tls-dashboard/node_app/get_cert_info.js

/**
 * TLS Dashboard by Craine Runton
 * Source: https://github.com/cmrunton/tls-dashboard
 * 
 * See /LICENSE for licensing details
 */

var https = require('https');
const fs = require('fs');
const config = require('./config');
const monitored_hosts = require('./monitored_hosts');

const run_date = new Date().toDateString();
var output = {},
  iteration = 1,
  errors = 0;

// Run the module
monitored_hosts.forEach(get_cert_parameters)

/**  
 * Creates a connection to the host, and then reads the resulting peer certificate to extract the desired info
 * 
 * @param {string} element The 
 * @param {int} index 
 * @param {array} array The 
 */
function get_cert_parameters(element, index, array) {
  var options = {
    hostname: element,
    port: 443,
    method: 'GET'
  };

  var req = https.request(options, function(res) {
    var cert = res.connection.getPeerCertificate();
    var parsed = {
      'server': element,
      'subject': {
        'org': cert.subject.O,
        'common_name': cert.subject.CN,
        'sans': cert.subjectaltname
      }, 
      'issuer': {
        'org': cert.issuer.O,
        'common_name': cert.issuer.CN
      },
      'info': {
        'valid_from': parse_date(cert.valid_from),
        'valid_to': parse_date(cert.valid_to),
        'days_left': get_days_left(cert.valid_to)
      }
    };
    add_cert_details(parsed, iteration);
    check_iterations();
  });

  // Abort the request when a timeout event is emitted
  req.on('timeout',  function () {
    this.abort();
  });

  // Handle errors generated by failed requests
  req.on('error', function(e) {
    // Increment the error count for the final output
    errors++;
    var parsed = {
      'server': element,
      'subject': {
        'org': 'Unknown',
        'common_name': '',
        'sans': 'Unknown'
      }, 
      'issuer': {
        'org': 'Unknown',
        'common_name': ''
      },
      'info': {
        'days_left': '',
        'sort_order': 100000,
        'background_class': ''
      }
    };

    if (e.hasOwnProperty('code')) {
      switch (e.code) {
        case 'CERT_HAS_EXPIRED':
          assert(false, element+' certificate expired.');
          parsed.subject.common_name = 'The certificate has expired';
          parsed.issuer.common_name = e.code;
          parsed.info.days_left = '0';
          parsed.info.sort_order = 0;
          parsed.info.background_class = 'danger';
          break;
        case 'ECONNRESET':
          assert(false, element+' connection timed out or was reset.');
          parsed.subject.common_name = 'The connection was reset by the server or timed out';
          parsed.issuer.common_name = e.code;
          parsed.info.days_left = '--';
          parsed.info.background_class = 'info';
          break;
        case 'ECONNREFUSED':
          assert(false, element+' connection refused by server.');
          parsed.subject.common_name = 'The connection was refused by the remote server';
          parsed.issuer.common_name = e.code;
          parsed.info.days_left = '--';
          parsed.info.background_class = 'info';
          break;
        case 'UNABLE_TO_VERIFY_LEAF_SIGNATURE':
          assert(false, element+' self-signed or incomplete certificate chain.');
          parsed.subject.common_name = 'The server provided a self-signed certificate or the provided certificate chain was incomplete';
          parsed.issuer.common_name = e.code;
          parsed.info.days_left = '--';
          parsed.info.background_class = 'info';
          break;
        default:
          assert(false, element+' unspecified error.');
          parsed.subject.common_name = 'An unspecified error occured';
          parsed.issuer.common_name = e.code;
          parsed.info.days_left = '--';
          parsed.info.background_class = 'info';
          break;
      };

    } else if (e.hasOwnProperty('reason')) {
      switch (e.reason) {
        default:
          assert(false, element+' hostname mismatch.');
          parsed.subject.common_name = 'There was mismatch between the requested hostname and the certificate presented by the server';
          parsed.issuer.common_name = 'HOSTNAME_MISMATCH';
          parsed.info.days_left = '--';
          parsed.info.background_class = 'info';
          break;
      }

    }
    add_cert_details(parsed, iteration);
    check_iterations();
  })

  // Set the timeout threshold for the https connection. Set in config.js, default 5000ms
  req.setTimeout(config.connection_timeout);
  
  // End the request
  req.end();
};

/**
 * Parses the date string passed to it and returs a new date object
 *
 * @param {string} date_string The human readble date string that needs to be parsed
 */
function parse_date(date_string) {
  var date = new Date(Date.parse(date_string));
  return date;
};

/** 
 * Takes a date string and returns the nuumber of days between now and the future date
 * 
 * @param {string} date_string The human readble date string that needs to be parsed
 */
function get_days_left(date_string) {
  var now = Date.now();
  var then = new Date(Date.parse(date_string));
  var days_left = Math.round((then - now)/86400000);
  return days_left;
};

/**
 * Helper function to put the resolved/parsed cert info into the module output object
 * 
 * @param {object} object Contains the parsed certificate info
 * @param {string} host The name of the host that the certificate info is taken from
 */
function add_cert_details(object, host) {
  output[host] = object;
};

/**
 * Checks the iteration count. If the forEach has iterated over all the hosts, then call the write_results function, 
 *   otherwise log the iteration to the console and increment the count
 */
function check_iterations() {
  if (iteration === monitored_hosts.length) {
    assert(true, 'Scanned '+iteration+' of '+monitored_hosts.length+' urls, with '+errors+' errors');
    write_results();
  } else {
    iteration++;
  }
};

/**
 * Writes out the final object to a file, along with the run date to be used by the HTML page later
 */
function write_results() {
  fs.writeFile(config.output_file.path+config.output_file.name, 'var run_date = \''+run_date+'\'; \nvar cert_info = '+JSON.stringify(output, null, 2), function(err) {
    // If the write errored out, notify
    if (err) { 
      console.log('Error writing file. \n');
    }
  })
};

/**
 * Test function and used to write out the final iteration in green
 */
function assert(value, desc) {
  if (value) {
    console.log("\033[32m "+desc+"\033[0m");
  } else {
    console.log("\033[31m "+desc+"\033[0m");
  }
};