/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*-
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
"use strict";

/*
 * These are helper functions to be included
 * pippki UI js files.
 */

function setText(id, value) {
  let element = document.getElementById(id);
  if (!element) {
    return;
  }
  if (element.hasChildNodes()) {
    element.removeChild(element.firstChild);
  }
  element.appendChild(document.createTextNode(value));
}

const nsICertificateDialogs = Components.interfaces.nsICertificateDialogs;
const nsCertificateDialogs = "@mozilla.org/nsCertificateDialogs;1";

function viewCertHelper(parent, cert) {
  if (!cert) {
    return;
  }

  var cd = Components.classes[nsCertificateDialogs].getService(nsICertificateDialogs);
  cd.viewCert(parent, cert);
}

function getDERString(cert)
{
  var length = {};
  var derArray = cert.getRawDER(length);
  var derString = '';
  for (var i = 0; i < derArray.length; i++) {
    derString += String.fromCharCode(derArray[i]);
  }
  return derString;
}

function getPKCS7String(cert, chainMode)
{
  var length = {};
  var pkcs7Array = cert.exportAsCMS(chainMode, length);
  var pkcs7String = '';
  for (var i = 0; i < pkcs7Array.length; i++) {
    pkcs7String += String.fromCharCode(pkcs7Array[i]);
  }
  return pkcs7String;
}

function getPEMString(cert)
{
  var derb64 = btoa(getDERString(cert));
  // Wrap the Base64 string into lines of 64 characters with CRLF line breaks
  // (as specified in RFC 1421).
  var wrapped = derb64.replace(/(\S{64}(?!$))/g, "$1\r\n");
  return "-----BEGIN CERTIFICATE-----\r\n"
         + wrapped
         + "\r\n-----END CERTIFICATE-----\r\n";
}

function alertPromptService(title, message)
{
  var ps = Components.classes["@mozilla.org/embedcomp/prompt-service;1"].
           getService(Components.interfaces.nsIPromptService);
  ps.alert(window, title, message);
}

const DEFAULT_CERT_EXTENSION = "crt";

/**
 * Generates a filename for a cert suitable to set as the |defaultString|
 * attribute on an nsIFilePicker.
 *
 * @param {nsIX509Cert} cert
 *        The cert to generate a filename for.
 * @returns {String}
 *          Generated filename.
 */
function certToFilename(cert) {
  let filename = cert.commonName;
  if (!filename) {
    filename = cert.windowTitle;
  }

  // Remove unneeded and/or unsafe characters.
  filename = filename.replace(/\s/g, "")
                     .replace(/\./g, "")
                     .replace(/\\/g, "")
                     .replace(/\//g, "");

  // nsIFilePicker.defaultExtension is more of a suggestion to some
  // implementations, so we include the extension in the file name as well. This
  // is what the documentation for nsIFilePicker.defaultString says we should do
  // anyways.
  return `${filename}.${DEFAULT_CERT_EXTENSION}`;
}

function exportToFile(parent, cert)
{
  var bundle = document.getElementById("pippki_bundle");
  if (!cert) {
    return;
  }

  var nsIFilePicker = Components.interfaces.nsIFilePicker;
  var fp = Components.classes["@mozilla.org/filepicker;1"].
           createInstance(nsIFilePicker);
  fp.init(parent, bundle.getString("SaveCertAs"),
          nsIFilePicker.modeSave);
  fp.defaultString = certToFilename(cert);
  fp.defaultExtension = DEFAULT_CERT_EXTENSION;
  fp.appendFilter(bundle.getString("CertFormatBase64"), "*.crt; *.pem");
  fp.appendFilter(bundle.getString("CertFormatBase64Chain"), "*.crt; *.pem");
  fp.appendFilter(bundle.getString("CertFormatDER"), "*.der");
  fp.appendFilter(bundle.getString("CertFormatPKCS7"), "*.p7c");
  fp.appendFilter(bundle.getString("CertFormatPKCS7Chain"), "*.p7c");
  fp.appendFilters(nsIFilePicker.filterAll);
  var res = fp.show();
  if (res != nsIFilePicker.returnOK && res != nsIFilePicker.returnReplace) {
    return;
  }

  var content = '';
  switch (fp.filterIndex) {
    case 1:
      content = getPEMString(cert);
      var chain = cert.getChain();
      for (let i = 1; i < chain.length; i++) {
        content += getPEMString(chain.queryElementAt(i, Components.interfaces.nsIX509Cert));
      }
      break;
    case 2:
      content = getDERString(cert);
      break;
    case 3:
      content = getPKCS7String(cert, Components.interfaces.nsIX509Cert.CMS_CHAIN_MODE_CertOnly);
      break;
    case 4:
      content = getPKCS7String(cert, Components.interfaces.nsIX509Cert.CMS_CHAIN_MODE_CertChainWithRoot);
      break;
    case 0:
    default:
      content = getPEMString(cert);
      break;
  }
  var msg;
  var written = 0;
  try {
    var file = Components.classes["@mozilla.org/file/local;1"].
               createInstance(Components.interfaces.nsILocalFile);
    file.initWithPath(fp.file.path);
    var fos = Components.classes["@mozilla.org/network/file-output-stream;1"].
              createInstance(Components.interfaces.nsIFileOutputStream);
    // flags: PR_WRONLY | PR_CREATE_FILE | PR_TRUNCATE
    fos.init(file, 0x02 | 0x08 | 0x20, 0o0644, 0);
    written = fos.write(content, content.length);
    fos.close();
  } catch (e) {
    switch (e.result) {
      case Components.results.NS_ERROR_FILE_ACCESS_DENIED:
        msg = bundle.getString("writeFileAccessDenied");
        break;
      case Components.results.NS_ERROR_FILE_IS_LOCKED:
        msg = bundle.getString("writeFileIsLocked");
        break;
      case Components.results.NS_ERROR_FILE_NO_DEVICE_SPACE:
      case Components.results.NS_ERROR_FILE_DISK_FULL:
        msg = bundle.getString("writeFileNoDeviceSpace");
        break;
      default:
        msg = e.message;
        break;
    }
  }
  if (written != content.length) {
    if (msg.length == 0) {
      msg = bundle.getString("writeFileUnknownError");
    }
    alertPromptService(bundle.getString("writeFileFailure"),
                       bundle.getFormattedString("writeFileFailed",
                       [fp.file.path, msg]));
  }
}
