added vulnerable auth check for the API

app/controllers/api/v1/users_controller.rb

@@ -2,19 +2,46 @@ class Api::V1::UsersController < ApplicationController
   
    skip_before_filter :authenticated
    before_filter :valid_api_token
+   before_filter :extrapolate_user
   
      respond_to :json
      
-     def valid_api_token
-       authenticate_or_request_with_http_token do |token, options|
-        # TODO :add some functionality to check if the HTTP Header is valid
-        return true
-       end
-     end
-     
      def index
-      respond_with User.all
+      respond_with @user
      end
      
+private
+
+      def valid_api_token
+        authenticate_or_request_with_http_token do |token, options|
+          # TODO :add some functionality to check if the HTTP Header is valid
+          identify_user(token)
+        end
+      end
+     
+     def identify_user(token="")
+        # We've had issues with URL encoding, etc. causing issues so just to be safe
+        # we will go ahead and unescape the user's token
+        unescape_token(token)
+        @clean_token =~ /(.*?)-(.*)/
+        id = $1
+        hash = $2
+        (id && hash) ? true : false
+        check_hash(id, hash) ? true : false
+     end
+     
+     def check_hash(id, hash)
+      digest = OpenSSL::Digest::SHA1.hexdigest("#{ACCESS_TOKEN_SALT}:#{id}")
+      hash == digest 
+     end
+     
+     def unescape_token(token="")
+       @clean_token = CGI::unescape(token)
+     end
+     
+     # Added a method to make it easy to figure out who the user is.
+     def extrapolate_user
+       @user = User.find_by_id(@clean_token.split("-").first)
+     end
      
 end