Azure Key Vault seal configuration

Seal wrapping requires Vault Enterprise

All Vault versions support auto-unseal for Azure Key Vault, but seal wrapping requires Vault Enterprise.

Vault Enterprise enables seal wrapping by default, which means the KMS service must be available at runtime and not just during the unseal process. Refer to the Seal wrap overview for more information.

The Azure Key Vault seal configures Vault to use Azure Key Vault as the seal wrapping mechanism. The Azure Key Vault seal is activated by one of the following:

The presence of a seal "azurekeyvault" block in Vault's configuration file.
The presence of the environment variable VAULT_SEAL_TYPE set to azurekeyvault. If enabling via environment variable, all other required values specific to Key Vault (i.e. VAULT_AZUREKEYVAULT_VAULT_NAME, etc.) must be also supplied, as well as all other Azure-related environment variables that lends to successful authentication (i.e. AZURE_TENANT_ID, etc.).

`azurekeyvault` example

This example shows configuring Azure Key Vault seal through the Vault configuration file by providing all the required values:

seal "azurekeyvault" {
  tenant_id      = "46646709-b63e-4747-be42-516edeaf1e14"
  client_id      = "03dc33fc-16d9-4b77-8152-3ec568f8af6e"
  client_secret  = "DUJDS3..."
  vault_name     = "hc-vault"
  key_name       = "vault_key"
}

`azurekeyvault` parameters

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

tenant_id (string: <required>): The tenant id for the Azure Active Directory organization. May also be specified by the AZURE_TENANT_ID environment variable.
client_id (string: <required or MSI>): The client id for credentials to query the Azure APIs. May also be specified by the AZURE_CLIENT_ID environment variable.
client_secret (string: <required or MSI>): The client secret for credentials to query the Azure APIs. May also be specified by the AZURE_CLIENT_SECRET environment variable.
environment (string: "AZUREPUBLICCLOUD"): The Azure Cloud environment API endpoints to use. May also be specified by the AZURE_ENVIRONMENT environment variable.
vault_name (string: <required>): The Key Vault vault to use the encryption keys for encryption and decryption. May also be specified by the VAULT_AZUREKEYVAULT_VAULT_NAME environment variable.
key_name (string: <required>): The Key Vault key to use for encryption and decryption. May also be specified by the VAULT_AZUREKEYVAULT_KEY_NAME environment variable.
resource (string: "vault.azure.net"): The AZ KeyVault resource's DNS Suffix to connect to. May also be specified in the AZURE_AD_RESOURCE environment variable. Needs to be changed to connect to Azure's Managed HSM KeyVault instance type.
disabled (string: ""): Set this to true if Vault is migrating from an auto seal configuration. Otherwise, set to false.

client_id, client_secret, and tenant_id can be indirect value references.

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.

Azure authentication values:

Note: If Vault is hosted on Azure, Vault can use Managed Service Identities (MSI) to access Azure instead of an environment and shared client id and secret. MSI must be enabled on the VMs hosting Vault, and it is the preferred configuration since MSI prevents your Azure credentials from being stored as clear text. Refer to the Production Hardening tutorial for more best practices.

Note: If you are using a Managed HSM KeyVault, AZURE_AD_RESOURCE or the resource configuration parameter must be specified; usually this should point to managedhsm.azure.net, but could point to other suffixes depending on Azure environment.

`azurekeyvault` environment variables

Alternatively, the Azure Key Vault seal can be activated by providing the following environment variables:

Key rotation

This seal supports rotating keys defined in Azure Key Vault. Key metadata is stored with the encrypted data to ensure the correct key is used during decryption operations. Simply set up Azure Key Vault with key rotation using Azure Automation Account and Vault will recognize newly rotated keys.

Tutorial

Refer to the Auto-unseal using Azure Key Vault tutorial to learn how to use the Azure Key Vault to auto-unseal a Vault server.