This plugin allows RabbitMQ clients authenticate using x509 certificates and TLS (PKI) peer verification mechanism instead of credentials (username/password pairs).

When a client connects and performs TLS upgrade, the username is obtained from the client's TLS (x509) certificate. The user's password is not checked.

In order to use this mechanism the client must connect with TLS enabled, and present a client certificate.

This mechanism must also be enabled in RabbitMQ's configuration file, see Authentication Mechanisms and Configuration guides for more details.

A couple of examples:

[
  {rabbit, [
    {auth_mechanisms, ['PLAIN', 'AMQPLAIN', 'EXTERNAL']}
  ]}
].

to allow this mechanism in addition to the defaults, or:

[
  {rabbit, [
    {auth_mechanisms, ['EXTERNAL']}
  ]}
].

to allow only this mechanism and prohibit connections that use username and passwords.

For safety the server must be configured with the SSL option 'verify' set to 'verify_peer', to ensure that if an SSL client presents a certificate, it gets verified.

By default this will set the username to an RFC 4514-ish string form of the certificate's subject's Distinguished Name, similar to that produced by OpenSSL's "-nameopt RFC 2253" option.

You can obtain this string form from a certificate with a command like:

openssl x509 -in path/to/cert.pem -nameopt RFC2253 -subject -noout

or from an existing amqps connection with commands like:

rabbitmqctl list_connections peer_cert_subject

To use the Common Name instead, set rabbit.ssl_cert_login_from to common_name:

[
  {rabbit, [
    {auth_mechanisms, ['PLAIN', 'AMQPLAIN', 'EXTERNAL']},
    {ssl_cert_login_from, common_name}
  ]}
].

Note that the authenticated user will then be looked up in the configured authentication / authorisation backend(s). This will be the internal node database by default but could include other backends if so configured.

(c) Pivotal Software Inc., 2007 — 2017.

Released under the same license as RabbitMQ.