Add Basic Authentication to your APIs, with username and password protection. The plugin will check for valid credentials in the Proxy-Authorization and Authorization header (in this order).


Configuration

Configuring the plugin is straightforward, you can add it on top of an API by executing the following request on your Kong server:

$ curl -X POST http://kong:8001/apis/{api}/plugins \
    --data "name=basic-auth" \
    --data "config.hide_credentials=true"

api: The id or name of the API that this plugin configuration will target

You can also apply it for every API using the http://kong:8001/plugins/ endpoint. Read the Plugin Reference for more information.

Once applied, any user with a valid credential can access the service/API. To restrict usage to only some of the authenticated users, also add the ACL plugin (not covered here) and create whitelist or blacklist groups of users.

form parameter default description
name The name of the plugin to use, in this case: basic-auth
config.hide_credentials
optional
false An optional boolean value telling the plugin to hide the credential to the upstream API server. It will be removed by Kong before proxying the request
config.anonymous
optional
`` An optional string (consumer uuid) value to use as an "anonymous" consumer if authentication fails. If empty (default), the request will fail with an authentication failure 4xx

Usage

In order to use the plugin, you first need to create a consumer to associate one or more credentials to. The Consumer represents a developer using the final service/API.

Create a Consumer

You need to associate a credential to an existing Consumer object, that represents a user consuming the API. To create a Consumer you can execute the following request:

curl -d "username=user123&custom_id=SOME_CUSTOM_ID" http://kong:8001/consumers/
parameter default description
username
semi-optional
The username of the consumer. Either this field or custom_id must be specified.
custom_id
semi-optional
A custom identifier used to map the consumer to another database. Either this field or username must be specified.

A Consumer can have many credentials.

If you are also using the ACL plugin and whitelists with this service, you must add the new consumer to a whitelisted group. See ACL: Associating Consumers for details.

Create a Credential

You can provision new username/password credentials by making the following HTTP request:

$ curl -X POST http://kong:8001/consumers/{consumer}/basic-auth \
    --data "username=Aladdin" \
    --data "password=OpenSesame"

consumer: The id or username property of the Consumer entity to associate the credentials to.

form parameter default description
username The username to use in the Basic Authentication
password
optional
The password to use in the Basic Authentication

Using the Credential

The authorization header must be base64 encoded. For example, if the credential uses Aladdin as the username and OpenSesame as the password, then the field's value is the base64-encoding of Aladdin:OpenSesame, or QWxhZGRpbjpPcGVuU2VzYW1l.

Then the Authorization (or Proxy-Authorization) header must appear as:

Authorization: Basic QWxhZGRpbjpPcGVuU2VzYW1l

Simply make a request with the header:

$ curl http://kong:8000/{api path} \
    -H 'Authorization: Basic QWxhZGRpbjpPcGVuU2VzYW1l'

Upstream Headers

When a client has been authenticated, the plugin will append some headers to the request before proxying it to the upstream API/Microservice, so that you can identify the consumer in your code:

  • X-Consumer-ID, the ID of the Consumer on Kong
  • X-Consumer-Custom-ID, the custom_id of the Consumer (if set)
  • X-Consumer-Username, the username of the Consumer (if set)
  • X-Credential-Username, the username of the Credential (only if the consumer is not the 'anonymous' consumer)
  • X-Anonymous-Consumer, will be set to true when authentication failed, and the 'anonymous' consumer was set instead.

You can use this information on your side to implement additional logic. You can use the X-Consumer-ID value to query the Kong Admin API and retrieve more information about the Consumer.