func TestLDAPUserCache(t *testing.T) {
	Convey("Given an LDAP user cache connected to our server", t, func() {
		// The SSH agent stuff was moved up here so that we can use it to
		// dynamically create the LDAP result object.
		sshSock := os.Getenv("SSH_AUTH_SOCK")
		if sshSock == "" {
			t.Skip()
		}

		c, err := net.Dial("unix", sshSock)
		if err != nil {
			t.Fatal(err)
		}
		agent := agent.NewClient(c)
		keys, err := agent.List()
		if err != nil {
			t.Fatal(err)
		}

		keyValue := base64.StdEncoding.EncodeToString(keys[0].Blob)

		// Load in an additional key from the test data.
		privateKey, _ := ssh.ParsePrivateKey(testKey)
		testPublicKey := base64.StdEncoding.EncodeToString(privateKey.PublicKey().Marshal())

		s := &StubLDAPServer{
			Keys: []string{keyValue, testPublicKey},
		}
		lc, err := server.NewLDAPUserCache(s, g2s.Noop(), "cn", "dc=testdn,dc=com")
		So(err, ShouldBeNil)
		So(lc, ShouldNotBeNil)

		Convey("It should retrieve users from LDAP", func() {
			So(lc.Users(), ShouldNotBeEmpty)
		})

		Convey("It should verify the current user positively.", func() {
			success := false

			for i := 0; i < len(keys); i++ {
				challenge := randomBytes(64)
				sig, err := agent.Sign(keys[i], challenge)
				if err != nil {
					t.Fatal(err)
				}
				verifiedUser, err := lc.Authenticate("ericallen", challenge, sig)
				success = success || (verifiedUser != nil)
			}

			So(success, ShouldEqual, true)
		})

		Convey("When a user is requested that cannot be found in the cache", func() {
			// Use an SSH key we're guaranteed to not have.
			oldKey := s.Keys[0]
			s.Keys[0] = testPublicKey
			lc.Update()

			// Swap the key back and try verifying.
			// We should still get a result back.
			s.Keys[0] = oldKey
			success := false

			for i := 0; i < len(keys); i++ {
				challenge := randomBytes(64)
				sig, err := agent.Sign(keys[i], challenge)
				if err != nil {
					t.Fatal(err)
				}
				verifiedUser, err := lc.Authenticate("ericallen", challenge, sig)
				success = success || (verifiedUser != nil)
			}

			Convey("Then it should update LDAP again and find the user.", func() {
				So(success, ShouldEqual, true)
			})
		})

		Convey("When a user with multiple SSH keys assigned tries to use Hologram", func() {
			Convey("The system should allow them to use any key.", func() {
				success := false

				for i := 0; i < len(keys); i++ {
					challenge := randomBytes(64)
					sig, err := privateKey.Sign(cryptrand.Reader, challenge)
					if err != nil {
						t.Fatal(err)
					}
					verifiedUser, err := lc.Authenticate("ericallen", challenge, sig)
					success = success || (verifiedUser != nil)
				}

				So(success, ShouldEqual, true)

			})
		})

		testAuthorizedKey := string(ssh.MarshalAuthorizedKey(privateKey.PublicKey()))

		s = &StubLDAPServer{
			Keys: []string{testAuthorizedKey},
		}
		lc, err = server.NewLDAPUserCache(s, g2s.Noop(), "cn", "dc=testdn,dc=com")
		So(err, ShouldBeNil)
		So(lc, ShouldNotBeNil)

		Convey("The usercache should understand the SSH authorized_keys format", func() {
			challenge := randomBytes(64)
			sig, err := privateKey.Sign(cryptrand.Reader, challenge)
			if err != nil {
				t.Fatal(err)
			}
			verifiedUser, err := lc.Authenticate("ericallen", challenge, sig)
			So(verifiedUser, ShouldNotBeNil)
			So(err, ShouldBeNil)
		})
	})
}
Beispiel #2
0
func main() {
	// Parse command-line flags for this system.
	var (
		listenAddress    = flag.String("addr", "", "Address to listen to incoming requests on.")
		ldapAddress      = flag.String("ldapAddr", "", "Address to connect to LDAP.")
		ldapBindDN       = flag.String("ldapBindDN", "", "LDAP DN to bind to for login.")
		ldapInsecure     = flag.Bool("insecureLDAP", false, "INSECURE: Don't use TLS for LDAP connection.")
		ldapBindPassword = flag.String("ldapBindPassword", "", "LDAP password for bind.")
		statsdHost       = flag.String("statsHost", "", "Address to send statsd metrics to.")
		iamAccount       = flag.String("iamaccount", "", "AWS Account ID for generating IAM Role ARNs")
		enableLDAPRoles  = flag.Bool("ldaproles", false, "Enable role support using LDAP directory.")
		roleAttribute    = flag.String("roleattribute", "", "Group attribute to get role from.")
		defaultRole      = flag.String("role", "", "AWS role to assume by default.")
		configFile       = flag.String("conf", "/etc/hologram/server.json", "Config file to load.")
		cacheTimeout     = flag.Int("cachetime", 3600, "Time in seconds after which to refresh LDAP user cache.")
		debugMode        = flag.Bool("debug", false, "Enable debug mode.")
		config           Config
	)

	flag.Parse()

	// Enable debug log output if the user requested it.
	if *debugMode {
		log.DebugMode(true)
		log.Debug("Enabling debug log output. Use sparingly.")
	}

	// Parse in options from the given config file.
	log.Debug("Loading configuration from %s", *configFile)
	configContents, configErr := ioutil.ReadFile(*configFile)
	if configErr != nil {
		log.Errorf("Could not read from config file. The error was: %s", configErr.Error())
		os.Exit(1)
	}

	configParseErr := json.Unmarshal(configContents, &config)
	if configParseErr != nil {
		log.Errorf("Error in parsing config file: %s", configParseErr.Error())
		os.Exit(1)
	}

	// Merge in command flag options.
	if *ldapAddress != "" {
		config.LDAP.Host = *ldapAddress
	}

	if *ldapInsecure {
		config.LDAP.InsecureLDAP = true
	}

	if *ldapBindDN != "" {
		config.LDAP.Bind.DN = *ldapBindDN
	}

	if *ldapBindPassword != "" {
		config.LDAP.Bind.Password = *ldapBindPassword
	}

	if *statsdHost != "" {
		config.Stats = *statsdHost
	}

	if *iamAccount != "" {
		config.AWS.Account = *iamAccount
	}

	if *listenAddress != "" {
		config.Listen = *listenAddress
	}

	if *defaultRole != "" {
		config.AWS.DefaultRole = *defaultRole
	}

	if *enableLDAPRoles {
		config.LDAP.EnableLDAPRoles = true
	}

	if *roleAttribute != "" {
		config.LDAP.RoleAttribute = *roleAttribute
	}

	if *cacheTimeout != 3600 {
		config.CacheTimeout = *cacheTimeout
	}

	var stats g2s.Statter
	var statsErr error

	if config.LDAP.UserAttr == "" {
		config.LDAP.UserAttr = "cn"
	}

	if config.Stats == "" {
		log.Debug("No statsd server specified; no metrics will be emitted by this program.")
		stats = g2s.Noop()
	} else {
		stats, statsErr = g2s.Dial("udp", config.Stats)
		if statsErr != nil {
			log.Errorf("Error connecting to statsd: %s. No metrics will be emitted by this program.", statsErr.Error())
			stats = g2s.Noop()
		} else {
			log.Debug("This program will emit metrics to %s", config.Stats)
		}
	}

	// Setup the server state machine that responds to requests.
	auth, err := aws.GetAuth(os.Getenv("HOLOGRAM_AWSKEY"), os.Getenv("HOLOGRAM_AWSSECRET"), "", time.Now())
	if err != nil {
		log.Errorf("Error getting instance credentials: %s", err.Error())
		os.Exit(1)
	}

	stsConnection := sts.New(auth, aws.Regions["us-east-1"])
	credentialsService := server.NewDirectSessionTokenService(config.AWS.Account, stsConnection)

	var ldapServer *ldap.Conn

	// Connect to the LDAP server using TLS or not depending on the config
	if config.LDAP.InsecureLDAP {
		log.Debug("Connecting to LDAP at server %s (NOT using TLS).", config.LDAP.Host)
		ldapServer, err = ldap.Dial("tcp", config.LDAP.Host)
		if err != nil {
			log.Errorf("Could not dial LDAP! %s", err.Error())
			os.Exit(1)
		}
	} else {
		// Connect to the LDAP server with sample credentials.
		tlsConfig := &tls.Config{
			InsecureSkipVerify: true,
		}

		log.Debug("Connecting to LDAP at server %s.", config.LDAP.Host)
		ldapServer, err = ldap.DialTLS("tcp", config.LDAP.Host, tlsConfig)
		if err != nil {
			log.Errorf("Could not dial LDAP! %s", err.Error())
			os.Exit(1)
		}
	}

	if bindErr := ldapServer.Bind(config.LDAP.Bind.DN, config.LDAP.Bind.Password); bindErr != nil {
		log.Errorf("Could not bind to LDAP! %s", bindErr.Error())
		os.Exit(1)
	}

	ldapCache, err := server.NewLDAPUserCache(ldapServer, stats, config.LDAP.UserAttr, config.LDAP.BaseDN, config.LDAP.EnableLDAPRoles, config.LDAP.RoleAttribute)
	if err != nil {
		log.Errorf("Top-level error in LDAPUserCache layer: %s", err.Error())
		os.Exit(1)
	}

	serverHandler := server.New(ldapCache, credentialsService, config.AWS.DefaultRole, stats, ldapServer, config.LDAP.UserAttr, config.LDAP.BaseDN, config.LDAP.EnableLDAPRoles)
	server, err := remote.NewServer(config.Listen, serverHandler.HandleConnection)

	// Wait for a signal from the OS to shutdown.
	terminate := make(chan os.Signal)
	signal.Notify(terminate, syscall.SIGINT, syscall.SIGTERM)

	// SIGUSR1 and SIGUSR2 should make Hologram enable and disable debug logging,
	// respectively.
	debugEnable := make(chan os.Signal)
	debugDisable := make(chan os.Signal)
	signal.Notify(debugEnable, syscall.SIGUSR1)
	signal.Notify(debugDisable, syscall.SIGUSR2)

	// SIGHUP should make Hologram server reload its cache of user information
	// from LDAP.
	reloadCacheSigHup := make(chan os.Signal)
	signal.Notify(reloadCacheSigHup, syscall.SIGHUP)

	// Reload the cache based on time set in configuration
	cacheTimeoutTicker := time.NewTicker(time.Duration(config.CacheTimeout) * time.Second)

	log.Info("Hologram server is online, waiting for termination.")

WaitForTermination:
	for {
		select {
		case <-terminate:
			break WaitForTermination
		case <-debugEnable:
			log.Info("Enabling debug mode.")
			log.DebugMode(true)
		case <-debugDisable:
			log.Info("Disabling debug mode.")
			log.DebugMode(false)
		case <-reloadCacheSigHup:
			log.Info("Force-reloading user cache.")
			ldapCache.Update()
		case <-cacheTimeoutTicker.C:
			log.Info("Cache timeout. Reloading user cache.")
			ldapCache.Update()
		}
	}

	log.Info("Caught signal; shutting down now.")
	server.Close()
}