OSIN is an OAuth2 server library for the Go language, as specified at http://tools.ietf.org/html/rfc6749 and http://tools.ietf.org/html/draft-ietf-oauth-v2-10.

It also includes support for PKCE, as specified at https://tools.ietf.org/html/rfc7636, which increases security for code-exchange flows for public OAuth clients.

Using it, you can build your own OAuth2 authentication service.

The library implements the majority of the specification, like authorization and token endpoints, and authorization code, implicit, resource owner and client credentials grant types.

import (
	"github.com/openshift/osin"
	ex "github.com/openshift/osin/example"
)

// ex.NewTestStorage implements the "osin.Storage" interface
server := osin.NewServer(osin.NewServerConfig(), ex.NewTestStorage())

// Authorization code endpoint
http.HandleFunc("/authorize", func(w http.ResponseWriter, r *http.Request) {
	resp := server.NewResponse()
	defer resp.Close()

	if ar := server.HandleAuthorizeRequest(resp, r); ar != nil {

		// HANDLE LOGIN PAGE HERE

		ar.Authorized = true
		server.FinishAuthorizeRequest(resp, r, ar)
	}
	osin.OutputJSON(resp, w, r)
})

// Access token endpoint
http.HandleFunc("/token", func(w http.ResponseWriter, r *http.Request) {
	resp := server.NewResponse()
	defer resp.Close()

	if ar := server.HandleAccessRequest(resp, r); ar != nil {
		ar.Authorized = true
		server.FinishAccessRequest(resp, r, ar)
	}
	osin.OutputJSON(resp, w, r)
})

http.ListenAndServe(":14000", nil)

Open in your web browser:

http://localhost:14000/authorize?response_type=code&client_id=1234&redirect_uri=http%3A%2F%2Flocalhost%3A14000%2Fappauth%2Fcode

There is a mock available at example/teststorage.go which you can use as a guide for writing your own.

You might want to check out other implementations for common database management systems as well:

• PostgreSQL
• MongoDB
• RethinkDB
• DynamoDB
• Couchbase
• MySQL
• Redis

The code is licensed using "New BSD" license.

Rangel Reale [email protected]

• NON-BREAKING CHANGES
  • Updated imports in examples to use github.com/openshift/osin instead of github.com/RangelReale/osin

• BREAKING CHANGES:

  • Storage interface has 2 new methods, Clone and Close, to better support storages that need to clone / close in each connection (mgo)

  • Client was changed to be an interface instead of an struct. Because of that, the Storage interface also had to change, as interface is already a pointer.

  • HOW TO FIX YOUR CODE:

    • In your Storage, add a Clone function returning itself, and a do nothing Close.

    • In your Storage, replace all *osin.Client with osin.Client (remove the pointer reference)

    • If you used the osin.Client struct directly in your code, change it to osin.DefaultClient, which is a struct with the same fields that implements the interface.

    • Change all accesses using osin.Client to use the methods instead of the fields directly.

    • You MUST defer Response.Close in all your http handlers, otherwise some Storages may not clean correctly.

        resp := server.NewResponse()
        defer resp.Close()