TIS0005 - Root CA Certificate Is Invalid or Has Expired

The root CA certificate is either invalid (missing required fields or improperly formatted) or has expired, causing potential failures in mutual TLS (mTLS) or other secure connections.

Recommendation: Verify and Update Your Root CA Certificate

By verifying and updating your root CA certificate to ensure it is valid and properly configured, you can maintain secure communication across your Istio-enabled environment.

Examples

1. Secret Containing an Expired Root CA Certificate

   apiVersion: v1
   kind: Secret
   metadata:
     name: root-ca
     namespace: istio-system
   type: Opaque
   data:
     ca-cert.pem: LS0tLS1CRUdJTiBDRVJUSUZJQ0FUR... # Expired certificate
     ca-key.pem: LS0tLS1CRUdJTiBQUklWQVRFIEtFWT...

   Explanation: The root CA certificate inside the ca-cert.pem file has passed its notAfter date. Any workloads relying on this certificate will fail to establish a secure connection once the certificate is expired.

2. Secret Missing Required Certificate Fields

   apiVersion: v1
   kind: Secret
   metadata:
     name: root-ca
     namespace: istio-system
   type: Opaque
   data:
     ca-cert.pem: LS0tLS1CRUdJTiBDRVJUSUZJQ0FUR... # Missing Subject or SAN fields
     ca-key.pem: LS0tLS1CRUdJTiBQUklWQVRFIEtFWT...

   Explanation: The provided CA certificate is missing critical fields (e.g., Subject or SAN) required for correct certificate validation. This could lead to trust issues or handshake failures in the service mesh.

3. Secret Missing ca-cert.pem

   apiVersion: v1
   kind: Secret
   metadata:
     name: root-ca
     namespace: istio-system
   type: Opaque
   data:
     # ca-cert.pem is completely missing
     ca-key.pem: LS0tLS1CRUdJTiBQUklWQVRFIEtFWT...

   Explanation: The Secret does not contain the ca-cert.pem file required for establishing trust. Without this file, Istio workloads cannot authenticate peer certificates or set up secure connections using mTLS.

Recommendation

1. Renew or Replace the Root CA Certificate

   Generate or obtain a new certificate before the current certificate expires, ensuring it includes required fields (e.g., Subject, SAN) and has an appropriate notAfter date.

   # Example: Generate a self-signed CA certificate with OpenSSL (for testing)
   openssl req -x509 -newkey rsa:4096 -nodes -keyout ca-key.pem -out ca-cert.pem -days 365 \
     -subj "/C=US/ST=Example/L=Example/O=Example/CN=example-ca"

2. Verify Certificate Validity Period and Configuration

   Regularly check the validity dates of your root CA certificate, ensuring it is not expired and that all required fields (e.g., Subject, SAN) are present.

   # Check dates of a certificate
   openssl x509 -noout -dates -in ca-cert.pem