PeerAuthentication

PeerAuthentication defines mutual TLS (mTLS) requirements for incoming connections.

In sidecar mode, PeerAuthentication determines whether or not mTLS is allowed or required for connections to an Envoy proxy sidecar.

In ambient mode, security is transparently enabled for a pod by the ztunnel node agent. (Traffic between proxies uses the HBONE protocol, which includes encryption with mTLS.) Because of this, DISABLE mode is not supported. STRICT mode is useful to ensure that connections that bypass the mesh are not possible.

Examples:

Policy to require mTLS traffic for all workloads under namespace foo:

apiVersion: security.istio.io/v1
kind: PeerAuthentication
metadata:
  name: default
  namespace: foo
spec:
  mtls:
    mode: STRICT

For mesh level, put the policy in root-namespace according to your Istio installation.

Policies to allow both mTLS and plaintext traffic for all workloads under namespace foo, but require mTLS for workload finance.

apiVersion: security.istio.io/v1
kind: PeerAuthentication
metadata:
  name: default
  namespace: foo
spec:
  mtls:
    mode: PERMISSIVE
---
apiVersion: security.istio.io/v1
kind: PeerAuthentication
metadata:
  name: finance
  namespace: foo
spec:
  selector:
    matchLabels:
      app: finance
  mtls:
    mode: STRICT

Policy that enables strict mTLS for all finance workloads, but leaves the port 8080 to plaintext. Note the port value in the portLevelMtls field refers to the port of the workload, not the port of the Kubernetes service.

apiVersion: security.istio.io/v1
kind: PeerAuthentication
metadata:
  name: default
  namespace: foo
spec:
  selector:
    matchLabels:
      app: finance
  mtls:
    mode: STRICT
  portLevelMtls:
    8080:
      mode: DISABLE

Policy that inherits mTLS mode from namespace (or mesh) settings, and disables mTLS for workload port 8080.

apiVersion: security.istio.io/v1
kind: PeerAuthentication
metadata:
  name: default
  namespace: foo
spec:
  selector:
    matchLabels:
      app: finance
  mtls:
    mode: UNSET
  portLevelMtls:
    8080:
      mode: DISABLE

PeerAuthentication

MutualTLS

Mode