Configuring K10 Encryption

K10 supports encryption for data and metadata stored in an object store or an NFS file store (e.g., for cross-cloud snapshot migration) via the use of the AES-256-GCM encryption algorithm. K10 encryption is always enabled for external data and metadata (more information below), it cannot be disabled. Multiple methods of encryption can be used and K10 can be configured to use any of them. K10 allows users to have multiple Passkeys. These Passkeys can be a combination of any of the different types listed below. However, only of them will be in use at any point in time.

A Passkey API resource is used to add, edit, list or remove a Passkey used for data and metadata encryption.

Bootstrapping Passkeys Before Install

If you do not specify a cluster secret, a Passkey with a random passphrase will be generated by K10 during install. The randomly generated Passkey can be changed via the Changing Passkeys instructions. However, if the passphrase needs to be specified before install, it can be done via the creation of a Kubernetes secret with a well-known name (k10-cluster-passphrase) in the namespace you will install K10 in (default kasten-io):

Warning

Once the cluster secret is set or auto-generated, do not modify or delete the cluster secret directly, please follow the Passkey change workflow below.

Passphrases

A passphrase is used to protect the encryption key used by K10 to encrypt application data.

$ kubectl create secret generic k10-cluster-passphrase \
    --namespace kasten-io \
    --from-literal passphrase=<key>

Note

The Passkey passphrase should be stored separately in a secure location for K10 Disaster Recovery.

AWS Customer Managed Keys

An AWS Customer Managed Key (CMK) can also be used to protect the encryption key used by K10 to encrypt application data.

$ kubectl create secret generic k10-cluster-passphrase \
    --namespace kasten-io \
    --from-literal awscmkkeyid=arn:aws:kms:us-west-2:111122223333:key/1234abcd-12ab-34cd-56ef-1234567890ab

IAM must be configured for K10. Refer to Using AWS IAM Roles for more information on IAM roles.

AWS keys are required while installing K10 in order to use the AWS Customer Manager Key. The IAM role is an optional value to be configured if K10 should assume a specific role.

$ helm install k10 kasten/k10 --namespace=kasten-io \
    --set secrets.awsAccessKeyId="${AWS_ACCESS_KEY_ID}" \
    --set secrets.awsSecretAccessKey="${AWS_SECRET_ACCESS_KEY}" \
    --set secrets.awsIamRole="${AWS_IAM_ROLE_ARN}"

Following is the AWS policy needed for access to AWS KMS.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "kms:Decrypt",
                "kms:Encrypt"
            ],
            "Resource": "arn:aws:kms:::key/${KMS_KEY_ID}"
        }
    ]
}

Additionally, the user/role needs to be added to the corresponding CMK policy as well.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Principal": {
              "AWS": [
                "arn:aws:iam::<AWS ACCOUNT>:role/<ROLE NAME>"
              ]
            },
            "Action": "kms:*",
            "Resource": "*"
        }
    ]
}

HashiCorp Vault Transit Secrets Engine

Configuring Vault Server for Kubernetes Auth

HashiCorp Vault Transit Secrets Engine can also be used to protect the encryption key used by K10 to encrypt application data.

Refer to the Vault Transit Secret Engine documentation for more information on configuring the transit secret engine.

$ kubectl create secret generic k10-cluster-passphrase \
  --namespace kasten-io \
  --from-literal vaulttransitkeyname=<vault_transit_key_name> \
  --from-literal vaulttransitpath=<vault_transit_path>

In addition to the Transit Secret Engine setup, K10 needs to be authorized to access Vault. Either token or kubernetes authentication is supported for the Vault server.

Token Auth

The token should be provided via a secret.

Warning

This method will be deprecated in the future in favor of kubernetes auth

$ kubectl create secret generic vault-creds \
     --namespace kasten-io \
     --from-literal vault_token=<vault_token>

Warning

This may cause the token to be stored in shell history. It is recommended to regularly rotate the token used for accessing Vault.

When a new token is generated, the vault-creds secret should be updated with the new token provided below:

$ kubectl patch secret vault-creds \
    --namespace kasten-io \
    --type='json' -p='[{"op" : "replace" ,"path" : "/data/vault_token" ,"value" : "<updated_vault_token>"}]'

Credentials can be provided with the Helm install or upgrade command using the following flags.

--set vault.address=<vault_server_address> \
--set vault.secretName=vault-creds

Kubernetes Auth

Refer to Configuring Vault Server For Kubernetes Auth prior to installing K10.

After setup is done, credentials can be provided with the Helm install or upgrade command using the following flags:

--set vault.address=<vault_server_address> \
--set vault.role=<vault_role> \
--set vault.serviceAccountTokenPath=<service_account_token_path>

vault.role is needed to authenticate via kubernetes service account tokens.

vault.serviceAccountTokenPath can be left blank if the service account path was not changed from the default of: /var/run/secrets/kubernetes.io/serviceaccount/token

Note

vault.secretName can be provided to the helm install to do a best-effort fallback to token auth if kubernetes authentication fails. If not present and kubernetes authentication fails, then the primary key encryption will not succeed and will return an error.

PassKey Management

Creating Passkeys

A Passkey that represents a passphrase, expects a Kubernetes Secret to be provided which contains the passphrase. This can be done via the creation of a Kubernetes secret in the K10 namespace:

$ kubectl create secret generic <secret-name> \
    --namespace kasten-io \
    --from-literal passphrase=<key>

As shown below, this secret can then be used to create a Passkey. Note that Passkeys are non-namespaced.

$ cat > sample-passkey.yaml <<EOF
apiVersion: vault.kio.kasten.io/v1alpha1
kind: Passkey
metadata:
  name: passkey1
spec:
  secret:
    # Reference to the passkey secret
    name: <secret-name>
    namespace: kasten-io
  usenow: false
EOF

$ kubectl create -f sample-passkey.yaml
vault.kio.kasten.io/passkey1 created

A Passkey can also be used to represent an AWS KMS Customer Managed Key(CMK). The AWS CMK key ID can be provided directly in the passkey.

$ cat > sample-passkey.yaml <<EOF
apiVersion: vault.kio.kasten.io/v1alpha1
kind: Passkey
metadata:
  name: passkey2
spec:
  awscmkkeyid: arn:aws:kms:us-west-2:111122223333:key/1234abcd-12ab-34cd-56ef-1234567890ab
  usenow: false
EOF

$ kubectl create -f sample-passkey.yaml
vault.kio.kasten.io/passkey2 created

A Passkey can also be used to represent a HashiCorp Vault Transit Secrets Engine. The Vault Transit key name and mount path can be provided directly in the passkey, as shown below.

In addition, a vault authentication role and path to the service account token used for Vault's Kubernetes Authentication method can be passed in, vaultauthrole and vaultk8sserviceaccounttokenpath, respectively. This will override those values originally set via the helm install Kubernetes Auth.

If using Token Auth, passing in these two values will have the effect of upgrading the authentication method from Token to Kubernetes. Please ensure your vault server is properly configured as shown in Configuring Vault Server for Kubernetes Auth before adding these to the Passkey.

$ cat > sample-passkey.yaml <<EOF
apiVersion: vault.kio.kasten.io/v1alpha1
kind: Passkey
metadata:
  name: passkey3
spec:
  vaulttransitkeyname: my-key
  vaulttransitpath: my-transit-path
  vaultauthrole: my-auth-role
  vaultk8sserviceaccounttokenpath: /var/run/secrets/kubernetes.io/serviceaccount/token
  usenow: false
EOF

$ kubectl create -f sample-passkey.yaml
vault.kio.kasten.io/passkey3 created

If usenow is set to true, while adding a Passkey, it will become the default Passkey. For changing the default (in use) Passkey, take a look at the Changing Passkeys instructions.

Multiple Passkeys can have their usenow flags sets but only one Passkey will be in use at any point in time. The Passkey that is most recently added with usenow set to true, will be the Passkey in use.

You can verify which Passkey is inuse by listing the Passkeys and checking the status. The status of the Passkey in use will have the inuse flag set to true.

Listing Passkeys

To list all Passkeys, simply run:

$ kubectl get passkeys.vault.kio.kasten.io
NAME              AGE
passkey1          1h
passkey2          2h

Getting Passkeys

To get a specific Passkey, run:

$ kubectl get passkeys.vault.kio.kasten.io passkey1
NAME              AGE
passkey1          1h

You may see additional Passkey detail by using the -o yaml option:

$ kubectl get passkeys.vault.kio.kasten.io passkey1 -o yaml
apiVersion: vault.kio.kasten.io/v1alpha1
metadata:
  name: passkey1
  creationtimestamp: <creation-time>
status:
  inuse: true

Deleting Passkeys

You can delete existing Passkeys if they are no longer required. If a Passkey is currently in use or only one Passkey exists, it cannot be deleted.

$ kubectl delete passkeys.vault.kio.kasten.io passkey1
  vault.kio.kasten.io/passkey1 deleted

Changing Passkeys

K10 allows you to change the current Passkey used for data and metadata encryption.

To change the Passkey, first add a new Passkey by following the instructions for adding Passkeys, but set the usenow flag to true.

You can then delete the old Passkey by following the instructions for deleting Passkeys.