JezK
Edit File: digestauth.rb
# # httpauth/digestauth.rb -- HTTP digest access authentication # # Author: IPR -- Internet Programming with Ruby -- writers # Copyright (c) 2003 Internet Programming with Ruby writers. # Copyright (c) 2003 H.M. # # The original implementation is provided by H.M. # URL: http://rwiki.jin.gr.jp/cgi-bin/rw-cgi.rb?cmd=view;name= # %C7%A7%BE%DA%B5%A1%C7%BD%A4%F2%B2%FE%C2%A4%A4%B7%A4%C6%A4%DF%A4%EB # # $IPR: digestauth.rb,v 1.5 2003/02/20 07:15:47 gotoyuzo Exp $ require 'webrick/config' require 'webrick/httpstatus' require 'webrick/httpauth/authenticator' require 'digest/md5' require 'digest/sha1' module WEBrick module HTTPAuth ## # RFC 2617 Digest Access Authentication for WEBrick # # Use this class to add digest authentication to a WEBrick servlet. # # Here is an example of how to set up DigestAuth: # # config = { :Realm => 'DigestAuth example realm' } # # htdigest = WEBrick::HTTPAuth::Htdigest.new 'my_password_file' # htdigest.set_passwd config[:Realm], 'username', 'password' # htdigest.flush # # config[:UserDB] = htdigest # # digest_auth = WEBrick::HTTPAuth::DigestAuth.new config # # When using this as with a servlet be sure not to create a new DigestAuth # object in the servlet's #initialize. By default WEBrick creates a new # servlet instance for every request and the DigestAuth object must be # used across requests. class DigestAuth include Authenticator AuthScheme = "Digest" # :nodoc: ## # Struct containing the opaque portion of the digest authentication OpaqueInfo = Struct.new(:time, :nonce, :nc) # :nodoc: ## # Digest authentication algorithm attr_reader :algorithm ## # Quality of protection. RFC 2617 defines "auth" and "auth-int" attr_reader :qop ## # Used by UserDB to create a digest password entry def self.make_passwd(realm, user, pass) pass ||= "" Digest::MD5::hexdigest([user, realm, pass].join(":")) end ## # Creates a new DigestAuth instance. Be sure to use the same DigestAuth # instance for multiple requests as it saves state between requests in # order to perform authentication. # # See WEBrick::Config::DigestAuth for default configuration entries # # You must supply the following configuration entries: # # :Realm:: The name of the realm being protected. # :UserDB:: A database of usernames and passwords. # A WEBrick::HTTPAuth::Htdigest instance should be used. def initialize(config, default=Config::DigestAuth) check_init(config) @config = default.dup.update(config) @algorithm = @config[:Algorithm] @domain = @config[:Domain] @qop = @config[:Qop] @use_opaque = @config[:UseOpaque] @use_next_nonce = @config[:UseNextNonce] @check_nc = @config[:CheckNc] @use_auth_info_header = @config[:UseAuthenticationInfoHeader] @nonce_expire_period = @config[:NonceExpirePeriod] @nonce_expire_delta = @config[:NonceExpireDelta] @internet_explorer_hack = @config[:InternetExplorerHack] case @algorithm when 'MD5','MD5-sess' @h = Digest::MD5 when 'SHA1','SHA1-sess' # it is a bonus feature :-) @h = Digest::SHA1 else msg = format('Algorithm "%s" is not supported.', @algorithm) raise ArgumentError.new(msg) end @instance_key = hexdigest(self.__id__, Time.now.to_i, Process.pid) @opaques = {} @last_nonce_expire = Time.now @mutex = Mutex.new end ## # Authenticates a +req+ and returns a 401 Unauthorized using +res+ if # the authentication was not correct. def authenticate(req, res) unless result = @mutex.synchronize{ _authenticate(req, res) } challenge(req, res) end if result == :nonce_is_stale challenge(req, res, true) end return true end ## # Returns a challenge response which asks for for authentication # information def challenge(req, res, stale=false) nonce = generate_next_nonce(req) if @use_opaque opaque = generate_opaque(req) @opaques[opaque].nonce = nonce end param = Hash.new param["realm"] = HTTPUtils::quote(@realm) param["domain"] = HTTPUtils::quote(@domain.to_a.join(" ")) if @domain param["nonce"] = HTTPUtils::quote(nonce) param["opaque"] = HTTPUtils::quote(opaque) if opaque param["stale"] = stale.to_s param["algorithm"] = @algorithm param["qop"] = HTTPUtils::quote(@qop.to_a.join(",")) if @qop res[@response_field] = "#{@auth_scheme} " + param.map{|k,v| "#{k}=#{v}" }.join(", ") info("%s: %s", @response_field, res[@response_field]) if $DEBUG raise @auth_exception end private # :stopdoc: MustParams = ['username','realm','nonce','uri','response'] MustParamsAuth = ['cnonce','nc'] def _authenticate(req, res) unless digest_credentials = check_scheme(req) return false end auth_req = split_param_value(digest_credentials) if auth_req['qop'] == "auth" || auth_req['qop'] == "auth-int" req_params = MustParams + MustParamsAuth else req_params = MustParams end req_params.each{|key| unless auth_req.has_key?(key) error('%s: parameter missing. "%s"', auth_req['username'], key) raise HTTPStatus::BadRequest end } if !check_uri(req, auth_req) raise HTTPStatus::BadRequest end if auth_req['realm'] != @realm error('%s: realm unmatch. "%s" for "%s"', auth_req['username'], auth_req['realm'], @realm) return false end auth_req['algorithm'] ||= 'MD5' if auth_req['algorithm'].upcase != @algorithm.upcase error('%s: algorithm unmatch. "%s" for "%s"', auth_req['username'], auth_req['algorithm'], @algorithm) return false end if (@qop.nil? && auth_req.has_key?('qop')) || (@qop && (! @qop.member?(auth_req['qop']))) error('%s: the qop is not allowed. "%s"', auth_req['username'], auth_req['qop']) return false end password = @userdb.get_passwd(@realm, auth_req['username'], @reload_db) unless password error('%s: the user is not allowed.', auth_req['username']) return false end nonce_is_invalid = false if @use_opaque info("@opaque = %s", @opaque.inspect) if $DEBUG if !(opaque = auth_req['opaque']) error('%s: opaque is not given.', auth_req['username']) nonce_is_invalid = true elsif !(opaque_struct = @opaques[opaque]) error('%s: invalid opaque is given.', auth_req['username']) nonce_is_invalid = true elsif !check_opaque(opaque_struct, req, auth_req) @opaques.delete(auth_req['opaque']) nonce_is_invalid = true end elsif !check_nonce(req, auth_req) nonce_is_invalid = true end if /-sess$/i =~ auth_req['algorithm'] ha1 = hexdigest(password, auth_req['nonce'], auth_req['cnonce']) else ha1 = password end if auth_req['qop'] == "auth" || auth_req['qop'] == nil ha2 = hexdigest(req.request_method, auth_req['uri']) ha2_res = hexdigest("", auth_req['uri']) elsif auth_req['qop'] == "auth-int" body_digest = @h.new req.body { |chunk| body_digest.update(chunk) } body_digest = body_digest.hexdigest ha2 = hexdigest(req.request_method, auth_req['uri'], body_digest) ha2_res = hexdigest("", auth_req['uri'], body_digest) end if auth_req['qop'] == "auth" || auth_req['qop'] == "auth-int" param2 = ['nonce', 'nc', 'cnonce', 'qop'].map{|key| auth_req[key] }.join(':') digest = hexdigest(ha1, param2, ha2) digest_res = hexdigest(ha1, param2, ha2_res) else digest = hexdigest(ha1, auth_req['nonce'], ha2) digest_res = hexdigest(ha1, auth_req['nonce'], ha2_res) end if digest != auth_req['response'] error("%s: digest unmatch.", auth_req['username']) return false elsif nonce_is_invalid error('%s: digest is valid, but nonce is not valid.', auth_req['username']) return :nonce_is_stale elsif @use_auth_info_header auth_info = { 'nextnonce' => generate_next_nonce(req), 'rspauth' => digest_res } if @use_opaque opaque_struct.time = req.request_time opaque_struct.nonce = auth_info['nextnonce'] opaque_struct.nc = "%08x" % (auth_req['nc'].hex + 1) end if auth_req['qop'] == "auth" || auth_req['qop'] == "auth-int" ['qop','cnonce','nc'].each{|key| auth_info[key] = auth_req[key] } end res[@resp_info_field] = auth_info.keys.map{|key| if key == 'nc' key + '=' + auth_info[key] else key + "=" + HTTPUtils::quote(auth_info[key]) end }.join(', ') end info('%s: authentication succeeded.', auth_req['username']) req.user = auth_req['username'] return true end def split_param_value(string) ret = {} while string.bytesize != 0 case string when /^\s*([\w\-\.\*\%\!]+)=\s*\"((\\.|[^\"])*)\"\s*,?/ key = $1 matched = $2 string = $' ret[key] = matched.gsub(/\\(.)/, "\\1") when /^\s*([\w\-\.\*\%\!]+)=\s*([^,\"]*),?/ key = $1 matched = $2 string = $' ret[key] = matched.clone when /^s*^,/ string = $' else break end end ret end def generate_next_nonce(req) now = "%012d" % req.request_time.to_i pk = hexdigest(now, @instance_key)[0,32] nonce = [now + ":" + pk].pack("m*").chop # it has 60 length of chars. nonce end def check_nonce(req, auth_req) username = auth_req['username'] nonce = auth_req['nonce'] pub_time, pk = nonce.unpack("m*")[0].split(":", 2) if (!pub_time || !pk) error("%s: empty nonce is given", username) return false elsif (hexdigest(pub_time, @instance_key)[0,32] != pk) error("%s: invalid private-key: %s for %s", username, hexdigest(pub_time, @instance_key)[0,32], pk) return false end diff_time = req.request_time.to_i - pub_time.to_i if (diff_time < 0) error("%s: difference of time-stamp is negative.", username) return false elsif diff_time > @nonce_expire_period error("%s: nonce is expired.", username) return false end return true end def generate_opaque(req) @mutex.synchronize{ now = req.request_time if now - @last_nonce_expire > @nonce_expire_delta @opaques.delete_if{|key,val| (now - val.time) > @nonce_expire_period } @last_nonce_expire = now end begin opaque = Utils::random_string(16) end while @opaques[opaque] @opaques[opaque] = OpaqueInfo.new(now, nil, '00000001') opaque } end def check_opaque(opaque_struct, req, auth_req) if (@use_next_nonce && auth_req['nonce'] != opaque_struct.nonce) error('%s: nonce unmatched. "%s" for "%s"', auth_req['username'], auth_req['nonce'], opaque_struct.nonce) return false elsif !check_nonce(req, auth_req) return false end if (@check_nc && auth_req['nc'] != opaque_struct.nc) error('%s: nc unmatched."%s" for "%s"', auth_req['username'], auth_req['nc'], opaque_struct.nc) return false end true end def check_uri(req, auth_req) uri = auth_req['uri'] if uri != req.request_uri.to_s && uri != req.unparsed_uri && (@internet_explorer_hack && uri != req.path) error('%s: uri unmatch. "%s" for "%s"', auth_req['username'], auth_req['uri'], req.request_uri.to_s) return false end true end def hexdigest(*args) @h.hexdigest(args.join(":")) end # :startdoc: end ## # Digest authentication for proxy servers. See DigestAuth for details. class ProxyDigestAuth < DigestAuth include ProxyAuthenticator private def check_uri(req, auth_req) # :nodoc: return true end end end end