code: function FileKeyInfo(file) {
    this.file = file
  
    this.getKeyInfo = function(key, prefix) {
      prefix = prefix || ''
      prefix = prefix ? prefix + ':' : prefix
      return "<" + prefix + "X509Data></" + prefix + "X509Data>"
    }
  
    this.getKey = function(keyInfo) {
      return fs.readFileSync(this.file)
    }
  }
docs: A key info provider implementation