diff options
Diffstat (limited to 'actionpack/lib/action_controller/http_authentication.rb')
| -rw-r--r-- | actionpack/lib/action_controller/http_authentication.rb | 191 |
1 files changed, 189 insertions, 2 deletions
diff --git a/actionpack/lib/action_controller/http_authentication.rb b/actionpack/lib/action_controller/http_authentication.rb index 2ed810db7d..3cb5829eca 100644 --- a/actionpack/lib/action_controller/http_authentication.rb +++ b/actionpack/lib/action_controller/http_authentication.rb @@ -55,7 +55,31 @@ module ActionController # end # end # - # + # Simple Digest example. Note the 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. + # + # class PostsController < ApplicationController + # Users = {"dhh" => "secret"} + # + # before_filter :authenticate, :except => [ :index ] + # + # def index + # render :text => "Everyone can see me!" + # end + # + # def edit + # render :text => "I'm only accessible if you know the password" + # end + # + # private + # def authenticate + # authenticate_or_request_with_http_digest(realm) do |user_name| + # Users[user_name] + # end + # end + # end + # + # # In your integration tests, you can do something like this: # # def test_access_granted_from_xml @@ -108,7 +132,10 @@ module ActionController end def decode_credentials(request) - ActiveSupport::Base64.decode64(authorization(request).split.last || '') + # Properly decode credentials spanning a new-line + auth = authorization(request) + auth.slice!('Basic ') + ActiveSupport::Base64.decode64(auth || '') end def encode_credentials(user_name, password) @@ -120,5 +147,165 @@ module ActionController controller.__send__ :render, :text => "HTTP Basic: Access denied.\n", :status => :unauthorized end end + + module Digest + extend self + + module ControllerMethods + def authenticate_or_request_with_http_digest(realm = "Application", &password_procedure) + begin + authenticate_with_http_digest!(realm, &password_procedure) + rescue ActionController::HttpAuthentication::Error => e + msg = e.message + msg = "#{msg} expected '#{e.expected}' was '#{e.was}'" unless e.expected.nil? + raise msg if e.fatal? + request_http_digest_authentication(realm, msg) + end + end + + # Authenticate using HTTP Digest, throwing ActionController::HttpAuthentication::Error on failure. + # This allows more detailed analysis of authentication failures + # to be relayed to the client. + def authenticate_with_http_digest!(realm = "Application", &login_procedure) + HttpAuthentication::Digest.authenticate(self, realm, &login_procedure) + end + + # Authenticate with HTTP Digest, returns true or false + def authenticate_with_http_digest(realm = "Application", &login_procedure) + HttpAuthentication::Digest.authenticate(self, realm, &login_procedure) rescue false + end + + # Render output including the HTTP Digest authentication header + def request_http_digest_authentication(realm = "Application", message = nil) + HttpAuthentication::Digest.authentication_request(self, realm, message) + end + + # Add HTTP Digest authentication header to result headers + def http_digest_authentication_header(realm = "Application") + HttpAuthentication::Digest.authentication_header(self, realm) + end + end + + # Raises error unless authentictaion succeeds, returns true otherwise + def authenticate(controller, realm, &password_procedure) + raise Error.new(false), "No authorization header found" unless authorization(controller.request) + validate_digest_response(controller, realm, &password_procedure) + true + end + + def authorization(request) + request.env['HTTP_AUTHORIZATION'] || + request.env['X-HTTP_AUTHORIZATION'] || + request.env['X_HTTP_AUTHORIZATION'] || + request.env['REDIRECT_X_HTTP_AUTHORIZATION'] + end + + # Raises error unless the request credentials response value matches the expected value. + def validate_digest_response(controller, realm, &password_procedure) + credentials = decode_credentials(controller.request) + + # Check the nonce, opaque and realm. + # Ignore nc, as we have no way to validate the number of times this nonce has been used + validate_nonce(controller.request, credentials[:nonce]) + raise Error.new(false, realm, credentials[:realm]), "Realm doesn't match" unless realm == credentials[:realm] + raise Error.new(true, opaque(controller.request), credentials[:opaque]),"Opaque doesn't match" unless opaque(controller.request) == credentials[:opaque] + + password = password_procedure.call(credentials[:username]) + raise Error.new(false), "No password" if password.nil? + expected = expected_response(controller.request.env['REQUEST_METHOD'], controller.request.url, credentials, password) + raise Error.new(false, expected, credentials[:response]), "Invalid response" unless expected == credentials[:response] + 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(':')) + 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) + "Digest " + credentials.sort_by {|x| x[0].to_s }.inject([]) {|a, v| a << "#{v[0]}='#{v[1]}'" }.join(', ') + end + + def decode_credentials(request) + authorization(request).to_s.gsub(/^Digest\s+/,'').split(',').inject({}) do |hash, pair| + key, value = pair.split('=', 2) + hash[key.strip.to_sym] = value.to_s.gsub(/^"|"$/,'').gsub(/'/, '') + hash + end + end + + def authentication_header(controller, realm) + controller.headers["WWW-Authenticate"] = %(Digest realm="#{realm}", qop="auth", algorithm=MD5, nonce="#{nonce(controller.request)}", opaque="#{opaque(controller.request)}") + end + + def authentication_request(controller, realm, message = "HTTP Digest: Access denied") + authentication_header(controller, realm) + controller.send! :render, :text => message, :status => :unauthorized + end + + # Uses an MD5 digest based on time to generate a value to be used only once. + # + # A server-specified data string which should be uniquely generated each time a 401 response is made. + # It is recommended that this string be base64 or hexadecimal data. + # Specifically, since the string is passed in the header lines as a quoted string, the double-quote character is not allowed. + # + # The contents of the nonce are implementation dependent. + # The quality of the implementation depends on a good choice. + # A nonce might, for example, be constructed as the base 64 encoding of + # + # => time-stamp H(time-stamp ":" ETag ":" private-key) + # + # where time-stamp is a server-generated time or other non-repeating value, + # ETag is the value of the HTTP ETag header associated with the requested entity, + # and private-key is data known only to the server. + # With a nonce of this form a server would recalculate the hash portion after receiving the client authentication header and + # reject the request if it did not match the nonce from that header or + # if the time-stamp value is not recent enough. In this way the server can limit the time of the nonce's validity. + # The inclusion of the ETag prevents a replay request for an updated version of the resource. + # (Note: including the IP address of the client in the nonce would appear to offer the server the ability + # to limit the reuse of the nonce to the same client that originally got it. + # However, that would break proxy farms, where requests from a single user often go through different proxies in the farm. + # Also, IP address spoofing is not that hard.) + # + # An implementation might choose not to accept a previously used nonce or a previously used digest, in order to + # protect against a replay attack. Or, an implementation might choose to use one-time nonces or digests for + # 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(request, time = Time.now) + session_id = request.is_a?(String) ? request : request.session.session_id + t = time.to_i + hashed = [t, session_id] + digest = ::Digest::MD5.hexdigest(hashed.join(":")) + Base64.encode64("#{t}:#{digest}").gsub("\n", '') + end + + def validate_nonce(request, value) + t = Base64.decode64(value).split(":").first.to_i + raise Error.new(true), "Stale Nonce" if (t - Time.now.to_i).abs > 10 * 60 + n = nonce(request, t) + raise Error.new(true, value, n), "Bad Nonce" unless n == value + end + + # Opaque based on digest of session_id + def opaque(request) + session_id = request.is_a?(String) ? request : request.session.session_id + @opaque ||= Base64.encode64(::Digest::MD5::hexdigest(session_id)).gsub("\n", '') + end + end + + class Error < RuntimeError + attr_accessor :expected, :was + def initialize(fatal = false, expected = nil, was = nil) + @fatal = fatal + @expected = expected + @was = was + end + + def fatal?; @fatal; end + end end end |