PDF Cert validation (#2394)

* verifyCerts

* cert info

* Hardening suggestions for Stirling-PDF / certValidate (#2395)

* Protect `readLine()` against DoS

* Switch order of literals to prevent NullPointerException

---------

Co-authored-by: pixeebot[bot] <104101892+pixeebot[bot]@users.noreply.github.com>

* some basic html excaping and translation fixing

---------

Co-authored-by: pixeebot[bot] <104101892+pixeebot[bot]@users.noreply.github.com>
Co-authored-by: a <a>

src/main/java/stirling/software/SPDF/controller/web/SecurityWebController.java

@@ -53,6 +53,13 @@ public class SecurityWebController {
         return "security/cert-sign";
     }
 
+    @GetMapping("/validate-signature")
+    @Hidden
+    public String certSignVerifyForm(Model model) {
+        model.addAttribute("currentPage", "validate-signature");
+        return "security/validate-signature";
+    }
+
     @GetMapping("/remove-cert-sign")
     @Hidden
     public String certUnSignForm(Model model) {