external node.js based authentication for Aspera NodeAPI

currently Linux only!

users need to use their system-user (aspera transfer user) to authenticate! if authentication is set to external_auth, NodeAPI does not translate the username that was sent to NodeAPI before calling this external_auth provider.

If the external_auth fails, NodeAPI itself retries the given user & password with the default asnodeadmin -au node_user -p node_password -x system_user configuration.

Flow is:

User (HTTP Basic) ->  NodeAPI ->  external_auth service ->  Authentication OK ?
    Yes -> NodeAPI returns authenticated - with the HTTP Basic Username as transfer User
    No  -> authentication request falls back to standard NodeAPI auth -> NodeAPI (asnodeadmin -u) auth OK?
        No -> NodeAPI returns authentication error
        Yes ->  NodeAPI returns authenticated - with the HTTP Basic Username translated to the transfer User (asnodeadmin -l) 

aspera.conf settings

set section (no asconfigurator possibility):

<server>
  <authentication>
    <provider>
      <type>external_auth</type>
      <spec>http://localhost:5555</spec>
    </provider>
 </authentication>
</server>

restart Aspera NodeAPI service: systemctl restart asperanoded

node.js rest service with pam auth

start node sever.js this has simple pam authentication and listen on the above port to authenticate users to linux system auth.

Todo

• npm module
• windows
• start as service
• ...