I have been trying to encrypt string using AES-128 CBC which was originally crypted using JAVA AES encryption. In java PKCS5 padding is used. And i have tried to encrypt using similar PHP code. But i am getting different result. I think I am getting wrong somewhere in IV parameter value. Can anyone help me on this.
JAVA Code
package com.idbi.ib.util;
import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;
public class AESEncryptionDecryptionAlg
{
public AESEncryptionDecryptionAlg()
{
}
public static String Encrypt(String text, String key) throws Exception {
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
byte[] keyBytes= new byte[16];
byte[] b= key.getBytes("UTF-8");
int len= b.length;
if (len > keyBytes.length) len = keyBytes.length;
System.arraycopy(b, 0, keyBytes, 0, len);
SecretKeySpec keySpec = new SecretKeySpec(keyBytes, "AES");
IvParameterSpec ivSpec = new IvParameterSpec(keyBytes);
cipher.init(Cipher.ENCRYPT_MODE,keySpec,ivSpec);
byte[] results = cipher.doFinal(text.getBytes("UTF-8"));
BASE64Encoder encoder = new BASE64Encoder();
return encoder.encode(results);
}
}
And the equivalent PHP code.
function mc_encrypt($plaintext,$key) {
$iv = $key;
//For PKCS5 padding
$block = mcrypt_get_block_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC);
$padding = $block - (strlen($plaintext) % $block);
$plaintext .= str_repeat(chr($padding), $padding);
$crypttext = mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $key, $plaintext, MCRYPT_MODE_CBC);
$crypttext64 = base64_encode($crypttext);
$plaintext = $crypttext64;
return $plaintext;
}
Related
I need to convert java code for encryption and decryption using AES/CBC/PKCS5Padding algorithm to dart code.
The java code of AES/CBC/PKCS5Padding encryption and decryption:
package test_Terminal.classes;
import java.nio.charset.StandardCharsets;
import java.util.Base64;
import javax.crypto.Cipher;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.SecretKeySpec;
/**
*
* #author jeena
*/
public class IOTEncodingDecoding {
SecretKeySpec secretKeySpec;
IvParameterSpec ivSpec;
String EncryptionKey = "733D3A17-D8A0-454B-AD22-88608FD0C46A";
String saltString = "FA9A4D0F-5523-4EEF-B226-9A3E8F14FEF8";
String algorithm = "AES/CBC/PKCS5Padding";
int encoding_mode;
test_Terminal.classes.general General = new test_Terminal.classes.general();
void setSecretKey() {
try {
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
PBEKeySpec pbeKeySpec = new PBEKeySpec(EncryptionKey.toCharArray(), saltString.getBytes(StandardCharsets.UTF_16LE), 1000, 384);
byte[] derivedData = factory.generateSecret(pbeKeySpec).getEncoded();
byte[] key = new byte[32];
byte[] iv = new byte[16];
System.arraycopy(derivedData, 0, key, 0, key.length);
System.arraycopy(derivedData, key.length, iv, 0, iv.length);
secretKeySpec = new SecretKeySpec(key, "AES");
ivSpec = new IvParameterSpec(iv);
} catch (Exception e) {
General.LogException("setSecretKey", e);
}
}
public String encrypt(String input) {
try {
Cipher cipher = Cipher.getInstance(algorithm);
cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec, ivSpec);
byte[] cipherText ;
if(encoding_mode==1)
cipherText = cipher.doFinal(input.getBytes(StandardCharsets.UTF_16LE));
else
cipherText = cipher.doFinal(input.getBytes());
return Base64.getEncoder().encodeToString(cipherText);
} catch (Exception e) {
General.LogException("encrypt", e);
}
return "";
}
public String decrypt(String cipherText) {
try {
Cipher cipher = Cipher.getInstance(algorithm);
cipher.init(Cipher.DECRYPT_MODE, secretKeySpec, ivSpec);
byte[] plainText = cipher.doFinal(Base64.getDecoder().decode(cipherText));
if(encoding_mode==1)
return new String(plainText, StandardCharsets.UTF_16LE);
else
return new String(plainText);
} catch (Exception e) {
General.LogException("decrypt", e);
General.LogActivity("decrypt", e.getMessage());
}
return "Ticket format error";
}
public void setMode() {
setSecretKey();
}
}
I need to get the following result:
Input(PlainText):C123492349C1CT20230206130645.
Output(Encrypted string):8tyHRaQCsxmmGW2xPBFYx/PALmvHkmjx/TzaXC2rIv0=
This is the dart code that I've got so far for decryption, but I'm getting error.
Uint8List? decrypt(String ciphertext, String password) {
Uint8List rawCipher = base64.decode(ciphertext);
var salt = rawCipher.sublist(0, 0 + 8);
var iv = rawCipher.sublist(8, 8 + 16);
var encrypted = rawCipher.sublist(8 + 16);
Uint8List key = generateKey(password, salt);
print('key => $key');
CBCBlockCipher cipher = CBCBlockCipher(AESEngine());
ParametersWithIV<KeyParameter> params =
ParametersWithIV<KeyParameter>(KeyParameter(key), iv);
PaddedBlockCipherParameters<ParametersWithIV<KeyParameter>, Null>
paddingParams =
PaddedBlockCipherParameters<ParametersWithIV<KeyParameter>, Null>(
params, null);
PaddedBlockCipherImpl paddingCipher =
PaddedBlockCipherImpl(PKCS7Padding(), cipher);
paddingCipher.init(false, paddingParams);
var val = paddingCipher.process(encrypted);
String res = String.fromCharCodes(val);
debugPrint('res => $res');
return val;
}
Uint8List generateKey(String passphrase, Uint8List salt) {
final derivator = PBKDF2KeyDerivator(HMac(SHA1Digest(), 64))
..init(Pbkdf2Parameters(salt, 1024, 16));
return derivator.process(utf8.encode(passphrase) as Uint8List);
}
I got this code from
The Exception that I'm getting is:
Exception has occurred.
ArgumentError (Invalid argument(s): Input data length must be a multiple of cipher's block size)
I think the values inside rawCipher.sublist() function is wrong. I'm stuck on this problem for few days, please help.
Both codes differ:
Regarding encodings: The Dart code does not consider the UTF-16 LE encoding of the salt. Furthermore, the encoding of the plaintext is unclear. For encoding_mode==1 it is UTF-16LE, otherwise it corresponds to the platform encoding in your environment (which only you know).
Regarding PBKDF2: The Java code derives key and IV from a static salt (note that a static salt is a vulnerability), while the Dart code assumes a concatenation in the order salt|IV|ciphertext during encryption (using a random 8 bytes salt and a random IV).
Also, different iteration counts are used: 1000 in the Java code, 1024 in the Dart code (note that both values are generally much too small for PBKDF2).
The differences can be fixed as follows:
Regarding encodings: In the Dart code, the salt must first be UTF-16 LE encoded: Since the utf package is deprecated, see e.g. here for a UTF-16 LE encoding and here for the decoding. The encoding can be adapted to:
Uint8List encodeUtf16LE(String salt) {
var byteData = ByteData(salt.codeUnits.length * 2);
for (var i = 0; i < salt.codeUnits.length; i += 1) {
byteData.setUint16(i * 2, salt.codeUnits[i], Endian.little);
}
return byteData.buffer.asUint8List();
}
Moreover, from the sample data it can be concluded (by testing) that the plaintext in the Java code has been encoded with UTF-8.
Regarding PBKDF2: In the Dart code, key and IV must be derived from the static salt applied in the Java code.
Also, the parameters from the Java code must be applied (digest: SHA-1, iteration count: 1000, keysize: 32 + 16 = 48 bytes):
Uint8List generateKey(String passphrase, Uint8List salt) {
final derivator = PBKDF2KeyDerivator(HMac(SHA1Digest(), 64))
..init(Pbkdf2Parameters(salt, 1000, 32 + 16));
return derivator.process(utf8.encode(passphrase) as Uint8List);
}
With these changes, key and IV can be derived as follows:
var salt = "FA9A4D0F-5523-4EEF-B226-9A3E8F14FEF8";
var passphrase = "733D3A17-D8A0-454B-AD22-88608FD0C46A";
var saltBytes = encodeUtf16LE(salt);
var keyIv = generateKey(passphrase, saltBytes);
var key = keyIv.sublist(0, 32);
var iv = keyIv.sublist(32, 32 + 16);
The decryption code can be applied unchanged, for decoding use utf8.decode() instead of String.fromCharCodes().
import 'dart:convert';
import 'dart:typed_data';
import 'package:pointycastle/export.dart';
...
var ciphertext = "8tyHRaQCsxmmGW2xPBFYx/PALmvHkmjx/TzaXC2rIv0=";
var encrypted = base64.decode(ciphertext);
var paddingCipher = PaddedBlockCipherImpl(PKCS7Padding(), CBCBlockCipher(AESEngine()))
..init(false, PaddedBlockCipherParameters(ParametersWithIV(KeyParameter(key), iv), null));
var decryptedBytes = paddingCipher.process(encrypted);
var decrypted = utf8.decode(decryptedBytes); // C123492349C1CT20230206130645
I want to encrypt the data in flutter using the AES cbc-128 algorithm. below is the java code for that i want to achieve the same functionality as below but in dart. i have tried
cryptography
dependency in flutter but the problem with that is that i want to use my own key in the algorithm as below in the java code. if you know any method for achieving this please let me know.
public static String Decrypt(String text, String key) throws Exception {
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
byte[] keyBytes = new byte[16];
byte[] b = key.getBytes("UTF-8");
int len = b.length;
if (len > keyBytes.length)
len = keyBytes.length;
System.arraycopy(b, 0, keyBytes, 0, len);
SecretKeySpec keySpec = new SecretKeySpec(keyBytes, "AES");
IvParameterSpec ivSpec = new IvParameterSpec(keyBytes);
cipher.init(Cipher.DECRYPT_MODE, keySpec, ivSpec);
BASE64Decoder decoder = new BASE64Decoder();
byte[] results = cipher.doFinal(decoder.decodeBuffer(text));
return new String(results, "UTF-8");
}
public static String Encrypt(String text, String key) throws Exception {
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
byte[] keyBytes = new byte[16];
byte[] b = key.getBytes("UTF-8");
int len = b.length;
if (len > keyBytes.length)
len = keyBytes.length;
System.arraycopy(b, 0, keyBytes, 0, len);
SecretKeySpec keySpec = new SecretKeySpec(keyBytes, "AES");
IvParameterSpec ivSpec = new IvParameterSpec(keyBytes);
cipher.init(Cipher.ENCRYPT_MODE, keySpec, ivSpec);
byte[] results = cipher.doFinal(text.getBytes("UTF-8"));
BASE64Encoder encoder = new BASE64Encoder();
return encoder.encode(results);
}
Test Case
For the following input
plainText="This is plain text";
key="sahtojetrout2";
i want the encrypted result to be
encryptedText="8FmSMnDsFJVyNUXunhJLSmhFnRq89fl5DyTp0wdYfgk=";
which Topaco has written in an online editor you can check out that here Java Code. In flutter i have tried the program given at the Flutter site
You can do AES CBC-128 encryption in flutter with the help of crypt library. It supports the AES cbc encryption. The following sample code accepts key-string and plain-text as arguments and encrypts it as you have mentioned. You can pass your own key here. For AES-128, you need 128 bit key or 16 character string.
import 'package:encrypt/encrypt.dart';
void main() {
final key = "Your16CharacterK";
final plainText = "lorem ipsum example example";
Encrypted encrypted = encrypt(key, plainText);
String decryptedText = decrypt(key, encrypted);
print(decryptedText);
}
String decrypt(String keyString, Encrypted encryptedData) {
final key = Key.fromUtf8(keyString);
final encrypter = Encrypter(AES(key, mode: AESMode.cbc));
final initVector = IV.fromUtf8(keyString.substring(0, 16));
return encrypter.decrypt(encryptedData, iv: initVector);
}
Encrypted encrypt(String keyString, String plainText) {
final key = Key.fromUtf8(keyString);
final encrypter = Encrypter(AES(key, mode: AESMode.cbc));
final initVector = IV.fromUtf8(keyString.substring(0, 16));
Encrypted encryptedData = encrypter.encrypt(plainText, iv: initVector);
return encryptedData;
}
In the above example, the IV is created from the key itself to keep the code easy to read. Use random data for IV for better security. Referred article for flutter encryption.
I am trying to reproduce the following encryption/decryption algorithm in Java, but I can't find the alternatives for multiple methods such as Rfc2898DeriveBytes() and RijndaelManaged(). How do I do this?
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
namespace CryptingTest
{
public static class StringCipher
{
// This constant is used to determine the keysize of the encryption algorithm in bits.
// We divide this by 8 within the code below to get the equivalent number of bytes.
private const int Keysize = 128;
// This constant determines the number of iterations for the password bytes generation function.
private const int DerivationIterations = 1000;
public static string Encrypt(string plainText, string passPhrase)
{
// Salt and IV is randomly generated each time, but is preprended to encrypted cipher text
// so that the same Salt and IV values can be used when decrypting.
var saltStringBytes = Generate128BitsOfRandomEntropy();
var ivStringBytes = Generate128BitsOfRandomEntropy();
var plainTextBytes = Encoding.UTF8.GetBytes(plainText);
using (var password = new Rfc2898DeriveBytes(passPhrase, saltStringBytes, DerivationIterations))
{
var keyBytes = password.GetBytes(Keysize / 8);
using (var symmetricKey = new RijndaelManaged())
{
symmetricKey.BlockSize = 128;
symmetricKey.Mode = CipherMode.CBC;
symmetricKey.Padding = PaddingMode.PKCS7;
using (var encryptor = symmetricKey.CreateEncryptor(keyBytes, ivStringBytes))
{
using (var memoryStream = new MemoryStream())
{
using (var cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write))
{
cryptoStream.Write(plainTextBytes, 0, plainTextBytes.Length);
cryptoStream.FlushFinalBlock();
// Create the final bytes as a concatenation of the random salt bytes, the random iv bytes and the cipher bytes.
var cipherTextBytes = saltStringBytes;
cipherTextBytes = cipherTextBytes.Concat(ivStringBytes).ToArray();
cipherTextBytes = cipherTextBytes.Concat(memoryStream.ToArray()).ToArray();
memoryStream.Close();
cryptoStream.Close();
return Convert.ToBase64String(cipherTextBytes);
}
}
}
}
}
}
public static string Decrypt(string cipherText, string passPhrase)
{
// Get the complete stream of bytes that represent:
// [32 bytes of Salt] + [16 bytes of IV] + [n bytes of CipherText]
var cipherTextBytesWithSaltAndIv = Convert.FromBase64String(cipherText);
// Get the saltbytes by extracting the first 16 bytes from the supplied cipherText bytes.
var saltStringBytes = cipherTextBytesWithSaltAndIv.Take(Keysize / 8).ToArray();
// Get the IV bytes by extracting the next 16 bytes from the supplied cipherText bytes.
var ivStringBytes = cipherTextBytesWithSaltAndIv.Skip(Keysize / 8).Take(Keysize / 8).ToArray();
// Get the actual cipher text bytes by removing the first 64 bytes from the cipherText string.
var cipherTextBytes = cipherTextBytesWithSaltAndIv.Skip((Keysize / 8) * 2).Take(cipherTextBytesWithSaltAndIv.Length - ((Keysize / 8) * 2)).ToArray();
using (var password = new Rfc2898DeriveBytes(passPhrase, saltStringBytes, DerivationIterations))
{
var keyBytes = password.GetBytes(Keysize / 8);
using (var symmetricKey = new RijndaelManaged())
{
symmetricKey.BlockSize = 128;
symmetricKey.Mode = CipherMode.CBC;
symmetricKey.Padding = PaddingMode.PKCS7;
using (var decryptor = symmetricKey.CreateDecryptor(keyBytes, ivStringBytes))
{
using (var memoryStream = new MemoryStream(cipherTextBytes))
{
using (var cryptoStream = new CryptoStream(memoryStream, decryptor, CryptoStreamMode.Read))
{
var plainTextBytes = new byte[cipherTextBytes.Length];
var decryptedByteCount = cryptoStream.Read(plainTextBytes, 0, plainTextBytes.Length);
memoryStream.Close();
cryptoStream.Close();
return Encoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount);
}
}
}
}
}
}
private static byte[] Generate128BitsOfRandomEntropy()
{
var randomBytes = new byte[16]; // 16 Bytes will give us 128 bits.
using (var rngCsp = new RNGCryptoServiceProvider())
{
// Fill the array with cryptographically secure random bytes.
rngCsp.GetBytes(randomBytes);
}
return randomBytes;
}
}
}
Any help would be really appreciated.
Here's a code snippet from what I tried so far but it's still off:
private static byte[] Generate128BitsOfRandomEntropy()
{
var randomBytes = new byte[16]; // 16 Bytes will give us 128 bits.
SecureRandom rngCsp = new SecureRandom();
// Fill the array with cryptographically secure random bytes.
rngCsp.nextBytes(randomBytes);
return randomBytes;
}
public static String encrypt(String plainText, String passPhrase)
{
try
{
var saltStringBytes = Generate128BitsOfRandomEntropy();
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
PBEKeySpec pbeKeySpec = new PBEKeySpec(passPhrase.toCharArray(), saltStringBytes, 1000, 384);
Key secretKey = factory.generateSecret(pbeKeySpec);
byte[] key = new byte[16];
byte[] iv = new byte[16];
System.arraycopy(secretKey.getEncoded(), 0, key, 0, 16);
System.arraycopy(secretKey.getEncoded(), 16, iv, 0, 16);
SecretKeySpec secret = new SecretKeySpec(key, "AES");
AlgorithmParameterSpec ivSpec = new IvParameterSpec(iv);
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, secret, ivSpec);
return Base64.getEncoder().encodeToString(cipher.doFinal(plainText.getBytes("UTF-8")));
}
catch (Exception e)
{
System.out.println("Error while encrypting: " + e.toString());
}
return null;
}
Rfc2898DeriveBytes implements PBKDF2, and RijndaelManaged with a block size of 128 bits implements AES. Both seem to be applied correctly in the Java code.
However, there are differences in determining the IV and regarding concatenation: In the C# code, the salt and IV are determined randomly and concatenated with the ciphertext at the end.
In the Java code only the salt is determined randomly, the IV is derived together with the key and the concatenation is missing.
I.e. the encrypt() method in the Java code could be changed for instance as follows, so that a decryption with the C# code is possible:
import java.nio.ByteBuffer;
import java.nio.charset.StandardCharsets;
import java.security.SecureRandom;
import java.security.spec.AlgorithmParameterSpec;
import java.util.Base64;
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.SecretKeySpec;
...
byte[] salt = Generate128BitsOfRandomEntropy();
byte[] iv = Generate128BitsOfRandomEntropy();
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
PBEKeySpec pbeKeySpec = new PBEKeySpec(passPhrase.toCharArray(), salt, 1000, 128);
SecretKey secretKey = factory.generateSecret(pbeKeySpec);
SecretKeySpec secretKeySpec = new SecretKeySpec(secretKey.getEncoded(), "AES");
AlgorithmParameterSpec ivSpec = new IvParameterSpec(iv);
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec, ivSpec);
byte[] ciphertext = cipher.doFinal(plainText.getBytes(StandardCharsets.UTF_8));
byte[] saltIvCiphertext = ByteBuffer.allocate(salt.length + iv.length + ciphertext.length).put(salt).put(iv).put(ciphertext).array();
return Base64.getEncoder().encodeToString(saltIvCiphertext);
Note that for PBKDF2, an iteration count of 1000 is generally too low.
I'm encrypting a JSON message and sending it to the user. When they decrypt it, some of the messages show special characters at the beginning of the messages.
When i tried to decrypt from my side it's working fine. If they are decrypting it it shows special characters, but only for some messages as some are decrypting just fine.
Below is the Java code I am using to encrypt the messages and also adding code they are using to decrypt in .NET. Please help me understand this situation and why it's happening.
JAVA CODE(Encryption):
package com.kcs.mule.encryption;
import javax.crypto.Cipher;
import org.apache.commons.codec.binary.Base64;
import org.mule.api.MuleEventContext;
import org.mule.api.lifecycle.Callable;
import java.security.AlgorithmParameters;
import java.security.SecureRandom;
import java.util.Arrays;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.SecretKeySpec;
public class AESEncryption implements Callable {
private static final String password = "fvtQhQcKZVWMCXRLbqmRgfEBXYWshTEP";
private static int pswdIterations = 65536;
private static int keySize = 256;
private static byte[] ivBytes;
#Override
public Object onCall(MuleEventContext eventContext) throws Exception {
String plainText = eventContext.getMessageAsString();
byte[] saltBytes = password.getBytes("UTF-8");
// Derive the key
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA256");
PBEKeySpec spec = new PBEKeySpec(password.toCharArray(), saltBytes, pswdIterations, keySize);
SecretKey secretKey = factory.generateSecret(spec);
SecretKeySpec secret = new SecretKeySpec(secretKey.getEncoded(), "AES");
// encrypt the message
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, secret);
AlgorithmParameters params = cipher.getParameters();
ivBytes = params.getParameterSpec(IvParameterSpec.class).getIV();
byte[] encryptedTextBytes = cipher.doFinal(plainText.getBytes("UTF-8"));
byte[] encryptedOutput = new byte[ivBytes.length+encryptedTextBytes.length];
System.arraycopy(ivBytes, 0, encryptedOutput, 0, ivBytes.length);
System.arraycopy(encryptedTextBytes,0,encryptedOutput,ivBytes.length,encryptedTextBytes.length);
return encryptedOutput;
}
}
DOT Net Code(Decryption code):
byte[] saltBytes = key;
PBEKeySpec keySpec = new PBEKeySpec(key, saltBytes, 65536);
var keyHash = keySpec.GetBytes(32);
using (Aes aesCrypto = Aes.Create())
{
//set the BlockSize and the KeySize before you set the Key and the IV
//to avoid padding exceptions.
aesCrypto.BlockSize = 128;
aesCrypto.KeySize = 256; // AES256
aesCrypto.Key = keyHash;
byte[] cipherTextCombined = request.MessageBytes;
byte[] IV = new byte[aesCrypto.BlockSize / 8];
byte[] cipherText = new byte[cipherTextCombined.Length - IV.Length];
Array.Copy(cipherTextCombined, IV, IV.Length);
Array.Copy(cipherTextCombined, IV.Length, cipherText, 0, cipherText.Length);
aesCrypto.IV = IV; //Initialization vector
aesCrypto.Mode = CipherMode.CBC; //Cipher Block Chaining mode
aesCrypto.Padding = PaddingMode.PKCS7;
// Create a decryptor to perform the stream transform.
ICryptoTransform decryptor = aesCrypto.CreateDecryptor(aesCrypto.Key, aesCrypto.IV);
// Create the streams used for decryption.
using (var msDecrypt = new MemoryStream(cipherText))
{
using (var csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
{
using (var srDecrypt = new StreamReader(csDecrypt, new UTF8Encoding(false)))
{
// Read the decrypted bytes from stream to string.
response.MessageText = srDecrypt.ReadToEnd();
}
}
}
}
}
Actual result:
����wߞ*�/�r5le": {
"System": "KCS",
"Train": {
"TrainNumber": "36181542",
"TrainID": "G-CDMY -26",
Expected Result:
TrainSchedule: {
"System": "KCS",
"Train": {
"TrainNumber": "36181542",
"TrainID": "G-CDMY -26",
It's possible You are not encrypting the string "TrainSchedule" but they are decrypting TrainSchedule along with the payload.
Either encrypt the header or tell them to separate the payload from the header before decrypting it and concatenate it after.
Or, they are only decrypting the payload and ignoring the header. Without looking at their code it's impossible to know.
PHP Encrypt Function
$privateKey = "1234567812345678";
$iv = "1234567812345678";
$data = "Test string";
$encrypted = mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $privateKey, $data, MCRYPT_MODE_CBC, $iv);
echo(base64_encode($encrypted));
Result: iz1qFlQJfs6Ycp+gcc2z4w==
When I try to decrypt this result in Java using the function below, all I get back is ì�š#ÔBKxnfÈ~¯Ô'M while I am expecting "Test string". Any ideas where I am wrong? Thanks
public static String decrypt() throws Exception{
try{
String Base64EncodedText = "iz1qFlQJfs6Ycp+gcc2z4w==";
String decodedText = com.sun.xml.internal.messaging.saaj.util.Base64.base64Decode(Base64EncodedText);
String key = "1234567812345678";
String iv = "1234567812345678";
javax.crypto.spec.SecretKeySpec keyspec = new javax.crypto.spec.SecretKeySpec(key.getBytes(), "AES");
javax.crypto.spec.IvParameterSpec ivspec = new javax.crypto.spec.IvParameterSpec(iv.getBytes());
javax.crypto.Cipher cipher = javax.crypto.Cipher.getInstance("AES/CBC/NoPadding");
cipher.init(javax.crypto.Cipher.DECRYPT_MODE, keyspec, ivspec);
byte[] decrypted = cipher.doFinal(decodedText.getBytes());
String str = new String(decrypted);
return str;
}catch(Exception e){
return null;
}
}
EDIT: As of Java 8 Java now includes an acceptable Base64 class, java.util.Base64.
This line
String decodedText = com.sun.xml.internal.messaging.saaj.util.Base64.base64Decode(Base64EncodedText);
looks wrong. Instead, use the apache commons codec classes or the Harder base64 class. Also the default padding used by mcrypt, zero padding, is arguably wrong and makes it difficult to use the results in other languages. The users comments section for the mcrypt_encrypt web pages has examples of how to do this.
Here is small example that uses the apache commons classes to decrypt your string.
import java.nio.charset.Charset;
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import org.apache.commons.codec.binary.Base64;
import org.apache.commons.codec.binary.Hex;
public class AESToy3 {
private static final Charset ASCII = Charset.forName("US-ASCII");
public static void main(String[] args) throws Exception {
String base64Cipher = "iz1qFlQJfs6Ycp+gcc2z4w==";
byte [] cipherBytes = Base64.decodeBase64(base64Cipher);
byte [] iv = "1234567812345678".getBytes(ASCII);
byte [] keyBytes = "1234567812345678".getBytes(ASCII);
SecretKey aesKey = new SecretKeySpec(keyBytes, "AES");
Cipher cipher = Cipher.getInstance("AES/CBC/NOPADDING");
cipher.init(Cipher.DECRYPT_MODE, aesKey, new IvParameterSpec(iv));
byte[] result = cipher.doFinal(cipherBytes);
System.out.println(Hex.encodeHexString(result));
}
}
this produces the following output:
5465737420737472696e670000000000
which when decoded as ASCII and removing the trailing zeros gives you Test string