Prototype with single host server and no admin panel (#2)

Reviewed-on: wrenn/sandbox#2
Co-authored-by: pptx704 <rafeed@omukk.dev>
Co-committed-by: pptx704 <rafeed@omukk.dev>

internal/api/middleware_hosttoken.go

@@ -0,0 +1,30 @@
+package api
+
+import (
+	"net/http"
+
+	"git.omukk.dev/wrenn/sandbox/internal/auth"
+)
+
+// requireHostToken validates the X-Host-Token header containing a host JWT,
+// verifies the signature and expiry, and stamps HostContext into the request context.
+func requireHostToken(secret []byte) func(http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			tokenStr := r.Header.Get("X-Host-Token")
+			if tokenStr == "" {
+				writeError(w, http.StatusUnauthorized, "unauthorized", "X-Host-Token header required")
+				return
+			}
+
+			claims, err := auth.VerifyHostJWT(secret, tokenStr)
+			if err != nil {
+				writeError(w, http.StatusUnauthorized, "unauthorized", "invalid or expired host token")
+				return
+			}
+
+			ctx := auth.WithHostContext(r.Context(), auth.HostContext{HostID: claims.HostID})
+			next.ServeHTTP(w, r.WithContext(ctx))
+		})
+	}
+}