We Keep Coding

AES encryption in JS equivalent of C#

I need to encrypt a string using AES encryption. This encryption was happening in C# earlier, but it needs to be converted into JavaScript (will be run on a browser).
The current code in C# for encryption is as following -
public static string EncryptString(string plainText, string encryptionKey)
{
byte[] clearBytes = Encoding.Unicode.GetBytes(plainText);
using (Aes encryptor = Aes.Create())
{
Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes(encryptionKey, new byte[] { 0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76 });
encryptor.Key = pdb.GetBytes(32);
encryptor.IV = pdb.GetBytes(16);
using (MemoryStream ms = new MemoryStream())
{
using (CryptoStream cs = new CryptoStream(ms, encryptor.CreateEncryptor(), CryptoStreamMode.Write))
{
cs.Write(clearBytes, 0, clearBytes.Length);
cs.Close();
}
plainText = Convert.ToBase64String(ms.ToArray());
}
}
return plainText;
}
I have tried to use CryptoJS to replicate the same functionality, but it's not giving me the equivalent encrypted base64 string. Here's my CryptoJS code -
function encryptString(encryptString, secretKey) {
var iv = CryptoJS.enc.Hex.parse('Ivan Medvedev');
var key = CryptoJS.PBKDF2(secretKey, iv, { keySize: 256 / 32, iterations: 500 });
var encrypted = CryptoJS.AES.encrypt(encryptString, key,{iv:iv);
return encrypted;
}
The encrypted string has to be sent to a server which will be able to decrypt it. The server is able to decrypt the encrypted string generated from the C# code, but not the encrypted string generated from JS code. I tried to compare the encrypted strings generated by both the code and found that the C# code is generating longer encrypted strings. For example keeping 'Example String' as plainText and 'Example Key' as the key, I get the following result -
C# - eAQO+odxOdGlNRB81SHR2XzJhyWtz6XmQDko9HyDe0w=
JS - 9ex5i2g+8iUCwdwN92SF+A==
The length of JS encrypted string is always shorter than the C# one. Is there something I am doing wrong? I just have to replicated the C# code into the JS code.
Update:
My current code after Zergatul's answer is this -
function encryptString(encryptString, secretKey) {
var keyBytes = CryptoJS.PBKDF2(secretKey, 'Ivan Medvedev', { keySize: 48 / 4, iterations: 1000 });
console.log(keyBytes.toString());
// take first 32 bytes as key (like in C# code)
var key = new CryptoJS.lib.WordArray.init(keyBytes.words, 32);
// skip first 32 bytes and take next 16 bytes as IV
var iv = new CryptoJS.lib.WordArray.init(keyBytes.words.splice(32 / 4), 16);
console.log(key.toString());
console.log(iv.toString());
var encrypted = CryptoJS.AES.encrypt(encryptString, key, { iv: iv });
return encrypted;
}
As illustrated in his/her answer that if the C# code converts the plainText into bytes using ASCII instead of Unicode, both the C# and JS code will produce exact results. But since I am not able to modify the decryption code, I have to convert the code to be equivalent of the original C# code which was using Unicode.
So, I tried to see, what's the difference between both the bytes array between ASCII and Unicode byte conversion in C#. Here's what I found -
ASCII Byte Array: [69,120,97,109,112,108,101,32,83,116, 114, 105, 110, 103]
Unicode Byte Array: [69,0,120,0,97,0,109,0,112,0,108,0,101,0,32,0,83,0,116,0, 114,0, 105,0, 110,0, 103,0]
So some extra bytes are available for each character in C# (So Unicode allocates twice as much bytes to each character than ASCII).
Here's the difference between both Unicode and ASCII conversion respectively -
ASCII
clearBytes: [69,120,97,109,112,108,101,32,83,116,114,105,110,103,]
encryptor.Key: [123,213,18,82,141,249,182,218,247,31,246,83,80,77,195,134,230,92,0,125,232,210,135,115,145,193,140,239,228,225,183,13,]
encryptor.IV: [101,74,46,177,46,233,68,252,83,169,211,13,249,61,118,167,]
Result: eQus9GLPKULh9vhRWOJjog==
Unicode:
clearBytes: [69,0,120,0,97,0,109,0,112,0,108,0,101,0,32,0,83,0,116,0,114,0,105,0,110,0,103,0,]
encryptor.Key: [123,213,18,82,141,249,182,218,247,31,246,83,80,77,195,134,230,92,0,125,232,210,135,115,145,193,140,239,228,225,183,13,]
encryptor.IV: [101,74,46,177,46,233,68,252,83,169,211,13,249,61,118,167,]
Result: eAQO+odxOdGlNRB81SHR2XzJhyWtz6XmQDko9HyDe0w=
So since both the key and iv being generated have exact same byte array in both Unicode and ASCII approach, it should not have generated different output, but somehow it's doing that. I think it's because of clearBytes' length, as it's using its length to write to CryptoStream.
I tried to see what's the output of the generated bytes in the JS code is and found that it uses words which needed to be converted into Strings using toString() method.
keyBytes: 7bd512528df9b6daf71ff653504dc386e65c007de8d2877391c18cefe4e1b70d654a2eb12ee944fc53a9d30df93d76a7
key: 7bd512528df9b6daf71ff653504dc386e65c007de8d2877391c18cefe4e1b70d
iv: 654a2eb12ee944fc53a9d30df93d76a7
Since, I am not able to affect the generated encrypted string's length in the JS code (No access to the write stream directly), thus still stuck here.

Here is the example how to reproduce the same ciphertext between C# and CryptoJS:
static void Main(string[] args)
{
byte[] plainText = Encoding.Unicode.GetBytes("Example String"); // this is UTF-16 LE
string cipherText;
using (Aes encryptor = Aes.Create())
{
var pdb = new Rfc2898DeriveBytes("Example Key", Encoding.ASCII.GetBytes("Ivan Medvedev"));
encryptor.Key = pdb.GetBytes(32);
encryptor.IV = pdb.GetBytes(16);
using (MemoryStream ms = new MemoryStream())
{
using (CryptoStream cs = new CryptoStream(ms, encryptor.CreateEncryptor(), CryptoStreamMode.Write))
{
cs.Write(plainText, 0, plainText.Length);
cs.Close();
}
cipherText = Convert.ToBase64String(ms.ToArray());
}
}
Console.WriteLine(cipherText);
}
And JS:
var keyBytes = CryptoJS.PBKDF2('Example Key', 'Ivan Medvedev', { keySize: 48 / 4, iterations: 1000 });
// take first 32 bytes as key (like in C# code)
var key = new CryptoJS.lib.WordArray.init(keyBytes.words, 32);
// skip first 32 bytes and take next 16 bytes as IV
var iv = new CryptoJS.lib.WordArray.init(keyBytes.words.splice(32 / 4), 16);
// use the same encoding as in C# code, to convert string into bytes
var data = CryptoJS.enc.Utf16LE.parse("Example String");
var encrypted = CryptoJS.AES.encrypt(data, key, { iv: iv });
console.log(encrypted.toString());
Both codes return: eAQO+odxOdGlNRB81SHR2XzJhyWtz6XmQDko9HyDe0w=

TL;DR the final code looks like this -
function encryptString(encryptString, secretKey) {
encryptString = addExtraByteToChars(encryptString);
var keyBytes = CryptoJS.PBKDF2(secretKey, 'Ivan Medvedev', { keySize: 48 / 4, iterations: 1000 });
console.log(keyBytes.toString());
var key = new CryptoJS.lib.WordArray.init(keyBytes.words, 32);
var iv = new CryptoJS.lib.WordArray.init(keyBytes.words.splice(32 / 4), 16);
var encrypted = CryptoJS.AES.encrypt(encryptString, key, { iv: iv, });
return encrypted;
}
function addExtraByteToChars(str) {
let strResult = '';
for (var i = 0; i < str.length; ++i) {
strResult += str.charAt(i) + String.fromCharCode(0);
}
return strResult;
}
Explanation:
The C# code in the Zergatul's answer (Thanks to him/her) was using ASCII to convert the plainText into bytes, while my C# code was using Unicode. Unicode was assigning extra byte to each character in the resultant byte array, which was not affecting the generation of both key and iv bytes, but affecting the result since the length of the encryptedString was dependent on the length of the bytes generated from plainText.
As seen in the following bytes generated for each of them using "Example String" and "Example Key" as the plainText and secretKey respectively -
ASCII
clearBytes: [69,120,97,109,112,108,101,32,83,116,114,105,110,103,]
encryptor.Key: [123,213,18,82,141,249,182,218,247,31,246,83,80,77,195,134,230,92,0,125,232,210,135,115,145,193,140,239,228,225,183,13,]
encryptor.IV: [101,74,46,177,46,233,68,252,83,169,211,13,249,61,118,167,]
Result: eQus9GLPKULh9vhRWOJjog==
Unicode:
clearBytes: [69,0,120,0,97,0,109,0,112,0,108,0,101,0,32,0,83,0,116,0,114,0,105,0,110,0,103,0,]
encryptor.Key: [123,213,18,82,141,249,182,218,247,31,246,83,80,77,195,134,230,92,0,125,232,210,135,115,145,193,140,239,228,225,183,13,]
encryptor.IV: [101,74,46,177,46,233,68,252,83,169,211,13,249,61,118,167,]
Result: eAQO+odxOdGlNRB81SHR2XzJhyWtz6XmQDko9HyDe0w=
The JS result was similar too, which confirmed that it's using ASCII byte conversion -
keyBytes: 7bd512528df9b6daf71ff653504dc386e65c007de8d2877391c18cefe4e1b70d654a2eb12ee944fc53a9d30df93d76a7
key: 7bd512528df9b6daf71ff653504dc386e65c007de8d2877391c18cefe4e1b70d
iv: 654a2eb12ee944fc53a9d30df93d76a7
Thus I just need to increase the length of the plainText to make it use Unicode equivalent byte generation (Sorry, not familiar with the term). Since Unicode was assigning 2 space for each character in the byteArray, keeping the second space as 0, I basically created gap in the plainText's characters and filled that gap with character whose ASCII value was 0 using the addExtraByteToChars() function. And it made all the difference.
It's a workaround for sure, but started working for my scenario. I suppose this may or may not prove useful to others, thus sharing the findings. If anyone can suggest better implementation of the addExtraByteToChars() function (probably some term for this conversion instead of ASCII to Unicode or a better, efficient, and not hacky way to do that), please suggest it.

AES Encryption with CryptoJS and PHP

I want to implement AES encryption using JavaScript. Used AES CBC Mode. I have managed to do it in PHP. It looks like:
public function encrypt($value) {
if (empty($value)) {
return $value;
}
$value = Unicode::convertToUtf8($value, 'UTF-8');
if ($key = $this->getEncryptionKey()) {
// Generates from key 1st 16 bytes.
$iv = mb_substr($key, 0, 16);
//encrypt message with key
$message = openssl_encrypt($value, 'AES-256-CBC', $key, OPENSSL_RAW_DATA, $iv);
return base64_encode($message);
}
}
public function getEncryptionKey() {
$key = 'secret';
$key = Unicode::convertToUtf8($key, 'UTF-8');
// Make sure the key is the correct size.
if (strlen($key) < 32) {
$key = str_pad($key, 32, "\0");
}
if (strlen($key) > 32) {
$key = mb_substr($key, 0, 32);
}
return $key;
}
If I give $value = retest2; it gives me ukUCH0SvgdmM8vTqQumAVg== output
I know it's right, I tried it using C# as well got the same result. But when I try to replicate this using JavaScript, I wasn't able to produce same PHP's output. Below is the javascript code that I have tried:
const message = utf8.encode('retest2');
const password = utf8.encode('secret').padEnd(32, '\0');
const key = CryptoJS.enc.Hex.parse(password);
const iv = CryptoJS.enc.Hex.parse(password.substring(0, 16));
const encrypted = CryptoJS.AES.encrypt(message, key, {
iv: iv
});
console.log(btoa(encrypted.toString()));
Using the same value I get dzd4bjNwenduQT09.
I have also read other similar questions asked on the same topic here, but I can't seem to figure out where I am going wrong?
Thanks!

As #symcbean said,
You shouldn't be using the key or data derived from it as your
initialization vector.
I assume, you have no option and you have to use key or data derived from it as your initialization vector.
A few months ago, I had the exact same situation and I did something like this,
const message = 'retest2';
let password = 'secret';
if (password.length < 32) {
password = password.padEnd(32, '\0');
}
const iv = CryptoJS.enc.Utf8.parse(password.substring(0, 16));
password = CryptoJS.enc.Utf8.parse(password);
const encrypted = CryptoJS.AES.encrypt((message), (password), {
iv: iv
});
console.log(CryptoJS.enc.Base64.stringify(encrypted.ciphertext));

These should be comments but space is limited....
You shouldn't be using the key or data derived from it as your initialization vector.
I know it's right, I tried it using C# as well
You should have shown us the code.
Your openssl call invokes the key derivation function to create a (better?) encryption key from the data you pass in the third parameter. OTOH, in crypto.js there is no implicit key derivation.

Uncaught URIError: URI malformed error with jQuery

I'm using node forge to encrypt a form before sending it to the server using AES.
The code for the crypto part for now is
const bigInt = require("big-integer");
const forge = require('node-forge');
function generateParams() {
// Cryptographic random number generator
var array = new Uint32Array(2);
var _key = bigInt(window.crypto.getRandomValues(array)[0]).toString();
var _iv = bigInt(window.crypto.getRandomValues(array)[1]).toString();
// generate random key and IV
var key = forge.util.encode64(_key);
var iv = forge.util.encode64(_iv);
const params = {
key: key,
iv: iv
}
return params;
}
function encrypt(params) {
var cipher = forge.rc2.createEncryptionCipher(params.key);
cipher.start(params.iv);
// Encrypting "testing"
cipher.update(forge.util.createBuffer("testing"));
cipher.finish();
return cipher.output;
}
function decrypt(params, encrypted) {
var cipher = forge.rc2.createDecryptionCipher(params.key);
cipher.start(params.iv);
cipher.update(encrypted);
cipher.finish();
return cipher.output;
}
and the jQuery function is (not posting yet)
$('#recordForm').submit(function(event) {
// Stop form from submitting normally
event.preventDefault();
// Grab form data
// Crypto
const params = generateParams();
const encryptedForm = {
test: encrypt(params),
}
console.log("Encrypted: " + encryptedForm.test);
const decryptedForm = {
test: decrypt(params, encryptedForm.id).data,
}
console.log("Decrypted: " + decryptedForm.test);
});
My problem is that I keep getting back (cryptob.js is the name of my file, generated with browserify)
Uncaught URIError: URI malformed
at decodeURIComponent (<anonymous>)
at Object.util.decodeUtf8 (cryptob.js:24437)
at ByteStringBuffer.util.ByteStringBuffer.toString (cryptob.js:23490)
at HTMLFormElement.<anonymous> (cryptob.js:1282)
at HTMLFormElement.dispatch (jquery-3.1.1.slim.min.js:3)
at HTMLFormElement.q.handle (jquery-3.1.1.slim.min.js:3)
when calling encrypt().
There is this answer here which recommends including a special meta tag. I have done that but it still doesn't work. Since some resources online say it is related to UTF-8 encoding, I tried replacing
cipher.update(forge.util.createBuffer("testing"));
with
cipher.update(forge.util.createBuffer(encodeURIComponent("testing")));
or
cipher.update(forge.util.createBuffer("testing", 'utf8'));
but it didn't work either (based on encodeURIComponent(str)).
You can test forge here, and if you run this code (which is essentially what I'm doing)
var forge = require("node-forge")
// generate a random key and IV
var key = forge.util.encode64("12354523465");
var iv = forge.util.encode64("2315");
// encrypt some bytes
var cipher = forge.rc2.createEncryptionCipher(key);
cipher.start(iv);
cipher.update(forge.util.createBuffer("testing"));
cipher.finish();
var encrypted = cipher.output;
console.log(encrypted);
// decrypt some bytes
var cipher = forge.rc2.createDecryptionCipher(key);
cipher.start(iv);
cipher.update(encrypted);
cipher.finish();
console.log(cipher.output.data)
it works fine.
How can I solve this?

It looks like this error is actually happening in the toString, where you generate your _key and _iv.
Try testing with some hard-coded strings, as used in the example code you posted. Then, use a method to generate random byte strings for the key and IV.
Also, for AES-256, the key should have 32 bytes (not bits) of entropy. The IV should have 16 bytes of entropy.

java encryption aes value and javascript encryption value does not match

I have java code which produce aes encryption code for me now I am trying to use it on javascript using crypto-js but both codes provides different keys I dont know why and how to get the same key here is my code
public static String encrypt(String text, byte[] iv, byte[] key)throws Exception{
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
SecretKeySpec keySpec = new SecretKeySpec(key, "AES");
System.out.println("KEY SPECCCC: "+keySpec);
IvParameterSpec ivSpec = new IvParameterSpec(iv);
cipher.init(Cipher.ENCRYPT_MODE,keySpec,ivSpec);
byte [] results = cipher.doFinal(text.getBytes("UTF-8"));
BASE64Encoder encoder = new BASE64Encoder();
return encoder.encode(results);
}
JavaScript code
require(["crypto-js/core", "crypto-js/aes"], function (CryptoJS, AES) {
ciphertext = CryptoJS.AES.encrypt(JSON.stringify(jsondata),
arr.toString(),arr.toString());
});
string to utf-8
var utf8 = unescape(encodeURIComponent(key));
var arr = [];
for (var i = 0; i < utf8.length; i++) {
arr.push(utf8.charCodeAt(i));
}

First of all even tough your code works fine you wont be able to decrypt it back properly because while you are creating your AES cipher in Java you are using CBC Cipher and You are implementing a Padding algorithm which is PKCS5Padding.
So your java code does the followings;
When it gets the input it first divide it into the 16 bits blocks then if your input doesnt divide into the 16 overall then the reminders will be padded for filling the block with the same number of reminder.You can see what i mean by the following picture.
So it will do the encryption with the padded ciphers in the java side but in the Javascript Part You neither declare what type of Mode Aes will use nor declaring the what type of Padding it suppose to do. So you should add those values into the your code.You can make search following code parts.
mode:CryptoJS.mode.CBC,
padding: CryptoJS.pad.Pkcs7
About the different keys it is occuring because you are sending a Byte[] in to the your Encrypt method then use this unknown Byte[] while you are creating your Key.You didnt mention why your encryption method will be used in your program but you should create that "Byte[] key" same way in the both method.For instance you can refer following code as a example of generating that but it is not secure way of generating keys I just added it for showing you what I mean by you should generate both keys in the same way.
//DONT USE THIS IMPLEMENTATION SINCE IT IS NOT SAFE!
byte[] key = (username + password).getBytes("UTF-8");

Java code generates an encrypted string and for JavaScript to also generate same encrypted string, Following code works!
(function (CryptoJS) {
var C_lib = CryptoJS.lib;
// Converts ByteArray to stadnard WordArray.
// Example: CryptoJS.MD5(CryptoJS.lib.ByteArray ([ Bytes ])).toString(CryptoJS.enc.Base64);
C_lib.ByteArray = function (arr) {
var word = [];
for (var i = 0; i < arr.length; i += 4) {
word.push (arr[i + 0] << 24 | arr[i + 1] << 16 | arr[i + 2] << 8 | arr[i + 3] << 0);
}
return C_lib.WordArray.create (word, arr.length);
};
})(CryptoJS);
var IVstring = CryptoJS.lib.ByteArray(your IV bytearray).toString(CryptoJS.enc.Base64);
var keystring = CryptoJS.lib.ByteArray(your KEY bytearray).toString(CryptoJS.enc.Base64);
var text = 'texttobeencrypted';
var key = CryptoJS.enc.Base64.parse(keystring);
var iv = CryptoJS.enc.Base64.parse(IVstring);
var encrypted = CryptoJS.AES.encrypt(text, key, {iv: iv});
console.log(encrypted.toString());
Edited: Removed dangerous third party resource reference.
aes encryption javascript cryptojs java

Encrypting data with forgejs on the client side, and decrypting with ruby

For a given project, I'm looking to encrypt a piece of data with AES 256, and then RSA encrypt the key. I've been using Forge and the Encryptor gem in ruby, and i can't seem get matching encryption values:
var key = 'strengthstrengthstrengthstrength';
var iv = 'cakecakecakecakecakecakecakecake';
var cipher = forge.aes.createEncryptionCipher(key, 'CBC');
cipher.start(iv);
cipher.update(forge.util.createBuffer("some string"));
cipher.finish();
var encrypted = cipher.output;
console.log(btoa(encrypted.data)); // outputs: CjLmWObDO2Dlwa5tJnRBRw==
Then in IRB:
Encryptor.encrypt 'some string', :key => 'strengthstrengthstrengthstrength', :key => 'cakecakecakecakecakecakecakecake'
Base64.encode64 _
# outputs: C9Gtk9YfciVMJEsbhZrQTw==\n
Over using string values for Key & IV, tried:
var key = forge.random.getBytesSync(32);
var iv = forge.random.getBytesSync(32);
Then doing a btoa() call on each of them. Using the Base64.decode64 on the ruby side, before passing them to Encryptor.decrypt, but still no luck.
Any idea where i've gone wrong?

I managed to get it to work. Since i'm just using one key to encrypt one value, i just used the key as the IV & Salt as well. This is not recommended if you are using the key to encrypt multiple values. You will then need to generate proper salt & iv values.
Also the gen key value is a pretty poor way, as Math.random is not secure. Just ran out of time to do this properly, but works okay for this case.
var Encryption = (function () {
var api = {
getKey: function () {
var possible = "ABCDEFabcdef0123456789";
var key = '';
for (var i = 0; i < 32; i++) {
key += possible.charAt(Math.floor(Math.random() * possible.length));
}
return key;
},
encryptPII: function (rawKey, value) {
var salt = rawKey;
var iv = rawKey;
var key = forge.pkcs5.pbkdf2(rawKey, salt, 2000, 32);
var cipher = forge.aes.createEncryptionCipher(key, 'CBC');
cipher.start(iv);
cipher.update(forge.util.createBuffer(value));
cipher.finish();
return btoa(cipher.output.data);
}
};
return api;
})();
The rawKey is the value returned from getKey(). The value property is the the string to be encrypted. I use the rawkey for iv & salt values, generate a key in the same way that the Encryptor gem in ruby does. Use forge to then encrypt the string value.
If i take the base64, decode it in ruby, and pass the same rawKey value to the encryptor gem for key, salt and iv, it works.