feat(auth): wire JWT validation into /v1/* LLM endpoints

internal/config/config.go

@@ -22,6 +22,8 @@ type Config struct {
 	Models map[string]*ModelUpstream
 	// Adapters holds service adapter definitions for X-Service routing.
 	Adapters []*serviceadapter.ServiceAdapter
+	// Auth holds JWT authentication configuration for /v1/* endpoints.
+	Auth AuthConfig
 }
 
 // ModelUpstream holds upstream configuration for a specific model.
@@ -32,6 +34,22 @@ type ModelUpstream struct {
 	Address string
 	// Path is the upstream path for this model (e.g., "/v1/chat/completions").
 	Path string
+	// AuthRequired indicates whether this model requires JWT authentication.
+	AuthRequired bool
+}
+
+// AuthConfig holds JWT authentication configuration.
+type AuthConfig struct {
+	// Enabled globally enables/disables auth for /v1/* endpoints.
+	Enabled bool
+	// Issuer is the expected JWT issuer (iss claim).
+	Issuer string
+	// Audience is the expected JWT audience (aud claim).
+	Audience string
+	// JWKSURL is the URL to fetch JSON Web Key Set for signature validation.
+	JWKSURL string
+	// RequiredCapability is the permission required for LLM inference (e.g., "llm:inference").
+	RequiredCapability string
 }
 
 // Route represents a single route and its upstream configuration.
@@ -98,18 +116,20 @@ func Load() (*Config, error) {
 		shutdownTimeout = d
 	}
 
-	// Load routes, models, and adapters from config file
+	// Load routes, models, adapters, and auth from config file
 	routes := make(map[string]*Route)
 	models := make(map[string]*ModelUpstream)
 	var adapters []*serviceadapter.ServiceAdapter
+	var authConfig AuthConfig
 	if configPath, ok := os.LookupEnv("CONFIG_PATH"); ok {
-		loadedRoutes, loadedModels, loadedAdapters, err := LoadRoutesAndModelsFromFile(configPath)
+		loadedRoutes, loadedModels, loadedAdapters, loadedAuth, err := LoadRoutesAndModelsFromFile(configPath)
 		if err != nil {
 			return nil, err
 		}
 		routes = loadedRoutes
 		models = loadedModels
 		adapters = loadedAdapters
+		authConfig = loadedAuth
 	}
 
 	return &Config{
@@ -118,5 +138,6 @@ func Load() (*Config, error) {
 		Routes:          routes,
 		Models:          models,
 		Adapters:        adapters,
+		Auth:            authConfig,
 	}, nil
 }

internal/config/loader.go

@@ -15,6 +15,16 @@ type rawConfig struct {
 	Routes   []rawRoute   `yaml:"routes"`
 	Models   []rawModel   `yaml:"models"`
 	Adapters []rawAdapter `yaml:"adapters"`
+	Auth     rawAuth      `yaml:"auth"`
+}
+
+// rawAuth represents auth configuration in YAML.
+type rawAuth struct {
+	Enabled            bool   `yaml:"enabled"`
+	Issuer             string `yaml:"issuer"`
+	Audience           string `yaml:"audience"`
+	JWKSURL            string `yaml:"jwksUrl"`
+	RequiredCapability string `yaml:"requiredCapability"`
 }
 
 // rawRoute represents a single route in the YAML configuration.
@@ -25,9 +35,10 @@ type rawRoute struct {
 
 // rawModel represents a single model entry in the YAML configuration.
 type rawModel struct {
-	Name    string `yaml:"name"`
-	Address string `yaml:"address"`
-	Path    string `yaml:"path"`
+	Name         string `yaml:"name"`
+	Address      string `yaml:"address"`
+	Path         string `yaml:"path"`
+	AuthRequired *bool  `yaml:"authRequired"`
 }
 
 // rawAdapter represents a service adapter in the YAML configuration.
@@ -64,32 +75,32 @@ type rawUpstream struct {
 	AuthRequired   *bool  `yaml:"authRequired"`
 }
 
-// LoadRoutesAndModelsFromFile loads route, model, and adapter configuration from a YAML file.
-func LoadRoutesAndModelsFromFile(path string) (map[string]*Route, map[string]*ModelUpstream, []*serviceadapter.ServiceAdapter, error) {
+// LoadRoutesAndModelsFromFile loads route, model, adapter, and auth configuration from a YAML file.
+func LoadRoutesAndModelsFromFile(path string) (map[string]*Route, map[string]*ModelUpstream, []*serviceadapter.ServiceAdapter, AuthConfig, error) {
 	data, err := os.ReadFile(path)
 	if err != nil {
-		return nil, nil, nil, fmt.Errorf("failed to read config file %q: %w", path, err)
+		return nil, nil, nil, AuthConfig{}, fmt.Errorf("failed to read config file %q: %w", path, err)
 	}
 
 	var raw rawConfig
 	if err := yaml.Unmarshal(data, &raw); err != nil {
-		return nil, nil, nil, fmt.Errorf("failed to parse config file %q: %w", path, err)
+		return nil, nil, nil, AuthConfig{}, fmt.Errorf("failed to parse config file %q: %w", path, err)
 	}
 
 	// Load routes
 	routes := make(map[string]*Route)
 	for _, rawRoute := range raw.Routes {
 		if rawRoute.Name == "" {
-			return nil, nil, nil, fmt.Errorf("route has empty name")
+			return nil, nil, nil, AuthConfig{}, fmt.Errorf("route has empty name")
 		}
 
 		if _, exists := routes[rawRoute.Name]; exists {
-			return nil, nil, nil, fmt.Errorf("duplicate route: \"%s\"", rawRoute.Name)
+			return nil, nil, nil, AuthConfig{}, fmt.Errorf("duplicate route: \"%s\"", rawRoute.Name)
 		}
 
 		upstream, err := parseUpstream(rawRoute.Name, rawRoute.Upstream)
 		if err != nil {
-			return nil, nil, nil, err
+			return nil, nil, nil, AuthConfig{}, err
 		}
 
 		routes[rawRoute.Name] = &Route{
@@ -102,21 +113,27 @@ func LoadRoutesAndModelsFromFile(path string) (map[string]*Route, map[string]*Mo
 	models := make(map[string]*ModelUpstream)
 	for _, rawModel := range raw.Models {
 		if rawModel.Name == "" {
-			return nil, nil, nil, fmt.Errorf("model has empty name")
+			return nil, nil, nil, AuthConfig{}, fmt.Errorf("model has empty name")
 		}
 		if _, exists := models[rawModel.Name]; exists {
-			return nil, nil, nil, fmt.Errorf("duplicate model: \"%s\"", rawModel.Name)
+			return nil, nil, nil, AuthConfig{}, fmt.Errorf("duplicate model: \"%s\"", rawModel.Name)
 		}
 		if rawModel.Address == "" {
-			return nil, nil, nil, fmt.Errorf("model \"%s\": field 'address' is required", rawModel.Name)
+			return nil, nil, nil, AuthConfig{}, fmt.Errorf("model \"%s\": field 'address' is required", rawModel.Name)
 		}
 		if _, _, err := net.SplitHostPort(rawModel.Address); err != nil {
-			return nil, nil, nil, fmt.Errorf("model \"%s\": invalid address \"%s\": %w", rawModel.Name, rawModel.Address, err)
+			return nil, nil, nil, AuthConfig{}, fmt.Errorf("model \"%s\": invalid address \"%s\": %w", rawModel.Name, rawModel.Address, err)
+		}
+		// Default authRequired to global auth.enabled if not specified per-model
+		authRequired := false
+		if rawModel.AuthRequired != nil {
+			authRequired = *rawModel.AuthRequired
 		}
 		models[rawModel.Name] = &ModelUpstream{
-			Name:    rawModel.Name,
-			Address: rawModel.Address,
-			Path:    rawModel.Path,
+			Name:         rawModel.Name,
+			Address:      rawModel.Address,
+			Path:         rawModel.Path,
+			AuthRequired: authRequired,
 		}
 	}
 
@@ -124,7 +141,7 @@ func LoadRoutesAndModelsFromFile(path string) (map[string]*Route, map[string]*Mo
 	adapters := make([]*serviceadapter.ServiceAdapter, 0, len(raw.Adapters))
 	for _, ra := range raw.Adapters {
 		if ra.ServiceName == "" {
-			return nil, nil, nil, fmt.Errorf("adapter has empty serviceName")
+			return nil, nil, nil, AuthConfig{}, fmt.Errorf("adapter has empty serviceName")
 		}
 		a := &serviceadapter.ServiceAdapter{
 			Name:        ra.ServiceName,
@@ -152,13 +169,22 @@ func LoadRoutesAndModelsFromFile(path string) (map[string]*Route, map[string]*Mo
 		adapters = append(adapters, a)
 	}
 
-	return routes, models, adapters, nil
+	// Parse auth config
+	authConfig := AuthConfig{
+		Enabled:            raw.Auth.Enabled,
+		Issuer:             raw.Auth.Issuer,
+		Audience:           raw.Auth.Audience,
+		JWKSURL:            raw.Auth.JWKSURL,
+		RequiredCapability: raw.Auth.RequiredCapability,
+	}
+
+	return routes, models, adapters, authConfig, nil
 }
 
 // LoadRoutesFromFile loads route configuration from a YAML file.
 // Deprecated: Use LoadRoutesAndModelsFromFile instead.
 func LoadRoutesFromFile(path string) (map[string]*Route, error) {
-	routes, _, _, err := LoadRoutesAndModelsFromFile(path)
+	routes, _, _, _, err := LoadRoutesAndModelsFromFile(path)
 	return routes, err
 }
 

internal/config/models_test.go

@@ -35,7 +35,7 @@ models:
 	tmpFile.WriteString(data)
 	tmpFile.Close()
 
-	_, models, _, err := LoadRoutesAndModelsFromFile(tmpFile.Name())
+	_, models, _, _, err := LoadRoutesAndModelsFromFile(tmpFile.Name())
 	if err != nil {
 		t.Fatalf("failed to load config: %v", err)
 	}
@@ -94,7 +94,7 @@ models:
 	tmpFile.WriteString(data)
 	tmpFile.Close()
 
-	_, _, _, err := LoadRoutesAndModelsFromFile(tmpFile.Name())
+	_, _, _, _, err := LoadRoutesAndModelsFromFile(tmpFile.Name())
 	if err == nil {
 		t.Errorf("expected error for duplicate model name, got nil")
 	}
@@ -127,7 +127,7 @@ models:
 	tmpFile.WriteString(data)
 	tmpFile.Close()
 
-	_, _, _, err := LoadRoutesAndModelsFromFile(tmpFile.Name())
+	_, _, _, _, err := LoadRoutesAndModelsFromFile(tmpFile.Name())
 	if err == nil {
 		t.Errorf("expected error for empty model name, got nil")
 	}
@@ -157,7 +157,7 @@ models:
 	tmpFile.WriteString(data)
 	tmpFile.Close()
 
-	_, _, _, err := LoadRoutesAndModelsFromFile(tmpFile.Name())
+	_, _, _, _, err := LoadRoutesAndModelsFromFile(tmpFile.Name())
 	if err == nil {
 		t.Errorf("expected error for missing address, got nil")
 	}
@@ -190,7 +190,7 @@ models:
 	tmpFile.WriteString(data)
 	tmpFile.Close()
 
-	_, _, _, err := LoadRoutesAndModelsFromFile(tmpFile.Name())
+	_, _, _, _, err := LoadRoutesAndModelsFromFile(tmpFile.Name())
 	if err == nil {
 		t.Errorf("expected error for invalid address, got nil")
 	}
@@ -219,7 +219,7 @@ models:
 	tmpFile.WriteString(data)
 	tmpFile.Close()
 
-	_, models, _, err := LoadRoutesAndModelsFromFile(tmpFile.Name())
+	_, models, _, _, err := LoadRoutesAndModelsFromFile(tmpFile.Name())
 	if err != nil {
 		t.Fatalf("failed to load config: %v", err)
 	}
@@ -261,7 +261,7 @@ models:
 	tmpFile.WriteString(data)
 	tmpFile.Close()
 
-	routes, models, _, err := LoadRoutesAndModelsFromFile(tmpFile.Name())
+	routes, models, _, _, err := LoadRoutesAndModelsFromFile(tmpFile.Name())
 	if err != nil {
 		t.Fatalf("failed to load config: %v", err)
 	}

internal/proxy/proxy.go

@@ -13,6 +13,7 @@ import (
 	"strings"
 	"time"
 
+	"forgejo.riotpiao.com/rock/homelab-frontend/internal/auth"
 	"forgejo.riotpiao.com/rock/homelab-frontend/internal/config"
 	"forgejo.riotpiao.com/rock/homelab-frontend/internal/logging"
 	"forgejo.riotpiao.com/rock/homelab-frontend/internal/tracing"
@@ -25,6 +26,8 @@ type Handler struct {
 	transports map[string]*http.Transport
 	// config holds the gateway configuration (for model registry, etc.)
 	config *config.Config
+	// jwtValidator validates JWT tokens for authenticated endpoints
+	jwtValidator *auth.Validator
 	// Default timeouts for synthesized routes (model-based dispatch)
 	defaultConnectTimeout time.Duration
 	defaultReadTimeout    time.Duration
@@ -73,6 +76,15 @@ func New(cfg *config.Config) *Handler {
 		defaultMaxBodySize:    100 * 1024 * 1024,
 	}
 
+	// Initialize JWT validator if auth is enabled
+	if cfg.Auth.Enabled && cfg.Auth.JWKSURL != "" {
+		h.jwtValidator = auth.NewValidator(
+			cfg.Auth.Issuer,
+			cfg.Auth.Audience,
+			cfg.Auth.JWKSURL,
+		)
+	}
+
 	for name, route := range cfg.Routes {
 		// Create a transport per unique upstream address for connection reuse
 		transport := h.getOrCreateTransport(route.Upstream.Address, &route.Upstream)
@@ -291,6 +303,51 @@ func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	// JWT Authentication for /v1/* endpoints
+	if h.jwtValidator != nil && strings.HasPrefix(r.URL.Path, "/v1/") {
+		authHeader := r.Header.Get("Authorization")
+		if authHeader == "" {
+			writeProblemDetail(w, http.StatusUnauthorized,
+				"https://api.example.com/problems/unauthorized",
+				"Unauthorized",
+				"Authorization header required",
+				nil)
+			logging.Errorf("auth failed", fmt.Errorf("missing auth header"), map[string]string{
+				"path": r.URL.Path,
+			})
+			return
+		}
+
+		claims, err := h.jwtValidator.ValidateBearerToken(authHeader)
+		if err != nil {
+			writeProblemDetail(w, http.StatusForbidden,
+				"https://api.example.com/problems/forbidden",
+				"Forbidden",
+				fmt.Sprintf("JWT validation failed: %v", err),
+				nil)
+			logging.Errorf("auth failed", err, map[string]string{
+				"path": r.URL.Path,
+			})
+			return
+		}
+
+		// Check required capability if configured
+		if h.config.Auth.RequiredCapability != "" {
+			if !h.jwtValidator.CheckPermissions(claims, h.config.Auth.RequiredCapability, "*") {
+				writeProblemDetail(w, http.StatusForbidden,
+					"https://api.example.com/problems/insufficient-permissions",
+					"Insufficient Permissions",
+					fmt.Sprintf("Required capability: %s", h.config.Auth.RequiredCapability),
+					nil)
+				logging.Errorf("auth failed", fmt.Errorf("insufficient permissions"), map[string]string{
+					"path":     r.URL.Path,
+					"required": h.config.Auth.RequiredCapability,
+				})
+				return
+			}
+		}
+	}
+
 	// Note: Body size checking already happened in RouteRequest (body was read for model dispatch).
 	// For other paths, we still need to enforce the cap.
 	// For /v1/chat/completions, the body was already read and validated.