feat(auth): support for forwarded auth provider

backend/app/api/providers/forwardauth.go

@@ -0,0 +1,36 @@
+package providers
+
+import (
+	"errors"
+	"net/http"
+
+	"github.com/hay-kot/homebox/backend/internal/core/services"
+	"github.com/hay-kot/homebox/backend/internal/sys/config"
+	"github.com/hay-kot/homebox/backend/pkgs/ipcheck"
+)
+
+type ForwardAuthProvider struct {
+	service    *services.UserService
+	authConfig *config.AuthConfig
+}
+
+func NewForwardAuthProvider(service *services.UserService, authConfig *config.AuthConfig) *ForwardAuthProvider {
+	return &ForwardAuthProvider{
+		service:    service,
+		authConfig: authConfig,
+	}
+}
+
+func (p *ForwardAuthProvider) Name() string {
+	return "forwardauth"
+}
+
+func (p *ForwardAuthProvider) Authenticate(w http.ResponseWriter, r *http.Request) (services.UserAuthTokenDetail, error) {
+	if !ipcheck.ValidateAgainstList(r.RemoteAddr, p.authConfig.ForwardAuthAllowedIps) {
+		return services.UserAuthTokenDetail{}, errors.New("forward authentication denied, IP address not allowed")
+	}
+
+	username := r.Header.Get(p.authConfig.ForwardAuthHeader)
+
+	return p.service.PasswordlessLogin(r.Context(), username, p.authConfig.ForwardAuthAutoRegister)
+}