@@ -68,8 +68,11 @@ module ActionController # # Simple Digest example: # + # require 'digest/md5' # class PostsController < ApplicationController - # USERS = {"dhh" => "secret"} + # REALM = "SuperSecret" + # USERS = {"dhh" => "secret", #plain text password + # "dap" => Digest:MD5::hexdigest(["dap",REALM,"secret"].join(":")) #ha1 digest password # # before_filter :authenticate, :except => [:index] # @@ -83,14 +86,18 @@ module ActionController # # private # def authenticate - # authenticate_or_request_with_http_digest(realm) do |username| + # authenticate_or_request_with_http_digest(REALM) do |username| # USERS[username] # end # end # end # - # NOTE: The +authenticate_or_request_with_http_digest+ block must return the user's password so the framework can appropriately - # hash it to check the user's credentials. Returning +nil+ will cause authentication to fail. + # NOTE: The +authenticate_or_request_with_http_digest+ block must return the user's password or the ha1 digest hash so the framework can appropriately + # hash to check the user's credentials. Returning +nil+ will cause authentication to fail. + # Storing the ha1 hash: MD5(username:realm:password), is better than storing a plain password. If + # the password file or database is compromised, the attacker would be able to use the ha1 hash to + # authenticate as the user at this +realm+, but would not have the user's password to try using at + # other sites. # # On shared hosts, Apache sometimes doesn't pass authentication headers to # FCGI instances. If your environment matches this description and you cannot @@ -177,26 +184,37 @@ module ActionController end # Raises error unless the request credentials response value matches the expected value. + # First try the password as a ha1 digest password. If this fails, then try it as a plain + # text password. def validate_digest_response(request, realm, &password_procedure) credentials = decode_credentials_header(request) valid_nonce = validate_nonce(request, credentials[:nonce]) - if valid_nonce && realm == credentials[:realm] && opaque(request.session.session_id) == credentials[:opaque] + if valid_nonce && realm == credentials[:realm] && opaque == credentials[:opaque] password = password_procedure.call(credentials[:username]) - expected = expected_response(request.env['REQUEST_METHOD'], credentials[:uri], credentials, password) - expected == credentials[:response] + + [true, false].any? do |password_is_ha1| + expected = expected_response(request.env['REQUEST_METHOD'], request.env['REQUEST_URI'], credentials, password, password_is_ha1) + expected == credentials[:response] + end end end # Returns the expected response for a request of +http_method+ to +uri+ with the decoded +credentials+ and the expected +password+ - def expected_response(http_method, uri, credentials, password) - ha1 = ::Digest::MD5.hexdigest([credentials[:username], credentials[:realm], password].join(':')) + # Optional parameter +password_is_ha1+ is set to +true+ by default, since best practice is to store ha1 digest instead + # of a plain-text password. + def expected_response(http_method, uri, credentials, password, password_is_ha1=true) + ha1 = password_is_ha1 ? password : ha1(credentials, password) ha2 = ::Digest::MD5.hexdigest([http_method.to_s.upcase, uri].join(':')) ::Digest::MD5.hexdigest([ha1, credentials[:nonce], credentials[:nc], credentials[:cnonce], credentials[:qop], ha2].join(':')) end - def encode_credentials(http_method, credentials, password) - credentials[:response] = expected_response(http_method, credentials[:uri], credentials, password) + def ha1(credentials, password) + ::Digest::MD5.hexdigest([credentials[:username], credentials[:realm], password].join(':')) + end + + def encode_credentials(http_method, credentials, password, password_is_ha1) + credentials[:response] = expected_response(http_method, credentials[:uri], credentials, password, password_is_ha1) "Digest " + credentials.sort_by {|x| x[0].to_s }.inject([]) {|a, v| a << "#{v[0]}='#{v[1]}'" }.join(', ') end @@ -213,8 +231,7 @@ module ActionController end def authentication_header(controller, realm) - session_id = controller.request.session.session_id - controller.headers["WWW-Authenticate"] = %(Digest realm="#{realm}", qop="auth", algorithm=MD5, nonce="#{nonce(session_id)}", opaque="#{opaque(session_id)}") + controller.headers["WWW-Authenticate"] = %(Digest realm="#{realm}", qop="auth", algorithm=MD5, nonce="#{nonce}", opaque="#{opaque}") end def authentication_request(controller, realm, message = nil) @@ -252,23 +269,36 @@ module ActionController # POST or PUT requests and a time-stamp for GET requests. For more details on the issues involved see Section 4 # of this document. # - # The nonce is opaque to the client. - def nonce(session_id, time = Time.now) + # The nonce is opaque to the client. Composed of Time, and hash of Time with secret + # key from the Rails session secret generated upon creation of project. Ensures + # the time cannot be modifed by client. + def nonce(time = Time.now) t = time.to_i - hashed = [t, session_id] + hashed = [t, secret_key] digest = ::Digest::MD5.hexdigest(hashed.join(":")) Base64.encode64("#{t}:#{digest}").gsub("\n", '') end - def validate_nonce(request, value) + # Might want a shorter timeout depending on whether the request + # is a PUT or POST, and if client is browser or web service. + # Can be much shorter if the Stale directive is implemented. This would + # allow a user to use new nonce without prompting user again for their + # username and password. + def validate_nonce(request, value, seconds_to_timeout=5*60) t = Base64.decode64(value).split(":").first.to_i - nonce(request.session.session_id, t) == value && (t - Time.now.to_i).abs <= 10 * 60 + nonce(t) == value && (t - Time.now.to_i).abs <= seconds_to_timeout end - # Opaque based on digest of session_id - def opaque(session_id) - Base64.encode64(::Digest::MD5::hexdigest(session_id)).gsub("\n", '') + # Opaque based on random generation - but changing each request? + def opaque() + ::Digest::MD5.hexdigest(secret_key) end + + # Set in /initializers/session_store.rb, and loaded even if sessions are not in use. + def secret_key + ActionController::Base.session_options[:secret] + end + end end end actionpack/lib/action_controller/http_authentication.rb @@ -5,7 +5,8 @@ class HttpDigestAuthenticationTest < ActionController::TestCase before_filter :authenticate, :only => :index before_filter :authenticate_with_request, :only => :display - USERS = { 'lifo' => 'world', 'pretty' => 'please' } + USERS = { 'lifo' => 'world', 'pretty' => 'please', + 'dhh' => ::Digest::MD5::hexdigest(["dhh","SuperSecret","secret"].join(":"))} def index render :text => "Hello Secret" @@ -107,8 +108,42 @@ class HttpDigestAuthenticationTest < ActionController::TestCase assert_equal 'Definitely Maybe', @response.body end - test "authentication request with relative URI" do - @request.env['HTTP_AUTHORIZATION'] = encode_credentials(:uri => "/", :username => 'pretty', :password => 'please') + test "authentication request with valid credential and nil session" do + @request.env['HTTP_AUTHORIZATION'] = encode_credentials(:username => 'pretty', :password => 'please') + + # session_id = "" in functional test, but is +nil+ in real life + @request.session.session_id = nil + get :display + + assert_response :success + assert assigns(:logged_in) + assert_equal 'Definitely Maybe', @response.body + end + + test "authentication request with request-uri that doesn't match credentials digest-uri" do + @request.env['HTTP_AUTHORIZATION'] = encode_credentials(:username => 'pretty', :password => 'please') + @request.env['REQUEST_URI'] = "/http_digest_authentication_test/dummy_digest/altered/uri" + get :display + + assert_response :unauthorized + assert_equal "Authentication Failed", @response.body + end + + test "authentication request with absolute uri" do + @request.env['HTTP_AUTHORIZATION'] = encode_credentials(:uri => "http://test.host/http_digest_authentication_test/dummy_digest/display", + :username => 'pretty', :password => 'please') + @request.env['REQUEST_URI'] = "http://test.host/http_digest_authentication_test/dummy_digest/display" + get :display + + assert_response :success + assert assigns(:logged_in) + assert_equal 'Definitely Maybe', @response.body + end + + test "authentication request with password stored as ha1 digest hash" do + @request.env['HTTP_AUTHORIZATION'] = encode_credentials(:username => 'dhh', + :password => ::Digest::MD5::hexdigest(["dhh","SuperSecret","secret"].join(":")), + :password_is_ha1 => true) get :display assert_response :success @@ -119,18 +154,22 @@ class HttpDigestAuthenticationTest < ActionController::TestCase private def encode_credentials(options) - options.reverse_merge!(:nc => "00000001", :cnonce => "0a4f113b") + options.reverse_merge!(:nc => "00000001", :cnonce => "0a4f113b", :password_is_ha1 => false) password = options.delete(:password) - # Perform unautheticated get to retrieve digest parameters to use on subsequent request + # Set in /initializers/session_store.rb. Used as secret in generating nonce + # to prevent tampering of timestamp + ActionController::Base.session_options[:secret] = "session_options_secret" + + # Perform unauthenticated GET to retrieve digest parameters to use on subsequent request get :index assert_response :unauthorized credentials = decode_credentials(@response.headers['WWW-Authenticate']) credentials.merge!(options) - credentials.reverse_merge!(:uri => "http://#{@request.host}#{@request.env['REQUEST_URI']}") - ActionController::HttpAuthentication::Digest.encode_credentials("GET", credentials, password) + credentials.reverse_merge!(:uri => "#{@request.env['REQUEST_URI']}") + ActionController::HttpAuthentication::Digest.encode_credentials("GET", credentials, password, options[:password_is_ha1]) end def decode_credentials(header) actionpack/test/controller/http_digest_authentication_test.rb 7b382cb9e5c5706f8d15216159a2873375915c9c Donald Parish Milhouse donald.parish@gmail.com http://github.com/rails/rails/commit/be7b64b35aac1c9e9063d1d8317f8b1be2a3411c be7b64b35aac1c9e9063d1d8317f8b1be2a3411c 2009-03-12T06:24:54-07:00 2009-03-12T06:24:54-07:00 Support MD5 passwords for Digest auth and use session_options[:secret] in nonce [#2209 state:resolved] Signed-off-by: Pratik Naik <pratiknaik@gmail.com> 39dc838e8ab9607f3ac838385090a0ce45ac99ee Pratik Naik lifo pratiknaik@gmail.com