require "base64" require "active_support/security_utils" module ActionController # Makes it dead easy to do HTTP Basic, Digest and Token authentication. module HttpAuthentication # Makes it dead easy to do HTTP \Basic authentication. # # === Simple \Basic example # # class PostsController < ApplicationController # http_basic_authenticate_with name: "dhh", password: "secret", except: :index # # def index # render plain: "Everyone can see me!" # end # # def edit # render plain: "I'm only accessible if you know the password" # end # end # # === Advanced \Basic example # # 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_action :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 # # In your integration tests, you can do something like this: # # def test_access_granted_from_xml # @request.env['HTTP_AUTHORIZATION'] = ActionController::HttpAuthentication::Basic.encode_credentials(users(:dhh).name, users(:dhh).password) # get "/notes/1.xml" # # assert_equal 200, status # end module Basic extend self module ControllerMethods extend ActiveSupport::Concern module ClassMethods def http_basic_authenticate_with(options = {}) before_action(options.except(:name, :password, :realm)) do authenticate_or_request_with_http_basic(options[:realm] || "Application") do |name, password| # This comparison uses & so that it doesn't short circuit and # uses `variable_size_secure_compare` so that length information # isn't leaked. ActiveSupport::SecurityUtils.variable_size_secure_compare(name, options[:name]) & ActiveSupport::SecurityUtils.variable_size_secure_compare(password, options[:password]) end end end end def authenticate_or_request_with_http_basic(realm = "Application", message = nil, &login_procedure) authenticate_with_http_basic(&login_procedure) || request_http_basic_authentication(realm, message) end def authenticate_with_http_basic(&login_procedure) HttpAuthentication::Basic.authenticate(request, &login_procedure) end def request_http_basic_authentication(realm = "Application", message = nil) HttpAuthentication::Basic.authentication_request(self, realm, message) end end def authenticate(request, &login_procedure) if has_basic_credentials?(request) login_procedure.call(*user_name_and_password(request)) end end def has_basic_credentials?(request) request.authorization.present? && (auth_scheme(request).downcase == "basic") end def user_name_and_password(request) decode_credentials(request).split(":", 2) end def decode_credentials(request) ::Base64.decode64(auth_param(request) || "") end def auth_scheme(request) request.authorization.to_s.split(" ", 2).first end def auth_param(request) request.authorization.to_s.split(" ", 2).second end def encode_credentials(user_name, password) "Basic #{::Base64.strict_encode64("#{user_name}:#{password}")}" end def authentication_request(controller, realm, message) message ||= "HTTP Basic: Access denied.\n" controller.headers["WWW-Authenticate"] = %(Basic realm="#{realm.tr('"'.freeze, "".freeze)}") controller.status = 401 controller.response_body = message end end # Makes it dead easy to do HTTP \Digest authentication. # # === Simple \Digest example # # require 'digest/md5' # class PostsController < ApplicationController # REALM = "SuperSecret" # USERS = {"dhh" => "secret", #plain text password # "dap" => Digest::MD5.hexdigest(["dap",REALM,"secret"].join(":"))} #ha1 digest password # # before_action :authenticate, except: [:index] # # def index # render plain: "Everyone can see me!" # end # # def edit # render plain: "I'm only accessible if you know the password" # end # # private # def authenticate # authenticate_or_request_with_http_digest(REALM) do |username| # USERS[username] # end # end # end # # === Notes # # 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. # # In rare instances, web servers or front proxies strip authorization headers before # they reach your application. You can debug this situation by logging all environment # variables, and check for HTTP_AUTHORIZATION, amongst others. module Digest extend self module ControllerMethods def authenticate_or_request_with_http_digest(realm = "Application", message = nil, &password_procedure) authenticate_with_http_digest(realm, &password_procedure) || request_http_digest_authentication(realm, message) end # Authenticate with HTTP Digest, returns true or false def authenticate_with_http_digest(realm = "Application", &password_procedure) HttpAuthentication::Digest.authenticate(request, realm, &password_procedure) 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 end # Returns false on a valid response, true otherwise def authenticate(request, realm, &password_procedure) request.authorization && validate_digest_response(request, realm, &password_procedure) end # Returns false 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) secret_key = secret_token(request) credentials = decode_credentials_header(request) valid_nonce = validate_nonce(secret_key, request, credentials[:nonce]) if valid_nonce && realm == credentials[:realm] && opaque(secret_key) == credentials[:opaque] password = password_procedure.call(credentials[:username]) return false unless password method = request.get_header("rack.methodoverride.original_method") || request.get_header("REQUEST_METHOD") uri = credentials[:uri] [true, false].any? do |trailing_question_mark| [true, false].any? do |password_is_ha1| _uri = trailing_question_mark ? uri + "?" : uri expected = expected_response(method, _uri, credentials, password, password_is_ha1) expected == credentials[:response] end end end end # Returns the expected response for a request of +http_method+ to +uri+ with the decoded +credentials+ and the expected +password+ # 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 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 }.map { |v| "#{v[0]}='#{v[1]}'" }.join(", ") end def decode_credentials_header(request) decode_credentials(request.authorization) end def decode_credentials(header) ActiveSupport::HashWithIndifferentAccess[header.to_s.gsub(/^Digest\s+/, "").split(",").map do |pair| key, value = pair.split("=", 2) [key.strip, value.to_s.gsub(/^"|"$/,"").delete('\'')] end] end def authentication_header(controller, realm) secret_key = secret_token(controller.request) nonce = self.nonce(secret_key) opaque = opaque(secret_key) controller.headers["WWW-Authenticate"] = %(Digest realm="#{realm}", qop="auth", algorithm=MD5, nonce="#{nonce}", opaque="#{opaque}") end def authentication_request(controller, realm, message = nil) message ||= "HTTP Digest: Access denied.\n" authentication_header(controller, realm) controller.status = 401 controller.response_body = message end def secret_token(request) key_generator = request.key_generator http_auth_salt = request.http_auth_salt key_generator.generate_key(http_auth_salt) 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, PUT, or PATCH 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. 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 modified by client. def nonce(secret_key, time = Time.now) t = time.to_i hashed = [t, secret_key] digest = ::Digest::MD5.hexdigest(hashed.join(":")) ::Base64.strict_encode64("#{t}:#{digest}") end # Might want a shorter timeout depending on whether the request # is a PATCH, PUT, or POST, and if the client is a 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 the user again for their # username and password. def validate_nonce(secret_key, request, value, seconds_to_timeout=5*60) return false if value.nil? t = ::Base64.decode64(value).split(":").first.to_i nonce(secret_key, t) == value && (t - Time.now.to_i).abs <= seconds_to_timeout end # Opaque based on digest of secret key def opaque(secret_key) ::Digest::MD5.hexdigest(secret_key) end end # Makes it dead easy to do HTTP Token authentication. # # Simple Token example: # # class PostsController < ApplicationController # TOKEN = "secret" # # before_action :authenticate, except: [ :index ] # # def index # render plain: "Everyone can see me!" # end # # def edit # render plain: "I'm only accessible if you know the password" # end # # private # def authenticate # authenticate_or_request_with_http_token do |token, options| # # Compare the tokens in a time-constant manner, to mitigate # # timing attacks. # ActiveSupport::SecurityUtils.secure_compare( # ::Digest::SHA256.hexdigest(token), # ::Digest::SHA256.hexdigest(TOKEN) # ) # end # end # end # # # Here is a more advanced Token example where only Atom feeds and the XML API is protected by HTTP token authentication, # the regular HTML interface is protected by a session approach: # # class ApplicationController < ActionController::Base # before_action :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_token { |t, o| @account.users.authenticate(t, o) } # @current_user = user # else # request_http_token_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 # # # In your integration tests, you can do something like this: # # def test_access_granted_from_xml # get( # "/notes/1.xml", nil, # 'HTTP_AUTHORIZATION' => ActionController::HttpAuthentication::Token.encode_credentials(users(:dhh).token) # ) # # 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 Token TOKEN_KEY = "token=" TOKEN_REGEX = /^(Token|Bearer)\s+/ AUTHN_PAIR_DELIMITERS = /(?:,|;|\t+)/ extend self module ControllerMethods def authenticate_or_request_with_http_token(realm = "Application", message = nil, &login_procedure) authenticate_with_http_token(&login_procedure) || request_http_token_authentication(realm, message) end def authenticate_with_http_token(&login_procedure) Token.authenticate(self, &login_procedure) end def request_http_token_authentication(realm = "Application", message = nil) Token.authentication_request(self, realm, message) end end # If token Authorization header is present, call the login # procedure with the present token and options. # # [controller] # ActionController::Base instance for the current request. # # [login_procedure] # Proc to call if a token is present. The Proc should take two arguments: # # authenticate(controller) { |token, options| ... } # # Returns the return value of login_procedure if a # token is found. Returns nil if no token is found. def authenticate(controller, &login_procedure) token, options = token_and_options(controller.request) unless token.blank? login_procedure.call(token, options) end end # Parses the token and options out of the token authorization header. # The value for the Authorization header is expected to have the prefix # "Token" or "Bearer". If the header looks like this: # Authorization: Token token="abc", nonce="def" # Then the returned token is "abc", and the options are # {nonce: "def"} # # request - ActionDispatch::Request instance with the current headers. # # Returns an +Array+ of [String, Hash] if a token is present. # Returns +nil+ if no token is found. def token_and_options(request) authorization_request = request.authorization.to_s if authorization_request[TOKEN_REGEX] params = token_params_from authorization_request [params.shift[1], Hash[params].with_indifferent_access] end end def token_params_from(auth) rewrite_param_values params_array_from raw_params auth end # Takes raw_params and turns it into an array of parameters def params_array_from(raw_params) raw_params.map { |param| param.split %r/=(.+)?/ } end # This removes the " characters wrapping the value. def rewrite_param_values(array_params) array_params.each { |param| (param[1] || "").gsub! %r/^"|"$/, "" } end # This method takes an authorization body and splits up the key-value # pairs by the standardized :, ;, or \t # delimiters defined in +AUTHN_PAIR_DELIMITERS+. def raw_params(auth) _raw_params = auth.sub(TOKEN_REGEX, "").split(/\s*#{AUTHN_PAIR_DELIMITERS}\s*/) if !(_raw_params.first =~ %r{\A#{TOKEN_KEY}}) _raw_params[0] = "#{TOKEN_KEY}#{_raw_params.first}" end _raw_params end # Encodes the given token and options into an Authorization header value. # # token - String token. # options - optional Hash of the options. # # Returns String. def encode_credentials(token, options = {}) values = ["#{TOKEN_KEY}#{token.to_s.inspect}"] + options.map do |key, value| "#{key}=#{value.to_s.inspect}" end "Token #{values * ", "}" end # Sets a WWW-Authenticate header to let the client know a token is desired. # # controller - ActionController::Base instance for the outgoing response. # realm - String realm to use in the header. # # Returns nothing. def authentication_request(controller, realm, message = nil) message ||= "HTTP Token: Access denied.\n" controller.headers["WWW-Authenticate"] = %(Token realm="#{realm.tr('"'.freeze, "".freeze)}") controller.__send__ :render, plain: message, status: :unauthorized end end end end