WebFinger endpoint

app/controllers/webfinger_controller.rb

@@ -0,0 +1,59 @@
+class WebfingerController < ApplicationController
+
+  before_action :allow_cross_origin, :only => [:show]
+
+  layout false
+
+  def show
+    resource = params[:resource]
+
+    if resource && resource.match(/acct:\w+/)
+      useraddress = resource.split(":").last
+      username, org = useraddress.split("@")
+      username.downcase!
+      unless User.where(cn: username, ou: org).any?
+        head 404 and return
+      end
+
+      render json: webfinger(useraddress).to_json,
+             content_type: "application/jrd+json"
+    else
+      head 422 and return
+    end
+  end
+
+  private
+
+  def webfinger(useraddress)
+    links = [];
+
+    links << remotestorage_link(useraddress) if Setting.remotestorage_enabled
+
+    { "links" => links }
+  end
+
+  def remotestorage_link(useraddress)
+    # TODO use when OAuth routes are available
+    # auth_url = new_rs_oauth_url(useraddress)
+    auth_url = "https://example.com/rs/oauth"
+    storage_url = "#{Setting.rs_storage_url}/#{useraddress}"
+
+    {
+      "rel" => "http://tools.ietf.org/id/draft-dejong-remotestorage",
+      "href" => storage_url,
+      "properties" => {
+        "http://remotestorage.io/spec/version" => "draft-dejong-remotestorage-13",
+        "http://tools.ietf.org/html/rfc6749#section-4.2" => auth_url,
+        "http://tools.ietf.org/html/rfc6750#section-2.3" => nil, # access token via a HTTP query parameter
+        "http://tools.ietf.org/html/rfc7233": "GET", # content range requests
+        "http://remotestorage.io/spec/web-authoring": nil
+      }
+    }
+  end
+
+  def allow_cross_origin
+    headers['Access-Control-Allow-Origin'] = '*'
+    headers['Access-Control-Allow-Methods'] = 'GET, POST, PUT, OPTIONS'
+  end
+
+end