auth-mux

auth-mux is an authentication multiplexer, its job is to accept many different authentication schemes and return a validation result which can optionally be used to issue new credentials using a different authentication scheme. It relies on being able to take an authentication request and return either an error message or a standard set of identity claims.

Use cases

• Transforming credentials from m issuers to a common authentication scheme
• Transforming credentials from some authentication scheme to the n different schemes supported by the systems that you run
• Supporting any of the m x n combinations above
• Securerly reissuing credentials while ensuring that the original m issuers cannot issue conflicting credentials
• Forking this repo and implementing a single interface to allow a non-standard authentication scheme to place nicely with the other systems that you run

Design

Authentication schemes are supported by implementing the Input or Output interface. An Input must implement a handler that takes an HTTP request and returns the Validation type which represents a validation result. An Output must implement a handler that takes this Validation type and returns an HTTP response.

These standard interfaces allow any Input and Output combination to be composed. The HTTP server automatically creates a handler for each combination with path /:input/:output. This allows the caller to use the HTTP path to select the authentication schemes, forming a multiplexer for the Input and a demultiplexer for the Output.