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awskms seal

The AWS KMS seal configures OpenBao to use AWS KMS as the seal wrapping mechanism. The AWS KMS seal is activated by one of the following:

  • The presence of a seal "awskms" block in OpenBao's configuration file
  • The presence of the environment variable VAULT_SEAL_TYPE set to awskms. If enabling via environment variable, all other required values specific to AWS KMS (i.e. VAULT_AWSKMS_SEAL_KEY_ID) must be also supplied, as well as all other AWS-related environment variables that lends to successful authentication (i.e. AWS_ACCESS_KEY_ID, etc.).

awskms example​

This example shows configuring AWS KMS seal through the OpenBao configuration file by providing all the required values:

seal "awskms" {
  region     = "us-east-1"
  access_key = "AKIAIOSFODNN7EXAMPLE"
  secret_key = "wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY"
  kms_key_id = "19ec80b0-dfdd-4d97-8164-c6examplekey"
  endpoint   = "https://vpce-0e1bb1852241f8cc6-pzi0do8n.kms.us-east-1.vpce.amazonaws.com"
}

awskms parameters​

These parameters apply to the seal stanza in the OpenBao configuration file:

  • region (string: "us-east-1"): The AWS region where the encryption key lives. If not provided, may be populated from the AWS_REGION or AWS_DEFAULT_REGION environment variables, from your ~/.aws/config file, or from instance metadata.

  • access_key (string: <required>): The AWS access key ID to use. May also be specified by the AWS_ACCESS_KEY_ID environment variable or as part of the AWS profile from the AWS CLI or instance profile.

  • session_token (string: ""): Specifies the AWS session token. This can also be provided via the environment variable AWS_SESSION_TOKEN.

  • secret_key (string: <required>): The AWS secret access key to use. May also be specified by the AWS_SECRET_ACCESS_KEY environment variable or as part of the AWS profile from the AWS CLI or instance profile.

  • kms_key_id (string: <required>): The AWS KMS key ID or ARN to use for encryption and decryption. May also be specified by the VAULT_AWSKMS_SEAL_KEY_ID environment variable. An alias in the format alias/key-alias-name may also be used here.

  • disabled (string: ""): Set this to true if OpenBao is migrating from an auto seal configuration. Otherwise, set to false.

  • endpoint (string: ""): The KMS API endpoint to be used to make AWS KMS requests. May also be specified by the AWS_KMS_ENDPOINT environment variable. This is useful, for example, when connecting to KMS over a VPC Endpoint. If not set, OpenBao will use the default API endpoint for your region.

Refer to the Seal Migration documentation for more information about the seal migration process.

Authentication​

Authentication-related values must be provided, either as environment variables or as configuration parameters.

warning

Note: Although the configuration file allows you to pass in AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY as part of the seal's parameters, it is strongly recommended to set these values via environment variables.

AWS authentication values:

  • AWS_REGION or AWS_DEFAULT_REGION
  • AWS_ACCESS_KEY_ID
  • AWS_SECRET_ACCESS_KEY

Note: The client uses the official AWS SDK and will use the specified credentials, environment credentials, shared file credentials, or IAM role/ECS task credentials in that order, if the above AWS specific values are not provided.

OpenBao needs the following permissions on the KMS key:

  • kms:Encrypt
  • kms:Decrypt
  • kms:DescribeKey

These can be granted via IAM permissions on the principal that OpenBao uses, on the KMS key policy for the KMS key, or via KMS Grants on the key.

awskms environment variables​

Alternatively, the AWS KMS seal can be activated by providing the following environment variables.

OpenBao Seal specific values:

  • VAULT_SEAL_TYPE
  • VAULT_AWSKMS_SEAL_KEY_ID

Key rotation​

This seal supports rotating the root keys defined in AWS KMS doc. Both automatic rotation and manual rotation is supported for KMS since the key information is stored with the encrypted data. Old keys must not be disabled or deleted and are used to decrypt older data. Any new or updated data will be encrypted with the current key defined in the seal configuration or set to current under a key alias.