Question

How does authentication to Key Vault work with managed identities?

Answer 1

Authentication to Azure Key Vault with managed identities occurs through automatic token retrieval from the Azure Instance Metadata Service, which the service uses to authenticate and subsequently access secrets within Key Vault. This process negates the need to manage credentials manually.

Step-by-step explanation:

Authentication to Azure Key Vault using managed identities simplifies the process of securing access to the Key Vault from Azure services. Managed identities eliminate the need for developers to manage credentials. Instead, Azure provides an identity for your service instance, such as Azure VM, App Service, or Azure Functions, which can be used for authentication with Azure Key Vault.

Here's how it works step-by-step:

1. An Azure service instance with managed identity enabled makes a request to the Azure Instance Metadata Service (IMDS) endpoint to get an access token.
2. The IMDS grants a token for the Azure service identity.
3. The Azure service uses this token to authenticate with Azure Key Vault.
4. Once authenticated, the service can then retrieve secrets, keys, or certificates as needed, following permissions assigned to the identity.

This process ensures your application does not hold direct credentials for Key Vault, thus enhancing security by using the Azure Active Directory (Azure AD) for authentication purposes.