Authentication with the API server

Kong Mesh exposes API server on ports 5681 and 5682 (protected by TLS).

An authenticated user can be authorized to execute administrative actions such as

• Managing administrative resources like Kong Mesh Secrets on Universal
• Generating user token, data plane proxy token, zone ingress token, zone token

User token

A user token is a signed JWT token that contains

• The name of the user
• The list of groups that a user belongs to
• Expiration date of the token

Groups

A user can be a part of many groups. Kong Mesh adds two groups to a user automatically:

• authenticated users are a part of mesh-system:authenticated.
• unauthenticated users are part of mesh-system:unauthenticated.

Admin user token

Kong Mesh creates an admin user token on the first start of the control plane. The admin user token is a user token issued for user mesh-system:admin that belongs to mesh-system:admin group. This group is authorized by default to execute all administrative operations.

Generate user tokens

You can generate user tokens only when you provide the credentials of a user authorized to generate user tokens . kumactl configured with admin user token extracted in the preceding section is authorized to do it.

kumactl generate user-token \
  --name john \
  --group team-a \
  --valid-for 24h

or you can use API

curl localhost:5681/tokens/user \
  -H'authentication: Bearer eyJhbGc...' \
  -H'content-type: application/json' \
  --data '{"name": "john","groups": ["team-a"], "validFor": "24h"}' 

Explore an example token

You can decode the tokens to validate the signature or explore details.

For example, run:

kumactl generate user-token \
  --name john \
  --group team-a \
  --valid-for 24h

which returns:

eyJhbGciOiJSUzI1NiIsImtpZCI6IjEiLCJ0eXAiOiJKV1QifQ.eyJOYW1lIjoiam9obiIsIkdyb3VwcyI6WyJ0ZWFtLWEiXSwiZXhwIjoxNjM2ODExNjc0LCJuYmYiOjE2MzY3MjQ5NzQsImlhdCI6MTYzNjcyNTI3NCwianRpIjoiYmYzZDBiMmUtZDg0MC00Y2I2LWJmN2MtYjkwZjU0MzkxNDY4In0.XsaPcQ5wVzRLs4o1FWywf6kw4r2ceyLGxYO8EbyA0fAxU6BPPRsW71ueD8ZlS4JlD4UrVtQQ7LG-z_nIxlDRAYhx4mmHnSjtqWZIsVS13QRrm41zccZ0SKHYxGvWMW4IkGwUbA0UZOJGno8vbpI6jTGfY9bmof5FpJJAj_sf99jCaI1H_n3n5UxtwKVN7dXXD82r6axj700jgQD-2O8gnejzlTjZkBpPF_lGnlBbd39S34VNwT0UlvRJLmCRdfh5EL24dFt0tyzQqDG2gE1RuGvTV9LOT77ZsjfMP9CITICivF6Z7uqvlOYal10jd5gN0A6w6KSI8CCaDLmVgUHvAw

Paste the token into the UI at jwt.io, or use jwt-cli tool

kumactl generate user-token --name=john --group=team-a --valid-for=24h | jwt

To verify on jwt.io:

https://jwt.io/#id_token=eyJhbGciOiJSUzI1NiIsImtpZCI6IjEiLCJ0eXAiOiJKV1QifQ.eyJOYW1lIjoiam9obiIsIkdyb3VwcyI6WyJ0ZWFtLWEiXSwiZXhwIjoxNjM2ODExNjc0LCJuYmYiOjE2MzY3MjQ5NzQsImlhdCI6MTYzNjcyNTI3NCwianRpIjoiYmYzZDBiMmUtZDg0MC00Y2I2LWJmN2MtYjkwZjU0MzkxNDY4In0.XsaPcQ5wVzRLs4o1FWywf6kw4r2ceyLGxYO8EbyA0fAxU6BPPRsW71ueD8ZlS4JlD4UrVtQQ7LG-z_nIxlDRAYhx4mmHnSjtqWZIsVS13QRrm41zccZ0SKHYxGvWMW4IkGwUbA0UZOJGno8vbpI6jTGfY9bmof5FpJJAj_sf99jCaI1H_n3n5UxtwKVN7dXXD82r6axj700jgQD-2O8gnejzlTjZkBpPF_lGnlBbd39S34VNwT0UlvRJLmCRdfh5EL24dFt0tyzQqDG2gE1RuGvTV9LOT77ZsjfMP9CITICivF6Z7uqvlOYal10jd5gN0A6w6KSI8CCaDLmVgUHvAw

✻ Header
{
  "alg": "RS256",
  "kid": "1",
  "typ": "JWT"
}

✻ Payload
{
  "Name": "john",
  "Groups": [
    "team-a"
  ],
  "exp": 1636811674,
  "nbf": 1636724974,
  "iat": 1636725274,
  "jti": "bf3d0b2e-d840-4cb6-bf7c-b90f54391468"
}
   Issued At: 1636725274 11/12/2021, 2:54:34 PM
   Not Before: 1636724974 11/12/2021, 2:49:34 PM
   Expiration Time: 1636811674 11/13/2021, 2:54:34 PM

✻ Signature XsaPcQ5wVzRLs4o1FWywf6kw4r2ceyLGxYO8EbyA0fAxU6BPPRsW71ueD8ZlS4JlD4UrVtQQ7LG-z_nIxlDRAYhx4mmHnSjtqWZIsVS13QRrm41zccZ0SKHYxGvWMW4IkGwUbA0UZOJGno8vbpI6jTGfY9bmof5FpJJAj_sf99jCaI1H_n3n5UxtwKVN7dXXD82r6axj700jgQD-2O8gnejzlTjZkBpPF_lGnlBbd39S34VNwT0UlvRJLmCRdfh5EL24dFt0tyzQqDG2gE1RuGvTV9LOT77ZsjfMP9CITICivF6Z7uqvlOYal10jd5gN0A6w6KSI8CCaDLmVgUHvAw

Token revocation

Kong Mesh doesn’t keep the list of issued tokens. To invalidate the token, you can add it to a revocation list. Every user token has its own ID. As you saw in the previous section, it’s available in payload under jti key. To revoke tokens, specify list of revoked IDs separated by , and store it as GlobalSecret named user-token-revocations

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

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

Signing key

A user token is signed by a signing key that’s autogenerated on the first start of the control plane. The signing key is a 2048-bit RSA key stored as a GlobalSecret with a name that looks like user-token-signing-key-{serialNumber}.

Signing key rotation

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

1. Generate a new signing key

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

   <div class="navtabs code">
   

   Kubernetes

   Universal

   Check what’s the current highest serial number.

      kubectl get secrets -n kong-mesh-system --field-selector='type=system.kuma.io/global-secret'
       NAME                          TYPE                           DATA   AGE
       user-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: user-token-signing-key-2
         namespace: kong-mesh-system
       type: system.kuma.io/global-secret
       " | kubectl apply -f - 
    

   Check what’s the current highest serial number.

      kumactl get global-secrets
       NAME                             AGE
       user-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: user-token-signing-key-2
       data: " | kumactl apply --var key=$(kumactl generate signing-key) -f -
    

   </div>

2. Regenerate user tokens

   Create new user tokens. Tokens are always signed by the signing key with the highest serial number. Starting from now, tokens signed by either new or old signing key are valid.

3. Remove the old signing key

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   Kubernetes

   Universal

      kubectl delete secret user-token-signing-key-1 -n kong-mesh-system
    

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

   </div>

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

Disabling bootstrap of the admin user token

You can remove the default admin user token from the storage and prevent it from being recreated. Keep in mind that even if you remove the admin user token, the signing key is still present. A malicious actor that acquires the signing key, can generate an admin token.

Admin client certificates

This section describes the alternative way of authenticating to API Server.

To use admin client certificates, set KUMA_API_SERVER_AUTHN_TYPE to adminClientCerts.

All users that provide client certificate are authenticated as a user with the name mesh-system:admin that belongs to group mesh-system:admin.

Usage

1. Generate client certificates by using kumactl

   kumactl generate tls-certificate --type=client \
     --cert-file=/tmp/tls.crt \
     --key-file=/tmp/tls.key
   

2. Configure the control plane with client certificates

   <div class="navtabs code">
   

   Kubernetes (kumactl)

   Kubernetes (HELM)

   Universal

   Create a secret in the namespace in which control plane is installed

      kubectl create secret generic api-server-client-certs -n kong-mesh-system \
         --from-file=client1.pem=/tmp/tls.crt \
    

   You can provide as many client certificates as you want. Remember to only provide certificates without keys.

   Point to this secret when installing Kong Mesh

      kumactl install control-plane \
         --tls-api-server-client-certs-secret=api-server-client-certs
    

   Create a secret in the namespace in which control plane is installed

      kubectl create secret generic api-server-client-certs -n kong-mesh-system \
         --from-file=client1.pem=/tmp/tls.crt \
    

   You can provide as many client certificates as you want. Remember to only provide certificates without keys.

   Set controlPlane.tls.apiServer.clientCertsSecretName to api-server-client-certs via HELM

   Put all the certificates in one directory

      mkdir /opt/client-certs
       cp /tmp/tls.crt /opt/client-certs/client1.pem 
    

   All client certificates must end with .pem extension. Remember to only provide certificates without keys.

   Configure control plane by pointing to this directory

      KUMA_API_SERVER_AUTH_CLIENT_CERTS_DIR=/opt/client-certs \
         kuma-cp run
    

   </div>

3. Configure kumactl with valid client certificate

   kumactl config control-planes add \
     --name=<NAME>
     --address=https://<KUMA_CP_DNS_NAME>:5682 \
     --client-cert-file=/tmp/tls.crt \
     --client-key-file=/tmp/tls.key \
     --ca-cert-file=/tmp/ca.crt
   

   If you want to skip CP verification, use --skip-verify instead of --ca-cert-file.

Multizone

In a multizone setup, users execute a majority of actions on the global control plane. However, some actions like generating dataplane tokens are available on the zone control plane. The global control plane doesn’t propagate authentication credentials to the zone control plane. You can set up consistent user tokens across the whole setup by manually copying signing key from global to zone control planes.