// Copyright (C) 2019 Nicola Murino // // This program is free software: you can redistribute it and/or modify // it under the terms of the GNU Affero General Public License as published // by the Free Software Foundation, version 3. // // This program is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU Affero General Public License for more details. // // You should have received a copy of the GNU Affero General Public License // along with this program. If not, see . // Package plugin provides support for the SFTPGo plugin system package plugin import ( "crypto/sha256" "crypto/x509" "encoding/hex" "errors" "fmt" "os" "os/exec" "path/filepath" "strings" "sync" "sync/atomic" "time" "github.com/hashicorp/go-hclog" "github.com/hashicorp/go-plugin" "github.com/sftpgo/sdk/plugin/auth" "github.com/sftpgo/sdk/plugin/eventsearcher" "github.com/sftpgo/sdk/plugin/ipfilter" kmsplugin "github.com/sftpgo/sdk/plugin/kms" "github.com/sftpgo/sdk/plugin/notifier" "github.com/drakkan/sftpgo/v2/internal/kms" "github.com/drakkan/sftpgo/v2/internal/logger" "github.com/drakkan/sftpgo/v2/internal/util" ) const ( logSender = "plugins" ) var ( // Handler defines the plugins manager Handler Manager pluginsLogLevel = hclog.Debug // ErrNoSearcher defines the error to return for events searches if no plugin is configured ErrNoSearcher = errors.New("no events searcher plugin defined") ) // Renderer defines the interface for generic objects rendering type Renderer interface { RenderAsJSON(reload bool) ([]byte, error) } // Config defines a plugin configuration type Config struct { // Plugin type Type string `json:"type" mapstructure:"type"` // NotifierOptions defines options for notifiers plugins NotifierOptions NotifierConfig `json:"notifier_options" mapstructure:"notifier_options"` // KMSOptions defines options for a KMS plugin KMSOptions KMSConfig `json:"kms_options" mapstructure:"kms_options"` // AuthOptions defines options for authentication plugins AuthOptions AuthConfig `json:"auth_options" mapstructure:"auth_options"` // Path to the plugin executable Cmd string `json:"cmd" mapstructure:"cmd"` // Args to pass to the plugin executable Args []string `json:"args" mapstructure:"args"` // SHA256 checksum for the plugin executable. // If not empty it will be used to verify the integrity of the executable SHA256Sum string `json:"sha256sum" mapstructure:"sha256sum"` // If enabled the client and the server automatically negotiate mTLS for // transport authentication. This ensures that only the original client will // be allowed to connect to the server, and all other connections will be // rejected. The client will also refuse to connect to any server that isn't // the original instance started by the client. AutoMTLS bool `json:"auto_mtls" mapstructure:"auto_mtls"` // EnvPrefix defines the prefix for env vars to pass from the SFTPGo process // environment to the plugin. Set to "none" to not pass any environment // variable, set to "*" to pass all environment variables. If empty, the // prefix is returned as the plugin name in uppercase with "-" replaced with // "_" and a trailing "_". For example if the plugin name is // sftpgo-plugin-eventsearch the prefix will be SFTPGO_PLUGIN_EVENTSEARCH_ EnvPrefix string `json:"env_prefix" mapstructure:"env_prefix"` // Additional environment variable names to pass from the SFTPGo process // environment to the plugin. EnvVars []string `json:"env_vars" mapstructure:"env_vars"` // unique identifier for kms plugins kmsID int } func (c *Config) getSecureConfig() (*plugin.SecureConfig, error) { if c.SHA256Sum != "" { checksum, err := hex.DecodeString(c.SHA256Sum) if err != nil { return nil, fmt.Errorf("invalid sha256 hash %q: %w", c.SHA256Sum, err) } return &plugin.SecureConfig{ Checksum: checksum, Hash: sha256.New(), }, nil } return nil, nil } func (c *Config) getEnvVarPrefix() string { if c.EnvPrefix == "none" { return "" } if c.EnvPrefix != "" { return c.EnvPrefix } prefix := strings.ToUpper(filepath.Base(c.Cmd)) + "_" return strings.ReplaceAll(prefix, "-", "_") } func (c *Config) getCommand() *exec.Cmd { cmd := exec.Command(c.Cmd, c.Args...) cmd.Env = []string{} if envVarPrefix := c.getEnvVarPrefix(); envVarPrefix != "" { if envVarPrefix == "*" { logger.Debug(logSender, "", "sharing all the environment variables with plugin %q", c.Cmd) cmd.Env = append(cmd.Env, os.Environ()...) return cmd } logger.Debug(logSender, "", "adding env vars with prefix %q for plugin %q", envVarPrefix, c.Cmd) for _, val := range os.Environ() { if strings.HasPrefix(val, envVarPrefix) { cmd.Env = append(cmd.Env, val) } } } logger.Debug(logSender, "", "additional env vars for plugin %q: %+v", c.Cmd, c.EnvVars) for _, key := range c.EnvVars { cmd.Env = append(cmd.Env, os.Getenv(key)) } return cmd } func (c *Config) newKMSPluginSecretProvider(base kms.BaseSecret, url, masterKey string) kms.SecretProvider { return &kmsPluginSecretProvider{ BaseSecret: base, URL: url, MasterKey: masterKey, config: c, } } // Manager handles enabled plugins type Manager struct { closed atomic.Bool done chan bool // List of configured plugins Configs []Config `json:"plugins" mapstructure:"plugins"` notifLock sync.RWMutex notifiers []*notifierPlugin kmsLock sync.RWMutex kms []*kmsPlugin authLock sync.RWMutex auths []*authPlugin searcherLock sync.RWMutex searcher *searcherPlugin ipFilterLock sync.RWMutex filter *ipFilterPlugin authScopes int hasSearcher bool hasNotifiers bool hasAuths bool hasIPFilter bool concurrencyGuard chan struct{} } // Initialize initializes the configured plugins func Initialize(configs []Config, logLevel string) error { logger.Debug(logSender, "", "initialize") Handler = Manager{ Configs: configs, done: make(chan bool), authScopes: -1, concurrencyGuard: make(chan struct{}, 250), } Handler.closed.Store(false) setLogLevel(logLevel) if len(configs) == 0 { return nil } if err := Handler.validateConfigs(); err != nil { return err } if err := initializePlugins(); err != nil { return err } startCheckTicker() return nil } func initializePlugins() error { kmsID := 0 for idx, config := range Handler.Configs { switch config.Type { case notifier.PluginName: plugin, err := newNotifierPlugin(config) if err != nil { return err } Handler.notifiers = append(Handler.notifiers, plugin) case kmsplugin.PluginName: plugin, err := newKMSPlugin(config) if err != nil { return err } Handler.kms = append(Handler.kms, plugin) Handler.Configs[idx].kmsID = kmsID kmsID++ kms.RegisterSecretProvider(config.KMSOptions.Scheme, config.KMSOptions.EncryptedStatus, Handler.Configs[idx].newKMSPluginSecretProvider) logger.Info(logSender, "", "registered secret provider for scheme: %v, encrypted status: %v", config.KMSOptions.Scheme, config.KMSOptions.EncryptedStatus) case auth.PluginName: plugin, err := newAuthPlugin(config) if err != nil { return err } Handler.auths = append(Handler.auths, plugin) if Handler.authScopes == -1 { Handler.authScopes = config.AuthOptions.Scope } else { Handler.authScopes |= config.AuthOptions.Scope } case eventsearcher.PluginName: plugin, err := newSearcherPlugin(config) if err != nil { return err } Handler.searcher = plugin case ipfilter.PluginName: plugin, err := newIPFilterPlugin(config) if err != nil { return err } Handler.filter = plugin default: return fmt.Errorf("unsupported plugin type: %v", config.Type) } } return nil } func (m *Manager) validateConfigs() error { kmsSchemes := make(map[string]bool) kmsEncryptions := make(map[string]bool) m.hasSearcher = false m.hasNotifiers = false m.hasAuths = false m.hasIPFilter = false for _, config := range m.Configs { switch config.Type { case kmsplugin.PluginName: if _, ok := kmsSchemes[config.KMSOptions.Scheme]; ok { return fmt.Errorf("invalid KMS configuration, duplicated scheme %q", config.KMSOptions.Scheme) } if _, ok := kmsEncryptions[config.KMSOptions.EncryptedStatus]; ok { return fmt.Errorf("invalid KMS configuration, duplicated encrypted status %q", config.KMSOptions.EncryptedStatus) } kmsSchemes[config.KMSOptions.Scheme] = true kmsEncryptions[config.KMSOptions.EncryptedStatus] = true case eventsearcher.PluginName: if m.hasSearcher { return errors.New("only one eventsearcher plugin can be defined") } m.hasSearcher = true case notifier.PluginName: m.hasNotifiers = true case auth.PluginName: m.hasAuths = true case ipfilter.PluginName: m.hasIPFilter = true } } return nil } // HasAuthenticators returns true if there is at least an auth plugin func (m *Manager) HasAuthenticators() bool { return m.hasAuths } // HasNotifiers returns true if there is at least a notifier plugin func (m *Manager) HasNotifiers() bool { return m.hasNotifiers } // NotifyFsEvent sends the fs event notifications using any defined notifier plugins func (m *Manager) NotifyFsEvent(event *notifier.FsEvent) { m.notifLock.RLock() defer m.notifLock.RUnlock() for _, n := range m.notifiers { n.notifyFsAction(event) } } // NotifyProviderEvent sends the provider event notifications using any defined notifier plugins func (m *Manager) NotifyProviderEvent(event *notifier.ProviderEvent, object Renderer) { m.notifLock.RLock() defer m.notifLock.RUnlock() for _, n := range m.notifiers { n.notifyProviderAction(event, object) } } // NotifyLogEvent sends the log event notifications using any defined notifier plugins func (m *Manager) NotifyLogEvent(event notifier.LogEventType, protocol, username, ip, role string, err error) { if !m.hasNotifiers { return } m.notifLock.RLock() defer m.notifLock.RUnlock() var e *notifier.LogEvent for _, n := range m.notifiers { if util.Contains(n.config.NotifierOptions.LogEvents, int(event)) { if e == nil { message := "" if err != nil { message = err.Error() } e = ¬ifier.LogEvent{ Timestamp: time.Now().UnixNano(), Event: event, Protocol: protocol, Username: username, IP: ip, Message: message, Role: role, } } n.notifyLogEvent(e) } } } // HasSearcher returns true if an event searcher plugin is defined func (m *Manager) HasSearcher() bool { return m.hasSearcher } // SearchFsEvents returns the filesystem events matching the specified filters func (m *Manager) SearchFsEvents(searchFilters *eventsearcher.FsEventSearch) ([]byte, error) { if !m.hasSearcher { return nil, ErrNoSearcher } m.searcherLock.RLock() plugin := m.searcher m.searcherLock.RUnlock() return plugin.searchear.SearchFsEvents(searchFilters) } // SearchProviderEvents returns the provider events matching the specified filters func (m *Manager) SearchProviderEvents(searchFilters *eventsearcher.ProviderEventSearch) ([]byte, error) { if !m.hasSearcher { return nil, ErrNoSearcher } m.searcherLock.RLock() plugin := m.searcher m.searcherLock.RUnlock() return plugin.searchear.SearchProviderEvents(searchFilters) } // SearchLogEvents returns the log events matching the specified filters func (m *Manager) SearchLogEvents(searchFilters *eventsearcher.LogEventSearch) ([]byte, error) { if !m.hasSearcher { return nil, ErrNoSearcher } m.searcherLock.RLock() plugin := m.searcher m.searcherLock.RUnlock() return plugin.searchear.SearchLogEvents(searchFilters) } // IsIPBanned returns true if the IP filter plugin does not allow the specified ip. // If no IP filter plugin is defined this method returns false func (m *Manager) IsIPBanned(ip, protocol string) bool { if !m.hasIPFilter { return false } m.ipFilterLock.RLock() plugin := m.filter m.ipFilterLock.RUnlock() if plugin.exited() { logger.Warn(logSender, "", "ip filter plugin is not active, cannot check ip %q", ip) return false } return plugin.filter.CheckIP(ip, protocol) != nil } // ReloadFilter sends a reload request to the IP filter plugin func (m *Manager) ReloadFilter() { if !m.hasIPFilter { return } m.ipFilterLock.RLock() plugin := m.filter m.ipFilterLock.RUnlock() if err := plugin.filter.Reload(); err != nil { logger.Error(logSender, "", "unable to reload IP filter plugin: %v", err) } } func (m *Manager) kmsEncrypt(secret kms.BaseSecret, url string, masterKey string, kmsID int) (string, string, int32, error) { m.kmsLock.RLock() plugin := m.kms[kmsID] m.kmsLock.RUnlock() return plugin.Encrypt(secret, url, masterKey) } func (m *Manager) kmsDecrypt(secret kms.BaseSecret, url string, masterKey string, kmsID int) (string, error) { m.kmsLock.RLock() plugin := m.kms[kmsID] m.kmsLock.RUnlock() return plugin.Decrypt(secret, url, masterKey) } // HasAuthScope returns true if there is an auth plugin that support the specified scope func (m *Manager) HasAuthScope(scope int) bool { if m.authScopes == -1 { return false } return m.authScopes&scope != 0 } // Authenticate tries to authenticate the specified user using an external plugin func (m *Manager) Authenticate(username, password, ip, protocol string, pkey string, tlsCert *x509.Certificate, authScope int, userAsJSON []byte, ) ([]byte, error) { switch authScope { case AuthScopePassword: return m.checkUserAndPass(username, password, ip, protocol, userAsJSON) case AuthScopePublicKey: return m.checkUserAndPublicKey(username, pkey, ip, protocol, userAsJSON) case AuthScopeKeyboardInteractive: return m.checkUserAndKeyboardInteractive(username, ip, protocol, userAsJSON) case AuthScopeTLSCertificate: cert, err := util.EncodeTLSCertToPem(tlsCert) if err != nil { logger.Error(logSender, "", "unable to encode tls certificate to pem: %v", err) return nil, fmt.Errorf("unable to encode tls cert to pem: %w", err) } return m.checkUserAndTLSCert(username, cert, ip, protocol, userAsJSON) default: return nil, fmt.Errorf("unsupported auth scope: %v", authScope) } } // ExecuteKeyboardInteractiveStep executes a keyboard interactive step func (m *Manager) ExecuteKeyboardInteractiveStep(req *KeyboardAuthRequest) (*KeyboardAuthResponse, error) { var plugin *authPlugin m.authLock.Lock() for _, p := range m.auths { if p.config.AuthOptions.Scope&AuthScopePassword != 0 { plugin = p break } } m.authLock.Unlock() if plugin == nil { return nil, errors.New("no auth plugin configured for keyaboard interactive authentication step") } return plugin.sendKeyboardIteractiveRequest(req) } func (m *Manager) checkUserAndPass(username, password, ip, protocol string, userAsJSON []byte) ([]byte, error) { var plugin *authPlugin m.authLock.Lock() for _, p := range m.auths { if p.config.AuthOptions.Scope&AuthScopePassword != 0 { plugin = p break } } m.authLock.Unlock() if plugin == nil { return nil, errors.New("no auth plugin configured for password checking") } return plugin.checkUserAndPass(username, password, ip, protocol, userAsJSON) } func (m *Manager) checkUserAndPublicKey(username, pubKey, ip, protocol string, userAsJSON []byte) ([]byte, error) { var plugin *authPlugin m.authLock.Lock() for _, p := range m.auths { if p.config.AuthOptions.Scope&AuthScopePublicKey != 0 { plugin = p break } } m.authLock.Unlock() if plugin == nil { return nil, errors.New("no auth plugin configured for public key checking") } return plugin.checkUserAndPublicKey(username, pubKey, ip, protocol, userAsJSON) } func (m *Manager) checkUserAndTLSCert(username, tlsCert, ip, protocol string, userAsJSON []byte) ([]byte, error) { var plugin *authPlugin m.authLock.Lock() for _, p := range m.auths { if p.config.AuthOptions.Scope&AuthScopeTLSCertificate != 0 { plugin = p break } } m.authLock.Unlock() if plugin == nil { return nil, errors.New("no auth plugin configured for TLS certificate checking") } return plugin.checkUserAndTLSCertificate(username, tlsCert, ip, protocol, userAsJSON) } func (m *Manager) checkUserAndKeyboardInteractive(username, ip, protocol string, userAsJSON []byte) ([]byte, error) { var plugin *authPlugin m.authLock.Lock() for _, p := range m.auths { if p.config.AuthOptions.Scope&AuthScopeKeyboardInteractive != 0 { plugin = p break } } m.authLock.Unlock() if plugin == nil { return nil, errors.New("no auth plugin configured for keyboard interactive checking") } return plugin.checkUserAndKeyboardInteractive(username, ip, protocol, userAsJSON) } func (m *Manager) checkCrashedPlugins() { m.notifLock.RLock() for idx, n := range m.notifiers { if n.exited() { defer func(cfg Config, index int) { Handler.restartNotifierPlugin(cfg, index) }(n.config, idx) } else { n.sendQueuedEvents() } } m.notifLock.RUnlock() m.kmsLock.RLock() for idx, k := range m.kms { if k.exited() { defer func(cfg Config, index int) { Handler.restartKMSPlugin(cfg, index) }(k.config, idx) } } m.kmsLock.RUnlock() m.authLock.RLock() for idx, a := range m.auths { if a.exited() { defer func(cfg Config, index int) { Handler.restartAuthPlugin(cfg, index) }(a.config, idx) } } m.authLock.RUnlock() if m.hasSearcher { m.searcherLock.RLock() if m.searcher.exited() { defer func(cfg Config) { Handler.restartSearcherPlugin(cfg) }(m.searcher.config) } m.searcherLock.RUnlock() } if m.hasIPFilter { m.ipFilterLock.RLock() if m.filter.exited() { defer func(cfg Config) { Handler.restartIPFilterPlugin(cfg) }(m.filter.config) } m.ipFilterLock.RUnlock() } } func (m *Manager) restartNotifierPlugin(config Config, idx int) { if m.closed.Load() { return } logger.Info(logSender, "", "try to restart crashed notifier plugin %q, idx: %v", config.Cmd, idx) plugin, err := newNotifierPlugin(config) if err != nil { logger.Error(logSender, "", "unable to restart notifier plugin %q, err: %v", config.Cmd, err) return } m.notifLock.Lock() plugin.queue = m.notifiers[idx].queue m.notifiers[idx] = plugin m.notifLock.Unlock() plugin.sendQueuedEvents() } func (m *Manager) restartKMSPlugin(config Config, idx int) { if m.closed.Load() { return } logger.Info(logSender, "", "try to restart crashed kms plugin %q, idx: %v", config.Cmd, idx) plugin, err := newKMSPlugin(config) if err != nil { logger.Error(logSender, "", "unable to restart kms plugin %q, err: %v", config.Cmd, err) return } m.kmsLock.Lock() m.kms[idx] = plugin m.kmsLock.Unlock() } func (m *Manager) restartAuthPlugin(config Config, idx int) { if m.closed.Load() { return } logger.Info(logSender, "", "try to restart crashed auth plugin %q, idx: %v", config.Cmd, idx) plugin, err := newAuthPlugin(config) if err != nil { logger.Error(logSender, "", "unable to restart auth plugin %q, err: %v", config.Cmd, err) return } m.authLock.Lock() m.auths[idx] = plugin m.authLock.Unlock() } func (m *Manager) restartSearcherPlugin(config Config) { if m.closed.Load() { return } logger.Info(logSender, "", "try to restart crashed searcher plugin %q", config.Cmd) plugin, err := newSearcherPlugin(config) if err != nil { logger.Error(logSender, "", "unable to restart searcher plugin %q, err: %v", config.Cmd, err) return } m.searcherLock.Lock() m.searcher = plugin m.searcherLock.Unlock() } func (m *Manager) restartIPFilterPlugin(config Config) { if m.closed.Load() { return } logger.Info(logSender, "", "try to restart crashed IP filter plugin %q", config.Cmd) plugin, err := newIPFilterPlugin(config) if err != nil { logger.Error(logSender, "", "unable to restart IP filter plugin %q, err: %v", config.Cmd, err) return } m.ipFilterLock.Lock() m.filter = plugin m.ipFilterLock.Unlock() } func (m *Manager) addTask() { m.concurrencyGuard <- struct{}{} } func (m *Manager) removeTask() { <-m.concurrencyGuard } // Cleanup releases all the active plugins func (m *Manager) Cleanup() { if m.closed.Swap(true) { return } logger.Debug(logSender, "", "cleanup") close(m.done) m.notifLock.Lock() for _, n := range m.notifiers { logger.Debug(logSender, "", "cleanup notifier plugin %v", n.config.Cmd) n.cleanup() } m.notifLock.Unlock() m.kmsLock.Lock() for _, k := range m.kms { logger.Debug(logSender, "", "cleanup kms plugin %v", k.config.Cmd) k.cleanup() } m.kmsLock.Unlock() m.authLock.Lock() for _, a := range m.auths { logger.Debug(logSender, "", "cleanup auth plugin %v", a.config.Cmd) a.cleanup() } m.authLock.Unlock() if m.hasSearcher { m.searcherLock.Lock() logger.Debug(logSender, "", "cleanup searcher plugin %v", m.searcher.config.Cmd) m.searcher.cleanup() m.searcherLock.Unlock() } if m.hasIPFilter { m.ipFilterLock.Lock() logger.Debug(logSender, "", "cleanup IP filter plugin %v", m.filter.config.Cmd) m.filter.cleanup() m.ipFilterLock.Unlock() } } func setLogLevel(logLevel string) { switch logLevel { case "info": pluginsLogLevel = hclog.Info case "warn": pluginsLogLevel = hclog.Warn case "error": pluginsLogLevel = hclog.Error default: pluginsLogLevel = hclog.Debug } } func startCheckTicker() { logger.Debug(logSender, "", "start plugins checker") go func() { ticker := time.NewTicker(30 * time.Second) defer ticker.Stop() for { select { case <-Handler.done: logger.Debug(logSender, "", "handler done, stop plugins checker") return case <-ticker.C: Handler.checkCrashedPlugins() } } }() }