Connects or reconnects a custom key store to its backing key store. For an CloudHSM key store, ConnectCustomKeyStore connects the key store to its associated CloudHSM cluster. For an external key store, ConnectCustomKeyStore connects the key store to the external key store proxy that communicates with your external key manager.

The custom key store must be connected before you can create KMS keys in the key store or use the KMS keys it contains. You can disconnect and reconnect a custom key store at any time.

The connection process for a custom key store can take an extended amount of time to complete. This operation starts the connection process, but it does not wait for it to complete. When it succeeds, this operation quickly returns an HTTP 200 response and a JSON object with no properties. However, this response does not indicate that the custom key store is connected. To get the connection state of the custom key store, use the DescribeCustomKeyStores operation.

This operation is part of the custom key stores feature in KMS, which combines the convenience and extensive integration of KMS with the isolation and control of a key store that you own and manage.

The ConnectCustomKeyStore operation might fail for various reasons. To find the reason, use the DescribeCustomKeyStores operation and see the ConnectionErrorCode in the response. For help interpreting the ConnectionErrorCode, see CustomKeyStoresListEntry.

To fix the failure, use the DisconnectCustomKeyStore operation to disconnect the custom key store, correct the error, use the UpdateCustomKeyStore operation if necessary, and then use ConnectCustomKeyStore again.

CloudHSM key store

During the connection process for an CloudHSM key store, KMS finds the CloudHSM cluster that is associated with the custom key store, creates the connection infrastructure, connects to the cluster, logs into the CloudHSM client as the kmsuser CU, and rotates its password.

To connect an CloudHSM key store, its associated CloudHSM cluster must have at least one active HSM. To get the number of active HSMs in a cluster, use the DescribeClusters operation. To add HSMs to the cluster, use the CreateHsm operation. Also, the kmsuser crypto user (CU) must not be logged into the cluster. This prevents KMS from using this account to log in.

If you are having trouble connecting or disconnecting a CloudHSM key store, see Troubleshooting an CloudHSM key store in the Key Management Service Developer Guide.

External key store

When you connect an external key store that uses public endpoint connectivity, KMS tests its ability to communicate with your external key manager by sending a request via the external key store proxy.

When you connect to an external key store that uses VPC endpoint service connectivity, KMS establishes the networking elements that it needs to communicate with your external key manager via the external key store proxy. This includes creating an interface endpoint to the VPC endpoint service and a private hosted zone for traffic between KMS and the VPC endpoint service.

To connect an external key store, KMS must be able to connect to the external key store proxy, the external key store proxy must be able to communicate with your external key manager, and the external key manager must be available for cryptographic operations.

If you are having trouble connecting or disconnecting an external key store, see Troubleshooting an external key store in the Key Management Service Developer Guide.

Cross-account use: No. You cannot perform this operation on a custom key store in a different Amazon Web Services account.

Required permissions: kms:ConnectCustomKeyStore (IAM policy)

Related operations

• CreateCustomKeyStore
• DeleteCustomKeyStore
• DescribeCustomKeyStores
• DisconnectCustomKeyStore
• UpdateCustomKeyStore