Auth Server Configuration

The Auth Server component exposes a service endpoint implementing Eclipse Hono™’s Authentication API. Other services use this component for authenticating clients and retrieving a JSON Web Token (JWT) asserting the client’s identity and corresponding authorities.

This component serves as a default implementation of the Authentication API only. On startup, it reads in all identities and their authorities from a JSON file from the file system. All data is then kept in memory and there are no remote service APIs for managing the identities and their authorities.

The Auth Server is implemented as a Quarkus application. It can be run either directly from the command line or by means of starting the corresponding Docker image created from it.

Service Configuration

The following table provides an overview of the configuration variables and corresponding system properties for configuring the Auth Server component:

The variables only need to be set if the default value does not match your environment.

In addition to the options described in the table above, this component supports the following standard configuration options:

• Common Java VM Options
• Common vert.x Options
• Monitoring Options

YAML File based Configuration

The configuration properties can also be set by means of a YAML file as described in the Quarkus documentation.

Port Configuration

The Auth Server can be configured to listen for connections on

• a secure port only (default) or
• an insecure port only or
• both a secure and an insecure port (dual port configuration)

The server will fail to start if none of the ports is configured properly.

Secure Port Only

The server needs to be configured with a private key, a certificate holding the public key and a trust store in order to open a TLS secured port.

There are two alternative ways for setting the private key and certificate:

1. Setting the HONO_AUTH_AMQP_KEYSTORE_PATH and the HONO_AUTH_AMQP_KEYSTOREPASSWORD variables in order to load the key & certificate from a password protected key store, or
2. setting the HONO_AUTH_AMQP_KEYPATH and HONO_AUTH_AMQPCERTPATH variables in order to load the key and certificate from two separate PEM files in PKCS8 format.

In order to set the trust store, the HONO_AUTH_AMQP_TRUSTSTOREPATH variable needs to be set to a key store containing the trusted root CA certificates. The HONO_AUTH_AMQP_TRUSTSTOREPASSWORD variable needs to be set if the key store requires a pass phrase for reading its contents.

When starting up, the server will bind a TLS secured socket to the default secure AMQP port 5671. The port number can also be set explicitly using the HONO_AUTH_AMQP_PORT variable.

The HONO_AUTH_AMQP_BINDADDRESS variable can be used to specify the network interface that the port should be exposed on. By default the port is bound to the loopback device only, i.e. the port will only be accessible from the local host. Setting this variable to 0.0.0.0 will let the port being bound to all network interfaces (be careful not to expose the port unintentionally to the outside world).

Insecure Port Only

The secure port will mostly be required for production scenarios. However, it might be desirable to expose a non-TLS secured port instead, e.g. for testing purposes. In any case, the non-secure port needs to be explicitly enabled either by

• explicitly setting HONO_AUTH_AMQP_INSECUREPORT to a valid port number, or by
• implicitly configuring the default AMQP port (5672) by simply setting HONO_AUTH_AMQP_INSECUREPORTENABLED to true.

The server issues a warning on the console if HONO_AUTH_AMQP_INSECUREPORT is set to the default secure AMQP port (5671).

The HONO_AUTH_AMQP_INSECUREPORTBINDADDRESS variable can be used to specify the network interface that the port should be exposed on. By default the port is bound to the loopback device only, i.e. the port will only be accessible from the local host. This variable might be used to e.g. expose the non-TLS secured port on a local interface only, thus providing easy access from within the local network, while still requiring encrypted communication when accessed from the outside over public network infrastructure.

Setting this variable to 0.0.0.0 will let the port being bound to all network interfaces (be careful not to expose the port unintentionally to the outside world).

Dual Port

In test setups and some production scenarios Hono server may be configured to open one secure and one insecure port at the same time.

This is achieved by configuring both ports correctly (see above). The server will fail to start if both ports are configured to use the same port number.

Since the secure port may need different visibility in the network setup compared to the secure port, it has its own binding address HONO_AUTH_AMQP_INSECUREPORTBINDADDRESS. This can be used to narrow the visibility of the insecure port to a local network e.g., while the secure port may be visible worldwide.

Ephemeral Ports

Both the secure as well as the insecure port numbers may be explicitly set to 0. The Auth Server will then use arbitrary (unused) port numbers determined by the operating system during startup.

Signing Key Configuration

The Auth server needs to be configured with key material that can be used to digitally sign the tokens that it creates.

The following table provides an overview of the configuration variables and corresponding system properties for configuring the Auth server’s signing process:

JSON Web Key Set Resource Configuration

The Auth server hosts an HTTP resource under URI /validating-keys that other components can use to retrieve a JSON Web Key set that contains the keys to use for validating the signature of tokens created by the Auth server.

The resource is served by the same HTTP server that is also used for hosting the health check resources described in the Monitoring & Tracing Admin Guide.

Metrics Configuration

See Monitoring & Tracing Admin Guide for details on how to configure the reporting of metrics.