package ca import ( "bytes" "context" "crypto/tls" "crypto/x509" "fmt" "log" "net" "net/http" "net/url" "reflect" "strings" "sync" "github.com/go-chi/chi" "github.com/pkg/errors" "github.com/smallstep/certificates/acme" acmeAPI "github.com/smallstep/certificates/acme/api" acmeNoSQL "github.com/smallstep/certificates/acme/db/nosql" "github.com/smallstep/certificates/api" "github.com/smallstep/certificates/authority" "github.com/smallstep/certificates/authority/admin" adminAPI "github.com/smallstep/certificates/authority/admin/api" "github.com/smallstep/certificates/authority/config" "github.com/smallstep/certificates/db" "github.com/smallstep/certificates/logging" "github.com/smallstep/certificates/monitoring" "github.com/smallstep/certificates/scep" scepAPI "github.com/smallstep/certificates/scep/api" "github.com/smallstep/certificates/server" "github.com/smallstep/nosql" "go.step.sm/cli-utils/step" "go.step.sm/crypto/x509util" ) type options struct { configFile string linkedCAToken string quiet bool password []byte issuerPassword []byte sshHostPassword []byte sshUserPassword []byte database db.AuthDB } func (o *options) apply(opts []Option) { for _, fn := range opts { fn(o) } } // Option is the type of options passed to the CA constructor. type Option func(o *options) // WithConfigFile sets the given name as the configuration file name in the CA // options. func WithConfigFile(name string) Option { return func(o *options) { o.configFile = name } } // WithPassword sets the given password as the configured password in the CA // options. func WithPassword(password []byte) Option { return func(o *options) { o.password = password } } // WithSSHHostPassword sets the given password to decrypt the key used to sign // ssh host certificates. func WithSSHHostPassword(password []byte) Option { return func(o *options) { o.sshHostPassword = password } } // WithSSHUserPassword sets the given password to decrypt the key used to sign // ssh user certificates. func WithSSHUserPassword(password []byte) Option { return func(o *options) { o.sshUserPassword = password } } // WithIssuerPassword sets the given password as the configured certificate // issuer password in the CA options. func WithIssuerPassword(password []byte) Option { return func(o *options) { o.issuerPassword = password } } // WithDatabase sets the given authority database to the CA options. func WithDatabase(d db.AuthDB) Option { return func(o *options) { o.database = d } } // WithLinkedCAToken sets the token used to authenticate with the linkedca. func WithLinkedCAToken(token string) Option { return func(o *options) { o.linkedCAToken = token } } // WithQuiet sets the quiet flag. func WithQuiet(quiet bool) Option { return func(o *options) { o.quiet = quiet } } // CA is the type used to build the complete certificate authority. It builds // the HTTP server, set ups the middlewares and the HTTP handlers. type CA struct { auth *authority.Authority config *config.Config srv *server.Server insecureSrv *server.Server opts *options renewer *TLSRenewer } // New creates and initializes the CA with the given configuration and options. func New(cfg *config.Config, opts ...Option) (*CA, error) { ca := &CA{ config: cfg, opts: new(options), } ca.opts.apply(opts) return ca.Init(cfg) } // Init initializes the CA with the given configuration. func (ca *CA) Init(cfg *config.Config) (*CA, error) { // Set password, it's ok to set nil password, the ca will prompt for them if // they are required. opts := []authority.Option{ authority.WithPassword(ca.opts.password), authority.WithSSHHostPassword(ca.opts.sshHostPassword), authority.WithSSHUserPassword(ca.opts.sshUserPassword), authority.WithIssuerPassword(ca.opts.issuerPassword), } if ca.opts.linkedCAToken != "" { opts = append(opts, authority.WithLinkedCAToken(ca.opts.linkedCAToken)) } if ca.opts.database != nil { opts = append(opts, authority.WithDatabase(ca.opts.database)) } auth, err := authority.New(cfg, opts...) if err != nil { return nil, err } ca.auth = auth tlsConfig, err := ca.getTLSConfig(auth) if err != nil { return nil, err } // Using chi as the main router mux := chi.NewRouter() handler := http.Handler(mux) insecureMux := chi.NewRouter() insecureHandler := http.Handler(insecureMux) // Add regular CA api endpoints in / and /1.0 api.Route(mux) mux.Route("/1.0", func(r chi.Router) { api.Route(r) }) //Add ACME api endpoints in /acme and /1.0/acme dns := cfg.DNSNames[0] u, err := url.Parse("https://" + cfg.Address) if err != nil { return nil, err } port := u.Port() if port != "" && port != "443" { dns = fmt.Sprintf("%s:%s", dns, port) } // ACME Router is only available if we have a database. var acmeDB acme.DB var acmeLinker acme.Linker if cfg.DB != nil { acmeDB, err = acmeNoSQL.New(auth.GetDatabase().(nosql.DB)) if err != nil { return nil, errors.Wrap(err, "error configuring ACME DB interface") } acmeLinker = acme.NewLinker(dns, "acme") mux.Route("/acme", func(r chi.Router) { acmeAPI.Route(r) }) // Use 2.0 because, at the moment, our ACME api is only compatible with v2.0 // of the ACME spec. mux.Route("/2.0/acme", func(r chi.Router) { acmeAPI.Route(r) }) } // Admin API Router if cfg.AuthorityConfig.EnableAdmin { adminDB := auth.GetAdminDatabase() if adminDB != nil { acmeAdminResponder := adminAPI.NewACMEAdminResponder() policyAdminResponder := adminAPI.NewPolicyAdminResponder() mux.Route("/admin", func(r chi.Router) { adminAPI.Route(r, acmeAdminResponder, policyAdminResponder) }) } } var scepAuthority *scep.Authority if ca.shouldServeSCEPEndpoints() { scepPrefix := "scep" scepAuthority, err = scep.New(auth, scep.AuthorityOptions{ Service: auth.GetSCEPService(), DNS: dns, Prefix: scepPrefix, }) if err != nil { return nil, errors.Wrap(err, "error creating SCEP authority") } // According to the RFC (https://tools.ietf.org/html/rfc8894#section-7.10), // SCEP operations are performed using HTTP, so that's why the API is mounted // to the insecure mux. insecureMux.Route("/"+scepPrefix, func(r chi.Router) { scepAPI.Route(r) }) // The RFC also mentions usage of HTTPS, but seems to advise // against it, because of potential interoperability issues. // Currently I think it's not bad to use HTTPS also, so that's // why I've kept the API endpoints in both muxes and both HTTP // as well as HTTPS can be used to request certificates // using SCEP. mux.Route("/"+scepPrefix, func(r chi.Router) { scepAPI.Route(r) }) } // helpful routine for logging all routes //dumpRoutes(mux) // Add monitoring if configured if len(cfg.Monitoring) > 0 { m, err := monitoring.New(cfg.Monitoring) if err != nil { return nil, err } handler = m.Middleware(handler) insecureHandler = m.Middleware(insecureHandler) } // Add logger if configured if len(cfg.Logger) > 0 { logger, err := logging.New("ca", cfg.Logger) if err != nil { return nil, err } handler = logger.Middleware(handler) insecureHandler = logger.Middleware(insecureHandler) } // Create context with all the necessary values. baseContext := buildContext(auth, scepAuthority, acmeDB, acmeLinker) ca.srv = server.New(cfg.Address, handler, tlsConfig) ca.srv.BaseContext = func(net.Listener) context.Context { return baseContext } // only start the insecure server if the insecure address is configured // and, currently, also only when it should serve SCEP endpoints. if ca.shouldServeSCEPEndpoints() && cfg.InsecureAddress != "" { // TODO: instead opt for having a single server.Server but two // http.Servers handling the HTTP and HTTPS handler? The latter // will probably introduce more complexity in terms of graceful // reload. ca.insecureSrv = server.New(cfg.InsecureAddress, insecureHandler, nil) ca.insecureSrv.BaseContext = func(net.Listener) context.Context { return baseContext } } return ca, nil } // buildContext builds the server base context. func buildContext(a *authority.Authority, scepAuthority *scep.Authority, acmeDB acme.DB, acmeLinker acme.Linker) context.Context { ctx := authority.NewContext(context.Background(), a) if authDB := a.GetDatabase(); authDB != nil { ctx = db.NewContext(ctx, authDB) } if adminDB := a.GetAdminDatabase(); adminDB != nil { ctx = admin.NewContext(ctx, adminDB) } if scepAuthority != nil { ctx = scep.NewContext(ctx, scepAuthority) } if acmeDB != nil { ctx = acme.NewContext(ctx, acmeDB, acme.NewClient(), acmeLinker, nil) } return ctx } // Run starts the CA calling to the server ListenAndServe method. func (ca *CA) Run() error { var wg sync.WaitGroup errs := make(chan error, 1) if !ca.opts.quiet { authorityInfo := ca.auth.GetInfo() log.Printf("Starting %s", step.Version()) log.Printf("Documentation: https://u.step.sm/docs/ca") log.Printf("Community Discord: https://u.step.sm/discord") if step.Contexts().GetCurrent() != nil { log.Printf("Current context: %s", step.Contexts().GetCurrent().Name) } log.Printf("Config file: %s", ca.opts.configFile) baseURL := fmt.Sprintf("https://%s%s", authorityInfo.DNSNames[0], ca.config.Address[strings.LastIndex(ca.config.Address, ":"):]) log.Printf("The primary server URL is %s", baseURL) log.Printf("Root certificates are available at %s/roots.pem", baseURL) if len(authorityInfo.DNSNames) > 1 { log.Printf("Additional configured hostnames: %s", strings.Join(authorityInfo.DNSNames[1:], ", ")) } for _, crt := range authorityInfo.RootX509Certs { log.Printf("X.509 Root Fingerprint: %s", x509util.Fingerprint(crt)) } if authorityInfo.SSHCAHostPublicKey != nil { log.Printf("SSH Host CA Key: %s\n", bytes.TrimSpace(authorityInfo.SSHCAHostPublicKey)) } if authorityInfo.SSHCAUserPublicKey != nil { log.Printf("SSH User CA Key: %s\n", bytes.TrimSpace(authorityInfo.SSHCAUserPublicKey)) } } if ca.insecureSrv != nil { wg.Add(1) go func() { defer wg.Done() errs <- ca.insecureSrv.ListenAndServe() }() } wg.Add(1) go func() { defer wg.Done() errs <- ca.srv.ListenAndServe() }() // wait till error occurs; ensures the servers keep listening err := <-errs wg.Wait() return err } // Stop stops the CA calling to the server Shutdown method. func (ca *CA) Stop() error { ca.renewer.Stop() if err := ca.auth.Shutdown(); err != nil { log.Printf("error stopping ca.Authority: %+v\n", err) } var insecureShutdownErr error if ca.insecureSrv != nil { insecureShutdownErr = ca.insecureSrv.Shutdown() } secureErr := ca.srv.Shutdown() if insecureShutdownErr != nil { return insecureShutdownErr } return secureErr } // Reload reloads the configuration of the CA and calls to the server Reload // method. func (ca *CA) Reload() error { cfg, err := config.LoadConfiguration(ca.opts.configFile) if err != nil { return errors.Wrap(err, "error reloading ca configuration") } logContinue := func(reason string) { log.Println(reason) log.Println("Continuing to run with the original configuration.") log.Println("You can force a restart by sending a SIGTERM signal and then restarting the step-ca.") } // Do not allow reload if the database configuration has changed. if !reflect.DeepEqual(ca.config.DB, cfg.DB) { logContinue("Reload failed because the database configuration has changed.") return errors.New("error reloading ca: database configuration cannot change") } newCA, err := New(cfg, WithPassword(ca.opts.password), WithSSHHostPassword(ca.opts.sshHostPassword), WithSSHUserPassword(ca.opts.sshUserPassword), WithIssuerPassword(ca.opts.issuerPassword), WithLinkedCAToken(ca.opts.linkedCAToken), WithQuiet(ca.opts.quiet), WithConfigFile(ca.opts.configFile), WithDatabase(ca.auth.GetDatabase()), ) if err != nil { logContinue("Reload failed because the CA with new configuration could not be initialized.") return errors.Wrap(err, "error reloading ca") } if ca.insecureSrv != nil { if err = ca.insecureSrv.Reload(newCA.insecureSrv); err != nil { logContinue("Reload failed because insecure server could not be replaced.") return errors.Wrap(err, "error reloading insecure server") } } if err = ca.srv.Reload(newCA.srv); err != nil { logContinue("Reload failed because server could not be replaced.") return errors.Wrap(err, "error reloading server") } // 1. Stop previous renewer // 2. Safely shutdown any internal resources (e.g. key manager) // 3. Replace ca properties // Do not replace ca.srv ca.renewer.Stop() ca.auth.CloseForReload() ca.auth = newCA.auth ca.config = newCA.config ca.opts = newCA.opts ca.renewer = newCA.renewer return nil } // getTLSConfig returns a TLSConfig for the CA server with a self-renewing // server certificate. func (ca *CA) getTLSConfig(auth *authority.Authority) (*tls.Config, error) { // Create initial TLS certificate tlsCrt, err := auth.GetTLSCertificate() if err != nil { return nil, err } // Start tls renewer with the new certificate. // If a renewer was started, attempt to stop it before. if ca.renewer != nil { ca.renewer.Stop() } ca.renewer, err = NewTLSRenewer(tlsCrt, auth.GetTLSCertificate) if err != nil { return nil, err } ca.renewer.Run() var tlsConfig *tls.Config if ca.config.TLS != nil { tlsConfig = ca.config.TLS.TLSConfig() } else { tlsConfig = &tls.Config{ MinVersion: tls.VersionTLS12, } } // GetCertificate will only be called if the client supplies SNI // information or if tlsConfig.Certificates is empty. // When client requests are made using an IP address (as opposed to a domain // name) the server does not receive any SNI and may fallback to using the // first entry in the Certificates attribute; by setting the attribute to // empty we are implicitly forcing GetCertificate to be the only mechanism // by which the server can find it's own leaf Certificate. tlsConfig.Certificates = []tls.Certificate{} tlsConfig.GetCertificate = ca.renewer.GetCertificateForCA // initialize a certificate pool with root CA certificates to trust when doing mTLS. certPool := x509.NewCertPool() for _, crt := range auth.GetRootCertificates() { certPool.AddCert(crt) } // adding the intermediate CA certificates to the pool will allow clients that // do mTLS but don't send an intermediate to successfully connect. The intermediates // added here are used when building a certificate chain. intermediates := tlsCrt.Certificate[1:] for _, certBytes := range intermediates { cert, err := x509.ParseCertificate(certBytes) if err != nil { return nil, err } certPool.AddCert(cert) } // Add support for mutual tls to renew certificates tlsConfig.ClientAuth = tls.VerifyClientCertIfGiven tlsConfig.ClientCAs = certPool return tlsConfig, nil } // shouldServeSCEPEndpoints returns if the CA should be // configured with endpoints for SCEP. This is assumed to be // true if a SCEPService exists, which is true in case a // SCEP provisioner was configured. func (ca *CA) shouldServeSCEPEndpoints() bool { return ca.auth.GetSCEPService() != nil } // nolint // ignore linters to allow keeping this function around for debugging func dumpRoutes(mux chi.Routes) { // helpful routine for logging all routes // walkFunc := func(method string, route string, handler http.Handler, middlewares ...func(http.Handler) http.Handler) error { fmt.Printf("%s %s\n", method, route) return nil } if err := chi.Walk(mux, walkFunc); err != nil { fmt.Printf("Logging err: %s\n", err.Error()) } }