name==\"https\")].nodePort}")
        stdout, err = cmd.Output()
        secureIngressPort := strings.TrimSpace(string(stdout))
        fmt.Println("secureIngressPort = " + secureIngressPort)

        client := &http.Client{
                Transport: &http.Transport{
                        DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
                                fmt.Println("address original =", addr)
                                if addr == keycloakAlias+":"+secureIngressPort {
                                        addr = ingressHost + ":" + secureIngressPort
                                        fmt.Println("address modified =", addr)
                                }
                                return dialer.DialContext(ctx, network, addr)
                        },
                        TLSClientConfig: &tls.Config{
                                RootCAs:      caCertPool,
                                Certificates: []tls.Certificate{cert},
                        },
                },
        }

        realmName := "x509provider"
        keycloakUrl := "https://" + keycloakAlias + ":" + secureIngressPort + "/auth/realms/" +
                        realmName + "/protocol/openid-connect/token"

        clientId := "x509provider-cli"
        clientId = "myclient"
        scope := "email openid"
        resp, err := client.PostForm(keycloakUrl,
                url.Values{"grant_type": {"password"}, "client_id": {clientId}, "scope": {scope}})
        if err != nil {
                panic(err)
        }
        defer resp.Body.Close()

        fmt.Println("response Status:", resp.Status)
        fmt.Println("response Headers:", resp.Header)
        body, _ := ioutil.ReadAll(resp.Body)
        fmt.Println("response Body:", string(body))
}


Note: If run outside the cluster the ISS will be "https://keycloak.est.tech:30338/auth/realms/<realm>" (the port number will doffer depending on your setup).

Inside the cluster it will be: "https://keycloak.est.tech:443/auth/realms/<realm>"

Note: Your istio  jwksUri won't be able to resolve the host alias so you should use the normal values for this e.g.  "https://keycloak.default:8443/auth/realms/<realm>/protocol/openid-connect/certs"

Note: The file above also allows for http calls to keycloak through the gateway, the ISS in this case is: "http://istio-ingressgateway.istio-system:80/auth/realms/<realm>". In this case the jwksUri  ahould be set to the default URI for in-cluster keycloak calls i.e. "http://keycloak.default:8080/auth/realms/<realm>/protocol/openid-connect/certs"


Client authentication with signed JWT

Another option for retrieving JWT tokens for confidentail clients is using client authentication with signed JWT.

Create a new confidential client and call it jwtclient.

In the credentials section choose "Signed JWT" from the Client Authenticator dropdown and choose RS256 as the Signature Algorithm.

Then in the Keys tab import the client.crt we generated earlier.

We need to create a self-signed JWT assertion to use this.

Create a public key from your private key with the following command: openssl rsa -in client.key -outform PEM -pubout -out client_pub.key

See the following link on how to do this: Creating and validating a JWT RSA token in Golang

We need to make some modifications to the token.go code to enable it to work for us.

The following fields need to be added to the claims map:

claims["jti"] = "myJWTId" + fmt.Sprint(now.UnixNano())
claims["sub"] = "jwtclient"
claims["iss"] = "jwtclient"
claims["aud"] = "http://192.168.49.2:31560/auth/realms/x509"

Also modify main.go so it uses you public and private keys and only outputs the token value.

Compile and run the code to produce the self-signed JWT assertion.

This can then be used to obtain  a JWT access token with the following curl command:

JWT Assertion
#!/bin/sh
HOST=$(minikube ip)
KEYCLOAK_PORT=$(kubectl -n default get service keycloak -o jsonpath='{.spec.ports[?(@.name=="http")].nodePort}')
REALM="x509"
CLIENT="jwtclient"


JWT=$(./main)

curl -k -X POST http://$HOST:$KEYCLOAK_PORT/auth/realms/$REALM/protocol/openid-connect/token  \
        -d "grant_type=client_credentials" -d "scope=openid profile" -d client_id=$CLIENT \
        -d "client_assertion_type=urn:ietf:params:oauth:client-assertion-type:jwt-bearer" \
        -d client_assertion=$JWT
echo ""


No client secret is required for this authentication.

These self-signed JWT assertions are for one time use only, the jti claim value must have a unique id for every call.

Note: we can also call this using https with some small modifications.


Client authentication with signed JWT with client secret

This is similar to the option above except we sign with the client secret instead of the private key. 

We also use a different algorithm.

The following code demonstrates this:

Signed JWT with client secret
        secret := "NKTh1bfR9HNwllMhdWrDMKhVJHTvwreC"

        token, err := jwt.NewWithClaims(jwt.SigningMethodHS256, claims).SignedString([]byte(secret))
        if err != nil {
                return "", fmt.Errorf("create: sign token: %w", err)
        }


Client keys tab

The client offer many different ways of configuring the authenticatio keys.

To use the JWKS option we need to create a jwks from our private key or public key.

The following code performs this operation:


PEM to JWKS
package main

import (
        "crypto/rsa"
        "crypto/sha1"
        "crypto/x509"
        "encoding/base64"
        "encoding/json"
        "encoding/pem"
        "flag"
        "fmt"
        "golang.org/x/crypto/ssh"
        "io/ioutil"
        "math/big"
)

type Jwks struct {
        Keys []Key `json:"keys"`
}
type Key struct {
        Kid string `json:"kid,omitempty"`
        Kty string `json:"kty"`
        Use string `json:"use"`
        N   string `json:"n"`
        E   string `json:"e"`
        X5c []string `json:"x5c"`
        X5t string `json:"x5t"`
}

var keyFile string
var keyType string
var certFile string

func getKeyFromPrivate(key []byte) (*rsa.PublicKey){
        parsed, err := ssh.ParseRawPrivateKey(key)
        if err != nil {
                fmt.Println(err)
        }

        // Convert back to an *rsa.PrivateKey
        privateKey := parsed.(*rsa.PrivateKey)

        publicKey := &privateKey.PublicKey
        return publicKey
}

func getKeyFromPublic(key []byte) (*rsa.PublicKey){
        pubPem, _ := pem.Decode(key)

        parsed, err := x509.ParsePKIXPublicKey(pubPem.Bytes)
        if err != nil {
                fmt.Println("Unable to parse RSA public key", err)
        }

        // Convert back to an *rsa.PublicKey
        publicKey := parsed.(*rsa.PublicKey)

        return publicKey
}

func getCert(cert []byte) *x509.Certificate {
        certPem, _ := pem.Decode(cert)
        if certPem == nil {
                panic("Failed to parse pem file")
        }

        // pass cert bytes
        certificate, err := x509.ParseCertificate(certPem.Bytes)
        if err != nil {
                fmt.Println("Unable to parse Certificate", err)
        }

        return certificate
}

func main() {
        flag.StringVar(&keyFile, "keyFile", "/mnt/c/Users/ktimoney/keycloak-certs/client_pub.key", "Location of key file")
        flag.StringVar(&keyType, "keyType", "public", "Type of key file")
        flag.StringVar(&certFile, "certFile", "/mnt/c/Users/ktimoney/keycloak-certs/client.crt", "Location of cert file")
        flag.Parse()

        key, err := ioutil.ReadFile(keyFile)
        if err != nil {
                fmt.Println(err)
        }

        var publicKey *rsa.PublicKey

        if keyType == "public" {
           publicKey = getKeyFromPublic(key)
        }else{
           publicKey = getKeyFromPrivate(key)
        }

        cert, err := ioutil.ReadFile(certFile)
        if err != nil {
                fmt.Println(err)
        }

        certificate := getCert(cert)
        // generate fingerprint with sha1
        // you can also use md5, sha256, etc.
        fingerprint := sha1.Sum(certificate.Raw)

        jwksKey := Key{
                Kid: "SIGNING_KEY",
                Kty: "RSA",
                Use: "sig",
                N: base64.RawStdEncoding.EncodeToString(publicKey.N.Bytes()),
                E: base64.RawStdEncoding.EncodeToString(big.NewInt(int64(publicKey.E)).Bytes()),
                X5c: []string{base64.RawStdEncoding.EncodeToString(certificate.Raw)},
                X5t: base64.RawStdEncoding.EncodeToString(fingerprint[:]),
        }
        jwksKeys := []Key{jwksKey}
        jwks := Jwks{jwksKeys}

        jwksJson, err := json.Marshal(jwks)
        if err != nil {
                fmt.Println(err)
                return
        }
        fmt.Println(string(jwksJson))

}


The output will look like this:

{"keys":[{"kid":"SIGNING_KEY","kty":"RSA","use":"sig","n":"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","e":"AQAB","x5c":["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"],"x5t":"IIj3g74+BJHIkUZxKWb4zwZeFuw"}]}


We can paste this into the "JWKS" test box.

Alternativley we can run a web server to produce this output and use the server url in the "JWKS URI" text box instead.


Note: There is also a nodejs utility available for this, running ssh-keygen -e -m pkcs8 -f /tmp/client.key | pem-jwk | jq '{ "keys":[{kid: "something", kty: .kty , use: "sig", n: .n , e: .e }]}'

will produce the same result as above.


You can also upload your private key and certificate to the realm you are using.

Go to Relam Settings → Keys - > Providers → Add Keystore → RSA

Upload both you private key and it's correspoding certificate.

Go to Relam Settings → General and click on "OpenID Endpoint configuration"

Search for jwks_url and you should see somthing like the following :

"jwks_uri":"http://127.0.0.1:33409/auth/realms/x509/protocol/openid-connect/certs"

Go to this URL, your jwks should be on the bottom.

For this to work with you JWT code you'll need to copy the "kid" value and update you code so this is included in the header: This is necessary when the JWKS has multiple keys.

JWT snippet
        claims["iss"] = "jwtclient3"
        claims["aud"] = "https://192.168.49.2:31561/auth/realms/x509"

        token := jwt.NewWithClaims(jwt.SigningMethodRS256, claims)
        token.Header["kid"] = "AKAwbsKtqu9OmIwIsPOUf5zTJkIC73hzY9Myv4srjTs"
        tokenString, err := token.SignedString(key)
        if err != nil {
                return "", fmt.Errorf("create: sign token: %w", err)
        }


        return tokenString, nil
}


Keycloak Authorization code grant

The OAuth Authorization Code Grant flow is recommended if your application support redirects.
e.g. your application is a Web application or a mobile application.

See this link to see how to setup your client - Keycloak: Authorization Code Grant Example

Here is a sample shell script to retrieve an authorization code:

Authorization Code
#!/bin/sh
HOST=$(minikube ip)
KEYCLOAK_PORT=$(kubectl -n default get service keycloak -o jsonpath='{.spec.ports[?(@.name=="http")].nodePort}')
REALM="jwtrealm"
CLIENT="jwtsecret"
AUTH_USERNAME="jwtuser"
AUTH_PASSWORD="secret"
STATE=$(uuidgen)

URL="http://$HOST:$KEYCLOAK_PORT/auth/realms/$REALM/protocol/openid-connect/auth?client_id=$CLIENT&response_type=code&state=$STATE"
STDOUT=$(curl -s -X GET $URL --insecure -D headers.out)
COOKIES=$(cat headers.out | grep set-cookie | cut -f2 -d' ' | tr -d '\n')
LOGIN_URL=$(echo $STDOUT | sed s'/.* action=//g' | cut -f1 -d' ' | sed s'/\"//g' | sed s'/amp;//g')

CURL_OUTPUT=$(curl -s --cookie $COOKIES -X POST "${LOGIN_URL}" -d "username=${AUTH_USERNAME}&password=${AUTH_PASSWORD}" --insecure -D headers.out)
CODE=$(cat headers.out | grep -i location | sed s'/.*code=//g')
echo CODE=$CODE
echo ACCESS_CODE=$CURL_OUTPUT
rm headers.out 2>/dev/null

To set this up so it retrieves the JWT access token once logged in we must configure the keycloak client with a "Valid Redirect URI", in this case it will be "http://192.168.49.2:31233/callback"

The following go sever is running at this URI:

Authorization server callback
package main

import (
        "encoding/json"
        "fmt"
        "io/ioutil"
        "net/http"
        "net/url"
)

type Jwttoken struct {
        Access_token       string
        Expires_in         int
        Refresh_expires_in int
        Refresh_token      string
        Token_type         string
        Not_before_policy  int
        Session_state      string
        Scope              string
}

var jwt Jwttoken

func getToken(auth_code string) string {
        clientSecret := "Ctz6aBahmjQvAt7Lwgg8qDNsniuPkNCC"
        clientId := "jwtsecret"
        realmName := "jwtrealm"
        keycloakHost := "keycloak"
        keycloakPort := "8080"
        keycloakUrl := "http://" + keycloakHost + ":" + keycloakPort + "/auth/realms/" + realmName + "/protocol/openid-connect/token"        
        resp, err := http.PostForm(keycloakUrl,
                     url.Values{"code": {auth_code}, "grant_type": {"authorization_code"},
                                "client_id": {clientId}, "client_secret": {clientSecret}})
        if err != nil {
                fmt.Println(err)
                panic("Something wrong with the credentials or url ")
        }
        defer resp.Body.Close()
        body, err := ioutil.ReadAll(resp.Body)
        fmt.Println(string(body))
        json.Unmarshal([]byte(body), &jwt)
        return jwt.Access_token
}

func noprefix(res http.ResponseWriter, req *http.Request) {
        // create response binary data
        data := []byte("Authorization code default") // slice of bytes
        // write `data` to response
        res.Write(data)
}

func callback(res http.ResponseWriter, req *http.Request) {
        query := req.URL.Query()
        code := query.Get("code")
        token := getToken(code)
                res.WriteHeader(http.StatusOK)
                res.Write([]byte(token))
}

func main() {
        // create a new handler
        callbackHandler := http.HandlerFunc(callback)
        http.Handle("/callback", callbackHandler)
        noPrefixHandler := http.HandlerFunc(noprefix)
        http.Handle("/", noPrefixHandler)
        http.ListenAndServe(":9000", nil)
}
  

Login will trigger a call to the /callback endpoint whcih in turn gets the JWT token and returns it to the user.


PKCE

PKCE stands for Proof Key for Code Exchange and the PKCE-enhanced Authorization Code Flow builds upon the standard Authorization Code Flow and it provides an additional level of security for OAuth clients.

For setting up the keycloak realm, client and user please see : PKCE Verification in Authorization Code Grant

In this example I will use a confidential client called oauth2-pkce in the OAuth2Realm.

I have also added an audience mapper to map the client to the the token.

You will need to copy the client secret into the cod for this to work.

Download the go code: oauth2.go

Update the code to match your keycloak setup.

Once the code has compiled create your docker image using: Dockerfile_oauth2

Start the service using: oauth2.yaml

This program uses PKCE code_challenge and code_challenge_method parameters when making the authorization code request and the PKCE  code_verifier parameter when exchanging the authorization code for a token.

If running on windows you may need to start a tunnel so your services are accessible from your windows browser (see Accessing apps)

You may also need to update your hosts file to add an alias of keycloak for your local ip. (e.g. 127.0.0.1 keycloak)

This is important because the iss of the token needs to match the keycloak url you provide.

If everything has been setup correctly when you hit the endpoint http://localhost:9000/ you should be redirected to the keycloak login screen.

Enter a username and password for your realm.

The authorization code will be sent to your call back URL (redirect_uri) where it can be exchanged for a token.

The token will be printed on the screen.

It should look something like this:

Token
{
    "TokenResponse": {
        "access_token": "eyJhbGciOiJSUzI1NiIsInR5cCIgOiAiSldUIiwia2lkIiA6ICJic0J4Z0lKd0dxS3B2YmROdjd0WHd2ZnUxSVFRNDZQb0M4SHFrdEYxTjVjIn0.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.VRBWjMUqnVgtQJ5PaYjcOnNt-9PvFkhbLnRw3qBF62N7eJPFexsnPVbB7Hy34TWYy9RKnJIwnIDcgmGAB0mw6XF9iVgQ_3uI0RDa-qbnpOmR9wImzKBFe1DV-KeQQQJTlZ4vsoJJzpdxWJNRwPCUqU9DCMAYVaVKoSfuAapL8v4Rp4H5zT7fjA-LXnvJ4rhypZBjQxu7vOb69_UD98f98av8b0ewg1nJxjkNB7gJRLrgA4CnBuCk5K-zLUWzZU7zub5Am5kjjEf7pBLWw3zsqD9ApBcWe44ySLurB_TRSFHgfL4T9BONG2Y4O1924HxMNlkQ2TaepGXfAuRu4ckuSw",
        "token_type": "Bearer",
        "refresh_token": "eyJhbGciOiJIUzI1NiIsInR5cCIgOiAiSldUIiwia2lkIiA6ICIyNGE3MzY3Zi1hNzJhLTRhMmYtYjI1OC1lNGZjMDJmNWMzZmIifQ.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.VFH5KZwtWHLbQyJIHMR0389azqcxKh7Reh6ze52UXsA",
        "expiry": "2022-05-05T14:01:42.0439809Z"
    },
    "IDToken": {
        "exp": 1651759302,
        "iat": 1651759002,
        "auth_time": 1651759002,
        "jti": "4318be76-d806-43a3-bb18-2e2c4b5cf601",
        "iss": "http://keycloak:8080/auth/realms/OAuth2Realm",
        "aud": "oauth2-pkce",
        "sub": "cc904513-0cb7-4bcd-922e-1176093c94a1",
        "typ": "ID",
        "azp": "oauth2-pkce",
        "session_state": "174e10af-de4b-43e8-917f-fc48e18889ca",
        "at_hash": "q0PPpL9nMeJupmHABtdOEw",
        "acr": "1",
        "sid": "174e10af-de4b-43e8-917f-fc48e18889ca",
        "email_verified": false,
        "preferred_username": "oauth2user"
    }
}

Copy the access token from the output and paste into an environment variable caled TOKEN

curl -H "Authorization: Bearer $TOKEN" localhost:9000
Hello World OAuth2!


See also: golang oauth2

Keycloak Rest API

Documentation for the keycloak Rest API is available here: Keycloak Admin REST API

Below is some sample code that calls the clients rest api to create a new client:

Keycloak Client Rest API
export ADMIN_TKN=$(curl -s -X POST --insecure https://$HOST:$KEYCLOAK_PORT/auth/realms/master/protocol/openid-connect/token \
 -H "Content-Type: application/x-www-form-urlencoded" \
 -d "username=admin" \
 -d 'password=admin' \
 -d 'grant_type=password' \
 -d 'client_id=admin-cli' | jq -r '.access_token')
echo "ADMIN CLIENT TOKEN = $ADMIN_TKN"

curl -X POST --insecure https://$HOST:$KEYCLOAK_PORT/auth/admin/realms/x509provider/clients \
 -H "authorization: Bearer $ADMIN_TKN" \
 -H "Content-Type: application/json" \
 --data \
 '
  {
    "id": "x509Client",
    "name": "x509Client",
    "enabled": "true",
    "defaultClientScopes": ["email"],
    "redirectUris": ["*"],
    "attributes": {"use.refresh.tokens": "true", "client_credentials.use_refresh_token": "true"}
  }
 '

Keycloak SSO & User management

Identity Providers

You can use keycloak for single-sign so users don't have to login to each application individually.

You can also use external identiity providers such as google or github if required.

See the "Identity Providers" menu in the keycloak UI.


User Federation

You can also use existing LDAP, active directory servers or relational databases for user management if this is required.

Open Source Identity and Access Management

See the "User Federation" menu in the keycloak UI.


Keycloak Authorization services

Authorization Services Guide

Keycloak Quickstarts Code Repository

REST Service Protected Using Keycloak Authorization Services

Easily secure your Spring Boot applications with Keycloak

A Quick Guide to Using Keycloak with Spring Boot

Istio External Authorization

Redhat AUTHORIZATION SERVICES

Sample External Authorization Server with Istio

Working example

  1. To use keycloak authoriztion services start by creating a confidential client.
  2. Set "Authoriztion  Enabled" to on.
  3. Create 2 roles rapp_admin and rapp_user and assigned them to the service account.
  4. Click on the authoriztion tab for the client  to setup your authoriztion policies.
  5. Start by creating 4 scopes (create,edit, delete and view) in the "Authoriztion scopes" section
  6. Next create a resource "Rapp resource", set the URI to /api/resources/* and set the scopes to create,edit, delete and view.
  7. Next create a policy "View Policy", select the "rapp_user" role and set required to on.
  8. Create an "Admin policy", select the "rapp_admin" role and set required to on.
  9. In the permission section, create a "Scope Based" permission -  for resouce choose the "Rapp resource" created earlier, scope should be set to view and select the "View Policy" for policy.
  10. Create another "Scope Based" permission -  for resouce choose the "Rapp resource" created earlier, scope should be set to create, edit and delete and select the "Admin Policy" for policy.


Create a spring-boot application to work with this "resouce server"

The following 4 files are all that is required:

pom.xml

application.properties

MyApplication.java

ApplicationController.java

Use mvn clean package spring-boot:repackage to create the jar file

Use mvn spring-boot:run to run the application from the comand line.

Alternatively you can package the jar into a docker file and run the app as part of your cluster

Dockerfile

rapp-resource-server.yaml

To test use the following script:

test.sh

You should see the following output:

GET request using service account access token
GET resources 1

PUT request using service account access token
PUT resources 1

POST request using service account access token
POST resources id=1

GET request using service account requesting party token
GET resources 1

POST request using service account requesting party token
POST resources id=1

PUT request using service account requesting party token
PUT resources 1


OPA

The Open Policy Agent (OPA) is an open source, general-purpose policy engine that unifies policy enforcement across the stack. OPA provides a high-level declarative language that lets you specify policy as code and simple APIs to offload policy decision-making from your software.

OPA policies are expressed in a high-level declarative language called Rego. Rego is purpose-built for expressing policies over complex hierarchical data structures. 

It even has a VSCode plugin that lets you highlight and evaluate rules and query policies right within the IDE.

Policy-based control for cloud native environments

Introducing Policy As Code: The Open Policy Agent (OPA)

Istio External Authorization with OPA

Rego playground

OPA and Istio Tutorial

Dynamic Policy Composition for OPA

Open Policy Agent: Authorization in a Cloud Native World

OPA On Kubernetes

Kubernetes Admission Control

Microservices Authorization using Open Policy Agent and Traefik (API Gateway)

A Study in Serverless Authorization with Open Policy Agent

OpenFaaS OPA

Godaddy Opa Lambda Extension Plugin

Extending OPA

OPA Ecosystem

GO

Go provides a library for opa.

GO OPA
package main

import (
        "context"
        "encoding/json"
        "fmt"
        "github.com/open-policy-agent/opa/rego"
        "io/ioutil"
        "net/http"
        "net/url"
        "os"
)

type Jwttoken struct {
        Access_token       string
        Expires_in         int
        Refresh_expires_in int
        Refresh_token      string
        Token_type         string
        Not_before_policy  int
        Session_state      string
        Scope              string
}

var token Jwttoken

var opaPolicy string = `
package authz

import future.keywords.in

default allow = false

jwks := jwks_request("http://keycloak:8080/auth/realms/opa/protocol/openid-connect/certs").body
filtered_jwks := [ key |
      some key in jwks.keys
      key.use == "sig"
    ]
token_cert := json.marshal({"keys": filtered_jwks})

token = { "isValid": isValid, "header": header, "payload": payload } {
        [isValid, header, payload] := io.jwt.decode_verify(input, { "cert": token_cert, "aud": "account", "iss": "http://keycloak:808
0/auth/realms/opa"})
}

allow {
    is_token_valid
}

is_token_valid {
        token.isValid
        now := time.now_ns() / 1000000000
        token.payload.iat <= now
        now < token.payload.exp
        token.payload.clientRole == "[opa-client-role]"
}

jwks_request(url) = http.send({
      "url": url,
      "method": "GET",
      "force_cache": true,
      "force_json_decode": true,
      "force_cache_duration_seconds": 3600 # Cache response for an hour
})
`

func getToken() string {
        clientSecret := "63wkv0RUXkp01pbqtNTSwghhTxeMW55I"
        clientId := "opacli"
        realmName := "opa"
        keycloakHost := "keycloak"
        keycloakPort := "8080"
        keycloakUrl := "http://" + keycloakHost + ":" + keycloakPort + "/auth/realms/" + realmName + "/protocol/openid-connect/token"        resp, err := http.PostForm(keycloakUrl,
                url.Values{"client_secret": {clientSecret}, "grant_type": {"client_credentials"}, "client_id": {clientId}})
        if err != nil {
                fmt.Println(err)
                panic("Something wrong with the credentials or url ")
        }
        defer resp.Body.Close()
        body, err := ioutil.ReadAll(resp.Body)
        json.Unmarshal([]byte(body), &token)
        return token.Access_token
}

func traceOpa(input string) {
        ctx := context.TODO()

        test := rego.New(
                rego.Query("x = data.authz.allow"),
                rego.Trace(true),
                rego.Module("example.rego", opaPolicy),
                rego.Input(input),
        )

        test.Eval(ctx)
        rego.PrintTraceWithLocation(os.Stdout, test)
}

func evaluateOpa(input string) {
        ctx := context.TODO()

        query, err := rego.New(
                rego.Query("x = data.authz.allow"),
                rego.Module("example.rego", opaPolicy),
        ).PrepareForEval(ctx)
        if err != nil {
                // Handle error.
                fmt.Println(err.Error())
        }

        results, err := query.Eval(ctx, rego.EvalInput(input))
        // Inspect results.
        if err != nil {
                // Handle evaluation error.
                fmt.Println("Error: " + err.Error())
        } else if len(results) == 0 {
                // Handle undefined result.
                fmt.Println("Results are empty")
        } else {
                // Handle result/decision.
                fmt.Printf("Results = %+v\n", results) //=> [{Expressions:[true] Bindings:map[x:true]}]
        }
  }

func main() {
        tokenStr := getToken()
        traceOpa(tokenStr)
        evaluateOpa(tokenStr)

}                                                                                                    


OPA bundles and dynamic composition

Method 1

We can combined OPA bundles with dynamic composition to provide different policies for differect services.

In the root directory of your bundle create main.rego

main.rego
package main

import input.attributes.request.http as http_request

default allow = false

name := trim_prefix(replace(http_request.path, "-", ""), "/")

router[policy] = data.policies[name][policy].deny

deny[msg] {
    policy := router[_]
    msg := policy[_]
}

allow {
count(deny) == 0
}

This main policy will use the request path to determine which policy to apply. (We remove the forward slash and and "-" characters)

Create a directory policies/<app name> off the main directory.

In here create a policy called policy.rego

policy.rego
package policies.rappopaprovider.policy

import input.attributes.request.http as http_request
import future.keywords.in

realm_name := "opa"
realm_url := sprintf("http://keycloak:8080/auth/realms/%v", [realm_name])
certs_url := sprintf("%v/protocol/openid-connect/certs", [realm_url])


jwks := jwks_request(certs_url).body
filtered_jwks := [ key |
      some key in jwks.keys
      key.use == "sig"
    ]
token_cert := json.marshal({"keys": filtered_jwks})

token = { "isValid": isValid, "header": header, "payload": payload } {
        [_, encoded] := split(http_request.headers.authorization, " ")
        [isValid, header, payload] := io.jwt.decode_verify(encoded, { "cert": token_cert, "aud": "account", "iss": realm_url})
 }

deny[msg] {
    not is_token_valid
    msg = "denied by rappopaprovider.policy: not a valid token"
}

is_token_valid {
  token.isValid
  now := time.now_ns() / 1000000000
  token.payload.iat <= now
  now < token.payload.exp
  token.payload.clientRole == "[opa-client-role]"
}

jwks_request(url) = http.send({
      "url": url,
      "method": "GET",
      "force_cache": true,
      "force_json_decode": true,
      "force_cache_duration_seconds": 3600 # Cache response for an hour
})

This policy will verify the jwt token, check the token issue time and expiration time against the current time and also ensure the token contains the correct role.

If all these condtions are met the user will be granted access to the resource.

NGINX can be used for the bundles server: nginx.yaml

OPA server: opa.yaml

rapp-opa-provider: rapp-opa-provider.yaml

To test retrieve the access token from keycloak and run the curl command for the rapp-opa-provider url

opa_test.sh
#!/bin/bash
INGRESS_HOST=$(minikube ip)
INGRESS_PORT=$(kubectl -n istio-system get service istio-ingressgateway -o jsonpath='{.spec.ports[?(@.name=="http2")].nodePort}')
TESTS=0
PASSED=0
FAILED=0
TEST_TS=$(date +%F-%T)
TOKEN=""
ACCESS_TOKEN=""
REFRESH_TOKEN=""

function get_token
{
    local prefix="${1}"
    url="http://${KEYCLOAK_HOST}:${KEYCLOAK_PORT}/auth/realms"
         TOKEN=$(curl -s -X POST $url/opa/protocol/openid-connect/token -H \
                 "Content-Type: application/x-www-form-urlencoded" -d client_secret=63wkv0RUXkp01pbqtNTSwghhTxeMW55I \
                 -d 'grant_type=client_credentials' -d client_id=opacli)
        ACCESS_TOKEN=$(echo $TOKEN | jq -r '.access_token')
}

function run_test
{
    local prefix="${1}" type=${2} msg="${3}" data=${4}
    TESTS=$((TESTS+1))
    echo "Test ${TESTS}: Testing $type /${prefix}"
    get_token $prefix
    url=$INGRESS_HOST:$INGRESS_PORT"/"$prefix
    result=$(curl -s -X ${type} -H "Content-type: application/json" -H "Authorization: Bearer $ACCESS_TOKEN" $url)
    echo $result
    if [ "$result" != "$msg" ]; then
            echo "FAIL"
            FAILED=$((FAILED+1))
    else
            echo "PASS"
            PASSED=$((PASSED+1))
    fi
    echo ""
}


run_test "rapp-opa-provider" "GET" "Hello OPA World!" ""

echo
echo "-----------------------------------------------------------------------"
echo "Number of Tests: $TESTS, Tests Passed: $PASSED, Tests Failed: $FAILED"
echo "Date: $TEST_TS"
echo "-----------------------------------------------------------------------"

Method 2

We can also organize the policies in the following way.

Create a new file in your bundle to do the common processing:

Common Rules
package policy.common.request

import input.attributes.request.http as http_request
import future.keywords.in

policy_realms := {
    "rappopaprovider": "opa"
}

method = http_request.method
path = input.parsed_path
policy = trim_prefix(replace(http_request.path, "-", ""), "/")

realm_name := policy_realms[policy]
realm_url := sprintf("http://keycloak:8080/auth/realms/%v", [realm_name])
certs_url := sprintf("%v/protocol/openid-connect/certs", [realm_url])

jwks := jwks_request(certs_url).body
filtered_jwks := [ key |
      some key in jwks.keys
      key.use == "sig"
    ]
token_cert := json.marshal({"keys": filtered_jwks})

token = { "isValid": isValid, "header": header, "payload": payload } {
        [_, encoded] := split(http_request.headers.authorization, " ")
        [isValid, header, payload] := io.jwt.decode_verify(encoded, { "cert": token_cert, "aud": "account", "iss": realm_url})
 }

jwks_request(url) = http.send({
      "url": url,
      "method": "GET",
      "force_cache": true,
      "force_json_decode": true,
      "force_cache_duration_seconds": 3600 # Cache response for an hour
})

user = token.payload.sub
clientRole = token.payload.clientRole
audience = token.payload.aud
exp = token.payload.exp
iat = token.payload.iat


Create another rules.rego file for you application e.g. policy/services/rappopaprovider/ingress/rules.rego

Application rules
package policy.services.rappopaprovider.ingress

import data.policy.common.request

allow = true {
request.token.isValid
request.method == "GET"
request.path == [ "rapp-opa-provider" ]
now := time.now_ns() / 1000000000
request.iat <= now
now < request.exp
request.clientRole == "[opa-client-role]"
}


Lastly create the parent rules file that will call the appropiates policy based on the http request path

Main Rules
package policy.ingress

import data.policy.common.request
import data.policy.services

allow = true {
 services[request.policy].ingress.allow
}

To use this set of rules make sure opa is pointing to the parent rules file : "–set=plugins.envoy_ext_authz_grpc.query=data.policy.ingress.allow"

Note If you do not wish to validate the jet you can use this code instead:

token = { "isValid": isValid, "payload": payload } {
authorization_header := input.attributes.request.http.headers.authorization
encoded_token := trim_prefix(authorization_header, "Bearer ")
payload := io.jwt.decode(encoded_token)[1]
isValid := true
}

OPA with prometheus and grafana

Add the following job to your prometheus.yaml file in the scrape_configs section:

- job_name: opa
scrape_interval: 10s
metrics_path: /metrics
static_configs:
- targets:
- opa.default:8181

This will enable metric collection from the opa /metrics endpoint:

The full ist is available here: Open Policy Agent Monitoring

Download the OPA metrics dashboard from grafana and import it into your grafance instance Open Policy Agent Metrics Dashboard

In the instance dropdown, type opa.default:8181 (assuming opa is running in the default namespace and metrics are being served on port 8181)

You should see a dashboard similar to the following:


OPA Profiling and Bench Marking

Policy Performance

Below is a sample file we can use for profiling/benchmarking

rbactest.rego
package rbactest

import data.policy.common.request
import data.policy.services

input =  {
    "attributes": {
      "destination": {
        "address": {
          "socketAddress": {
            "address": "172.17.0.15",
            "portValue": 9000
          }
        },
        "principal": "spiffe://cluster.local/ns/istio-nonrtric/sa/default"
      },
      "metadataContext": {},
      "request": {
        "http": {
          "headers": {
            ":authority": "192.168.49.2:31000",
            ":method": "GET",
            ":path": "/rapp-opa-provider",
            ":scheme": "http",
            "accept": "*/*",
            "authorization": "Bearer eyJhbGciOiJSUzI1NiIsInR5cCIgOiAiSldUIiwia2lkIiA6ICJDamJ4a2FONjRVcUdYNThWU2R3WjBxQTdWRmN1TGdEQWhnUWJTVG55UE9JIn0.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.k_NtngXgWyTPB2z8IArnxqvx3iYP18xc-1fWQoZ0Az2BOK3kfWrdSmIngn_ilwLXrTSdX-n_Tx_o2NLlwQ13RMRXN5zoJaCnU2iSXvel7hjYA_PSDZbv3MW1boqOZmqzuTA5ugRXuVAGQ42k0PIPNWqSm6JujUGfVzB_mrc43I3jXNuHuqwx6miat4NmJo2MCxM_Y1s39ixxREfQIovqFz1ky69IKfz8QcxyFhSsCmydjk4T6HufC3_SJO0XaBKWAoJpdcgdom1kYcIeoGxWWn3lX5E0kQ3eL4TH0F6IfCtjLZwFlzlhtDJItD6ddglJpEsc6rcuLw-06_VyjeqzSg",
            "content-type": "application/json",
            "user-agent": "curl/7.68.0",
          },
          "host": "192.168.49.2:31000",
          "id": "15472195549358141958",
          "method": "GET",
          "path": "/rapp-opa-provider",
          "protocol": "HTTP/1.1",
          "scheme": "http"
        },
        "time": "2022-06-28T07:07:47.099076Z"
      },
      "source": {
        "address": {
          "socketAddress": {
            "address": "172.17.0.4",
            "portValue": 54862
          }
        },
        "principal": "spiffe://cluster.local/ns/istio-system/sa/istio-ingressgateway-service-account"
      }
    },
    "parsed_body": null,
    "parsed_path": [
      "rapp-opa-provider"
    ],
    "parsed_query": {},
    "truncated_body": false,
    "version": {
      "encoding": "protojson",
      "ext_authz": "v3"
    }
  }


default allow = false


allow = true {
 services[request.policy].ingress.allow
}


opa eval --data rbactest.rego --profile --count=100 --format=pretty 'data.rbactest.allow'
false
+--------------------------------+---------+---------+--------------+-------------------+------------------------+
| METRIC | MIN | MAX | MEAN | 90% | 99% |
+--------------------------------+---------+---------+--------------+-------------------+------------------------+
| timer_rego_external_resolve_ns | 300 | 2400 | 461 | 600 | 2382.9999999999914 |
| timer_rego_load_files_ns | 3069300 | 6160300 | 4.024052e+06 | 4.82397e+06 | 6.152662999999996e+06 |
| timer_rego_module_compile_ns | 690400 | 2288700 | 983743 | 1.42366e+06 | 2.2863819999999986e+06 |
| timer_rego_module_parse_ns | 439300 | 1834400 | 613517 | 882270.0000000001 | 1.832610999999999e+06 |
| timer_rego_query_compile_ns | 49500 | 190100 | 68390 | 93410 | 189761.99999999983 |
| timer_rego_query_eval_ns | 25600 | 423300 | 40197 | 42630.00000000001 | 421415.99999999907 |
| timer_rego_query_parse_ns | 44700 | 674500 | 70035 | 81690 | 671625.9999999986 |
+--------------------------------+---------+---------+--------------+-------------------+------------------------+
+--------+--------+----------+---------+-----------+----------+----------+---------------------+
| MIN | MAX | MEAN | 90% | 99% | NUM EVAL | NUM REDO | LOCATION |
+--------+--------+----------+---------+-----------+----------+----------+---------------------+
| 14.1µs | 404µs | 25.251µs | 28.82µs | 402.438µs | 1 | 1 | data.rbactest.allow |
| 9.8µs | 27.8µs | 12.843µs | 16.48µs | 27.756µs | 1 | 1 | rbactest.rego:62 |
+--------+--------+----------+---------+-----------+----------+----------+---------------------+


opa bench --data rbactest.rego 'data.rbactest.allow'
+-------------------------------------------------+------------+
| samples | 22605 |
| ns/op | 47760 |
| B/op | 6269 |
| allocs/op | 112 |
| histogram_timer_rego_external_resolve_ns_75% | 400 |
| histogram_timer_rego_external_resolve_ns_90% | 500 |
| histogram_timer_rego_external_resolve_ns_95% | 500 |
| histogram_timer_rego_external_resolve_ns_99% | 871 |
| histogram_timer_rego_external_resolve_ns_99.9% | 29394 |
| histogram_timer_rego_external_resolve_ns_99.99% | 29800 |
| histogram_timer_rego_external_resolve_ns_count | 22605 |
| histogram_timer_rego_external_resolve_ns_max | 29800 |
| histogram_timer_rego_external_resolve_ns_mean | 434 |
| histogram_timer_rego_external_resolve_ns_median | 400 |
| histogram_timer_rego_external_resolve_ns_min | 200 |
| histogram_timer_rego_external_resolve_ns_stddev | 1045 |
| histogram_timer_rego_query_eval_ns_75% | 31100 |
| histogram_timer_rego_query_eval_ns_90% | 37210 |
| histogram_timer_rego_query_eval_ns_95% | 47160 |
| histogram_timer_rego_query_eval_ns_99% | 91606 |
| histogram_timer_rego_query_eval_ns_99.9% | 630561 |
| histogram_timer_rego_query_eval_ns_99.99% | 631300 |
| histogram_timer_rego_query_eval_ns_count | 22605 |
| histogram_timer_rego_query_eval_ns_max | 631300 |
| histogram_timer_rego_query_eval_ns_mean | 29182 |
| histogram_timer_rego_query_eval_ns_median | 25300 |
| histogram_timer_rego_query_eval_ns_min | 15200 |
| histogram_timer_rego_query_eval_ns_stddev | 32411 |
+-------------------------------------------------+------------+

OPA & Minio

OPA & MinIO's Access Management Plugin

OPA Sidecar injection

First create a namespace for your apps and enable istio and opa 

kubectl create ns opa
kubectl label namespace opa opa-istio-injection="enabled"
kubectl label namespace opa istio-injection="enabled"

Create the opa injection obects using:

kubectl create -f opa_inject.yaml

Ensure your istio mesh config has been setup to include grcp local authorizer

kubectl edit configmap istio -n istio-system

extensionProviders
    extensionProviders:
    - envoyExtAuthzGrpc:
        port: "9191"
        service: local-opa-grpc.local
      name: opa-local



Update your rapp-provider authorization policy to use this provider:





AuthorizationPolicy
apiVersion: security.istio.io/v1beta1
kind: AuthorizationPolicy
metadata:
  name: rapp-opa-provider-opa
  namespace: opa
spec:
  selector:
    matchLabels:
      app: rapp-opa-provider
  action: CUSTOM
  provider:
    name: "opa-local"
  rules:
  - to:
    - operation:
        paths: ["/rapp-opa-provider"]
        notPaths: ["/health"]



Run the opa_test.sh script above and you should see a message confirming your connection to the service.

Note: References to keycloak need to be updated to include the keycloak schema i.e keycloak.default

Basic Authentication

We can add basic authentication to our NGINX bubdle server by following these steps:

Create a password file using the following command:   sudo htpasswd -c .htpasswd <user>, you will be prompted to input the password.

This will produce a file called .htpasswd containing the username and encrypted password

e.g. admin:$apr1$tPQCjrVW$sokcSj4QVkncEDna0Fc2o/

Add the following configmap definitions to your nginx.yaml

configMaps
apiVersion: v1
kind: ConfigMap
metadata:
  name: nginx-pwd-config
  namespace: default
data:
  .htpasswd: |
    admin:$apr1$tPQCjrVW$sokcSj4QVkncEDna0Fc2o/
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: nginx-conf-config
  namespace: default
data:
  default.conf: |
   server {
           server_name localhost;

           location ~ ^/bundles/(.*)$ {
           root /usr/share/nginx/html/bundles;
           try_files /$1 =404;
           auth_basic "Restricted";
           auth_basic_user_file /etc/nginx/conf.d/conf/.htpasswd;
           }
   }
---


Then update your volumes and volume mounts to include these files with your deployment

Volumes
        volumeMounts:
        - name: bundlesdir
          mountPath: /usr/share/nginx/html/bundles
          readOnly: true
        - name: nginx-conf
          mountPath: /etc/nginx/conf.d/default.conf
          subPath: default.conf
        - name: nginx-pwd
          mountPath: /etc/nginx/conf.d/conf/.htpasswd
          subPath: .htpasswd
      volumes:
      - name: bundlesdir
        hostPath:
          # Ensure the file directory is created.
           path: /var/opa/bundles
           type: DirectoryOrCreate
      - name: nginx-conf
        configMap:
          name: nginx-conf-config
          defaultMode: 0644
      - name: nginx-pwd
        configMap:
          name: nginx-pwd-config
          defaultMode: 0644

This will add basic authentication to your bundles directory.

Run echo -n <username>:<password> | base64 to encrpt your usename and password

e.g. echo -n admin:admin | base64
YWRtaW46YWRtaW4=

Update the opa-istio-config ConfigMap in the opa_inject.yaml file to include the encrypted string as a token in the cedentials section:

opa-istio-config
apiVersion: v1
kind: ConfigMap
metadata:
  name: opa-istio-config
  namespace: opa
data:
  config.yaml: |
    plugins:
      envoy_ext_authz_grpc:
        addr: :9191
        path: policy/ingress/allow
    decision_logs:
      console: true
    services:
      - name: bundle-server
        url: http://bundle-server.default
        credentials:
          bearer:
            token: YWRtaW46YWRtaW4=
            scheme: Basic

    bundles:
      authz:
        service: bundle-server
        resource: bundles/opa-bundle.tar.gz
        persist: true
        polling:
          min_delay_seconds: 10
          max_delay_seconds: 20
---

Your bundle is now protected with basic authentication.


JWT Injection

To enable automatic include a jwt token in our rapp request we need to enable some k8s objects:

1) MutatingWebhookConfiguration to inject jwt retrieval pod as a sidecar. The MutatingWebhookConfiguration uses a pod mutating serive to alter our pod and add the new sidecar.

Mutating Webhook
package main

import (
        "encoding/json"
        "errors"
        "flag"
        "fmt"
        "io/ioutil"
        "k8s.io/api/admission/v1beta1"
        v1 "k8s.io/api/core/v1"
        "k8s.io/apimachinery/pkg/runtime"
        "k8s.io/apimachinery/pkg/runtime/serializer"
        "log"
        "net/http"
        "strconv"
)

type ServerParameters struct {
        port     int    // webhook server port
        certFile string // path to the x509 cert
        keyFile  string // path to the x509 private key
}

type patchOperation struct {
        Op    string      `json:"op"`
        Path  string      `json:"path"`
        Value interface{} `json:"value,omitempty"`
}

var parameters ServerParameters
var (
        universalDeserializer = serializer.NewCodecFactory(runtime.NewScheme()).UniversalDeserializer()
)

func main() {
        flag.IntVar(&parameters.port, "port", 8443, "Webhook server port.")
        flag.StringVar(&parameters.certFile, "tlsCertFile", "/certs/tls.crt", "File containing the x509 certificate")
        flag.StringVar(&parameters.keyFile, "tlsKeyFile", "/certs/tls.key", "File containing the x509 private key")
        flag.Parse()

        http.HandleFunc("/inject-sidecar", HandleSideCarInjection)
        log.Fatal(http.ListenAndServeTLS(":"+strconv.Itoa(parameters.port), parameters.certFile, parameters.keyFile, nil))
}

func HandleSideCarInjection(w http.ResponseWriter, r *http.Request) {

        body, err := ioutil.ReadAll(r.Body)
        err = ioutil.WriteFile("/tmp/request", body, 0644)
        if err != nil {
                panic(err.Error())
        }

        var admissionReviewReq v1beta1.AdmissionReview

        if _, _, err := universalDeserializer.Decode(body, nil, &admissionReviewReq); err != nil {
                w.WriteHeader(http.StatusBadRequest)
                fmt.Errorf("Could not deserialize request: %v", err)
        } else if admissionReviewReq.Request == nil {
                w.WriteHeader(http.StatusBadRequest)
                errors.New("Malformed admission review - request is empty")
        }

        fmt.Printf("Received Admission Review Request - Type: %v \t Event: %v \t Name: %v \n",
                admissionReviewReq.Request.Kind,
                admissionReviewReq.Request.Operation,
                admissionReviewReq.Request.Name,
        )

        var pod v1.Pod

        err = json.Unmarshal(admissionReviewReq.Request.Object.Raw, &pod)

        if err != nil {
                fmt.Errorf("Could not unmarshal pod from admission request: %v", err)
        }

        var patches []patchOperation

        labels := pod.ObjectMeta.Labels
        labels["sidecar-injection-webhook"] = "jwt-proxy"

        patches = append(patches, patchOperation{
                Op:    "add",
                Path:  "/metadata/labels",
                Value: labels,
        })

        var containers []v1.Container
        containers = append(containers, pod.Spec.Containers...)
        container := v1.Container{
                Name:            "jwt-proxy",
                Image:           "ktimoney/rapps-jwt",
                ImagePullPolicy: v1.PullIfNotPresent,
                Ports: []v1.ContainerPort{
                        {
                                Name:          "http",
                                Protocol:      v1.ProtocolTCP,
                                ContainerPort: 8888,
                        },
                },
                VolumeMounts: []v1.VolumeMount{
                        {
                                Name:      "certsdir",
                                MountPath: "/certs",
                                ReadOnly:  true,
                        },
                },
        }

        containers = append(containers, container)
        fmt.Println(containers)

        patches = append(patches, patchOperation{
                Op:    "add",
                Path:  "/spec/containers",
                Value: containers,
        })

        pathType := v1.HostPathDirectoryOrCreate
        pathTypePtr := &pathType
        var volumes []v1.Volume
        volumes = append(volumes, pod.Spec.Volumes...)
        volume := v1.Volume{
                Name: "certsdir",
                VolumeSource: v1.VolumeSource{
                        HostPath: &v1.HostPathVolumeSource{
                                Path: "/var/rapps/certs",
                                Type: pathTypePtr,
                        },
                },
        }
        volumes = append(volumes, volume)
        fmt.Println(volumes)

        patches = append(patches, patchOperation{
                Op:    "add",
                Path:  "/spec/volumes",
                Value: volumes,
        })
        fmt.Println(patches)

        patchBytes, err := json.Marshal(patches)

        if err != nil {
                fmt.Errorf("Error occurred when trying to marshal JSON patch: %v", err)
        }

        admissionReviewResponse := v1beta1.AdmissionReview{
                Response: &v1beta1.AdmissionResponse{
                        UID:     admissionReviewReq.Request.UID,
                        Allowed: true,
                },
        }

        admissionReviewResponse.Response.Patch = patchBytes

        bytes, err := json.Marshal(&admissionReviewResponse)
        if err != nil {
                fmt.Errorf("Error occurred when trying to marshal Aadmission Review response: %v", err)
        }

        w.Write(bytes)

}


rapps-webhook.yaml

MutatingWebhookConfiguration.yaml

Note: You'll need to configure your deployment to include a tls.crt and tls.key secret. Your MutatingWebhookConfiguration will need to include the corresponding ca bubdle.

2) Envoyfilter to update request header with jwt token.


Envoy Filter
apiVersion: networking.istio.io/v1alpha3
kind: EnvoyFilter
metadata:
  name: RAPP-NAME-outbound-filter
  namespace: RAPP-NS
spec:
  workloadSelector:
    labels:
      app.kubernetes.io/name: RAPP-NAME
  configPatches:
    # The first patch adds the lua filter to the listener/http connection manager
  - applyTo: HTTP_FILTER
    match:
      context: SIDECAR_OUTBOUND
      listener:
        filterChain:
          filter:
            name: "envoy.filters.network.http_connection_manager"
            subFilter:
              name: "envoy.filters.http.router"
    patch:
      operation: INSERT_BEFORE
      value: # lua filter specification
        name: envoy.lua
        typed_config:
          "@type": "type.googleapis.com/envoy.extensions.filters.http.lua.v3.Lua"
          inlineCode: |
            function envoy_on_request(request_handle)
              local uri = request_handle:headers():get(":path")
              local method = request_handle:headers():get(":method")
              if (method ~= "POST" and path ~= "/auth/realms/REALM-NAME/protocol/openid-connect/token")
              then
               -- Make an HTTP call to an upstream host with the following headers, body, and timeout.
               local headers, body = request_handle:httpCall(
                "jwt_cluster",
                {
                 [":method"] = "GET",
                 [":path"] = "/token",
                 [":authority"] = "jwt-proxy",
                 ["realm"] = "REALM-NAME",
                 ["client"] = "CLIENT-NAME"
                },
               "jwt call",
               5000)
               if (headers["authorization"] ~= nil)
               then
                   request_handle:headers():add("authorization", headers["authorization"])
               end
              end
            end
  - applyTo: CLUSTER
    match:
      context: SIDECAR_OUTBOUND
    patch:
      operation: ADD
      value: # cluster specification
        name: jwt_cluster
        type: STRICT_DNS
        connect_timeout: 60s
        lb_policy: ROUND_ROBIN
        load_assignment:
          cluster_name: jwt_cluster
          endpoints:
          - lb_endpoints:
            - endpoint:
                address:
                  socket_address:
                    address: 0.0.0.0
                    port_value: 8888


CFSSL

CFSSL is CloudFlare's PKI/TLS tool. It is both a command line tool and an HTTP API server for signing, verifying, and bundling TLS certificates. 

To run this you first need to create an image with cfssl installed:

cfssl
FROM debian:latest
RUN apt-get update && apt-get install -y curl && \
curl -L https://github.com/cloudflare/cfssl/releases/download/v1.5.0/cfssl_1.5.0_linux_amd64 -o /usr/local/bin/cfssl && \
curl -L https://github.com/cloudflare/cfssl/releases/download/v1.5.0/cfssljson_1.5.0_linux_amd64 -o /usr/local/bin/cfssljson && \
chmod +x /usr/local/bin/cfssl && \
chmod +x /usr/local/bin/cfssljson
RUN mkdir  /config
RUN mkdir  /config
RUN mkdir  /certs
WORKDIR /certs
EXPOSE 8888
EXPOSE 8889
ENTRYPOINT ["cfssl version"]

This will install cfssl on a debian image.

You can then use this image to create a cfssl service in your k8s cluster.

kubectl create -f rapps-cfssl.yaml

Note: If you want to use this with a postgres db you'll need to setup a new database and username/password and then create the tables.

cfssl create db and user
    SELECT 'CREATE DATABASE cfssl'
    WHERE NOT EXISTS (SELECT FROM pg_database WHERE datname = 'cfssl')\gexec
    DO $$
    BEGIN
      IF NOT EXISTS (SELECT FROM pg_user WHERE  usename = 'cfssl') THEN
         CREATE USER cfssl WITH PASSWORD 'cfssl';
         GRANT ALL PRIVILEGES ON DATABASE cfssl TO cfssl;
      END IF;
    END
    $$;

Login as the cfssl  user then create the tables:

cfssl create tables
      CREATE TABLE IF NOT EXISTS certificates (
       serial_number            bytea NOT NULL,
       authority_key_identifier bytea NOT NULL,
       ca_label                 bytea,
       status                   bytea NOT NULL,
       reason                   int,
       expiry                   timestamptz,
       revoked_at               timestamptz,
       pem                      bytea NOT NULL,
       issued_at                timestamptz,
       not_before               timestamptz,
       metadata                 jsonb,
       sans                     jsonb,
       common_name              TEXT,
      PRIMARY KEY(serial_number, authority_key_identifier)
      );

      CREATE TABLE IF NOT EXISTS ocsp_responses (
       serial_number            bytea NOT NULL,
       authority_key_identifier bytea NOT NULL,
       body                     bytea NOT NULL,
       expiry                   timestamptz,
       PRIMARY KEY(serial_number, authority_key_identifier),
       FOREIGN KEY(serial_number, authority_key_identifier) REFERENCES certificates(serial_number, authority_key_identifier)
       );


Once the pod is up and running you can connect to it by using port forwarding:

kubectl port-forward service/rapps-cfssl 8888:8888

You can generate signed certificates using a post request like the following:

curl -s -X POST -H "Content-Type: application/json" -d @./rapp-helloworld-provider-server.json http://127.0.0.1:8888/api/v1/cfssl/newcert

The rapp-helloworld-provider-server.json  looks like this:

rapp-helloworld-provider-server
{
   "request":{
      "hosts":[
         "rapp-helloworld-provider"
      ],
      "names":[
         {
            "C":"IE",
            "ST":"Ireland",
            "L":"Dublin",
            "O":"EST Rapp Provider",
            "OU":"EST Rapp Provider hosts"
         }
      ],
      "CN":"rapp-helloworld-provider",
      "key":{
         "algo":"rsa",
         "size":2048
      }
   },
   "profile":"server"
}

To parse the response contents you can use the following method:

NEWCERT=$(curl -s -X POST -H "Content-Type: application/json" -d @./rapp-helloworld-provider-server.json http://127.0.0.1:8888/api/v1/cfssl/newcert)

echo $NEWCERT | jq -r .result.certificate

echo $NEWCERT | jq -r .result.private_key

OCSP & CRL 

OCSP and CRL are ways of checking a certificates validity.

The cfssl crl endpoint run on port 8888: 127.0.0.1:8888/api/v1/cfssl/crl

For ocsp to run you need to run the following commands in your container:

cfssl ocsprefresh -db-config /config/db-pg.json -ca /certs/ca-server.pem -responder /certs/server-ocsp.pem -responder-key /certs/server-ocsp-key.pem
 cfssl ocspdump -db-config /config/db-pg.json > ocspdump.txt
 cfssl ocspserve -port=8889 -responses=/config/ocspdump.txt -loglevel=0


These commands will need to be re-run every time a new revoke request is received.

To revoke a certificate use:

curl -d '{ "serial": "708853190752997406197199597002842275021840632879", "authority_key_id": "dd2cdb5b5b8abbe2fba81fd6c04393938f802b03", "reason": "superseded" }' http://localhost:8888/api/v1/cfssl/revoke

You can obtain the serial and authority_key_id from your database using the following SQL:

select encode(authority_key_identifier,'escape') a_key, encode(serial_number,'escape') serial, encode(status,'escape') status from certificates;

You can also obtain the serial and authority_key_id from the certinfo endpoint

  1. Convert your certificate into a variable: pem=$(cat my.crt | sed -z 's/\n/\\n/g')
  2. curl -d '{"certificate": "'"$pem"'"}' http://localhost:8888/api/v1/cfssl/certinfo
  3. The serial number will come back as is but the authority_key_id needs to be converted: echo "22:8B:FA:ED:8B:FF:66:E7:05:A3:08:3A:41:33:D8:01:20:CA:CC:F4"| tr '[:upper:]' '[:lower:]' | sed s'/://'g =228bfaed8bff66e705a3083a4133d80120caccf4

You can check your certificate against ocsp and crl using the following code:

Verifyc Certificate
package main

import (
        "bytes"
        "context"
        "crypto"
        "crypto/x509"
        "crypto/x509/pkix"
        "encoding/json"
        "encoding/pem"
        "flag"
        "fmt"
        "golang.org/x/crypto/ocsp"
        "io/ioutil"
        "log"
        "net/http"
        "net/url"
        "os"
        "time"
)

type Cfinfo struct {
        Success string `json:"success,omitempty"`
        Result  struct {
                Certificate string   `json:"certificate"`
                Usages      []string `json:"usages"`
                Expiry      string   `json:"expiry"`
        }
        Errors   []string `json:"errors"`
        Messages []string `json:"messages"`
}

var cfinfo Cfinfo

type Crlinfo struct {
        Success  bool     `json:"success,omitempty"`
        Result   string   `json:"result,omitempty"`
        Errors   []string `json:"errors"`
        Messages []string `json:"messages"`
}

var crlinfo Crlinfo

type ServerParameters struct {
        certFile  string // path to the x509 cert
        issuerUrl string // webhook server port
        crlUrl    string // webhook server port
}

var parameters ServerParameters

func main() {
        flag.StringVar(¶meters.certFile, "certFile", "", "File containing the x509 certificate")
        flag.StringVar(¶meters.issuerUrl, "issuerUrl", "http://127.0.0.1:8888/api/v1/cfssl/info", "Url for retrieving the issuer certificate")
        flag.StringVar(¶meters.crlUrl, "crlUrl", "http://127.0.0.1:8888/api/v1/cfssl/crl", "Url for retrieving the crl")
        flag.Parse()
        if parameters.certFile == "" {
                flag.Usage()
                os.Exit(1)
        }
        // read x509 certificate from PEM encoded file
        cert_bytes := readFile(parameters.certFile)
        cert, err := decodeCert(cert_bytes)
        if err != nil {
                log.Fatal(err)
        }

        issuer_bytes, err := getIssuer(parameters.issuerUrl) //readCert(os.Args[2])
        if err != nil {
                log.Fatal(err)
        }

        issuer, err := decodeCert(issuer_bytes)
        if err != nil {
                log.Fatal(err)
        }

        // Perform OCSP Check
        fmt.Println("Checing OCSP")
        status, err := checkOCSPStatus(cert, issuer)
        if err != nil {
                fmt.Println(err)
        } else {
                switch status {
                case ocsp.Good:
                        fmt.Printf("[+] Certificate status is Good\n")
                case ocsp.Revoked:
                        fmt.Printf("[-] Certificate status is Revoked\n")
                case ocsp.Unknown:
                        fmt.Printf("[-] Certificate status is Unknown\n")
                }

        crl_bytes, err := getCrl(parameters.crlUrl) //readCert(os.Args[2])
        if err != nil {
                log.Fatal(err)
        }

        crl, err := decodeCrl(crl_bytes)
        if err != nil {
                log.Fatal(err)
        }

        fmt.Println("\nChecing CRL")
        _, err = checkCRLStatus(cert, issuer, crl)
        if err != nil {
                log.Fatal(err)
        }else{
                fmt.Println("[+] Certificate status is not Revoked\n")
        }
}
func checkCRLStatus(cert *x509.Certificate, issuer *x509.Certificate, crl *pkix.CertificateList) (bool, error) {
        var revoked = false
        // Check CRL signature
        err := issuer.CheckCRLSignature(crl)
        if err != nil {
                return revoked, err
        }

        // Check CRL validity
        if crl.TBSCertList.NextUpdate.Before(time.Now()) {
                return revoked, fmt.Errorf("CRL is outdated")
        }
         
        // Searching for our certificate in CRL
        for _, revokedCertificate := range crl.TBSCertList.RevokedCertificates {
                if revokedCertificate.SerialNumber.Cmp(cert.SerialNumber) == 0 {
                        //Found validated certificate in list of revoked ones
                        revoked = true
                        return revoked, fmt.Errorf("[-] Certificate status is Revoked\n")
                }
        }

        return revoked, nil
}

// CheckOCSPStatus will make an OCSP request for the provided certificate.
// If the status of the certificate is not good, then an error is returned.
func checkOCSPStatus(cert *x509.Certificate, issuer *x509.Certificate) (int, error) {
        var (
                ctx     = context.Background()
                ocspURL = cert.OCSPServer[0]
        )

        // Build OCSP request
        buffer, err := ocsp.CreateRequest(cert, issuer, &ocsp.RequestOptions{
                Hash: crypto.SHA256,
        })
        if err != nil {
                return ocsp.Unknown, fmt.Errorf("creating ocsp request body: %w", err)
        }

        req, err := http.NewRequest(http.MethodPost, ocspURL, bytes.NewBuffer(buffer))
        if err != nil {
                return ocsp.Unknown, fmt.Errorf("creating http request: %w", err)
        }

        ocspUrl, err := url.Parse(ocspURL)
        if err != nil {
                return ocsp.Unknown, fmt.Errorf("parsing ocsp url: %w", err)
        }

        req.Header.Add("Content-Type", "application/ocsp-request")
        req.Header.Add("Accept", "application/ocsp-response")
        req.Header.Add("host", ocspUrl.Host)
        req = req.WithContext(ctx)

        // Make OCSP request
        httpResponse, err := http.DefaultClient.Do(req)
        if err != nil {
                return ocsp.Unknown, fmt.Errorf("making ocsp request: %w", err)
        }

        defer httpResponse.Body.Close()

        output, err := ioutil.ReadAll(httpResponse.Body)
        if err != nil {
                return ocsp.Unknown, fmt.Errorf("reading response body: %w", err)
        }

        // Parse response
        ocspResponse, err := ocsp.ParseResponse(output, issuer)
        if err != nil {
                return ocsp.Unknown, fmt.Errorf("parsing ocsp response: %w", err)
        }
        return ocspResponse.Status, nil
}

func readFile(file string) []byte {
        cert, err := ioutil.ReadFile(file)
        if err != nil {
                log.Fatalln(err)
        }
        return cert
}

func decodeCert(cert_bytes []byte) (*x509.Certificate, error) {
        b, _ := pem.Decode(cert_bytes)
        var cert *x509.Certificate

        cert, err := x509.ParseCertificate(b.Bytes)
        if err != nil {
                fmt.Println("Parse Error")
                return nil, fmt.Errorf("parsing certificate: %w", err)
        }

        return cert, err
}
func decodeCrl(cert_bytes []byte) (*pkix.CertificateList, error) {
        b, _ := pem.Decode(cert_bytes)

        crl, err := x509.ParseCRL(b.Bytes)
        if err != nil {
                return nil, fmt.Errorf("parsing crl: %w", err)
        }
        return crl, err
}

func getIssuer(issuerUrl string) ([]byte, error) {
        var resp = &http.Response{}
        values := map[string]string{"label": "intermediate"}
        jsonValue, _ := json.Marshal(values)
        resp, err := http.Post(issuerUrl, "application/json", bytes.NewBuffer(jsonValue))
        if err != nil {
                fmt.Println(err)
                panic("Something wrong with the post request")
        }

        defer resp.Body.Close()
        body, err := ioutil.ReadAll(resp.Body)
        json.Unmarshal([]byte(body), &cfinfo)
        return []byte(cfinfo.Result.Certificate), nil
}

func getCrl(crlUrl string) ([]byte, error) {
        resp, err := http.Get(crlUrl)
        if err != nil {
                return nil, err
        }
        defer resp.Body.Close()

        if resp.StatusCode >= 300 {
                return nil, fmt.Errorf("failed to retrieve CRL")
        }

        body, err := ioutil.ReadAll(resp.Body)
        json.Unmarshal([]byte(body), &crlinfo)
        crlString := "-----BEGIN X509 CRL-----\n" + crlinfo.Result + "\n-----END X509 CRL-----"

        return []byte(crlString), err
}                                                            
                                                                                                                                                                                                                                                                                                                                             


Kafka

Strimzi

You can install strimzi kafka using the quick start guide: Strimzi Quickstarts

You'll need to overwrite the kafka cluster with your own definition: my-cluster.yaml

This file includes an authorization section:

opa
      authorization:
        type: opa
        url: http://opa.default:8181/v1/data/policy/kafka/authz/allow
        allowOnError: false
        initialCacheCapacity: 1000
        maximumCacheSize: 10000
        expireAfterMs: 10 #60000
        superUsers:
          - CN=henri
          - anwar
          - CN=wesley
          - CN=my-user

This file includes an listeners section:

listeners
      listeners:
      - name: plain
        port: 9092
        tls: false
        type: internal
      - name: tls
        port: 9093
        tls: true
        type: internal
      - name: plain3
        port: 9097
        tls: false
        type: internal
        authentication:
          type: oauth
          checkIssuer: false
          checkAccessTokenType: true
          accessTokenIsJwt: true
          enableOauthBearer: true
          introspectionEndpointUri: http://keycloak.default:8080/auth/realms/opa/protocol/openid-connect/token/introspect
          clientId: opacli
          clientSecret:
            secretName: my-cluster-oauth
            key: clientSecret
          validIssuerUri: http://keycloak.default:8080/auth/realms/opa
          clientAudience: account
          customClaimCheck: "@.resource_access['opacli'].roles[0] == 'opa-client-role'"

Where opa and keycloak are configured.

If you are publishing or subscribing using this listener you will need to provide a JWT with your request.

The token will be verified using keycloak along with the audience field and the resource access['opaclii'].roles field.

Kafka will then pass the authorizaton on to opa where other checks will take place.

Below is a sample opa policy you might use to check the kafka input:

opa rules
package policy.kafka.authz 

default allow = false

allow = true {
    allowedActions :=  ["DESCRIBE", "DESCRIBE_CONFIGS", "READ"]
    input.action.operation == allowedActions[_]
    input.requestContext.header.name.clientId == "kowl" 
}

allow = true {
    allowedActions :=  ["DESCRIBE", "DESCRIBE_CONFIGS"]
    allowedTopics :=  ["__consumer_offsets","__strimzi_store_topic", "__strimzi-topic-operator-kstreams-topic-store-changelog",]
    input.action.resourcePattern.name == allowedTopics[_]
}

allow = true {
    allowedActions :=  ["DESCRIBE", "READ"]
    input.action.operation == allowedActions[_]
    allowedResourceTypes := ["GROUP"]
    input.action.resourcePattern.resourceType == allowedResourceTypes[_]
    input.requestContext.principal.name == "service-account-opacli"  
}

allow = true {
    input.action.operation == "CREATE"
    input.action.resourcePattern.name == "kafka-cluster"
    input.action.resourcePattern.resourceType == "CLUSTER"   
    input.requestContext.principal.name == "service-account-opacli"
    input.requestContext.header.name.clientId == "consumer-client"
}


allow = true {
    allowedActions :=  ["DESCRIBE","READ"]
    input.action.operation == allowedActions[_]
    input.action.resourcePattern.name == "my-topic"
    input.action.resourcePattern.resourceType == "TOPIC"   
    input.requestContext.principal.name == "service-account-opacli"
    input.requestContext.header.name.clientId == "consumer-client"  
}


allow = true {
    allowedActions :=  ["DESCRIBE","WRITE"]
    input.action.operation == allowedActions[_]
    input.action.resourcePattern.name == "my-topic"
    input.action.resourcePattern.resourceType == "TOPIC"   
    input.requestContext.principal.name == "service-account-opacli"
    input.requestContext.header.name.clientId == "producer-client"
}

The default value of the sub field (principal name) in keycloak is the user id, this can be changed to the user name using a property mapper:

kube-mgmt

By default the entire policy and data cache are defined by the opa bundle.

If you need to add data from other sources you need to define the bundle root directories in the .manifest file

e.g.

manifest
{
  "revision" : "1",
  "roots": ["policy", "roles"]
}

You can then add the kube-mgmt sidecar to your opa deployment and this will pull data from configmaps in the namespace speciiied

e.g.

        - name: kube-mgmt
          image: openpolicyagent/kube-mgmt:latest
          args:
            - "--namespaces=opa"
hello-data.yaml
kind: ConfigMap
apiVersion: v1
metadata:
  name: hello-data
  namespace: opa
  labels:
    openpolicyagent.org/data: opa
data:
  x.json: |
    {"a": [1,2,3,4]}
token.json
    {
      "access_token": "eyJhbGciOiJSUzI1NiIsInR5cCIgOiAiSldUIiwia2lkIiA6ICJDamJ4a2FONjRVcUdYNThWU2R3WjBxQTdWRmN1TGdEQWhnUWJTVG55UE9JIn0.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.B0X0zhAintHAXAtjiOngzTM0Wdv_aWM8qdyF4MXEZmE6AxoaMpaNQ6B18k1pkMz60qmTUUcYJOm-xHAdipnxptAf44_YmaybVE9_otjO59RBLonUlFtWDnNV4EqixLDaXN33Z54S1iWCPjBvI58sH_jQyMiXM7ur1FfjCCEeQwP2D9CgWY_3-Vg4Wy4cMAbsxOhZZog-QmKV8nkeyELqUS24xk_vpPkYOdG1ztc5SxHnLLsT4iwXgzYjAveiXyKyyYOC0oJP5zgCYEkQCvRORmuU0whN_5g4oTSIFcqN88KsrYb-R0I2RS7mQI8LXHrNIqMlNN2j5PoHZmgvMrpO3w"
    }

You can also add extra data using curl e.g. curl -X PUT $host:31182/v1/data/jwt -d @token.json

You can view all the data available to opa using curl: curl <opa host>:<port>/v1/data

You should see something similar to the following output:

opa data
{
   "decision_id":"067f7d2d-0e5d-4ca8-8cb0-6d38543c6b2f",
   "result":{
      "jwt":{      "access_token":"eyJhbGciOiJSUzI1NiIsInR5cCIgOiAiSldUIiwia2lkIiA6ICJDamJ4a2FONjRVcUdYNThWU2R3WjBxQTdWRmN1TGdEQWhnUWJTVG55UE9JIn0.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.B0X0zhAintHAXAtjiOngzTM0Wdv_aWM8qdyF4MXEZmE6AxoaMpaNQ6B18k1pkMz60qmTUUcYJOm-xHAdipnxptAf44_YmaybVE9_otjO59RBLonUlFtWDnNV4EqixLDaXN33Z54S1iWCPjBvI58sH_jQyMiXM7ur1FfjCCEeQwP2D9CgWY_3-Vg4Wy4cMAbsxOhZZog-QmKV8nkeyELqUS24xk_vpPkYOdG1ztc5SxHnLLsT4iwXgzYjAveiXyKyyYOC0oJP5zgCYEkQCvRORmuU0whN_5g4oTSIFcqN88KsrYb-R0I2RS7mQI8LXHrNIqMlNN2j5PoHZmgvMrpO3w"
      },
      "opa":{
         "hello-data":{
            "x.json":{
               "a":[
                  1,
                  2,
                  3,
                  4
               ]
            }
         }
      },
      "servers":{
         "id":"s1",
         "name":"app",
         "ports":[
            "p1",
            "p2",
            "p3"
         ],
         "protocols":[
            "https",
            "ssh"
         ]
      }
   }
}

You can get individual values like this: curl <opa host>:<port>/v1/data/jwt/access_token or refer to them in your code like this: data.opa["hello-data"]["x.json"].a[0]

Strimzi Bridge

You can communicate with kafka over http by adding strimzi bridge:

Strimzi Bridge
apiVersion: kafka.strimzi.io/v1beta2
kind: KafkaBridge
metadata:
  name: strimzi-bridge
  namespace: kafka
spec:
  replicas: 1
  bootstrapServers: my-cluster-kafka-bootstrap:9092
  http:
    port: 8080



See also:

Using Open Policy Agent with Strimzi and Apache Kafka

Using Strimzi

kube-mgmt

Styra opa-kafka-plugin

Secure Kafka with Keycloak: SASL OAuth Bearer

Enforce Custom Resource policies with Open Policy Agent Gatekeeper

How to integrate Kafka with Istio

Example with JWT payload passed from Envoy

Kafka Broker filter

Kafka mesh filter in Envoy

Kafka authentication using OAuth 2.0

A deep dive into Strimzi

Using HTTP Bridge as a Kubernetes sidecar

Kafka SSL : Setup with self signed certificate

Kafka & Istio

Integration of Istio with Kafka is limited.

The Kafka Protocol is a TCP level protocol (Layer 4)

Kafka is a binary wrapper over TCP protocol.

Istio mainly supports HTTP/HTTPS on layer 7. 

Higher level protocols such as HTTP have access to metadata so they can properly route requests, this is not the case with the Kafka protocol.

Service Mesh and Proxies: Examples for Kafka


Setting up Strimzi bridge with Istio Authorization and ACLs



The Kiali screenshot above represents both  a producer and a consumer connecting to Kafka through the Strmzi bridge.

Access to the bridge is controlled using JWT which is checked using an Istio AuthorizationPolicy.

AuthorizationPolicy
apiVersion: "security.istio.io/v1beta1"
kind: "AuthorizationPolicy"
metadata:
  name: "kafka-bridge-policy"
  namespace: kafka
spec:
  selector:
    matchLabels:
      app.kubernetes.io/name: kafka-bridge
  action: ALLOW
  rules:
  - from:
    - source:
        requestPrincipals: ["http://keycloak.default:8080/auth/realms/opa", "http://istio-ingressgateway.istio-system:80/auth/realms/opa"]
  - to:
    - operation:
        methods: ["POST", "GET"]
        paths: ["/topics", "/topics/*", "/consumers/*"]
    when:
    - key: request.auth.claims[clientRole]
      values: ["opa-client-role"]


By enabling tls on one of our bootstrap listeners user certificates are automatically created when we create a new KafkaUser

      - name: tlsauth
        type: internal
        port: 9096
        tls: true
        authentication:
          type: tls

Setting the authentication type to tls also ensure secure communication between Kafka and zookeeper.

We also set authorization to simple for the Kafka cluster, this means ACLs will be used.

     kafka:
      authorization:
        type: simple
        superUsers:
          - CN=kowl

Any users you want to by-pass ACL checks should be listed under superUsers.

We can then setup our bridge user and include the ACL permissions as part of the KafkaUser definition:

KafkaUser
apiVersion: kafka.strimzi.io/v1beta1
kind: KafkaUser
metadata:
  name: bridge
  namespace: kafka
  labels:
    strimzi.io/cluster: my-cluster
spec:
  authentication:
    type: tls
  authorization:
    type: simple
    acls:
      # access to the topic
      - resource:
          type: topic
          name: my-topic
        operations:
          - Create
          - Describe
          - Read
          - Write
          - AlterConfigs
        host: "*"
      # access to the group
      - resource:
          type: group
          name: my-group
        operations:
          - Describe
          - Read
        host: "*"
      # access to the cluster
      - resource:
          type: cluster
        operations:
          - Alter
          - AlterConfigs
        host: "*"


Authorization between the bridge and Kafka is done using user certificates.


KafkaBridge
apiVersion: kafka.strimzi.io/v1beta2
kind: KafkaBridge
metadata:
  name: strimzi-bridge
  namespace: kafka
spec:
  replicas: 1
  bootstrapServers: my-cluster-kafka-bootstrap:9096
  http:
    port: 8080
  logging:
    type: inline
    loggers:
      logger.bridge.level: "DEBUG"
      logger.send.name: "http.openapi.operation.send"
      logger.send.level: "DEBUG"
  tls:
    trustedCertificates:
      - secretName: my-cluster-cluster-ca-cert
        certificate: ca.crt
  authentication:
    type: tls
    certificateAndKey:
      secretName: bridge
      certificate: user.crt
      key: user.key


Records can then to be posted to a topic with a call like this:

Endpoint:

http://istio-ingressgateway.istio-system:80/topics/my-topic

Payload: {"records":[{"key":"key-366","value":"value-366"}]}

and read from a topic using the following syntax:

i) Create a consumer group

Endpoint: http://istio-ingressgateway.istio-system:80/consumers/my-group

Payload: {"name":"my-consumer","format":"json","auto.offset.reset":"earliest","enable.auto.commit":false}

ii) subscribe to a topic

Endpoint: http://istio-ingressgateway.istio-system:80/consumers/my-group/instances/my-consumer/subscription

Payload: {"topics":["my-topic"]}

iii) Read records from a topic

Endpoint: http://istio-ingressgateway.istio-system:80/consumers/my-group/instances/my-consumer/records


These calls will be redirected to the bridge using a gateway and a virtual service

Gateway/VirtualService
apiVersion: networking.istio.io/v1beta1
kind: Gateway
metadata:
  name: strimzi-bridge-gateway
  namespace: kafka
spec:
  selector:
    istio: ingressgateway # use Istio gateway implementation
  servers:
  - port:
      number: 80
      name: http
      protocol: HTTP
    hosts:
    - "*"
---
apiVersion: networking.istio.io/v1beta1
kind: VirtualService
metadata:
  name: strimzi-bridge-vs
  namespace: kafka
spec:
  hosts:
  - "*"
  gateways:
  - strimzi-bridge-gateway
  http:
  - name: "strimzi-bridge-routes"
    match:
    - uri:
        prefix: "/topics"
    - uri:
        prefix: "/consumers"
    route:
    - destination:
        port:
          number: 8080
        host: strimzi-bridge-bridge-service.kafka.svc.cluster.local


Note: To use Kowl with this setup you'll need to create a kowl user and configure kowl to use tls

Kowl
apiVersion: kafka.strimzi.io/v1beta1
kind: KafkaUser
metadata:
  name: kowl
  namespace: kafka
  labels:
    strimzi.io/cluster: my-cluster
spec:
  authentication:
    type: tls


Kowl configmap
apiVersion: v1
kind: ConfigMap
metadata:
  name: kowl-config-cm
  namespace: kafka
data:
  config.yaml: |
    kafka:
      brokers:
        - my-cluster-kafka-0.my-cluster-kafka-brokers.kafka.svc:9093
      tls:
        enabled: true
        caFilepath: /etc/strimzi/ca/ca.crt
        certFilepath: /etc/strimzi/user-crt/crt/user.crt
        keyFilepath: /etc/strimzi/user-key/key/user.key


  • ca.crt is obtained from the my-cluster-cluster-ca-cert secret, user.crt and user.key are obtained from the kowl secret.


Admission Controllers

An admission controller is a piece of code that intercepts requests to the Kubernetes API server prior to persistence of the object, but after the request is authenticated and authorized.

Admission Controllers Reference

Kyverno

https://kyverno.io/

Opa Gatekeeper

Open-policy-agent Gatekeeper

OPA Gatekeeper: Policy and Governance for Kubernetes