docs: function readCaChain(caChain){
      var ret = [];
      if (caChain instanceof Array){
          caChain.forEach(function(fileName){
              try{
                  ret.push(fs.readFileSync(fileName , "utf-8"))
              }catch(e){
                  console.log("---readCaChain--- Error reading CA chain file");
                  console.log(e);
                  return null;
              }
          });
      }
      // IF it is a string, it should be directly a file name and not a chain
      if (caChain instanceof String){
          try{
              ret.push(fs.readFileSync(caChain) , "utf-8");
          }catch(e){
              console.log("---readCaChain--- Error reading CA chain file");
              console.log(e);
              return null;
          }
      }
      return ret;
  }