Transport Encryption for Knative Eventing

Transport Encryption for Knative Eventing

Flag name: transport-encryption

Stage: Beta, disabled by default

Tracking issue: #5957

Overview

By default, event delivery within the cluster is unencrypted. This limits the types of events which can be transmitted to those of low compliance value (or a relaxed compliance posture) or, alternatively, forces administrators to use a service mesh or encrypted CNI to encrypt the traffic, which poses many challenges to Knative Eventing adopters.

Knative Brokers and Channels provides HTTPS endpoints to receive events. Given that these endpoints typically do not have public DNS names (e.g. svc.cluster.local or the like), these need to be signed by a non-public CA (cluster or organization specific CA).

Event producers are be able to connect to HTTPS endpoints with cluster-internal CA certificates.

Prerequisites

In order to enable the transport encryption feature, you will need to install cert-manager operator by following the cert-manager operator installation instructions.
Eventing installation

Installation

Setup `SelfSigned` `ClusterIssuer`

Note

ClusterIssuers, are Kubernetes resources that represent certificate authorities (CAs) that are able to generate signed certificates by honoring certificate signing requests. All cert-manager certificates require a referenced issuer that is in a ready condition to attempt to honor the request. Reference: cert-manager.io/docs/concepts/issuer/

Important

For the simplicity of this guide, we will use a SelfSigned issuer as root certificate, however, be aware of the implications and limitations as documented at cert-manager.io/docs/configuration/selfsigned/ of this method. If you’re running your company specific Private Key Infrastructure (PKI), we recommend the CA issuer. Refer to the cert-manager documentation for more details: cert-manager.io/docs/configuration/ca/, however, you can use any other issuer that is usable for cluster-local services.

Create a SelfSigned ClusterIssuer:

apiVersion: cert-manager.io/v1
kind: ClusterIssuer
metadata:
  name: knative-eventing-selfsigned-issuer
spec:
  selfSigned: {}

Apply the ClusterIssuer resource:
```
$ kubectl apply -f <filename>
```

Create a root certificate using the previously created SelfSigned ClusterIssuer:

apiVersion: cert-manager.io/v1
kind: Certificate
metadata:
  name: knative-eventing-selfsigned-ca
  namespace: cert-manager # the cert-manager operator namespace
spec:
   # Secret name later used for the ClusterIssuer for Eventing
  secretName: knative-eventing-ca
  isCA: true
  commonName: selfsigned-ca
  privateKey:
    algorithm: ECDSA
    size: 256
  issuerRef:
    name: knative-eventing-selfsigned-issuer
    kind: ClusterIssuer
    group: cert-manager.io

Apply the Certificate resource:
```
$ kubectl apply -f <filename>
```

Setup `ClusterIssuer` for Eventing

Create the knative-eventing-ca-issuer ClusterIssuer for Eventing:

# This is the issuer that every Eventing component use to issue their server's certs.
apiVersion: cert-manager.io/v1
kind: ClusterIssuer
metadata:
  name: knative-eventing-ca-issuer
spec:
  ca:
    # Secret name in the Cert-Manager Operator namespace (cert-manager by default) containing
    # the certificate that can then be used by Knative Eventing components for new certificates.
    secretName: knative-eventing-ca

!!! important The name of the ClusterIssuer must be knative-eventing-ca-issuer.

Apply the ClusterIssuer resource:
```
$ kubectl apply -f <filename>
```

Install the certificates for Eventing components

Eventing components use cert-manager issuers and certificates to provision TLS certificates and in the release assets, we release the certificates for Eventing servers that can be customized as necessary.

Install certificates, run the following command:

kubectl apply -f https://github.com/knative/eventing/releases/download/knative-v1.16.0/eventing-tls-networking.yaml

[Optional] If you’re using Eventing Kafka components, install certificates for Kafka components by running the following command:

kubectl apply -f https://github.com/knative-extensions/eventing-kafka-broker/releases/download/knative-v1.16.0/eventing-kafka-tls-networking.yaml

Verify issuers and certificates are ready

kubectl get certificates.cert-manager.io -n knative-eventing

Example output:

NAME                           READY   SECRET                         AGE
imc-dispatcher-server-tls      True    imc-dispatcher-server-tls      14s
mt-broker-filter-server-tls    True    mt-broker-filter-server-tls    14s
mt-broker-ingress-server-tls   True    mt-broker-ingress-server-tls   14s
selfsigned-ca                  True    eventing-ca                    14s
...

Transport Encryption configuration

The transport-encryption feature flag is an enum configuration that configures how Addressables ( Broker, Channel, Sink) should accept events.

The possible values for transport-encryption are:

disabled (this is equivalent to the current behavior)
- Addressables may accept events to HTTPS endpoints
- Producers may send events to HTTPS endpoints
permissive
- Addressables should accept events on both HTTP and HTTPS endpoints
- Addressables should advertise both HTTP and HTTPS endpoints
- Producers should prefer sending events to HTTPS endpoints, if available
strict
- Addressables must not accept events to non-HTTPS endpoints
- Addressables must only advertise HTTPS endpoints

Important

The strict is only enforced on the Broker and Channel receiver/ingress. When a broker or channel sends events to a subscriber, if that subscriber only has an HTTP address, the broker or channel can still send events over HTTP instead of HTTPS

For example, to enable strict transport encryption, the config-features ConfigMap will look like the following:

apiVersion: v1
kind: ConfigMap
metadata:
  name: config-features
  namespace: knative-eventing
data:
  transport-encryption: "strict"

Configure additional CA trust bundles

By default, Eventing clients trusts the system root CA (public CA).

If you need to add additional CA bundles for Eventing, you can do so by creating ConfigMaps in the knative-eventing namespace with label networking.knative.dev/trust-bundle: true:

Important

Whenever CA bundles ConfigMaps are updated, the Eventing clients will automatically add them to their trusted CA bundles when a new connection is established.

Create a CA bundle for Eventing:

kind: ConfigMap
metadata:
  name: my-org-eventing-bundle
  namespace: knative-eventing
  labels:
    networking.knative.dev/trust-bundle: "true"
# All data keys containing valid PEM-encoded CA bundles will be trusted by Eventing clients.
data:
  ca.crt: ...
  ca1.crt: ...
  tls.crt: ...

Important

Use a name that is unlikely to conflict with existing or future Eventing-provided ConfigMap name.

For distributing CA trust bundles, you can leverage trust-manager, however, it is not required.

Trusting CA for a specific event sender

Event sources, triggers or subscriptions are considered event senders, and they can be configured to trust specific CA certificates.

Important

The CA certs must be PEM formatted certificates. Since it’s a multi-line YAML string make sure that the CACerts value is indented correctly, otherwise when creating the resource it will be rejected.

Triggers and subscriptions can be configured as follows:

spec:
  # ...
  subscriber:
    uri: https://mycorp-internal-example.com/v1/api
    CACerts: |-
      -----BEGIN CERTIFICATE-----
      MIIFWjCCA0KgAwIBAgIQT9Irj/VkyDOeTzRYZiNwYDANBgkqhkiG9w0BAQsFADBH
      MQswCQYDVQQGEwJDTjERMA8GA1UECgwIVW5pVHJ1c3QxJTAjBgNVBAMMHFVDQSBF
      eHRlbmRlZCBWYWxpZGF0aW9uIFJvb3QwHhcNMTUwMzEzMDAwMDAwWhcNMzgxMjMx
      MDAwMDAwWjBHMQswCQYDVQQGEwJDTjERMA8GA1UECgwIVW5pVHJ1c3QxJTAjBgNV
      BAMMHFVDQSBFeHRlbmRlZCBWYWxpZGF0aW9uIFJvb3QwggIiMA0GCSqGSIb3DQEB
      AQUAA4ICDwAwggIKAoICAQCpCQcoEwKwmeBkqh5DFnpzsZGgdT6o+uM4AHrsiWog
      D4vFsJszA1qGxliG1cGFu0/GnEBNyr7uaZa4rYEwmnySBesFK5pI0Lh2PpbIILvS
      sPGP2KxFRv+qZ2C0d35qHzwaUnoEPQc8hQ2E0B92CvdqFN9y4zR8V05WAT558aop
      O2z6+I9tTcg1367r3CTueUWnhbYFiN6IXSV8l2RnCdm/WhUFhvMJHuxYMjMR83dk
      sHYf5BA1FxvyDrFspCqjc/wJHx4yGVMR59mzLC52LqGj3n5qiAno8geK+LLNEOfi
      c0CTuwjRP+H8C5SzJe98ptfRr5//lpr1kXuYC3fUfugH0mK1lTnj8/FtDw5lhIpj
      VMWAtuCeS31HJqcBCF3RiJ7XwzJE+oJKCmhUfzhTA8ykADNkUVkLo4KRel7sFsLz
      KuZi2irbWWIQJUoqgQtHB0MGcIfS+pMRKXpITeuUx3BNr2fVUbGAIAEBtHoIppB/
      TuDvB0GHr2qlXov7z1CymlSvw4m6WC31MJixNnI5fkkE/SmnTHnkBVfblLkWU41G
      sx2VYVdWf6/wFlthWG82UBEL2KwrlRYaDh8IzTY0ZRBiZtWAXxQgXy0MoHgKaNYs
      1+lvK9JKBZP8nm9rZ/+I8U6laUpSNwXqxhaN0sSZ0YIrO7o1dfdRUVjzyAfd5LQD
      fwIDAQABo0IwQDAdBgNVHQ4EFgQU2XQ65DA9DfcS3H5aBZ8eNJr34RQwDwYDVR0T
      AQH/BAUwAwEB/zAOBgNVHQ8BAf8EBAMCAYYwDQYJKoZIhvcNAQELBQADggIBADaN
      l8xCFWQpN5smLNb7rhVpLGsaGvdftvkHTFnq88nIua7Mui563MD1sC3AO6+fcAUR
      ap8lTwEpcOPlDOHqWnzcSbvBHiqB9RZLcpHIojG5qtr8nR/zXUACE/xOHAbKsxSQ
      VBcZEhrxH9cMaVr2cXj0lH2RC47skFSOvG+hTKv8dGT9cZr4QQehzZHkPJrgmzI5
      c6sq1WnIeJEmMX3ixzDx/BR4dxIOE/TdFpS/S2d7cFOFyrC78zhNLJA5wA3CXWvp
      4uXViI3WLL+rG761KIcSF3Ru/H38j9CHJrAb+7lsq+KePRXBOy5nAliRn+/4Qh8s
      t2j1da3Ptfb/EX3C8CSlrdP6oDyp+l3cpaDvRKS+1ujl5BOWF3sGPjLtx7dCvHaj
      2GU4Kzg1USEODm8uNBNA4StnDG1KQTAYI1oyVZnJF+A83vbsea0rWBmirSwiGpWO
      vpaQXUJXxPkUAzUrHC1RVwinOt4/5Mi0A3PCwSaAuwtCH60NryZy2sy+s6ODWA2C
      xR9GUeOcGMyNm43sSet1UNWMKFnKdDTajAshqx7qG+XH/RU+wBeq+yNuJkbL+vmx
      cmtpzyKEC2IPrNkZAJSidjzULZrtBJ4tBmIQN1IchXIbJ+XMxjHsN+xjWZsLHXbM
      fjKaiJUINlK73nZfdklJrX+9ZSCyycErdhh2n1ax
      -----END CERTIFICATE-----

Similarly, sources can be configured as follows:

spec:
  # ...
  sink:
    uri: https://mycorp-internal-example.com/v1/api
    CACerts: |-
      -----BEGIN CERTIFICATE-----
      MIIFWjCCA0KgAwIBAgIQT9Irj/VkyDOeTzRYZiNwYDANBgkqhkiG9w0BAQsFADBH
      MQswCQYDVQQGEwJDTjERMA8GA1UECgwIVW5pVHJ1c3QxJTAjBgNVBAMMHFVDQSBF
      eHRlbmRlZCBWYWxpZGF0aW9uIFJvb3QwHhcNMTUwMzEzMDAwMDAwWhcNMzgxMjMx
      MDAwMDAwWjBHMQswCQYDVQQGEwJDTjERMA8GA1UECgwIVW5pVHJ1c3QxJTAjBgNV
      BAMMHFVDQSBFeHRlbmRlZCBWYWxpZGF0aW9uIFJvb3QwggIiMA0GCSqGSIb3DQEB
      AQUAA4ICDwAwggIKAoICAQCpCQcoEwKwmeBkqh5DFnpzsZGgdT6o+uM4AHrsiWog
      D4vFsJszA1qGxliG1cGFu0/GnEBNyr7uaZa4rYEwmnySBesFK5pI0Lh2PpbIILvS
      sPGP2KxFRv+qZ2C0d35qHzwaUnoEPQc8hQ2E0B92CvdqFN9y4zR8V05WAT558aop
      O2z6+I9tTcg1367r3CTueUWnhbYFiN6IXSV8l2RnCdm/WhUFhvMJHuxYMjMR83dk
      sHYf5BA1FxvyDrFspCqjc/wJHx4yGVMR59mzLC52LqGj3n5qiAno8geK+LLNEOfi
      c0CTuwjRP+H8C5SzJe98ptfRr5//lpr1kXuYC3fUfugH0mK1lTnj8/FtDw5lhIpj
      VMWAtuCeS31HJqcBCF3RiJ7XwzJE+oJKCmhUfzhTA8ykADNkUVkLo4KRel7sFsLz
      KuZi2irbWWIQJUoqgQtHB0MGcIfS+pMRKXpITeuUx3BNr2fVUbGAIAEBtHoIppB/
      TuDvB0GHr2qlXov7z1CymlSvw4m6WC31MJixNnI5fkkE/SmnTHnkBVfblLkWU41G
      sx2VYVdWf6/wFlthWG82UBEL2KwrlRYaDh8IzTY0ZRBiZtWAXxQgXy0MoHgKaNYs
      1+lvK9JKBZP8nm9rZ/+I8U6laUpSNwXqxhaN0sSZ0YIrO7o1dfdRUVjzyAfd5LQD
      fwIDAQABo0IwQDAdBgNVHQ4EFgQU2XQ65DA9DfcS3H5aBZ8eNJr34RQwDwYDVR0T
      AQH/BAUwAwEB/zAOBgNVHQ8BAf8EBAMCAYYwDQYJKoZIhvcNAQELBQADggIBADaN
      l8xCFWQpN5smLNb7rhVpLGsaGvdftvkHTFnq88nIua7Mui563MD1sC3AO6+fcAUR
      ap8lTwEpcOPlDOHqWnzcSbvBHiqB9RZLcpHIojG5qtr8nR/zXUACE/xOHAbKsxSQ
      VBcZEhrxH9cMaVr2cXj0lH2RC47skFSOvG+hTKv8dGT9cZr4QQehzZHkPJrgmzI5
      c6sq1WnIeJEmMX3ixzDx/BR4dxIOE/TdFpS/S2d7cFOFyrC78zhNLJA5wA3CXWvp
      4uXViI3WLL+rG761KIcSF3Ru/H38j9CHJrAb+7lsq+KePRXBOy5nAliRn+/4Qh8s
      t2j1da3Ptfb/EX3C8CSlrdP6oDyp+l3cpaDvRKS+1ujl5BOWF3sGPjLtx7dCvHaj
      2GU4Kzg1USEODm8uNBNA4StnDG1KQTAYI1oyVZnJF+A83vbsea0rWBmirSwiGpWO
      vpaQXUJXxPkUAzUrHC1RVwinOt4/5Mi0A3PCwSaAuwtCH60NryZy2sy+s6ODWA2C
      xR9GUeOcGMyNm43sSet1UNWMKFnKdDTajAshqx7qG+XH/RU+wBeq+yNuJkbL+vmx
      cmtpzyKEC2IPrNkZAJSidjzULZrtBJ4tBmIQN1IchXIbJ+XMxjHsN+xjWZsLHXbM
      fjKaiJUINlK73nZfdklJrX+9ZSCyycErdhh2n1ax
      -----END CERTIFICATE-----

Configure custom event sources to trust the Eventing CA

The recommended way of creating custom event sources is using a SinkBinding, SinkBinding will inject the configured CA trust bundles as projected volume into each container using the directory /knative-custom-certs.

Note

Some organizations might inject company specific CA trust bundles into base container images and automatically configure runtimes (openjdk, node, etc) to trust that CA bundle. In that case, you might not need to configure your clients.

Using the previous example of the my-org-eventing-bundle ConfigMap with data keys being ca.crt, ca1.crt and tls.crt, you will have a /knative-custom-certs directory that will have the following layout:

/knative-custom-certs/ca.crt
/knative-custom-certs/ca1.crt
/knative-custom-certs/tls.crt

Those files can then be used to add CA trust bundles to HTTP clients sending events to Eventing.

Note

Depending on the runtime, programming language or library that you’re using, there are different ways of configuring custom CA certs files using command line flags, environment variables, or by reading the content of those files. Refer to their documentation for more details.

Adding `SelfSigned` `ClusterIssuer` to CA trust bundles

In case you are using a SelfSigned ClusterIssuer as described in the Setup SelfSigned ClusterIssuer section, you can add the CA to the Eventing CA trust bundles by running the following commands:

Export the CA from the knative-eventing-ca secret in the OpenShift Cert-Manager Operator namespace, cert-manager by default:
```
$ kubectl get secret -n cert-manager knative-eventing-ca -o=jsonpath='{.data.ca\.crt}' | base64 -d > ca.crt
```

Create a CA trust bundle in the knative-eventing namespace:

$ kubectl create configmap -n knative-eventing my-org-selfsigned-ca-bundle --from-file=ca.crt

Label the ConfigMap with networking.knative.dev/trust-bundle: “true” label:

$ kubectl label configmap -n knative-eventing my-org-selfsigned-ca-bundle networking.knative.dev/trust-bundle=true

Verifying that the feature is working

Save the following YAML into a file called default-broker-example.yaml

# default-broker-example.yaml
apiVersion: eventing.knative.dev/v1
kind: Broker
metadata:
  name: br
---
apiVersion: eventing.knative.dev/v1
kind: Trigger
metadata:
  name: tr
spec:
  broker: br
  subscriber:
    ref:
      apiVersion: v1
      kind: Service
      name: event-display
---
apiVersion: v1
kind: Service
metadata:
  name: event-display
spec:
  selector:
    app: event-display
  ports:
    - protocol: TCP
      port: 80
      targetPort: 8080
---
apiVersion: v1
kind: Pod
metadata:
  name: event-display
  labels:
    app: event-display
spec:
  containers:
    - name: event-display
      image: gcr.io/knative-releases/knative.dev/eventing/cmd/event_display
      imagePullPolicy: Always
      ports:
        - containerPort: 8080

Apply the default-broker-example.yaml file into a test namespace transport-encryption-test:

kubectl create namespace transport-encryption-test
kubectl apply -n transport-encryption-test -f defautl-broker-example.yaml

Verify that addresses are all HTTPS:

kubectl get brokers.eventing.knative.dev -n transport-encryption-test br -oyaml

Example output:

apiVersion: eventing.knative.dev/v1
kind: Broker
metadata:
  # ...
  name: br
  namespace: transport-encryption-test
# ...
status:
  address:
    CACerts: |
      -----BEGIN CERTIFICATE-----
      MIIBbzCCARagAwIBAgIQAur7vdEcreEWSEQatCYlNjAKBggqhkjOPQQDAjAYMRYw
      FAYDVQQDEw1zZWxmc2lnbmVkLWNhMB4XDTIzMDgwMzA4MzA1N1oXDTIzMTEwMTA4
      MzA1N1owGDEWMBQGA1UEAxMNc2VsZnNpZ25lZC1jYTBZMBMGByqGSM49AgEGCCqG
      SM49AwEHA0IABBqkD9lAwrnXCo/OOdpKzJROSbzCeC73FE/Np+/j8n862Ox5xYwJ
      tAp/o3RDpDa3omhzqZoYumqdtneozGFY/zGjQjBAMA4GA1UdDwEB/wQEAwICpDAP
      BgNVHRMBAf8EBTADAQH/MB0GA1UdDgQWBBSHoKjXzfxfudt3mVGU3VudSi6TrTAK
      BggqhkjOPQQDAgNHADBEAiA5z0/TpD7T6vRpN9VQisQMtum/Zg3tThnYA5nFnAW7
      KAIgKR/EzW7f8BPcnlcgXt5kp3Fdqye1SAkjxZzr2a0Zik8=
      -----END CERTIFICATE-----
    name: https
    url: https://broker-ingress.knative-eventing.svc.cluster.local/transport-encryption-test/br
  addresses:
  - CACerts: |
      -----BEGIN CERTIFICATE-----
      MIIBbzCCARagAwIBAgIQAur7vdEcreEWSEQatCYlNjAKBggqhkjOPQQDAjAYMRYw
      FAYDVQQDEw1zZWxmc2lnbmVkLWNhMB4XDTIzMDgwMzA4MzA1N1oXDTIzMTEwMTA4
      MzA1N1owGDEWMBQGA1UEAxMNc2VsZnNpZ25lZC1jYTBZMBMGByqGSM49AgEGCCqG
      SM49AwEHA0IABBqkD9lAwrnXCo/OOdpKzJROSbzCeC73FE/Np+/j8n862Ox5xYwJ
      tAp/o3RDpDa3omhzqZoYumqdtneozGFY/zGjQjBAMA4GA1UdDwEB/wQEAwICpDAP
      BgNVHRMBAf8EBTADAQH/MB0GA1UdDgQWBBSHoKjXzfxfudt3mVGU3VudSi6TrTAK
      BggqhkjOPQQDAgNHADBEAiA5z0/TpD7T6vRpN9VQisQMtum/Zg3tThnYA5nFnAW7
      KAIgKR/EzW7f8BPcnlcgXt5kp3Fdqye1SAkjxZzr2a0Zik8=
      -----END CERTIFICATE-----
    name: https
    url: https://broker-ingress.knative-eventing.svc.cluster.local/transport-encryption-test/br
  annotations:
    knative.dev/channelAPIVersion: messaging.knative.dev/v1
    knative.dev/channelAddress: https://imc-dispatcher.knative-eventing.svc.cluster.local/transport-encryption-test/br-kne-trigger
    knative.dev/channelCACerts: |
      -----BEGIN CERTIFICATE-----
      MIIBbzCCARagAwIBAgIQAur7vdEcreEWSEQatCYlNjAKBggqhkjOPQQDAjAYMRYw
      FAYDVQQDEw1zZWxmc2lnbmVkLWNhMB4XDTIzMDgwMzA4MzA1N1oXDTIzMTEwMTA4
      MzA1N1owGDEWMBQGA1UEAxMNc2VsZnNpZ25lZC1jYTBZMBMGByqGSM49AgEGCCqG
      SM49AwEHA0IABBqkD9lAwrnXCo/OOdpKzJROSbzCeC73FE/Np+/j8n862Ox5xYwJ
      tAp/o3RDpDa3omhzqZoYumqdtneozGFY/zGjQjBAMA4GA1UdDwEB/wQEAwICpDAP
      BgNVHRMBAf8EBTADAQH/MB0GA1UdDgQWBBSHoKjXzfxfudt3mVGU3VudSi6TrTAK
      BggqhkjOPQQDAgNHADBEAiA5z0/TpD7T6vRpN9VQisQMtum/Zg3tThnYA5nFnAW7
      KAIgKR/EzW7f8BPcnlcgXt5kp3Fdqye1SAkjxZzr2a0Zik8=
      -----END CERTIFICATE-----
    knative.dev/channelKind: InMemoryChannel
    knative.dev/channelName: br-kne-trigger
  conditions:
  # ...

Sending events to the Broker using HTTPS endpoints:

kubectl run curl -n transport-encryption-test --image=curlimages/curl -i --tty -- sh

Save the CA certs from the Broker’s .status.address.CACerts field into /tmp/cacerts.pem

cat <<EOF >> /tmp/cacerts.pem
-----BEGIN CERTIFICATE-----
MIIBbzCCARagAwIBAgIQAur7vdEcreEWSEQatCYlNjAKBggqhkjOPQQDAjAYMRYw
FAYDVQQDEw1zZWxmc2lnbmVkLWNhMB4XDTIzMDgwMzA4MzA1N1oXDTIzMTEwMTA4
MzA1N1owGDEWMBQGA1UEAxMNc2VsZnNpZ25lZC1jYTBZMBMGByqGSM49AgEGCCqG
SM49AwEHA0IABBqkD9lAwrnXCo/OOdpKzJROSbzCeC73FE/Np+/j8n862Ox5xYwJ
tAp/o3RDpDa3omhzqZoYumqdtneozGFY/zGjQjBAMA4GA1UdDwEB/wQEAwICpDAP
BgNVHRMBAf8EBTADAQH/MB0GA1UdDgQWBBSHoKjXzfxfudt3mVGU3VudSi6TrTAK
BggqhkjOPQQDAgNHADBEAiA5z0/TpD7T6vRpN9VQisQMtum/Zg3tThnYA5nFnAW7
KAIgKR/EzW7f8BPcnlcgXt5kp3Fdqye1SAkjxZzr2a0Zik8=
-----END CERTIFICATE-----
EOF

Send the event by running the following command:

curl -v -X POST -H "content-type: application/json" -H "ce-specversion: 1.0" -H "ce-source: my/curl/command" -H "ce-type: my.demo.event" -H "ce-id: 6cf17c7b-30b1-45a6-80b0-4cf58c92b947" -d '{"name":"Knative Demo"}' --cacert /tmp/cacert
s.pem https://broker-ingress.knative-eventing.svc.cluster.local/transport-encryption-test/br

Example output:

* processing: https://broker-ingress.knative-eventing.svc.cluster.local/transport-encryption-test/br
*   Trying 10.96.174.249:443...
* Connected to broker-ingress.knative-eventing.svc.cluster.local (10.96.174.249) port 443
* ALPN: offers h2,http/1.1
* TLSv1.3 (OUT), TLS handshake, Client hello (1):
*  CAfile: /tmp/cacerts.pem
*  CApath: none
* TLSv1.3 (IN), TLS handshake, Server hello (2):
* TLSv1.3 (IN), TLS handshake, Encrypted Extensions (8):
* TLSv1.3 (IN), TLS handshake, Certificate (11):
* TLSv1.3 (IN), TLS handshake, CERT verify (15):
* TLSv1.3 (IN), TLS handshake, Finished (20):
* TLSv1.3 (OUT), TLS change cipher, Change cipher spec (1):
* TLSv1.3 (OUT), TLS handshake, Finished (20):
* SSL connection using TLSv1.3 / TLS_AES_128_GCM_SHA256
* ALPN: server accepted h2
* Server certificate:
*  subject: O=local
*  start date: Aug  3 08:31:02 2023 GMT
*  expire date: Nov  1 08:31:02 2023 GMT
*  subjectAltName: host "broker-ingress.knative-eventing.svc.cluster.local" matched cert's "broker-ingress.knative-eventing.svc.cluster.local"
*  issuer: CN=selfsigned-ca
*  SSL certificate verify ok.
* TLSv1.3 (IN), TLS handshake, Newsession Ticket (4):
* using HTTP/2
* h2 [:method: POST]
* h2 [:scheme: https]
* h2 [:authority: broker-ingress.knative-eventing.svc.cluster.local]
* h2 [:path: /transport-encryption-test/br]
* h2 [user-agent: curl/8.2.1]
* h2 [accept: */*]
* h2 [content-type: application/json]
* h2 [ce-specversion: 1.0]
* h2 [ce-source: my/curl/command]
* h2 [ce-type: my.demo.event]
* h2 [ce-id: 6cf17c7b-30b1-45a6-80b0-4cf58c92b947]
* h2 [content-length: 23]
* Using Stream ID: 1
> POST /transport-encryption-test/br HTTP/2
> Host: broker-ingress.knative-eventing.svc.cluster.local
> User-Agent: curl/8.2.1
> Accept: */*
> content-type: application/json
> ce-specversion: 1.0
> ce-source: my/curl/command
> ce-type: my.demo.event
> ce-id: 6cf17c7b-30b1-45a6-80b0-4cf58c92b947
> Content-Length: 23
> 
< HTTP/2 202 
< allow: POST, OPTIONS
< content-length: 0
< date: Thu, 03 Aug 2023 10:08:22 GMT
< 
* Connection #0 to host broker-ingress.knative-eventing.svc.cluster.local left intact

Transport Encryption

Transport Encryption for Knative Eventing

Overview

Prerequisites

Installation

Setup SelfSigned ClusterIssuer

Setup ClusterIssuer for Eventing

Install the certificates for Eventing components

Transport Encryption configuration

Configure additional CA trust bundles

Trusting CA for a specific event sender

Configure custom event sources to trust the Eventing CA

Adding SelfSigned ClusterIssuer to CA trust bundles

Verifying that the feature is working

Setup `SelfSigned` `ClusterIssuer`

Setup `ClusterIssuer` for Eventing

Adding `SelfSigned` `ClusterIssuer` to CA trust bundles