Styjun

I am trying to replicate the java code for AES encryption into Golang.
However I am not getting the same output in golang

I tried below code:

Java Code:

package EncryptionTest;

import java.security.Key;
import java.util.Base64;

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;

public class EncryptionDecryptionAES 

 static Cipher cipher;

 public static void main(String[] args) throws Exception 
 Key secretKey;
 secretKey = (Key)new SecretKeySpec("0123456789012345".getBytes(), "AES");
 cipher = Cipher.getInstance("AES");
 String plainText = "AES Symmetric Encryption Decryption";
 System.out.println("Plain Text Before Encryption: " + plainText);
 String encryptedText = encrypt(plainText, secretKey);
 System.out.println("Encrypted Text After Encryption: " + encryptedText);
 String decryptedText = decrypt(encryptedText, secretKey);
 System.out.println("Decrypted Text After Decryption: " + decryptedText);
 

 public static String encrypt(String plainText, Key secretKey) throws Exception 
 byte[] plainTextByte = plainText.getBytes();
 cipher.init(Cipher.ENCRYPT_MODE, secretKey);
 byte[] encryptedByte = cipher.doFinal(plainTextByte);
 Base64.Encoder encoder = Base64.getEncoder();
 String encryptedText = encoder.encodeToString(encryptedByte);
 return encryptedText;
 

 public static String decrypt(String encryptedText, Key secretKey) throws Exception 
 Base64.Decoder decoder = Base64.getDecoder();
 byte[] encryptedTextByte = decoder.decode(encryptedText);
 cipher.init(Cipher.DECRYPT_MODE, secretKey);
 byte[] decryptedByte = cipher.doFinal(encryptedTextByte);
 String decryptedText = new String(decryptedByte);
 return decryptedText;
 

Java code output:
Plain Text Before Encryption: AES Symmetric Encryption Decryption
Encrypted Text After Encryption: vSmrgH3qU+qEq+3ui0YvwCa6PDBcMyhgOlbh3+zzM+cON6feLk2u1iPW7lITD3vn
Decrypted Text After Decryption: AES Symmetric Encryption Decryption

Golang Code:

package main

import (
 "crypto/aes"
 "crypto/cipher"
 "encoding/base64"
 "fmt"
)

const NONCESIZE = 12

func main() 
 key := []byte("0123456789012345")
 plaintext := []byte("AES Symmetric Encryption Decryption")
 block, err := aes.NewCipher(key)
 if err != nil 
 panic(err.Error())
 
 nonce := make([]byte, NONCESIZE)
 aesgcm, err := cipher.NewGCM(block)
 if err != nil 
 panic(err.Error())
 
 ciphertext := aesgcm.Seal(nil, nonce, plaintext, nil)
 fmt.Println("Encrypted Text is : ", base64.StdEncoding.EncodeToString(ciphertext))

Golang Code output:
Encrypted Text is : 7UMh49c5Wqb2BzlttKBEnq5g4fxMK9oJs1EUDIgWzVwlY28k+qd/oFG9SJckBsaX6DHp

In the go code, you are using AES in GCM mode with 12 bytes of zero as IV, but in java code you are using default mode of AES which is not the same in different java versions.

By using GCM mode(Provided in BouncyCastle) and setting the same IV(12 bytes of zero) I got same output:

package EncryptionTest;

import org.bouncycastle.jce.provider.BouncyCastleProvider;

import java.security.Key;
import java.security.Security;
import java.util.Base64;

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

public class EncryptionDecryptionAES 

 static Cipher cipher;

 public static void main(String[] args) throws Exception 
 Security.addProvider(new BouncyCastleProvider());


 Key secretKey;
 secretKey = (Key)new SecretKeySpec("0123456789012345".getBytes(), "AES");

 cipher = Cipher.getInstance("AES/GCM/NoPadding", "BC");

 String plainText = "AES Symmetric Encryption Decryption";
 System.out.println("Plain Text Before Encryption: " + plainText);
 String encryptedText = encrypt(plainText, secretKey);
 System.out.println("Encrypted Text After Encryption: " + encryptedText);
 String decryptedText = decrypt(encryptedText, secretKey);
 System.out.println("Decrypted Text After Decryption: " + decryptedText);
 

 public static String encrypt(String plainText, Key secretKey) throws Exception 
 byte[] plainTextByte = plainText.getBytes();


 byte[] iv = new byte[12];
 IvParameterSpec ivParameterSpec = new IvParameterSpec(iv);
 cipher.init(Cipher.ENCRYPT_MODE, secretKey, ivParameterSpec);

 byte[] encryptedByte = cipher.doFinal(plainTextByte);
 Base64.Encoder encoder = Base64.getEncoder();
 String encryptedText = encoder.encodeToString(encryptedByte);
 return encryptedText;
 

 public static String decrypt(String encryptedText, Key secretKey) throws Exception 
 Base64.Decoder decoder = Base64.getDecoder();
 byte[] encryptedTextByte = decoder.decode(encryptedText);

 byte[] iv = new byte[12];
 IvParameterSpec ivParameterSpec = new IvParameterSpec(iv);
 cipher.init(Cipher.DECRYPT_MODE, secretKey, ivParameterSpec);

 byte[] decryptedByte = cipher.doFinal(encryptedTextByte);
 String decryptedText = new String(decryptedByte);
 return decryptedText;
 

Output:

Plain Text Before Encryption: AES Symmetric Encryption Decryption
Encrypted Text After Encryption: 7UMh49c5Wqb2BzlttKBEnq5g4fxMK9oJs1EUDIgWzVwlY28k+qd/oFG9SJckBsaX6DHp
Decrypted Text After Decryption: AES Symmetric Encryption Decryption