module ActionController
module HttpAuthentication
# Makes it dead easy to do HTTP Basic authentication.
#
# Simple Basic example:
#
# class PostsController < ApplicationController
# USER_NAME, PASSWORD = "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_basic do |user_name, password|
# user_name == USER_NAME && password == PASSWORD
# end
# end
# end
#
#
# Here is a more advanced Basic example where only Atom feeds and the XML API is protected by HTTP authentication,
# the regular HTML interface is protected by a session approach:
#
# class ApplicationController < ActionController::Base
# before_filter :set_account, :authenticate
#
# protected
# def set_account
# @account = Account.find_by_url_name(request.subdomains.first)
# end
#
# def authenticate
# case request.format
# when Mime::XML, Mime::ATOM
# if user = authenticate_with_http_basic { |u, p| @account.users.authenticate(u, p) }
# @current_user = user
# else
# request_http_basic_authentication
# end
# else
# if session_authenticated?
# @current_user = @account.users.find(session[:authenticated][:user_id])
# else
# redirect_to(login_url) and return false
# end
# end
# 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
# get(
# "/notes/1.xml", nil,
# :authorization => ActionController::HttpAuthentication::Basic.encode_credentials(users(:dhh).name, users(:dhh).password)
# )
#
# assert_equal 200, status
# end
#
#
# On shared hosts, Apache sometimes doesn't pass authentication headers to
# FCGI instances. If your environment matches this description and you cannot
# authenticate, try this rule in your Apache setup:
#
# RewriteRule ^(.*)$ dispatch.fcgi [E=X-HTTP_AUTHORIZATION:%{HTTP:Authorization},QSA,L]
module Basic
extend self
module ControllerMethods
def authenticate_or_request_with_http_basic(realm = "Application", &login_procedure)
authenticate_with_http_basic(&login_procedure) || request_http_basic_authentication(realm)
end
def authenticate_with_http_basic(&login_procedure)
HttpAuthentication::Basic.authenticate(self, &login_procedure)
end
def request_http_basic_authentication(realm = "Application")
HttpAuthentication::Basic.authentication_request(self, realm)
end
end
def authenticate(controller, &login_procedure)
unless authorization(controller.request).blank?
login_procedure.call(*user_name_and_password(controller.request))
end
end
def user_name_and_password(request)
decode_credentials(request).split(/:/, 2)
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
def decode_credentials(request)
# Properly decode credentials spanning a new-line
auth = authorization(request)
auth.slice!('Basic ')
ActiveSupport::Base64.decode64(auth || '')
end
def encode_credentials(user_name, password)
"Basic #{ActiveSupport::Base64.encode64("#{user_name}:#{password}")}"
end
def authentication_request(controller, realm)
controller.headers["WWW-Authenticate"] = %(Basic realm="#{realm.gsub(/"/, "")}")
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
