Zone Egress authentication

To obtain a configuration from the control plane, a zone egress must authenticate itself. There are several authentication methods available.

Service Account Token

On Kubernetes, A ZoneEgress proxy proves its identity by leveraging the ServiceAccountToken that is mounted in every pod.

Zone Token

On Universal, a ZoneEgress proxy must be explicitly configured with a unique security token (Zone token) with appropriate scope (egress), that will be used to prove its identity.

The zone token used to identify zone egresses is a JWT token that contains:

• Zone in which zone egress operates
• Expiration date of the token (required, 10 years if not specified)
• Scope as a list of items where the token will be valid (required, egress if not specified)

The zone token is signed by a signing key that is autogenerated during the first start of the control plane. Tokens are never stored in the control plane, the only thing that is stored are signing keys that are used to verify if a token is valid. The signing key is RSA256 encrypted.

You can check for the signing key:

kumactl get global-secrets

which returns something like:

NAME                       AGE
zone-token-signing-key-1   7s

Usage

Generate the token with the REST API:

curl -XPOST \
  -H "Content-Type: application/json" \
  --data '{"zone": "us-east", "validFor": "720h", "scope": ["egress"]}' \
  http://localhost:5681/tokens/zone

or with kumactl:

kumactl generate zone-token \
  --zone us-east \
  --scope egress \
  --valid-for 720h > /tmp/kuma-egress-token

The token should be stored in a file and then passed when you start kuma-dp:

kuma-dp run \
  --proxy-type=egress \
  --dataplane-file=egress.yaml
  --cp-address=https://127.0.0.1:5678 \
  --dataplane-token-file=/tmp/kuma-egress-token

You can also pass the token as a KUMA_DATAPLANE_RUNTIME_TOKEN environment variable.

Token Revocation

Kuma does not keep the list of issued tokens. Whenever the single token is compromised, we can add it to revocation list, so it’s no longer valid.

Every token has its own ID which is available in payload under jti key. You can extract ID from token using jwt.io or jwt-cli tool. Here is example of jti

0e120ec9-6b42-495d-9758-07b59fe86fb9

Specify list of revoked IDs separated by , and store it as GlobalSecret named zoneegress-token-revocations

REVOCATIONS=$(echo '0e120ec9-6b42-495d-9758-07b59fe86fb9' | base64) && echo "apiVersion: v1
kind: Secret
metadata:
  name: zone-token-revocations
  namespace: kuma-system
data:
  value: $REVOCATIONS
type: system.kuma.io/global-secret" | kubectl apply -f -

echo "
type: GlobalSecret
name: zone-token-revocations
data: " | kumactl apply --var revocations=$(echo '0e120ec9-6b42-495d-9758-07b59fe86fb9' | base64) -f -

Signing key rotation

If the signing key is compromised, we must rotate it and all the tokens that were signed by it.

1. Generate new signing key The signing key is stored as a GlobalSecret with a name that looks like zone-token-signing-key-{serialNumber}.

   Make sure to generate the new signing key with a serial number greater than the serial number of the current signing key.

   • Kubernetes
   • Universal

   Check what is the current highest serial number.

   kubectl get secrets -n kuma-system --field-selector='type=system.kuma.io/global-secret'
   NAME                       TYPE                           DATA   AGE
   zone-token-signing-key-1   system.kuma.io/global-secret   1      25m

   In this case, the highest serial number is 1. Generate a new signing key with a serial number of 2

   TOKEN="$(kumactl generate signing-key)" && echo "
   apiVersion: v1
   data:
     value: $TOKEN
   kind: Secret
   metadata:
     name: zone-token-signing-key-2
     namespace: kuma-system
   type: system.kuma.io/global-secret
   " | kubectl apply -f -

   Check what is the current highest serial number.

   kumactl get global-secrets
   NAME                       AGE
   zone-token-signing-key-1   36m

   In this case, the highest serial number is 1. Generate a new signing key with a serial number of 2

   echo "
   type: GlobalSecret
   name: zone-token-signing-key-2
   data: " | kumactl apply --var key=$(kumactl generate signing-key) -f -

2. Regenerate tokens These tokens are automatically created with the signing key that’s assigned the highest serial number, so they’re created with the new signing key. At this point, tokens signed by either new or old signing key are valid.

3. Remove the old signing key

   • Kubernetes
   • Universal

   kubectl delete secret zone-token-signing-key-1 -n kuma-system

   kumactl delete global-secret zone-token-signing-key-1

   All new connections to the control plane now require tokens signed with the new signing key.

Multi-zone

When running in multi-zone mode, we can generate zone tokens only on the global control plane.

None

You can turn off authentication by setting KUMA_DP_SERVER_AUTH_TYPE to none.