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Encrypt payload using a key and iv by AES/GCM/NoPadding algorithm in node js and decrypt in java

I have encrypt the file using node.js and decrypt in JAVA. Decryption is done in JAVA using "AES/GCM/Nopadding" algorithm and it is third party app hence I cannot see the JAVA code.
I am encrypting the payload in node.js using "aes-128-gcm" algorithm.
for this, I am try mimicking a working java encryption code
I have tried with crypto and node-forge.
iam getting the output but am getting an error "Bad encryption - payload is not encrypted properly" when submitting payload.
pleas help me to find what I did wrong in this code.
working code in java
public void encrypt(#NonNull final byte[] payload, #NonNull final byte[] key) throws GeneralSecurityException
{
SecretKeySpec codingKey = new SecretKeySpec(key, AES);
Cipher cipher = AEC_GCM_THREAD_CIPHER.get();
byte[] iv = new byte[cipher.getBlockSize()];
RANDOM.nextBytes(iv);
cipher.init(Cipher.ENCRYPT_MODE, codingKey, new IvParameterSpec(iv));
final byte[] encryptedPayload = cipher.doFinal(payload);
byte[] encryptMerchantKey = encryptMerchantKey(key);
String payloadFinal = encodeToUrlString(encryptedPayload); // final payload
String ivFinal = encodeToUrlString(iv); // final iv
String keyFinal = encodeToUrlString(encryptMerchantKey); // final key
System.out.println("Payload");
System.out.println(payloadFinal);
System.out.println("iv");
System.out.println(ivFinal);
System.out.println("key");
System.out.println(keyFinal);
}
code iam tried in node js
function encrypt(payload) {
let key = forge.random.getBytesSync(16);
let iv = forge.random.getBytesSync(16);
let cipher = forge.cipher.createCipher("AES-GCM", key);
cipher.start({ iv: iv});
cipher.update(forge.util.createBuffer(payload));
cipher.finish();
let encrypted = forge.util.encode64(cipher.output.getBytes());
let tag = forge.util.encode64(cipher.mode.tag.getBytes());
let iv64 = forge.util.encode64(iv);
let encryptedPayload = encrypted+tag;
//RSA Encryption
encryptedkey = RSAencrypt(forge.util.encode64(key));
return {
"payload" : base64url.fromBase64(encryptedPayload) ,
"iv" : base64url.fromBase64(iv64).length,
"key" : base64url.fromBase64(encryptedkey)
};
}
Rsa description is working fine abling to decrypt the key.
some problem with aes encryption. as see the code, I added auth tag and encrypted data together but no use.

I have complete example of encryption and decryption in angular and java you can take this example as it is and make changes according to you.
Install node-forge with command "npm install node-forge".
encrypt(msg, pass) {
const key = CryptoJS.lib.WordArray.random(8).toString();
const iv = CryptoJS.lib.WordArray.random(8).toString();
// encrypt some bytes using GCM mode
const cipher = forge.cipher.createCipher('AES-GCM', key);
cipher.start({
iv: iv,
additionalData: 'nvn', // optional
tagLength: 128 // optional, defaults to 128 bits
});
cipher.update(forge.util.createBuffer(msg));
cipher.finish();
const encrypted = cipher.output;
const encodedB64 = forge.util.encode64(encrypted.data);
const tag = cipher.mode.tag;
const tagB64 = forge.util.encode64(tag.data);
// outputs encrypted hex
const trasmitmsg = key+iv+tagB64+encodedB64;
return trasmitmsg
}
I have used CryptoJS to generate random string because random of node-forge giving nontransferable strings.
java code to decrypt this trasmitmsg is
public String getDecrypt(String transmsg) throws Exception {
String keyString = transmsg.substring(0, 16);
String ivString = transmsg.substring(16, 32);
String additionalString = transmsg.substring(32, 56);
String cipherString = transmsg.substring(56);
byte[] keyBytes = keyString.getBytes();
SecretKey key = new SecretKeySpec(keyBytes, "AES");
byte[] ivBytes = ivString.getBytes();
byte[] one = Base64.getDecoder().decode(cipherString);
byte[] two = Base64.getDecoder().decode(additionalString);
byte[] cipherText = ArrayUtils.addAll(one, two);
return decrypt(cipherText, key, ivBytes);
}
public static String decrypt(byte[] cipherText, SecretKey key, byte[] IV) throws Exception {
// Get Cipher Instance
Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
// Create SecretKeySpec
SecretKeySpec keySpec = new SecretKeySpec(key.getEncoded(), "AES");
// Create GCMParameterSpec
GCMParameterSpec gcmParameterSpec = new GCMParameterSpec(GCM_TAG_LENGTH , IV);
// Initialize Cipher for DECRYPT_MODE
cipher.init(Cipher.DECRYPT_MODE, keySpec, gcmParameterSpec);
cipher.updateAAD("nvn".getBytes());
byte[] decryptedText = cipher.doFinal(cipherText);
return new String(decryptedText);
}
Cheers!!!

The problem was with forge buffer it need to convert to node buffer
this code is working now. thanks, #Maarten Bodewes for the advice.
function encrypt(payload) {
//initialize forge random buffer
var key = forge.random.getBytesSync(16);
var iv = forge.random.getBytesSync(16);
let cipher = forge.cipher.createCipher("AES-GCM", key);
cipher.start({iv : iv});
cipher.update(forge.util.createBuffer(payload));
cipher.finish();
let encrypted = cipher.output.data;
let tag = cipher.mode.tag.data;
let encryptedLoad = encrypted+tag;
// node buffer and forge buffer differ, so the forge buffer must be converted to node Buffer
iv = Buffer.from(iv, "binary");
encryptedLoad = Buffer.from(encryptedLoad, "binary");
//Calling RSA Encryption
encryptedKey = RSAencrypt(key);
return {
"payload" : base64url(encryptedLoad) ,
"iv" : base64url(iv),
"key" : base64url.fromBase64(encryptedKey)
};
}

Few strings are failed to encrypt using AES256 in Java

This specific case is coming whenever i tried to encrypt single char strings in application. When i tried to encrypt the same string with main method then i was able to encrypt it. But when i run with the application then this specific issue is coming. I felt this is strange because it is working with the main method.
My encryption code will be as follows.
public static String encryptWithAES256(String strToEncrypt) throws Exception
{
MessageDigest digest = MessageDigest.getInstance("SHA-256");
byte[] encodedhash = digest.digest(KEY.getBytes(StandardCharsets.UTF_8));
IvParameterSpec ivspec = new IvParameterSpec(Arrays.copyOf(KEY.getBytes(),16));
SecretKeySpec secretKey = new SecretKeySpec(encodedhash, AES_ENCRYPTION_ALGORITHM);
Cipher cipher = Cipher.getInstance(CIPHER_TRANSFORMATION);
cipher.init(Cipher.ENCRYPT_MODE, secretKey, ivspec);
return new String(Base64.encodeBase64(cipher.doFinal(strToEncrypt.getBytes(CHARACTER_ENCODING))));
}

Java AES Decryption: random chars & message at the end

I have a problem with decrypting a message using AES. At the end when I expect a message, e.g.
ala123
Instead of that I receive sth like:
...6�b}\7�k�8�vFP�8~%��_zժF��FW��O_e���ó������������ala123
The message I pass to encryption is built as:
cipher key is SHA-256 from AES_TOKEN
cipher IV is some characters, which are then stored in the message (at the beginnig)
decrypted message is wrapped up into Base64
The question is why at the end I eventually receive my expected message, but with a lot of rubbish chars at the beggining?
My encryption code is:
private static final String AES_TOKEN = "my_very_secret_token";
// encrypted is base64 string
public String decrypt(String encrypted) throws Exception {
byte[] decrypted = Base64.getDecoder().decode(encrypted);
return new String(aesDecrypt(decrypted), "UTF-8");
}
private byte[] aesDecrypt(byte[] message) throws Exception {
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
byte[] token = MessageDigest.getInstance("SHA-256").digest(AES_TOKEN.getBytes());
SecretKeySpec secretKey = new SecretKeySpec(token, "AES");
IvParameterSpec iv = new IvParameterSpec(Arrays.copyOf(message, 16));
cipher.init(Cipher.DECRYPT_MODE, secretKey, iv);
return cipher.doFinal(message);
}

It looks like you aren't removing the IV from the beginning of message after reading it in to iv. That would explain the garbage being at the start of the decrypted message.

Convert Java code to NodeJS - Encryption method

I want to duplicate the JAVA encryption code in NodeJS.
private String DEFAULT_KEY = "abcdwAYserXbzcSeqL/zPg==";
private String text = "abc";
Base64 base64decoder = new Base64();
byte[] raw = base64decoder.decode(key);
SecretKeySpec fSecretKeySpec = new SecretKeySpec(raw, "AES");
Cipher cipher = Cipher.getInstance("AES");
cipher.init(Cipher.ENCRYPT_MODE, fSecretKeySpec);
byte[] encrypted = cipher.doFinal(text.getBytes());
Base64 base64encoder = new Base64();
result = base64encoder.encodeToString(encrypted);
System.out.println("result: "+ result);
The above code generate the encrypted code as: ZkojvMTW+9EEK0owxMuA7A==
I have tried few ways in NodeJS. It is not generating same code for me.
I have tried the following code.
var bKey = new Buffer('abcdwAYserXbzcSeqL/zPg==', 'base64');
var cipher = crypto.createCipher('aes-128-ecb',bKey);
//cipher.setAutoPadding(auto_padding=false);
var crypted = cipher.update('abc',null,'base64');
crypted+=cipher.final('base64');
console.log(crypted);
Can someone help me out?

You probably are running into the issue that createCipher with two arguments takes a password, not a key. This password is first run through a key derivation function before it becomes a key.
Try to use the createCipheriv method instead, using any value for the IV. ECB mode doesn't take an IV, but at least you would be using a key instead of a password.

How to generate secret key in Java once and use that key in 2 different programs

My aim is to write a Java program to encrypt a text file (cipher text) using AES algorithm. And then, write another program to decrypt that encrypted file (cipher text) to get the plain text back. I want to use same key (same key, generate once, save it somewhere, and use it in both encryption and decryption program) for encryption and decryption process. If I generate key and do the encryption and decryption line by line in the same program then it works perfectly. Here is the working code snippet for that:
String strDataToEncrypt = new String();
String strCipherText = new String();
String strDecryptedText = new String();
KeyGenerator keyGen = KeyGenerator.getInstance("AES");
keyGen.init(128);
SecretKey secretKey = keyGen.generateKey();
Cipher aesCipher = Cipher.getInstance("AES");
aesCipher.init(Cipher.ENCRYPT_MODE,secretKey);
strDataToEncrypt = "any text input";
byte[] byteDataToEncrypt = strDataToEncrypt.getBytes();
byte[] byteCipherText = aesCipher.doFinal(byteDataToEncrypt);
strCipherText = new BASE64Encoder().encode(byteCipherText);
System.out.println("cipher text: " +strCipherText);
aesCipher.init(Cipher.DECRYPT_MODE,secretKey,aesCipher.getParameters());
byte[] byteDecryptedText = aesCipher.doFinal(new BASE64Decoder().decodeBuffer(strCipherText));
strDecryptedText = new String(byteDecryptedText);
System.out.println("plain text again: " +strDecryptedText);
But, I need to have two different programs (java files) for encryption and decryption. So, I have to somehow generate a key and save that somewhere. Then use the same key for both encryption and decryption program. How can I do that?
EDIT_1
KeyGenerator keyGen = KeyGenerator.getInstance("AES");
keyGen.init(128);
SecretKey secretKey = keyGen.generateKey();
byte[] encoded = secretKey.getEncoded();
System.out.println("key: "+encoded);// key: [B#52b2a2d8
I can get the encoded key value using the above program. But my question is how to generate the SecretKey using this value in my decryption program?

Forgive me if I misunderstood your question but I believe you wish to reconstruct a SecretKey object from a existing key encoded in a byte array.
This can be performed simply by using the javax.crypto.spec.SecretKeySpec's constructor as such:
byte[] encoded = //Key data
SecretKey secretKey = new SecretKeySpec(encoded, "AES");
Since SecretKeySpec is a subclass of SecretKey no casting is needed. Should your encryption/decrption algorithm change please make sure to change the string literal used in the constructor AES to whatever algorithm you decided to use in the future.

Here's one way to print out the values in a byte[] array in hex:
byte[] a = {-120, 17, 42,121};
for (byte b : a)
{
System.out.printf("%2X",b);
}
System.out.println();