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Exchanging encrypted messages between python and swift

I need to have a python code and a swift code exchange encrypted message.
Here's what I tried:
Fernet
After a review of the options, I thought that a symetric key algorithm could work well.
In python (as usual), it is straightforward to encrypt and decrypt:
Fernet(key).encrypt(b"mdg") # encrypt
Fernet(key).decrypt(encryptedMsg) # decrypt
In swift, it seemed initially straightforward with something along the lines of:
func encrypt(key: String, msg: String) throws -> String {
let data = Data(base64URL: key)!
let symetricKey = try! SymmetricKey(data: d)
let msgUtf8 = msg.data(using: .utf8)!
let sealBox = try! AES.GCM.seal(msgUtf8, using: symetricKey, nonce: nil)
return sealBox.combined.base64EncodedString();
}
However, I have been unable to find the algorithm in swift matching python's Fernet.
ChaCha
While searching for the problem, I landed on this amazing answer from Bram. Very unfortunately it only solves one side of my problem : encrypting messages in python and decoding them in swift. I also need the reverse process.
How to solve this?

To start, we first need a way to create secure random values to generate the IV and keys. You can also generate the keys using CryptoKit's SymmetricKey and extract the data from them, but for now, I'll use this function.
extension Data {
static func secureRandom(ofSize size: Int) -> Data {
var output = [UInt8](repeating: 0, count: size)
_ = SecRandomCopyBytes(kSecRandomDefault, size, &output)
return Data(output)
}
}
We then require the possibility to compute the AES CBC ciphertext, which can be done using CommonCrypto.
func encrypt(plaintext: Data, key: Data, iv: Data) -> Data {
var encryptor: CCCryptorRef?
defer {
CCCryptorRelease(encryptor)
}
var key = Array(key)
var iv = Array(iv)
var plaintext = Array(plaintext)
CCCryptorCreate(CCOperation(kCCEncrypt), CCAlgorithm(kCCAlgorithmAES), CCOperation(kCCOptionPKCS7Padding), &key, key.count, &iv, &encryptor)
var outputBytes = [UInt8](repeating: 0, count: CCCryptorGetOutputLength(encryptor, plaintext.count, false))
CCCryptorUpdate(encryptor, &plaintext, plaintext.count, &outputBytes, outputBytes.count, nil)
var movedBytes = 0
var finalBytes = [UInt8](repeating: 0, count: CCCryptorGetOutputLength(encryptor, 0, true))
CCCryptorFinal(encryptor, &finalBytes, finalBytes.count, &movedBytes)
return Data(outputBytes + finalBytes[0 ..< movedBytes])
}
and the HMAC with the SHA-256 hash function. I recommend using CryptoKit's HMAC implementation here, but to keep things simple, I went with the CommonCrypto implementation.
func computeHMAC(_ data: Data, using key: Data) -> Data {
var data = Array(data)
var key = Array(key)
var macOut = [UInt8](repeating: 0, count: Int(CC_SHA256_DIGEST_LENGTH))
CCHmac(CCHmacAlgorithm(kCCHmacAlgSHA256), &key, key.count, &data, data.count, &macOut)
return Data(macOut)
}
This brings all of this together into the following
let plaintext = Data("Hello world!".utf8)
let signingKey = Data.secureRandom(ofSize: kCCKeySizeAES128)
let cryptoKey = Data.secureRandom(ofSize: kCCKeySizeAES128)
let fernetKey = (signingKey + cryptoKey).base64EncodedString()
let version: [UInt8] = [0x80]
let timestamp: [UInt8] = {
let timestamp = Int(Date().timeIntervalSince1970).bigEndian
return withUnsafeBytes(of: timestamp, Array.init)
}()
let iv = Data.secureRandom(ofSize: kCCBlockSizeAES128)
let ciphertext = encrypt(plaintext: plaintext, key: cryptoKey, iv: iv)
let hmac = computeHMAC(version + timestamp + iv + ciphertext, using: signingKey)
let fernetToken = (version + timestamp + iv + ciphertext + hmac).base64EncodedString()
print("Fernet key: \(fernetKey)")
print("Fernet token: \(fernetToken)")
An example output can be
Fernet key: 7EwFlYNKTGfj+2fSgL3AUqtrRqRs4D1TWNK7t2XbGJQ=
Fernet token: gAAAAABivCLM0y0poDtGOohT1yK4XTDJppYPJdu4fuDTZ5tb9P9KP5ACgX8aJq4imsSdbzOCcvY3Tueo4FYbwyG+ZugozILL+Q==
We can use this in python using cryptography.io's implementation
from cryptography.fernet import Fernet
key = b'7EwFlYNKTGfj+2fSgL3AUqtrRqRs4D1TWNK7t2XbGJQ='
token = b'gAAAAABivCLM0y0poDtGOohT1yK4XTDJppYPJdu4fuDTZ5tb9P9KP5ACgX8aJq4imsSdbzOCcvY3Tueo4FYbwyG+ZugozILL+Q=='
Fernet(key).decrypt(token)
# b'Hello world!'

AES 128 how to brute force with partial key in python

I am beginner in python so I need help
I have encrypted file and partial key file ,the partial key file have 96 bit out of 128 so i need to guess
the rest of the key and decrypt the file ,the hint is the first word is "hello" in the encrypted
my questions:
how to guess the rest of key ?
how to check if the key is the right key and how much time did take?

Sorry that the source code in my answer is in Java but up to now I never wrote a single line in python. As you showed us nearly no self written code I assume you need a path to find a way to do it in python.
Some basics to start with - AES 128 encryption has a 128 bit or 16 bytes long key for encryption and later decryption. You told us that you already know 96 bits = 12 bytes so there are "just" 4 bytes left to guess. Each byte has a "capacity" of (integer) 256 so in maximum you would have to test 256 * 256 * 256 * 256 combinations = 4,294,967,296 combinations. Assuming that the key is of random you need half of this to try to find the real key so in real there are 2,147,483,648 combinations - a todays home computer does this within an hour or less.
Below you find my code and I setup an online compiler with the code - in this code I "restricted" the search for the last 2 bytes (so it assumes that 14 of the
16 bytes are known) because the online compiler would abort the program with a "running too long" runtime error.
The code is well commented and not optimized for speed but for readability. In the end you get an output like this one (as I'm using a random key and
initialization vector for AES in CBC mode your output will be different), the online compiler is available here: https://repl.it/#javacrypto/JavaAesCbc128BruteForce:
AES CBC String Encryption - brute force decryption
key length: 16 data: 0cb878f9da009be3ef487f54aa8c3230
keyGuess length: 16 data: 0cb878f9da009be3ef487f54aa8c0000
*** key found ***
key length: 16 data: 0cb878f9da009be3ef487f54aa8c3230
plaintext: hello this is just plaintext
code:
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.nio.ByteBuffer;
import java.nio.charset.StandardCharsets;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
public class Main {
public static void main(String[] args) throws Exception {
System.out.println("AES CBC String Encryption - brute force decryption");
String plaintext = "hello this is just plaintext";
// this plaintext beginning is known
String plaintextKnown = "hello";
byte[] plaintextKnownByte = plaintextKnown.getBytes(StandardCharsets.UTF_8);
// number of known bytes of the key
int numberKeyBytes = 14; // 14 bytes = 112 bit known bits
// random key & iv
SecureRandom random = new SecureRandom();
byte[] key = new byte[16]; // 16 byte = 128 bit keylength
random.nextBytes(key);
byte[] iv = new byte[16];
random.nextBytes(iv);
System.out.println("key length: " + key.length + " data: " + bytesToHex(key));
// setup cbc
SecretKeySpec keySpec = new SecretKeySpec(key, "AES");
IvParameterSpec ivParameterSpec = new IvParameterSpec(iv);
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, keySpec, ivParameterSpec);
// get plaintext
byte[] plaintextByte = plaintext.getBytes(StandardCharsets.UTF_8);
byte[] ciphertextByte = cipher.doFinal(plaintextByte);
byte[] keyGuessed = new byte[16];
System.arraycopy(key, 0, keyGuessed, 0, numberKeyBytes ); // copy first 14 bytes = 112 bit
System.out.println("keyGuess length: " + keyGuessed.length + " data: " + bytesToHex(keyGuessed));
for (int a = 0; a < 256; a++) {
for (int b = 0; b < 256; b++) {
for (int c = 0; c < 256; c++) {
for (int d = 0; d < 256; d++) {
keyGuessed[15] = (byte) d;
//System.out.println("keyGuess length: " + keyGuessed.length + " data: " + bytesToHex(keyGuessed));
decryptAesCbc128(keyGuessed, iv, ciphertextByte, plaintextKnownByte);
}
keyGuessed[14] = (byte) c;
}
keyGuessed[13] = (byte) b;
}
keyGuessed[12] = (byte) a;
}
}
private static boolean decryptAesCbc128(byte[] key, byte[] iv, byte[] ciphertext, byte[] plaintextbyteKnown) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidAlgorithmParameterException, InvalidKeyException {
SecretKeySpec keySpecDecode = new SecretKeySpec(key, "AES");
IvParameterSpec ivParameterSpecDecode = new IvParameterSpec(iv);
Cipher cipherDecrypt = Cipher.getInstance("AES/CBC/PKCS5Padding");
cipherDecrypt.init(Cipher.DECRYPT_MODE, keySpecDecode, ivParameterSpecDecode);
byte[] decryptedtext = new byte[0];
try {
decryptedtext = cipherDecrypt.doFinal(ciphertext);
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
//e.printStackTrace();
return false;
}
// partial array comparison
boolean found = ByteBuffer.wrap(decryptedtext, 0, 5).equals(ByteBuffer.wrap(plaintextbyteKnown, 0, 5));
if (found == false) {return false;}
System.out.println("*** key found ***");
System.out.println("key length: " + key.length + " data: " + bytesToHex(key));
System.out.println("plaintext: " + new String(decryptedtext));
System.exit(0);
return true;
}
private static String bytesToHex(byte[] bytes) {
StringBuffer result = new StringBuffer();
for (byte b : bytes) result.append(Integer.toString((b & 0xff) + 0x100, 16).substring(1));
return result.toString();
}
}

Hashing algorithm Node js vs Python

I was trying to convert a hash algorithm which is written on Python to node.js
The python code looks something as
import uuid
import hashlib
import struct
CLIENT_ID = uuid.UUID('c5f92e0d-e762-32cd-98cb-8c546c410dbe')
SECRET = uuid.UUID('2cf26ff5-bd06-3245-becf-4d5a3baa704f')
data = CLIENT_ID.bytes_le + SECRET.bytes_le + struct.pack("I", 2017) + struct.pack("I", 9) + struct.pack("I", 2)
token = str(uuid.UUID(bytes_le=hashlib.sha256(data).digest()[0:16]))
The token generated is 32d86f00-eb49-2739-e957-91513d2b9969
Here the date values struct.pack values are generated using datetime but for convenient I have hard coded here.
I tried to convert the same by looking at the python doc for the respective libraries and did so far as
let CLIENT_ID = new Buffer('c5f92e0d-e762-32cd-98cb-8c546c410dbe');
let SECRET = new Buffer('2cf26ff5-bd06-3245-becf-4d5a3baa704f');
let d = new Buffer(2);
let m = new Buffer(9);
let y = new Buffer(2017);
let data = CLIENT_ID+SECRET+y+m+d;
const uuidv4 = require('uuid/v4');
const hash = crypto.createHash('sha256');
let token = uuidv4({random: hash.update(data, 'utf8').digest().slice(0, 16)}, 0);
And the hash it generates is b7b82474-eab4-4295-8318-cc258577ff9b
So, basically I am miserably missing something for the nodejs part.
Could you please guide me on where what went wrong. Thanks for the help

There's a lot of missed parts actually it tuned out.
###node parts:
new Buffer('c5')
does not represent <Buffer c5>, but <Buffer 63 35>.
To write c5 you would need to use Buffer.from([0xc5]) or Buffer.from([197]) (dec).
new Buffer(2)
does not represent <Buffer 02>, it just allocates 2 bytes.
CLIENT_ID+SECRET+y+m+d
concatenation of buffers does not work that way.
Use array of buffers and Buffer.concat([buffers]) to concatenate buffers.
###uuid parts:
it turned out that uuid operates modified version of buffers (bytes_le part in python code)
#the most interesting part:
in the python version of uuid, if no version argument is passed to uuid.UUID(...), uuid would generate an ID without fixing bits
According to the RFC-4122 4.4 uuid should fix that bits.
uuid.py skips RFC-4122 4.4
node-uuid/v4.js fixes required bits
that way even with the same results for sha256 hashing, the results between python and node implementation still would differ
python: 32d86f00-eb49-2739-e957-91513d2b9969
node: 32d86f00-eb49-4739-a957-91513d2b9969
^ ^
So, I see here 2 options
to pass version to python uuid (only for the last uuid call uuid.UUID(bytes_le=..., version=4)), that way python would return 32d86f00-eb49-4739-a957-91513d2b9969
if there's no way to change source code in python project, I guess there's an option to fork uuid and remove two lines of code in node-uuid/v4.js?
##See node version of your code below:
const uuidv4 = require('uuid/v4');
const crypto = require('crypto');
const hash = crypto.createHash('sha256');
const client_id_hex_str = "c5f92e0d-e762-32cd-98cb-8c546c410dbe".replace(/-/g, "");
const secret_hex_str = "2cf26ff5-bd06-3245-becf-4d5a3baa704f".replace(/-/g, "");
let CLIENT_ID = Buffer.from(to_bytes_le(to_bytes(client_id_hex_str, null, 16, 'big')));
let SECRET = Buffer.from(to_bytes_le(to_bytes(secret_hex_str, null, 16, 'big')));
let d = Buffer.from(to_bytes(null, 2, 4));
let m = Buffer.from(to_bytes(null, 9, 4));
let y = Buffer.from(to_bytes(null, 2017, 4));
let data = Buffer.concat([CLIENT_ID, SECRET, y, m, d]);
let hashBytes = hash.update(data, 'utf8').digest().slice(0, 16);
hashBytes = [].slice.call(hashBytes, 0);
hashBytes = Buffer.from(to_bytes_le(hashBytes));
let token = uuidv4({random: hashBytes});
console.log(token);
// https://stackoverflow.com/questions/16022556/has-python-3-to-bytes-been-back-ported-to-python-2-7
function to_bytes(hexString, number, length, endianess) {
if (hexString == null && number == null) {
throw new Error("Missing hex string or number.");
}
if (!length || isNaN(length)) {
throw new Error("Missing or invalid bytes array length number.");
}
if (hexString && typeof hexString != "string") {
throw new Error("Invalid format for hex value.");
}
if (hexString == null) {
if (isNaN(number)) {
throw new Error("Invalid number.");
}
hexString = number.toString(16);
}
let byteArray = [];
if (hexString.length % 2 !== 0) {
hexString = '0' + hexString;
}
const bitsLength = length * 2
hexString = ("0".repeat(bitsLength) + hexString).slice(-1 * bitsLength);
for (let i = 0; i < hexString.length; i += 2) {
const byte = hexString[i] + hexString[i + 1];
byteArray.push(parseInt(byte, 16));
}
if (endianess !== "big") {
byteArray = byteArray.reverse();
}
return byteArray;
}
// https://github.com/python/cpython/blob/master/Lib/uuid.py#L258
function to_bytes_le(bytes) {
const p1 = bytes.slice(0, 4).reverse();
const p2 = bytes.slice(4, 6).reverse();
const p3 = bytes.slice(6, 8).reverse();
const p4 = bytes.slice(8);
const bytes_le = [].concat.apply([], [p1, p2, p3, p4]);
return bytes_le;
}

Do you want the hashing of the data to be the same as the Python code above?
If not, you can take a look at the the Sha256 module below in NodeJS
https://www.npmjs.com/package/sha256

Different Results in Go and Pycrypto when using AES-CFB

I am adding a go application to an already existing python codebase. I've been having trouble dealing with encryption between the languages. This is using go 1.2.1 and Python 2.7.x / PyCrypto 2.7a1.
Here is the Python sample:
import Crypto.Cipher
import Crypto.Hash.HMAC
import Crypto.Hash.SHA256
import Crypto.PublicKey.RSA
from binascii import hexlify, unhexlify
#encrypt
payload = unhexlify("abababababababababababababababababababababababababababababababab")
password = unhexlify("0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF")
iv = unhexlify("00000000000000000000000000000000")
print "IV: ", hexlify(iv), "len: ", len(iv)
print "Password length: ", len(password)
cipher = Crypto.Cipher.AES.new(
key=password,
mode=Crypto.Cipher.AES.MODE_CFB,
IV=iv)
payload = cipher.encrypt(payload)
print hexlify(payload) #dbf6b1877ba903330cb9cf0c4f530d40bf77fe2bf505820e993741c7f698ad6b
And this is the Go sample:
package main
import (
"fmt"
"crypto/cipher"
"crypto/aes"
"encoding/hex"
)
// encrypt
func main() {
payload, err1 := hex.DecodeString("abababababababababababababababababababababababababababababababab")
password, err2 := hex.DecodeString("0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF")
iv, err3 := hex.DecodeString("00000000000000000000000000000000")
if err1 != nil {
fmt.Printf("error 1: %v", err1)
return
}
if err2 != nil {
fmt.Printf("error 2: %v", err2)
return
}
if err3 != nil {
fmt.Printf("error 3: %v", err3)
return
}
aesBlock, err4 := aes.NewCipher(password)
fmt.Printf("IV length:%v\n", len(iv))
fmt.Printf("password length:%v\n", len(password))
if err4 != nil {
fmt.Printf("error 4: %v", err4)
return
}
cfbDecrypter := cipher.NewCFBEncrypter(aesBlock, iv)
cfbDecrypter.XORKeyStream(payload, payload)
fmt.Printf("%v\n", hex.EncodeToString(payload)) // db70cd9e6904359cb848410bfa38d7d0a47b594f7eff72d547d3772c9d4f5dbe
}
Here is the golang link, I could not find a Python pastebin that had PyCrypto installed.
As suggested by the title & source, the two snippets produce different cyphertext:
Python: dbf6b1877ba903330cb9cf0c4f530d40bf77fe2bf505820e993741c7f698ad6b
Golang: db70cd9e6904359cb848410bfa38d7d0a47b594f7eff72d547d3772c9d4f5dbe
Both languages can decrypt their 'native' cypthertext, but neither can decrypt the others'. Because the python implementation already exists, I'm looking for a solution that will allow Go to decrypt cyphertext encrypted with the example PyCrypto AES settings & key size.

Research on the current system has revealed that our python system uses CFB8 (8 bit segments). Go does not support this out of the box, but the source code used in the current CFBDecrypter / CFBEncrypter looks like it can be adapted fairly easily.

If anyone is looking for Go implementation of CFB mode with segment size = 8 you can use this:
import "crypto/cipher"
// CFB stream with 8 bit segment size
// See http://csrc.nist.gov/publications/nistpubs/800-38a/sp800-38a.pdf
type cfb8 struct {
b cipher.Block
blockSize int
in []byte
out []byte
decrypt bool
}
func (x *cfb8) XORKeyStream(dst, src []byte) {
for i := range src {
x.b.Encrypt(x.out, x.in)
copy(x.in[:x.blockSize-1], x.in[1:])
if x.decrypt {
x.in[x.blockSize-1] = src[i]
}
dst[i] = src[i] ^ x.out[0]
if !x.decrypt {
x.in[x.blockSize-1] = dst[i]
}
}
}
// NewCFB8Encrypter returns a Stream which encrypts with cipher feedback mode
// (segment size = 8), using the given Block. The iv must be the same length as
// the Block's block size.
func newCFB8Encrypter(block cipher.Block, iv []byte) cipher.Stream {
return newCFB8(block, iv, false)
}
// NewCFB8Decrypter returns a Stream which decrypts with cipher feedback mode
// (segment size = 8), using the given Block. The iv must be the same length as
// the Block's block size.
func newCFB8Decrypter(block cipher.Block, iv []byte) cipher.Stream {
return newCFB8(block, iv, true)
}
func newCFB8(block cipher.Block, iv []byte, decrypt bool) cipher.Stream {
blockSize := block.BlockSize()
if len(iv) != blockSize {
// stack trace will indicate whether it was de or encryption
panic("cipher.newCFB: IV length must equal block size")
}
x := &cfb8{
b: block,
blockSize: blockSize,
out: make([]byte, blockSize),
in: make([]byte, blockSize),
decrypt: decrypt,
}
copy(x.in, iv)
return x
}

It seems that the cipher can be made compatible to Go's crypto/cipher if we change segment_size of AES object from the default 8 to AES.block_size*8 (which is 128), like this:
Crypto.Cipher.AES.new(
key=password,
mode=Crypto.Cipher.AES.MODE_CFB,
IV=iv,
segment_size=AES.block_size*8
)

I found that easiest way to deal with this from Python side is to use M2Crypto library.
Final code looks like:
import M2Crypto.EVP
iv = ciphertext[:16]
ciphertext = ciphertext[16:]
cipher = M2Crypto.EVP.Cipher('aes_256_cfb', t, iv, 0)
text = cipher.update(ciphertext)
print text
Works perfect without need to change something in Go.

i solve by adapt python code like this (golang encode and python decode):
# golang encode
padNum := len(data) % 16
if padNum != 0 {
for i := 0; i < 16-padNum; i++ {
data = append(data, ',')
}
}
# python decode
cipher = AES.new(key=self.key, mode=AES.MODE_CFB, IV=iv,segment_size=128)

Python AES encryption(PyCrypto) -> AS3 decryption (as3Crypto) using AES

I've a django app which serves encrypted media files to Flash apps. Encryption in python is done with PyCrypto as follows (I include description too in case useful):
def encrypt_aes(key, text):
try:
raw = _pad(text)
iv = Random.new().read(AES.block_size)
cipher = AES.new(key, AES.MODE_CBC, iv)
return base64.b64encode(iv + cipher.encrypt(raw))
except Exception as e:
print e.message
return text
def decrypt_aes(key, text):
try:
enc = base64.b64decode(text)
iv = enc[:AES.block_size]
cipher = AES.new(key, AES.MODE_CBC, iv)
return _unpad(cipher.decrypt(enc[AES.block_size:]))
except Exception as e:
print e.message
return text
def _pad(s):
bs = 16
return s + (bs - len(s) % bs) * chr(bs - len(s) % bs)
def _unpad(s):
return s[:-ord(s[len(s) - 1:])]
I cannot yet decrypt the Python provided media files (downloaded with LoaderMax by GreenSock, using 'DataLoader'). My AS3 code (using AS3Crypto) is as follows:
public static function decipher(_key:String):void{
key=_key;
cipher = Crypto.getCipher("simple-aes-cbc", Hex.toArray(key));
cipher.decrypt(ByteArray(_content));
}
I get
RangeError: Error #2006
One suspicion is that in Python I have 64bit base but I think that AS3 ByteArray is 32bit base. I have tried the below, but get the same Error.
cipher.decrypt(ByteArray(com.hurlant.util.Base64.decodeToByteArray(_content)));
Another suspicion is that I have not appropriately removed 'padding' from the _content / set up my IV appropriately (which is specified by the padding I must remove from the _content). This should be done via that "simple" statement however. I have been trying this, but with no success:
var pad:IPad = new PKCS5
cipher = Crypto.getCipher("simple-aes", Hex.toArray(key),pad);
pad.setBlockSize(cipher.getBlockSize());
Could anyone advise on how I can fix this ? :)
Many thanks!

OK finally figured out what was going wrong. Besides some AS3 tweaks, we wrongly were transmitting files as MP3/image (should have been text/html).
Our Python remains as above. Our AS3 is tweaked to the below.
Here's the AS3 class we used:
package com.xperiment.preloader
{
import com.greensock.loading.DataLoader;
import com.hurlant.crypto.Crypto;
import com.hurlant.crypto.symmetric.ICipher;
import com.hurlant.util.Base64;
import flash.events.Event;
import flash.utils.ByteArray;
public class EncryptedDataLoader extends DataLoader
{
private static var backlog:Vector.<EncryptedDataLoader>;
private static var cipher:ICipher;
private var decrypted:Boolean = true;
public function EncryptedDataLoader(urlOrRequest:*, vars:Object=null)
{
this.addEventListener(Event.COMPLETE,decryptL);
super(urlOrRequest, vars);
}
public function decryptL(e:Event):void {
trace("start decrypt");
e.stopImmediatePropagation();
this.removeEventListener(Event.COMPLETE,decryptL);
backlog ||= new Vector.<EncryptedDataLoader>;
backlog.push(this);
if(cipher) pingBacklog();
}
public function decipher():void
{
_content = Base64.decodeToByteArray( _content );
cipher.decrypt( _content );
decrypted=true;
this.dispatchEvent(new Event(Event.COMPLETE));
}
public static function setCipher(_key:String):void{
var keyBA:ByteArray = new ByteArray;
keyBA.writeMultiByte(_key, "iso-8859-1");
cipher = Crypto.getCipher("simple-aes", keyBA);
pingBacklog();
}
public static function kill():void{
cipher.dispose();
cipher = null;
}
public static function pingBacklog():void{
if(backlog){
var encrypted:EncryptedDataLoader;
while(backlog.length>0){
encrypted=backlog.shift();
encrypted.decipher();
}
backlog=null;
}
}
}
}