// scanHandler is an HTTP handler that accepts GET parameters for host (required)
// family and scanner, and uses these to perform scans, returning a JSON blob result.
func scanHandler(w http.ResponseWriter, r *http.Request) error {
	if err := r.ParseForm(); err != nil {
		log.Warningf("failed to parse body: %v", err)
		return errors.NewBadRequest(err)
	}

	family := r.Form.Get("family")
	scanner := r.Form.Get("scanner")
	ip := r.Form.Get("ip")
	host := r.Form.Get("host")
	if host == "" {
		log.Warningf("no host given")
		return errors.NewBadRequestString("no host given")
	}

	results, err := scan.Default.RunScans(host, ip, family, scanner, 0)
	if err != nil {
		log.Warningf("%v", err)
		return errors.NewBadRequest(err)
	}

	response := api.NewSuccessResponse(results)
	enc := json.NewEncoder(w)
	return enc.Encode(response)
}

// serverMain is the command line entry point to the API server. It sets up a
// new HTTP server to handle sign, bundle, and validate requests.
func serverMain(args []string, c cli.Config) error {
	conf = c
	// serve doesn't support arguments.
	if len(args) > 0 {
		return errors.New("argument is provided but not defined; please refer to the usage by flag -h")
	}

	bundler.IntermediateStash = conf.IntDir
	var err error

	if err = ubiquity.LoadPlatforms(conf.Metadata); err != nil {
		return err
	}

	log.Info("Initializing signer")
	if s, err = sign.SignerFromConfig(c); err != nil {
		log.Warningf("couldn't initialize signer: %v", err)
	}

	if ocspSigner, err = ocspsign.SignerFromConfig(c); err != nil {
		log.Warningf("couldn't initialize ocsp signer: %v", err)
	}

	registerHandlers()

	addr := net.JoinHostPort(conf.Address, strconv.Itoa(conf.Port))
	log.Info("Now listening on ", addr)
	return http.ListenAndServe(addr, nil)
}

// Handle responds to requests for the CA to generate a new private
// key and certificate request on behalf of the client. The format for
// these requests is documented in the API documentation.
func (g *GeneratorHandler) Handle(w http.ResponseWriter, r *http.Request) error {
	log.Info("request for CSR")
	req := new(csr.CertificateRequest)
	body, err := ioutil.ReadAll(r.Body)
	if err != nil {
		log.Warningf("failed to read request body: %v", err)
		return errors.NewBadRequest(err)
	}

	err = json.Unmarshal(body, req)
	if err != nil {
		log.Warningf("failed to unmarshal request: %v", err)
		return errors.NewBadRequest(err)
	}

	key, csr, err := g.generator.ProcessRequest(req)
	if err != nil {
		log.Warningf("failed to process CSR: %v", err)
		// The validator returns a *cfssl/errors.HttpError
		return err
	}

	// Both key and csr are returned PEM-encoded.
	response := newSuccessResponse(&CertRequest{string(key), string(csr)})
	w.Header().Set("Content-Type", "application/json")
	enc := json.NewEncoder(w)
	err = enc.Encode(response)
	return err
}

// Handle listens for incoming requests for CA information, and returns
// a list containing information on each root certificate.
func (h *Handler) Handle(w http.ResponseWriter, r *http.Request) error {
	req := new(info.Req)
	body, err := ioutil.ReadAll(r.Body)
	if err != nil {
		log.Warningf("failed to read request body: %v", err)
		return errors.NewBadRequest(err)
	}
	r.Body.Close()

	err = json.Unmarshal(body, req)
	if err != nil {
		log.Warningf("failed to unmarshal request: %v", err)
		return errors.NewBadRequest(err)
	}

	resp, err := h.sign.Info(*req)
	if err != nil {
		return err
	}

	response := api.NewSuccessResponse(resp)
	w.Header().Set("Content-Type", "application/json")
	enc := json.NewEncoder(w)
	return enc.Encode(response)
}

// initialCAHandler is an HTTP handler that accepts a JSON blob in the
// same format as the CSR endpoint; this blob should contain the
// identity information for the CA's root key. This endpoint is not
// suitable for creating intermediate certificates.
func initialCAHandler(w http.ResponseWriter, r *http.Request) error {
	log.Info("setting up initial CA handler")
	body, err := ioutil.ReadAll(r.Body)
	if err != nil {
		log.Warningf("failed to read request body: %v", err)
		return errors.NewBadRequest(err)
	}
	r.Body.Close()

	req := new(csr.CertificateRequest)
	req.KeyRequest = csr.NewBasicKeyRequest()
	err = json.Unmarshal(body, req)
	if err != nil {
		log.Warningf("failed to unmarshal request: %v", err)
		return errors.NewBadRequest(err)
	}

	cert, _, key, err := initca.New(req)
	if err != nil {
		log.Warningf("failed to initialise new CA: %v", err)
		return err
	}

	response := api.NewSuccessResponse(&NewCA{string(key), string(cert)})

	enc := json.NewEncoder(w)
	err = enc.Encode(response)
	return err
}

// Handle implements an http.Handler interface for the bundle handler.
func (h *Handler) Handle(w http.ResponseWriter, r *http.Request) (err error) {
	blob, matched, err := api.ProcessRequestFirstMatchOf(r,
		[][]string{
			[]string{"certificate"},
			[]string{"domain"},
		})
	if err != nil {
		log.Warningf("invalid request: %v", err)
		return err
	}

	var cert *certinfo.Certificate
	switch matched[0] {
	case "domain":
		if cert, err = certinfo.ParseCertificateDomain(blob["domain"]); err != nil {
			log.Warningf("couldn't parse remote certificate: %v", err)
			return err
		}
	case "certificate":
		if cert, err = certinfo.ParseCertificatePEM([]byte(blob["certificate"])); err != nil {
			log.Warningf("bad PEM certifcate: %v", err)
			return err
		}
	}

	return api.SendResponse(w, cert)
}

// scanHandler is an HTTP handler that accepts GET parameters for host (required)
// family and scanner, and uses these to perform scans, returning a JSON blob result.
func scanHandler(w http.ResponseWriter, r *http.Request) error {
	if err := r.ParseForm(); err != nil {
		log.Warningf("failed to parse body: %v", err)
		return errors.NewBadRequest(err)
	}

	if len(r.Form["host"]) == 0 {
		log.Warningf("no host given")
		return errors.NewBadRequestString("no host given")
	}
	host := r.Form["host"][0]

	var family, scanner string
	if len(r.Form["family"]) > 0 {
		family = r.Form["family"][0]
	}

	if len(r.Form["scanner"]) > 0 {
		scanner = r.Form["scanner"][0]
	}

	results, err := scan.Default.RunScans(host, family, scanner)
	if err != nil {
		log.Warningf("%v", err)
		return errors.NewBadRequest(err)
	}

	response := api.NewSuccessResponse(results)
	enc := json.NewEncoder(w)
	return enc.Encode(response)
}

// Handle accepts client information requests, and uses the label to
// look up the signer whose public certificate should be retrieved. If
// the label is empty, the default label is used.
func (h *MultiHandler) Handle(w http.ResponseWriter, r *http.Request) error {
	req := new(info.Req)
	body, err := ioutil.ReadAll(r.Body)
	if err != nil {
		log.Warningf("failed to read request body: %v", err)
		return errors.NewBadRequest(err)
	}
	err = json.Unmarshal(body, req)
	if err != nil {
		log.Warningf("failed to unmarshal request: %v", err)
		return errors.NewBadRequest(err)
	}

	log.Debug("checking label")
	if req.Label == "" {
		req.Label = h.defaultLabel
	}

	if _, ok := h.signers[req.Label]; !ok {
		log.Warningf("request for invalid endpoint")
		return errors.NewBadRequestString("bad label")
	}

	log.Debug("getting info")
	resp, err := h.signers[req.Label].Info(*req)
	if err != nil {
		log.Infof("error getting certificate: %v", err)
		return err
	}

	response := api.NewSuccessResponse(resp)
	w.Header().Set("Content-Type", "application/json")
	enc := json.NewEncoder(w)
	return enc.Encode(response)
}

// Handle implements an http.Handler interface for the bundle handler.
func (h *Handler) Handle(w http.ResponseWriter, r *http.Request) error {
	blob, matched, err := api.ProcessRequestFirstMatchOf(r,
		[][]string{
			{"certificate"},
			{"domain"},
		})
	if err != nil {
		log.Warningf("invalid request: %v", err)
		return err
	}

	flavor := blob["flavor"]
	bf := bundler.Ubiquitous
	if flavor != "" {
		bf = bundler.BundleFlavor(flavor)
	}
	log.Infof("request for flavor %v", bf)

	var result *bundler.Bundle
	switch matched[0] {
	case "domain":
		bundle, err := h.bundler.BundleFromRemote(blob["domain"], blob["ip"], bf)
		if err != nil {
			log.Warningf("couldn't bundle from remote: %v", err)
			return err
		}
		result = bundle
	case "certificate":
		bundle, err := h.bundler.BundleFromPEMorDER([]byte(blob["certificate"]), []byte(blob["private_key"]), bf, "")
		if err != nil {
			log.Warning("bad PEM certifcate or private key")
			return err
		}

		serverName := blob["domain"]
		ip := blob["ip"]

		if serverName != "" {
			err := bundle.Cert.VerifyHostname(serverName)
			if err != nil {
				return errors.Wrap(errors.CertificateError, errors.VerifyFailed, err)
			}

		}

		if ip != "" {
			err := bundle.Cert.VerifyHostname(ip)
			if err != nil {
				return errors.Wrap(errors.CertificateError, errors.VerifyFailed, err)
			}
		}

		result = bundle
	}
	log.Info("wrote response")
	return api.SendResponse(w, result)
}

// registerHandlers instantiates various handlers and assoicate them to corresponding endpoints.
func registerHandlers() error {
	log.Info("Setting up signer endpoint")
	signHandler, err := api.NewSignHandler(Config.caFile, Config.caKeyFile)
	if err != nil {
		log.Warningf("endpoint '/api/v1/cfssl/sign' is disabled: %v", err)
	} else {
		http.Handle("/api/v1/cfssl/sign", signHandler)
	}

	log.Info("Setting up bundler endpoint")
	bundleHandler, err := api.NewBundleHandler(Config.caBundleFile, Config.intBundleFile)
	if err != nil {
		log.Warningf("endpoint '/api/v1/cfssl/bundle' is disabled: %v", err)
	} else {
		http.Handle("/api/v1/cfssl/bundle", bundleHandler)
	}

	log.Info("Setting up CSR endpoint")
	generatorHandler, err := api.NewGeneratorHandler(api.CSRValidate)
	if err != nil {
		log.Errorf("Failed to set up CSR endpoint: %v", err)
		return err
	}
	http.Handle("/api/v1/cfssl/newkey", generatorHandler)

	log.Info("Setting up new cert endpoint")
	newCertGenerator, err := api.NewCertGeneratorHandler(api.CSRValidate,
		Config.caFile, Config.caKeyFile)
	if err != nil {
		log.Errorf("endpoint '/api/v1/cfssl/newcert' is disabled")
	} else {
		http.Handle("/api/v1/cfssl/newcert", newCertGenerator)
	}

	log.Info("Setting up initial CA endpoint")
	http.Handle("/api/v1/cfssl/init_ca", api.NewInitCAHandler())

	if Config.remote != "" {
		log.Info("Remote CFSSL endpoint given, setting up remote certificate generator")
		if rcg, err := api.NewRemoteCertGenerator(api.CSRValidate, Config.remote); err != nil {
			log.Errorf("Failed to set up remote certificate generator: %v", err)
			return err
		} else {
			http.Handle("/api/v1/cfssl/remotecert", rcg)
		}
	}

	log.Info("Handler set up complete.")
	return nil
}

// check a cert against a specific CRL. Returns the same bool pair
// as revCheck.
func certIsRevokedCRL(cert *x509.Certificate, url string) (revoked, ok bool) {
	crl, ok := CRLSet[url]
	if ok && crl == nil {
		ok = false
		crlLock.Lock()
		delete(CRLSet, url)
		crlLock.Unlock()
	}

	var shouldFetchCRL = true
	if ok {
		if !crl.HasExpired(time.Now()) {
			shouldFetchCRL = false
		}
	}

	issuer := getIssuer(cert)

	if shouldFetchCRL {
		var err error
		crl, err = fetchCRL(url)
		if err != nil {
			log.Warningf("failed to fetch CRL: %v", err)
			return false, false
		}

		// check CRL signature
		if issuer != nil {
			err = issuer.CheckCRLSignature(crl)
			if err != nil {
				log.Warningf("failed to verify CRL: %v", err)
				return false, false
			}
		}

		crlLock.Lock()
		CRLSet[url] = crl
		crlLock.Unlock()
	}

	for _, revoked := range crl.TBSCertList.RevokedCertificates {
		if cert.SerialNumber.Cmp(revoked.SerialNumber) == 0 {
			log.Info("Serial number match: intermediate is revoked.")
			return true, true
		}
	}

	return false, true
}

// worker does all the parsing and validation of the certificate(s)
// contained in a single file. It first reads all the data in the
// file, then begins parsing certificates in the file. Those
// certificates are then checked for revocation.
func worker(paths chan string, bundler chan *x509.Certificate, pool *sync.WaitGroup) {
	defer (*pool).Done()
	for {
		path, ok := <-paths
		if !ok {
			return
		}

		log.Infof("Loading %s", path)

		fileData, err := ioutil.ReadFile(path)
		if err != nil {
			log.Warningf("%v", err)
			continue
		}

		for {
			var block *pem.Block
			if len(fileData) == 0 {
				break
			}
			block, fileData = pem.Decode(fileData)
			if block == nil {
				log.Warningf("%s: no PEM data found", path)
				break
			} else if block.Type != "CERTIFICATE" {
				log.Info("Skipping non-certificate")
				continue
			}

			cert, err := x509.ParseCertificate(block.Bytes)
			if err != nil {
				log.Warningf("Invalid certificate: %v", err)
				continue
			}

			log.Infof("Validating %+v", cert.Subject)
			revoked, ok := revoke.VerifyCertificate(cert)
			if !ok {
				log.Warning("Failed to verify certificate.")
			} else if !revoked {
				bundler <- cert
			} else {
				log.Info("Skipping revoked certificate")
			}
		}
	}
}

// check a cert against a specific CRL. Returns the same bool pair
// as revCheck.
func certIsRevokedCRL(cert *x509.Certificate, url string) (revoked, ok bool) {
	crl, ok := CRLSet[url]
	if ok && crl == nil {
		ok = false
		delete(CRLSet, url)
	}

	var shouldFetchCRL = true
	if ok {
		if !crl.HasExpired(time.Now()) {
			shouldFetchCRL = false
		}
	}

	if shouldFetchCRL {
		var err error
		crl, err = fetchCRL(url)
		if err != nil {
			log.Warningf("failed to fetch CRL: %v", err)
			return false, false
		}
		CRLSet[url] = crl
	}

	for _, revoked := range crl.TBSCertList.RevokedCertificates {
		if cert.SerialNumber.Cmp(revoked.SerialNumber) == 0 {
			log.Info("Serial number match: intermediate is revoked.")
			return true, true
		}
	}

	return false, true
}

func scanMain(args []string, c cli.Config) (err error) {
	if c.List {
		printJSON(scan.Default)
	} else {
		if err = scan.LoadRootCAs(c.CABundleFile); err != nil {
			return
		}

		if len(args) >= c.MaxHosts {
			log.Warningf("Only scanning max-hosts=%d out of %d args given", c.MaxHosts, len(args))
			args = args[:c.MaxHosts]
		} else if c.CSVFile != "" {
			args, err = parseCSV(args, c.CSVFile, c.MaxHosts)
			if err != nil {
				return
			}
		}

		ctx := newContext(c, c.NumWorkers)
		// Execute for each HOST argument given
		for len(args) > 0 {
			var host string
			host, args, err = cli.PopFirstArgument(args)
			if err != nil {
				return
			}

			ctx.hosts <- host
		}
		close(ctx.hosts)
		ctx.Wait()
	}
	return
}

// registerHandlers instantiates various handlers and associate them to corresponding endpoints.
func registerHandlers() {
	for path, getHandler := range endpoints {
		log.Debugf("getHandler for %s", path)
		if handler, err := getHandler(); err != nil {
			log.Warningf("endpoint '%s' is disabled: %v", path, err)
		} else {
			if path, handler, err = wrapHandler(path, handler, err); err != nil {
				log.Warningf("endpoint '%s' is disabled by wrapper: %v", path, err)
			} else {
				log.Infof("endpoint '%s' is enabled", path)
				http.Handle(path, handler)
			}
		}
	}
	log.Info("Handler set up complete.")
}

func (ctx *context) copyResults(timeout time.Duration) map[string]FamilyResult {
	var timedOut bool
	done := make(chan bool, 1)
	results := make(map[string]FamilyResult)

	go func() {
		for result := range ctx.resultChan {
			if timedOut {
				log.Debugf("Received result after timeout: %v", result)
				continue
			}

			if results[result.Family] == nil {
				results[result.Family] = make(FamilyResult)
			}

			results[result.Family][result.Scanner] = result.ScannerResult
		}
		done <- true
	}()

	select {
	case <-done:
	case <-time.After(timeout):
		timedOut = true
		log.Warningf("Scan timed out after %v", timeout)
	}

	return results
}

// RunScans iterates over AllScans, running scans matching the family and scanner
// regular expressions.
func (fs FamilySet) RunScans(host, family, scanner string, dur time.Duration) (map[string]FamilyResult, error) {
	if _, _, err := net.SplitHostPort(host); err != nil {
		host = net.JoinHostPort(host, "443")
	}

	familyRegexp, err := regexp.Compile(family)
	if err != nil {
		return nil, err
	}

	scannerRegexp, err := regexp.Compile(scanner)
	if err != nil {
		return nil, err
	}

	results := make(chan map[string]FamilyResult)
	timeout := make(chan bool)

	if dur > 0 {
		go startTimer(dur, timeout)
	}

	familyResults := make(map[string]FamilyResult)

	go func() {
		for familyName, family := range fs {
			if familyRegexp.MatchString(familyName) {
				scannerResults := make(map[string]ScannerResult)

				for scannerName, scanner := range family.Scanners {
					if scannerRegexp.MatchString(scannerName) {
						grade, output, err := scanner.Scan(host)

						result := ScannerResult{
							Grade:  grade.String(),
							Output: output,
						}
						if err != nil {
							result.Error = err.Error()
						}

						scannerResults[scannerName] = result
					}
				}
				familyResults[familyName] = scannerResults
			}
		}
		results <- familyResults
	}()

	select {
	case <-timeout:
		log.Warningf("scan: %s timed out after %v", host, dur)
		return nil, nil
	case res := <-results:
		return res, nil
	}
}

// Handle responds to requests for the CA to generate a new private
// key and certificate request on behalf of the client. The format for
// these requests is documented in the API documentation.
func (g *Handler) Handle(w http.ResponseWriter, r *http.Request) error {
	log.Info("request for CSR")
	body, err := ioutil.ReadAll(r.Body)
	if err != nil {
		log.Warningf("failed to read request body: %v", err)
		return errors.NewBadRequest(err)
	}
	r.Body.Close()

	req := new(csr.CertificateRequest)
	req.KeyRequest = csr.NewBasicKeyRequest()
	err = json.Unmarshal(body, req)
	if err != nil {
		log.Warningf("failed to unmarshal request: %v", err)
		return errors.NewBadRequest(err)
	}

	if req.CA != nil {
		log.Warningf("request received with CA section")
		return errors.NewBadRequestString("ca section only permitted in initca")
	}

	csr, key, err := g.generator.ProcessRequest(req)
	if err != nil {
		log.Warningf("failed to process CSR: %v", err)
		// The validator returns a *cfssl/errors.HttpError
		return err
	}

	sum, err := computeSum(csr)
	if err != nil {
		return errors.NewBadRequest(err)
	}

	// Both key and csr are returned PEM-encoded.
	response := api.NewSuccessResponse(&CertRequest{
		Key:  string(key),
		CSR:  string(csr),
		Sums: map[string]Sum{"certificate_request": sum},
	})
	w.Header().Set("Content-Type", "application/json")
	enc := json.NewEncoder(w)
	err = enc.Encode(response)
	return err
}

// We can't handle LDAP certificates, so this checks to see if the
// URL string points to an LDAP resource so that we can ignore it.
func ldapURL(url string) bool {
	u, err := neturl.Parse(url)
	if err != nil {
		log.Warningf("error parsing url %s: %v", url, err)
		return false
	}
	if u.Scheme == "ldap" {
		return true
	}
	return false
}

// registerHandlers instantiates various handlers and associate them to corresponding endpoints.
func registerHandlers() {
	for path, getHandler := range v1Endpoints {
		path = "/api/v1/cfssl/" + path
		log.Infof("Setting up '%s' endpoint", path)
		if handler, err := getHandler(); err != nil {
			log.Warningf("endpoint '%s' is disabled: %v", path, err)
		} else {
			http.Handle(path, handler)
		}
	}
	for path, getHandler := range staticEndpoints {
		log.Infof("Setting up '%s' endpoint", path)
		if handler, err := getHandler(); err != nil {
			log.Warningf("endpoint '%s' is disabled: %v", path, err)
		} else {
			http.Handle(path, handler)
		}
	}

	log.Info("Handler set up complete.")
}