crypto.js

function pgpEncrypt(randomKey, pubKey) {
	// $('#composeMain').html('<pre>'+pubKey+'</pre>');
	console.log('pubKey: '+pubKey);
	randomKey = encode_utf8_base64(randomKey);
	var _pubKey = openpgp.key.readArmored(pubKey).keys[0];
	console.log('_pubKey: '+_pubKey);
	console.log('randomKey: '+randomKey);
	return openpgp.encryptMessage([_pubKey], randomKey);
}

function pgpDecrypt(encRandomKey, prKey, prKeyPassCode) {
	var _encRandomKey = openpgp.message.readArmored(encRandomKey);
	var _prKey = openpgp.key.readArmored(prKey).keys[0];
	if(_prKey.decrypt(prKeyPassCode)) {
		return decode_utf8_base64(openpgp.decryptMessage(_prKey, _encRandomKey));
	}
	else return -1;
}

function generateRandomKey() {
	var randomKey = openpgp.crypto.generateSessionKey("aes256");
	return randomKey;
}

function encryptMessage(message, randomKey) {

	message = encode_utf8_base64(message);
	// padding 
    var residual = message.length % 32;
	if((residual) != 0) {
		for(var i = 0; i < 32 - residual; i++) {
			message = message + ' ';
		}
	}
	var cipher = openpgp.crypto.cfb.encrypt(openpgp.crypto.getPrefixRandom("aes256"), "aes256", message, randomKey, true);
	cipher = encode_utf8_base64(cipher);
	return cipher;
}

function decryptMessage(encMessage, randomKey) {
	encMessage = decode_utf8_base64(encMessage);
	return decode_utf8_base64(openpgp.crypto.cfb.decrypt("aes256",randomKey,encMessage,true));
}

var headerMessage = "---BEGIN ENCRYPTED MESSAGE---";
var tailMessage = "---END ENCRYPTED MESSAGE---";
var headerRandomKey = "---BEGIN ENCRYPTED RANDOM KEY---";
var tailRandomKey = "---END ENCRYPTED RANDOM KEY---";

function generateEmailPM(encMessage, encRandomKey) {
  var EmailPM = headerMessage + encMessage + tailMessage;
  EmailPM += "||" + headerRandomKey + encRandomKey + tailRandomKey;
  return EmailPM; 
}

function getEncMessageFromEmailPM(EmailPM) {
  var begin = EmailPM.search(headerMessage) + headerMessage.length;
  var end = EmailPM.search(tailMessage);
  return EmailPM.substring(begin, end);
}

function getEncRandomKeyFromEmailPM(EmailPM) {
  var begin = EmailPM.search(headerRandomKey) + headerRandomKey.length;
  var end = EmailPM.search(tailRandomKey); 
  return EmailPM.substring(begin, end);
}

function getHashedPassword(password) {
  var hashed = openpgp.crypto.hash.sha512(password);
  hashed = btoa(hashed);
  return hashed; 
}

function checkMailboxPw(pubKey, prKey, prKeyPassCode) {
	var testMsg = "sPKkm9lk6hSSZ49rRFwg";
	var encrypted = pgpEncrypt(testMsg, pubKey);
	var decrypted = pgpDecrypt(encrypted, prKey, prKeyPassCode);
	if(testMsg == decrypted) return 1; // good
	else return 0; // bad
}
 
function encode_utf8_base64(data) {
  return btoa(unescape(encodeURIComponent(data))).trim();
}

function decode_utf8_base64(data) {
  return decodeURIComponent(escape(atob(data.trim())));
}

function getNewEncPrivateKey(prKey, oldMailPwd, newMailPwd) {
  var _prKey = openpgp.key.readArmored(prKey).keys[0];
  if(_prKey.decrypt(oldMailPwd)) {
    _prKey.primaryKey.encrypt(newMailPwd);
    _prKey.subKeys[0].subKey.encrypt(newMailPwd);
    return _prKey.armor();
  }
  else return -1;
}