AWS KMS

Note: This secret engine requires Vault Enterprise with the Advanced Data Protection Module.

The Key Management secrets engine supports lifecycle management of keys in AWS KMS regions. This is accomplished by configuring a KMS provider resource with the awskms provider and other provider-specific parameter values.

The following sections describe how to properly configure the secrets engine to enable the functionality.

Authentication

The Key Management secrets engine must be configured with credentials that have sufficient permissions to manage keys in an AWS KMS region. The authentication parameters are described in the credentials section of the API documentation. The authentication parameters will be set with the following order of precedence:

KMS provider credentials
Environment variables
Shared credentials file
IAM role for AWS EC2 or ECS task

The IAM principal associated with the provided credentials must have the following minimum AWS KMS permissions:

Configuration

The following is an example of how to configure the KMS provider resource using the Vault CLI:

$ vault write keymgmt/kms/example-kms \
    provider="awskms" \
    key_collection="us-west-1" \
    credentials=access_key="ASIADJO3WTX6WPLJM42V" \
    credentials=secret_key="bCiYmNroLxLmPNQ47VIvjlm8mQu5oktZcQdq195w"

Refer to the AWS KMS API documentation for a detailed description of individual configuration parameters.

Key transfer specification

Keys are securely transferred from the secrets engine to AWS KMS regions in accordance with the AWS KMS Bring Your Own Key specification.

Key rotation

AWS KMS keys with imported key material are not eligible for automatic key rotation within AWS KMS. As such, key rotations performed by the secrets engine use the manual key rotation process. Applications should refer to the alias associated with imported keys. Aliases will always have the form: hashicorp/<key_name>-<unix_timestamp>.

Key purpose compatability

The following table defines which key purposes can be used for each key type supported by AWS KMS.

Key Type	Purpose
`aes256-gcm96`	`encrypt` and `decrypt`