Secure your API with Entra ID¶

This how-to guides you through the steps required to secure your API using Entra ID:

Grant access to consumers¶

Depending on who your consumers are, you must grant access to either applications, users, or both.

Applications¶

By default, no applications have access to your API. You must explicitly grant access to consumer applications.

spec:
  accessPolicy:
    inbound:
      rules:
        - application: app-a

        - application: app-b
          namespace: other-namespace

        - application: app-c
          namespace: other-namespace
          cluster: other-cluster

The above configuration authorizes the following applications:

• application app-a running in the same namespace and same cluster as your application
• application app-b running in the namespace other-namespace in the same cluster
• application app-c running in the namespace other-namespace in the cluster other-cluster

Users¶

By default, no users have access to your application. You must explicitly grant access to either specific groups, all users, or both.

Groups¶

The following configuration only grants users that are direct members of the specified groups access to your application:

spec:
  azure:
    application:
      enabled: true
      allowAllUsers: false
      claims:
        groups:
          - id: "<group identifier>"

where each group is specified by their unique identifier.

To find your group's identifier, see finding the group identifier.

All users¶

The following configuration grants all users access your application:

spec:
  azure:
    application:
      enabled: true
      allowAllUsers: true

Groups and all users¶

If you want to implement custom group-based authorization logic in your application, combine the above two configurations:

spec:
  azure:
    application:
      enabled: true
      allowAllUsers: true
      claims:
        groups:
          - id: "<group identifier>"

This has the following effects:

• All users will have access to your application
• If a given user is a direct member of any matching group, the group's identifier will be emitted in the groups claim.

Now that you have granted access to your consumers, they can now acquire tokens that target your application, either:

• on behalf of an employee, or
• as an application

You will need to validate these tokens in your application.

Validate tokens¶

Verify incoming requests from consumers by validating the JWT Bearer token in the Authorization header.

To validate a token, you can either:

• validate tokens with Texas, or
• validate JWTs manually in your application

Validate with Texas¶

Send a HTTP POST request to the endpoint found in the NAIS_TOKEN_INTROSPECTION_ENDPOINT environment variable. The request must have a Content-Type header set to either:

• application/json or
• application/x-www-form-urlencoded

The body of the request should contain the following parameters:

POST ${NAIS_TOKEN_INTROSPECTION_ENDPOINT} HTTP/1.1
Content-Type: application/json

{
    "identity_provider": "azuread",
    "token": "eyJra..."
}

POST ${NAIS_TOKEN_INTROSPECTION_ENDPOINT} HTTP/1.1
Content-Type: application/x-www-form-urlencoded

identity_provider=azuread&
token=eyJra...

The response is always a HTTP 200 OK response with a JSON body.

It always contains the active field, which is a boolean value that indicates whether the token is valid or not.

Success response¶

If the token is valid, the response will also contain all the token's claims:

{
    "active": true,
    "exp": 1730980893,
    "iat": 1730977293,
    ...
}

Texas validates the standard claims. Other claims are not validated. Your application must validate these claims according to your own requirements.

Error response¶

If the token is invalid, the only additional field in the response is the error field:

{
    "active": false,
    "error": "token is expired"
}

The error field contains a human-readable error message that describes why the token is invalid.

Validate JWT manually¶

Validating a JWT involves a number of steps. These steps are outlined and described below in a language- and framework-agnostic way.

To validate the token, start by validating the signature and standard time-related claims.

Additionally, perform the following validations:

Issuer Validation

Validate that the iss claim has a value that is equal to either:

1. the AZURE_OPENID_CONFIG_ISSUER environment variable, or
2. the issuer property from the metadata discovery document. The document is found at the endpoint pointed to by the AZURE_APP_WELL_KNOWN_URL environment variable.

Audience Validation

Validate that the aud claim is equal to the AZURE_APP_CLIENT_ID environment variable.

Signature Validation

Validate that the token is signed with a public key published at the JWKS endpoint. This endpoint URI can be found in one of two ways:

1. the AZURE_OPENID_CONFIG_JWKS_URI environment variable, or
2. the jwks_uri property from the metadata discovery document. The document is found at the endpoint pointed to by the AZURE_APP_WELL_KNOWN_URL environment variable.

Claims Validation

Other claims may be present in the token. Validation of these claims is optional.