LibTLS: Add self signage information to our parsed certificates

Author: https://github.com/fdellwing
Commit: 114a383af3
Pull-request: https://github.com/SerenityOS/serenity/pull/17955
Reviewed-by: https://github.com/gmta ✅
Reviewed-by: https://github.com/kleinesfilmroellchen ✅

Userland/Libraries/LibTLS/Certificate.cpp

@@ -349,6 +349,11 @@ Optional<Certificate> Certificate::parse_asn1(ReadonlyBytes buffer, bool)
             return {};
     }
 
+    // self issued
+    {
+        certificate.is_self_issued = certificate.issuer_identifier_string() == certificate.subject_identifier_string();
+    }
+
     // extensions
     {
         if (certificate.version == 2) {