Allow specifying SECRET_KEY_URI, similar to INTERNAL_TOKEN_URI (#19663)

Only load SECRET_KEY and INTERNAL_TOKEN if they exist.
Never write the config file if the keys do not exist, which was only a fallback for Gitea upgraded from < 1.5

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

cmd/web.go

@@ -203,7 +203,7 @@ func setPort(port string) error {
 		defaultLocalURL += ":" + setting.HTTPPort + "/"
 
 		// Save LOCAL_ROOT_URL if port changed
-		setting.CreateOrAppendToCustomConf(func(cfg *ini.File) {
+		setting.CreateOrAppendToCustomConf("server.LOCAL_ROOT_URL", func(cfg *ini.File) {
 			cfg.Section("server").Key("LOCAL_ROOT_URL").SetValue(defaultLocalURL)
 		})
 	}

custom/conf/app.example.ini

@@ -379,14 +379,19 @@ LOG_SQL = false ; if unset defaults to true
 ;; Whether the installer is disabled (set to true to disable the installer)
 INSTALL_LOCK = false
 ;;
-;; Global secret key that will be used - if blank will be regenerated.
+;; Global secret key that will be used
+;; This key is VERY IMPORTANT. If you lose it, the data encrypted by it (like 2FA secret) can't be decrypted anymore.
 SECRET_KEY =
 ;;
+;; Alternative location to specify secret key, instead of this file; you cannot specify both this and SECRET_KEY, and must pick one
+;; This key is VERY IMPORTANT. If you lose it, the data encrypted by it (like 2FA secret) can't be decrypted anymore.
+;SECRET_KEY_URI = file:/etc/gitea/secret_key
+;;
 ;; Secret used to validate communication within Gitea binary.
 INTERNAL_TOKEN=
 ;;
-;; Instead of defining internal token in the configuration, this configuration option can be used to give Gitea a path to a file that contains the internal token (example value: file:/etc/gitea/internal_token)
-;INTERNAL_TOKEN_URI = ;e.g. /etc/gitea/internal_token
+;; Alternative location to specify internal token, instead of this file; you cannot specify both this and INTERNAL_TOKEN, and must pick one
+;INTERNAL_TOKEN_URI = file:/etc/gitea/internal_token
 ;;
 ;; How long to remember that a user is logged in before requiring relogin (in days)
 ;LOGIN_REMEMBER_DAYS = 7

docs/content/doc/advanced/config-cheat-sheet.en-us.md

@@ -494,7 +494,8 @@ Certain queues have defaults that override the defaults set in `[queue]` (this o
 ## Security (`security`)
 
 - `INSTALL_LOCK`: **false**: Controls access to the installation page. When set to "true", the installation page is not accessible.
-- `SECRET_KEY`: **\<random at every install\>**: Global secret key. This should be changed.
+- `SECRET_KEY`: **\<random at every install\>**: Global secret key. This key is VERY IMPORTANT, if you lost it, the data encrypted by it (like 2FA secret) can't be decrypted anymore.
+- `SECRET_KEY_URI`: **<empty>**: Instead of defining SECRET_KEY, this option can be used to use the key stored in a file (example value: `file:/etc/gitea/secret_key`). It shouldn't be lost like SECRET_KEY.
 - `LOGIN_REMEMBER_DAYS`: **7**: Cookie lifetime, in days.
 - `COOKIE_USERNAME`: **gitea\_awesome**: Name of the cookie used to store the current username.
 - `COOKIE_REMEMBER_NAME`: **gitea\_incredible**: Name of cookie used to store authentication
@@ -520,7 +521,7 @@ Certain queues have defaults that override the defaults set in `[queue]` (this o
 - `ONLY_ALLOW_PUSH_IF_GITEA_ENVIRONMENT_SET`: **true**: Set to `false` to allow local users to push to gitea-repositories without setting up the Gitea environment. This is not recommended and if you want local users to push to Gitea repositories you should set the environment appropriately.
 - `IMPORT_LOCAL_PATHS`: **false**: Set to `false` to prevent all users (including admin) from importing local path on server.
 - `INTERNAL_TOKEN`: **\<random at every install if no uri set\>**: Secret used to validate communication within Gitea binary.
-- `INTERNAL_TOKEN_URI`: **<empty>**: Instead of defining internal token in the configuration, this configuration option can be used to give Gitea a path to a file that contains the internal token (example value: `file:/etc/gitea/internal_token`)
+- `INTERNAL_TOKEN_URI`: **<empty>**: Instead of defining INTERNAL_TOKEN in the configuration, this configuration option can be used to give Gitea a path to a file that contains the internal token (example value: `file:/etc/gitea/internal_token`)
 - `PASSWORD_HASH_ALGO`: **pbkdf2**: The hash algorithm to use \[argon2, pbkdf2, scrypt, bcrypt\], argon2 will spend more memory than others.
 - `CSRF_COOKIE_HTTP_ONLY`: **true**: Set false to allow JavaScript to read CSRF cookie.
 - `MIN_PASSWORD_LENGTH`: **6**: Minimum password length for new users.

modules/setting/lfs.go

@@ -62,7 +62,7 @@ func newLFSService() {
 			}
 
 			// Save secret
-			CreateOrAppendToCustomConf(func(cfg *ini.File) {
+			CreateOrAppendToCustomConf("server.LFS_JWT_SECRET", func(cfg *ini.File) {
 				cfg.Section("server").Key("LFS_JWT_SECRET").SetValue(LFS.JWTSecretBase64)
 			})
 		}

modules/setting/setting.go

@@ -21,7 +21,6 @@ import (
 	"text/template"
 	"time"
 
-	"code.gitea.io/gitea/modules/generate"
 	"code.gitea.io/gitea/modules/json"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/user"
@@ -923,9 +922,15 @@ func loadFromConf(allowEmpty bool, extraConfig string) {
 
 	sec = Cfg.Section("security")
 	InstallLock = sec.Key("INSTALL_LOCK").MustBool(false)
-	SecretKey = sec.Key("SECRET_KEY").MustString("!#@FDEWREWR&*(")
 	LogInRememberDays = sec.Key("LOGIN_REMEMBER_DAYS").MustInt(7)
 	CookieUserName = sec.Key("COOKIE_USERNAME").MustString("gitea_awesome")
+	SecretKey = loadSecret(sec, "SECRET_KEY_URI", "SECRET_KEY")
+	if SecretKey == "" {
+		// FIXME: https://github.com/go-gitea/gitea/issues/16832
+		// Until it supports rotating an existing secret key, we shouldn't move users off of the widely used default value
+		SecretKey = "!#@FDEWREWR&*(" // nolint:gosec
+	}
+
 	CookieRememberName = sec.Key("COOKIE_REMEMBER_NAME").MustString("gitea_incredible")
 
 	ReverseProxyAuthUser = sec.Key("REVERSE_PROXY_AUTHENTICATION_USER").MustString("X-WEBAUTH-USER")
@@ -948,11 +953,7 @@ func loadFromConf(allowEmpty bool, extraConfig string) {
 	PasswordCheckPwn = sec.Key("PASSWORD_CHECK_PWN").MustBool(false)
 	SuccessfulTokensCacheSize = sec.Key("SUCCESSFUL_TOKENS_CACHE_SIZE").MustInt(20)
 
-	InternalToken = loadInternalToken(sec)
-	if InstallLock && InternalToken == "" {
-		// if Gitea has been installed but the InternalToken hasn't been generated (upgrade from an old release), we should generate
-		generateSaveInternalToken()
-	}
+	InternalToken = loadSecret(sec, "INTERNAL_TOKEN_URI", "INTERNAL_TOKEN")
 
 	cfgdata := sec.Key("PASSWORD_COMPLEXITY").Strings(",")
 	if len(cfgdata) == 0 {
@@ -1141,51 +1142,36 @@ func parseAuthorizedPrincipalsAllow(values []string) ([]string, bool) {
 	return authorizedPrincipalsAllow, true
 }
 
-func loadInternalToken(sec *ini.Section) string {
-	uri := sec.Key("INTERNAL_TOKEN_URI").String()
-	if uri == "" {
-		return sec.Key("INTERNAL_TOKEN").String()
+func loadSecret(sec *ini.Section, uriKey, verbatimKey string) string {
+	// don't allow setting both URI and verbatim string
+	uri := sec.Key(uriKey).String()
+	verbatim := sec.Key(verbatimKey).String()
+	if uri != "" && verbatim != "" {
+		log.Fatal("Cannot specify both %s and %s", uriKey, verbatimKey)
 	}
+
+	// if we have no URI, use verbatim
+	if uri == "" {
+		return verbatim
+	}
+
 	tempURI, err := url.Parse(uri)
 	if err != nil {
-		log.Fatal("Failed to parse INTERNAL_TOKEN_URI (%s): %v", uri, err)
+		log.Fatal("Failed to parse %s (%s): %v", uriKey, uri, err)
 	}
 	switch tempURI.Scheme {
 	case "file":
 		buf, err := os.ReadFile(tempURI.RequestURI())
-		if err != nil && !os.IsNotExist(err) {
-			log.Fatal("Failed to open InternalTokenURI (%s): %v", uri, err)
-		}
-		// No token in the file, generate one and store it.
-		if len(buf) == 0 {
-			token, err := generate.NewInternalToken()
-			if err != nil {
-				log.Fatal("Error generate internal token: %v", err)
-			}
-			err = os.WriteFile(tempURI.RequestURI(), []byte(token), 0o600)
-			if err != nil {
-				log.Fatal("Error writing to InternalTokenURI (%s): %v", uri, err)
-			}
-			return token
+		if err != nil {
+			log.Fatal("Failed to read %s (%s): %v", uriKey, tempURI.RequestURI(), err)
 		}
 		return strings.TrimSpace(string(buf))
+
+	// only file URIs are allowed
 	default:
 		log.Fatal("Unsupported URI-Scheme %q (INTERNAL_TOKEN_URI = %q)", tempURI.Scheme, uri)
+		return ""
 	}
-	return ""
-}
-
-// generateSaveInternalToken generates and saves the internal token to app.ini
-func generateSaveInternalToken() {
-	token, err := generate.NewInternalToken()
-	if err != nil {
-		log.Fatal("Error generate internal token: %v", err)
-	}
-
-	InternalToken = token
-	CreateOrAppendToCustomConf(func(cfg *ini.File) {
-		cfg.Section("security").Key("INTERNAL_TOKEN").SetValue(token)
-	})
 }
 
 // MakeAbsoluteAssetURL returns the absolute asset url prefix without a trailing slash
@@ -1249,7 +1235,12 @@ func MakeManifestData(appName, appURL, absoluteAssetURL string) []byte {
 
 // CreateOrAppendToCustomConf creates or updates the custom config.
 // Use the callback to set individual values.
-func CreateOrAppendToCustomConf(callback func(cfg *ini.File)) {
+func CreateOrAppendToCustomConf(purpose string, callback func(cfg *ini.File)) {
+	if CustomConf == "" {
+		log.Error("Custom config path must not be empty")
+		return
+	}
+
 	cfg := ini.Empty()
 	isFile, err := util.IsFile(CustomConf)
 	if err != nil {
@@ -1264,8 +1255,6 @@ func CreateOrAppendToCustomConf(callback func(cfg *ini.File)) {
 
 	callback(cfg)
 
-	log.Info("Settings saved to: %q", CustomConf)
-
 	if err := os.MkdirAll(filepath.Dir(CustomConf), os.ModePerm); err != nil {
 		log.Fatal("failed to create '%s': %v", CustomConf, err)
 		return
@@ -1273,6 +1262,7 @@ func CreateOrAppendToCustomConf(callback func(cfg *ini.File)) {
 	if err := cfg.SaveTo(CustomConf); err != nil {
 		log.Fatal("error saving to custom config: %v", err)
 	}
+	log.Info("Settings for %s saved to: %q", purpose, CustomConf)
 
 	// Change permissions to be more restrictive
 	fi, err := os.Stat(CustomConf)

routers/private/internal.go

@@ -24,6 +24,11 @@ func CheckInternalToken(next http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
 		tokens := req.Header.Get("Authorization")
 		fields := strings.SplitN(tokens, " ", 2)
+		if setting.InternalToken == "" {
+			log.Warn(`The INTERNAL_TOKEN setting is missing from the configuration file: %q, internal API can't work.`, setting.CustomConf)
+			http.Error(w, http.StatusText(http.StatusForbidden), http.StatusForbidden)
+			return
+		}
 		if len(fields) != 2 || fields[0] != "Bearer" || fields[1] != setting.InternalToken {
 			log.Debug("Forbidden attempt to access internal url: Authorization header: %s", tokens)
 			http.Error(w, http.StatusText(http.StatusForbidden), http.StatusForbidden)

services/auth/source/oauth2/jwtsigningkey.go

@@ -364,7 +364,7 @@ func loadOrCreateSymmetricKey() (interface{}, error) {
 			return nil, err
 		}
 
-		setting.CreateOrAppendToCustomConf(func(cfg *ini.File) {
+		setting.CreateOrAppendToCustomConf("oauth2.JWT_SECRET", func(cfg *ini.File) {
 			secretBase64 := base64.RawURLEncoding.EncodeToString(key)
 			cfg.Section("oauth2").Key("JWT_SECRET").SetValue(secretBase64)
 		})