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Plain text encrypt from Dart code but decrypt from Java code

When I encrypt plain text using Dart,and encrypted text is decrypted from Java code, I get this error:
javax.crypto.BadPaddingException: pad block corrupted
at org.bouncycastle.jcajce.provider.symmetric.util.BaseBlockCipher$BufferedGenericBlockCipher.doFinal(Unknown Source)
at org.bouncycastle.jcajce.provider.symmetric.util.BaseBlockCipher.engineDoFinal(Unknown Source)
at javax.crypto.Cipher.doFinal(Cipher.java:2168)
at AesUtil.doFinal(AesUtil.java:75)
at AesUtil.decrypt(AesUtil.java:60)
at Main.main(Main.java:18)
Same IV, salt and passphase value using Java side for key generation, but the generated key is different and also cipher test is different. I am using same method for key generation. I don't know what is missing in Dart code.
dependencies:
encrypt: ^5.0.1
hex: ^0.2.0
password_hash_plus: ^4.0.0
Dart code is:
var random = Random.secure();
var values = List<int>.generate(16, (i) => random.nextInt(255));
// final salt = aes.IV.fromSecureRandom(16);
final salt = hex.encode(values);
final generator = PBKDF2(hashAlgorithm: sha1);
final key = aes.Key.fromBase64(generator.generateBase64Key("1234567891234567", salt, 1000, 16));
final iv = aes.IV.fromSecureRandom(16);
final encrypter =
aes.Encrypter(aes.AES(key, mode: aes.AESMode.cbc, padding: 'PKCS7'));
final encrypted = encrypter.encrypt(st.password!, iv: iv);
var str = '${iv.base16}::${salt}::${encrypted.base64}';
var bytes = utf8.encode(str);
var base64Str = base64.encode(bytes);
//final decrypt = encrypter.decrypt64("/vvAYMc3rgCvPvuSVU/qQw==", iv: iv);
print(
'------------------------------,\n encrypt ${(encrypted.base64)}-----------'
//'--\ndecrypted ${decrypt}-----------base64--------$base64Str-----'
'\nkey = ${key.base64} array--\niv = ${iv.base16}--salt= {${salt}');
And Java code is:
class Main {
public static void main(String[] args) {
AesUtil aesUtil = new AesUtil();
String encrypt = aesUtil.encrypt("b9266c74df614967d9acaa2878bff87c", "6ab7c799d6411f9d0c8e048ad526eeee", "1234567891234567", "Jitu#123456");
String a = aesUtil.decrypt("01e6a073a4255c92e704bd94d76d75c5", "98a21e07ed34afc523c5f5938c9202db", "1234567891234567", "MumTfpnzZh9bk94yiTuA+g==");
System.out.println("encrypt = " + encrypt + " \ndecrpty valaue----" + a);
}
}
Encryption code in Java:
import java.io.UnsupportedEncodingException;
import java.security.*;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.KeySpec;
import java.util.Arrays;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.SecretKeySpec;
import org.apache.commons.codec.DecoderException;
import org.apache.commons.codec.binary.Base64;
import org.apache.commons.codec.binary.Hex;
import org.springframework.stereotype.Component;
public class AesUtil {
private final int keySize;
private final int iterationCount;
private final Cipher cipher;
public AesUtil() {
this.keySize = 128;
this.iterationCount = 1000;
try {
Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
cipher = Cipher.getInstance("AES/CBC/PKCS7Padding", "BC");
} catch (NoSuchAlgorithmException | NoSuchPaddingException e) {
e.printStackTrace();
throw fail(e);
} catch (NoSuchProviderException e) {
throw new RuntimeException(e);
}
}
public String encrypt(String salt, String iv, String passphrase, String plaintext) {
try {
SecretKey key = generateKey(salt, passphrase);
System.out.println("encryption key-------= " + base64(key.getEncoded()));
byte[] encrypted = doFinal(Cipher.ENCRYPT_MODE, key, iv, plaintext.getBytes("ISO-8859-1"));
return base64(encrypted);
} catch (UnsupportedEncodingException e) {
throw fail(e);
}
}
public String decrypt(String salt, String iv, String passphrase, String ciphertext) {
try {
SecretKey key = generateKey(salt, passphrase);
System.out.println("decrypt key-------= " + base64(key.getEncoded()));
byte[] decrypted = doFinal(Cipher.DECRYPT_MODE, key, iv, base64(ciphertext));
return new String(decrypted, "ISO-8859-1");
} catch (UnsupportedEncodingException e) {
return null;
} catch (Exception e) {
return null;
}
}
private byte[] doFinal(int encryptMode, SecretKey key, String iv, byte[] bytes) {
try {
IvParameterSpec IivParameterSpec = new IvParameterSpec(hex(iv));
System.out.println("----iv--= " + hex(IivParameterSpec.getIV()));
cipher.init(encryptMode, key, IivParameterSpec);
return cipher.doFinal(bytes);
} catch (InvalidKeyException
| InvalidAlgorithmParameterException
| IllegalBlockSizeException
| BadPaddingException e) {
e.printStackTrace();
return null;
}
}
private SecretKey generateKey(String salt, String passphrase) {
try {
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
byte[] s = hex(salt);
System.out.println("salt-= " + hex(s));
KeySpec spec = new PBEKeySpec(passphrase.toCharArray(), s, iterationCount, keySize);
SecretKey key = new SecretKeySpec(factory.generateSecret(spec).getEncoded(), "AES");
return key;
} catch (NoSuchAlgorithmException | InvalidKeySpecException e) {
return null;
}
}
public static String random(int length) {
byte[] salt = new byte[length];
new SecureRandom().nextBytes(salt);
return hex(salt);
}
public static String base64(byte[] bytes) {
return Base64.encodeBase64String(bytes);
}
public static byte[] base64(String str) {
return Base64.decodeBase64(str);
}
public static String hex(byte[] bytes) {
return Hex.encodeHexString(bytes);
}
public static byte[] hex(String str) {
try {
return Hex.decodeHex(str.toCharArray());
} catch (DecoderException e) {
throw new IllegalStateException(e);
}
}
private IllegalStateException fail(Exception e) {
return null;
}
public static byte[][] GenerateKeyAndIV(int keyLength, int ivLength, int iterations, byte[] salt, byte[] password, MessageDigest md) {
int digestLength = md.getDigestLength();
int requiredLength = (keyLength + ivLength + digestLength - 1) / digestLength * digestLength;
byte[] generatedData = new byte[requiredLength];
int generatedLength = 0;
try {
md.reset();
// Repeat process until sufficient data has been generated
while (generatedLength < keyLength + ivLength) {
// Digest data (last digest if available, password data, salt if available)
if (generatedLength > 0)
md.update(generatedData, generatedLength - digestLength, digestLength);
md.update(password);
if (salt != null)
md.update(salt, 0, 8);
md.digest(generatedData, generatedLength, digestLength);
// additional rounds
for (int i = 1; i < iterations; i++) {
md.update(generatedData, generatedLength, digestLength);
md.digest(generatedData, generatedLength, digestLength);
}
generatedLength += digestLength;
}
// Copy key and IV into separate byte arrays
byte[][] result = new byte[2][];
result[0] = Arrays.copyOfRange(generatedData, 0, keyLength);
if (ivLength > 0)
result[1] = Arrays.copyOfRange(generatedData, keyLength, keyLength + ivLength);
return result;
} catch (DigestException e) {
throw new RuntimeException(e);
} finally {
// Clean out temporary data
Arrays.fill(generatedData, (byte) 0);
}
}
}

The decryption fails because in both codes different salts are used and therefore different keys are generated. Ultimately, this is due to an inappropriate design of the PBKDF2 implementation of the password_hash_plus Dart library.
In the Java code a random salt is applied, in this case 0xb9266c74df614967d9acaa2878bff87c. In main(), the salt is passed hex encoded to encrypt(), hex decoded in generateKey(), and the resulting byte sequence is used for key derivation.
The generateBase64Key() method of the password_hash_plus library, on the other hand, expects the salt as string and does a UTF-8 encoding internally, see here. Therefore, only salts that are UTF-8 decodable can be processed. This is generally not true for random salts, since these are corrupted by a UTF-8 decoding.
The hex encoding of the salt applied in the Dart code does not work either, of course, because generateBase64Key() does not perform a hex decoding internally but a UTF-8 encoding.
Since salts are generally random byte sequences, the design of the PBKDF2 implementation of the password_hash_plus library is unsuitable. Instead, an implementation is required where the salt is passed as byte sequence (Uint8List or List<int>), e.g. the PBKDF2 implementation of PointyCastle:
import 'package:pointycastle/export.dart';
import 'dart:typed_data';
...
final key = aes.Key(deriveKey("1234567891234567", Uint8List.fromList(values))); // Raw salt for key derivation!
final salt = hex.encode(values); // Hex encoded salt for output!
...
Uint8List deriveKey(String passphrase, Uint8List salt){
Uint8List passphraseBytes = Uint8List.fromList(utf8.encode(passphrase));
KeyDerivator derivator = PBKDF2KeyDerivator(HMac(SHA1Digest(), 64)); // 64 byte block size
Pbkdf2Parameters params = Pbkdf2Parameters(salt, 1000, 16); // 16 byte key size
derivator.init(params);
return derivator.process(passphraseBytes);
}
...
The Dart code returns salt and IV hex encoded and the ciphertext Base64 encoded. If this data is passed with these encodings to the decrypt() method of the Java code, decryption is successful.
Be aware that an iteration count of 1000 is generally too small for PBKDF2.

Looking for Java implementation for decrypting a message encrypted using openssl -aes-256-cbc -a -salt command?

I am looking for any sample java code that will decrypt the messages encrypted using "openssl enc -aes-256-cbc) -a -salt" command provided the key is known.
https://pastebin.com/YiwbCAW8
So far i was able to get the following java code that encrypts and also decrypts the message. But i am not able to decrypt the encrypted message using openssl command. Getting "Bad Magic Number" error. Any idea ?
Encrypt the message using the code >
Encrypt("sample text", "test$password") = "i+5zkPPgnDdV7fr/w8uHkw=="
Decrypt("i+5zkPPgnDdV7fr/w8uHkw==", "test$password") = "sample text"
Decrypt the message using openssl >
F:\cipher>echo i+5zkPPgnDdV7fr/w8uHkw== | openssl aes-256-cbc -a -salt -d
enter aes-256-cbc decryption password:
bad magic number
import java.security.spec.KeySpec;
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;
public class AES {
private static final byte[] SALT = {
(byte) 0xA9, (byte) 0x9B, (byte) 0xC8, (byte) 0x32,
(byte) 0x56, (byte) 0x35, (byte) 0xE3, (byte) 0x03
};
private static final int ITERATION_COUNT = 65536;
private static final int KEY_LENGTH = 256;
private Cipher ecipher;
private Cipher dcipher;
AES(String passPhrase) throws Exception {
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
KeySpec spec = new PBEKeySpec(passPhrase.toCharArray(), SALT, ITERATION_COUNT, KEY_LENGTH);
SecretKey tmp = factory.generateSecret(spec);
SecretKey secret = new SecretKeySpec(tmp.getEncoded(), "AES");
ecipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
ecipher.init(Cipher.ENCRYPT_MODE, secret);
dcipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
byte[] iv = ecipher.getParameters().getParameterSpec(IvParameterSpec.class).getIV();
dcipher.init(Cipher.DECRYPT_MODE, secret, new IvParameterSpec(iv));
}
public String encrypt(String encrypt) throws Exception {
byte[] bytes = encrypt.getBytes("UTF8");
byte[] encrypted = encrypt(bytes);
return Base64.getEncoder().encodeToString(encrypted);
}
public byte[] encrypt(byte[] plain) throws Exception {
return ecipher.doFinal(plain);
}
public String decrypt(String encrypt) throws Exception {
byte[] bytes = Base64.getDecoder().decode(encrypt);
byte[] decrypted = decrypt(bytes);
return new String(decrypted, "UTF8");
}
public byte[] decrypt(byte[] encrypt) throws Exception {
return dcipher.doFinal(encrypt);
}
public static void main(String[] args) throws Exception {
String message = "sample text";
String password = "test$password";
AES encrypter = new AES(password);
String encrypted = encrypter.encrypt(message);
String decrypted = encrypter.decrypt(encrypted);
System.out.println("Encrypt(\"" + message + "\", \"" + password + "\") = \"" + encrypted + "\"");
System.out.println("Decrypt(\"" + encrypted + "\", \"" + password + "\") = \"" + decrypted + "\"");
}
}

You may search stackoverflow for many similar questions.
you have multiple issues in your code:
You use different keys:
In Java you use PBKDF2 to generate an encryption key from the provided password. Openssl uses its EVP_BytesToKey. Search internet for Java implementation. Please note the hash used in the EVP_BytesToKey changed with some openssl version (from MD5 to SHA-1 SHA-256), if someone is having more details, please comment
And you use random IV. you don't pass the IV along the ciphertext, so you may be able to decrypt the ciphertext with the same cipher instance (kkeping the same iv), but lets try your Java code to decrypt your ciphertext other time or with other instance, it won't work. You need to pass IV along the ciphertext (usually it's prepended)
Openssl expect following format:
Salted_<8 byte salt>ciphertext
Salted__<8 byte salt>ciphertext
8 byte salt is a random byte array used to generate the encryption key and IV from the provided password. Try encrypt with openssl with -pparameter, it will print the salt, IV and Key generated so you can check and compare
Using CBC without any integrity check (hmac, ..) may be unsafe in many implementations
Suggestions:
you can find an openssl java library implementing the same required (EVP_BytesToKey)
you can implement EVP_BytesToKey yourself
you can use openssl directly with -K/-ivparameters providing the encryption key and IV (in hex format) instead of password, then openssl expects pure ciphertext (no Salted_ or salt inside the input)

Thanks a lot for the clues. As mentioned, did some search and modified the code from one of the post. I have seen similar code with EVP_BytesToKeys in many places, but took some time to figure out the usage. I am able to decrypt the msg encrypted by openssl.
Trying to search the code for encryption as well. Meanwhile any help of encryption is appreciated as well.
import java.nio.charset.Charset;
import java.security.MessageDigest;
import java.util.Arrays;
import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import org.apache.commons.codec.binary.Base64;
public class AES5 {
private static final Charset ASCII = Charset.forName("ASCII");
private static final int INDEX_KEY = 0;
private static final int INDEX_IV = 1;
private static final int ITERATIONS = 1;
private static final int SALT_OFFSET = 8;
private static final int SALT_SIZE = 8;
private static final int CIPHERTEXT_OFFSET = SALT_OFFSET + SALT_SIZE;
private static final int KEY_SIZE_BITS = 256;
/**
* Thanks go to Ola Bini for releasing this source on his blog. The source was
* obtained from here
*
*/
public static byte[][] EVP_BytesToKey(int key_len, int iv_len, MessageDigest md, byte[] salt, byte[] data,
int count) {
byte[][] both = new byte[2][];
byte[] key = new byte[key_len];
int key_ix = 0;
byte[] iv = new byte[iv_len];
int iv_ix = 0;
both[0] = key;
both[1] = iv;
byte[] md_buf = null;
int nkey = key_len;
int niv = iv_len;
int i = 0;
if (data == null) {
return both;
}
int addmd = 0;
for (;;) {
md.reset();
if (addmd++ > 0) {
md.update(md_buf);
}
md.update(data);
if (null != salt) {
md.update(salt, 0, 8);
}
md_buf = md.digest();
for (i = 1; i < count; i++) {
md.reset();
md.update(md_buf);
md_buf = md.digest();
}
i = 0;
if (nkey > 0) {
for (;;) {
if (nkey == 0)
break;
if (i == md_buf.length)
break;
key[key_ix++] = md_buf[i];
nkey--;
i++;
}
}
if (niv > 0 && i != md_buf.length) {
for (;;) {
if (niv == 0)
break;
if (i == md_buf.length)
break;
iv[iv_ix++] = md_buf[i];
niv--;
i++;
}
}
if (nkey == 0 && niv == 0) {
break;
}
}
for (i = 0; i < md_buf.length; i++) {
md_buf[i] = 0;
}
return both;
}
public static byte[][] getKeyIV(byte[] headerSaltAndCipherText, Cipher aesCBC, String password) {
byte[] salt = Arrays.copyOfRange(headerSaltAndCipherText, SALT_OFFSET, SALT_OFFSET + SALT_SIZE);
byte[][] keyAndIV=null;
try {
MessageDigest md5 = MessageDigest.getInstance("MD5");
keyAndIV = EVP_BytesToKey(KEY_SIZE_BITS / Byte.SIZE, aesCBC.getBlockSize(), md5, salt,
password.getBytes(ASCII), ITERATIONS);
} catch (Exception e) {e.printStackTrace();}
return keyAndIV;
}
// https://stackoverflow.com/questions/11783062/how-to-decrypt-file-in-java-encrypted-with-openssl-command-using-aes
public static String decrypt(String encryptedMsg, String password) {
String decryptedMsg =null;
byte[] headerSaltAndCipherText = Base64.decodeBase64(encryptedMsg);
byte[] encrypted = Arrays.copyOfRange(headerSaltAndCipherText, CIPHERTEXT_OFFSET, headerSaltAndCipherText.length);
try {
Cipher aesCBC = Cipher.getInstance("AES/CBC/PKCS5Padding");
final byte[][] keyAndIV = getKeyIV(headerSaltAndCipherText, aesCBC, password);
SecretKeySpec key = new SecretKeySpec(keyAndIV[INDEX_KEY], "AES");
IvParameterSpec iv = new IvParameterSpec(keyAndIV[INDEX_IV]);
aesCBC.init(Cipher.DECRYPT_MODE, key, iv);
byte[] decrypted = aesCBC.doFinal(encrypted);
decryptedMsg = new String(decrypted, ASCII);
} catch (Exception e) {e.printStackTrace();}
return decryptedMsg;
}
//TODO - Encrypt the msg in same manner as "openssl enc -aes-256-cbc -a -salt"
public static String encrypt(String msg, String password) {
String decryptedMsg =null;
byte[] headerSaltAndCipherText = Base64.decodeBase64(msg);
byte[] encrypted = Arrays.copyOfRange(headerSaltAndCipherText, CIPHERTEXT_OFFSET, headerSaltAndCipherText.length);
try {
Cipher aesCBC = Cipher.getInstance("AES/CBC/PKCS5Padding");
final byte[][] keyAndIV = getKeyIV(headerSaltAndCipherText, aesCBC, password);
SecretKeySpec key = new SecretKeySpec(keyAndIV[INDEX_KEY], "AES");
IvParameterSpec iv = new IvParameterSpec(keyAndIV[INDEX_IV]);
aesCBC.init(Cipher.ENCRYPT_MODE, key, iv);
byte[] decrypted = aesCBC.doFinal(encrypted);
decryptedMsg = new String(decrypted, ASCII);
} catch (Exception e) {e.printStackTrace();}
return decryptedMsg;
}
public static void main(String[] args) {
String msg = "the decrypted message is this";
String password = "pass";
System.out.println(encrypt(msg, password));
String encryptedMsg = "U2FsdGVkX190A5FsNTanwTKBdex29SpnH4zWkZN+Ld+MmbJgK4BH1whGIRRSpOJT";
System.out.println(decrypt(encryptedMsg, password));
}
}

Also got an improved solution from the following site. Got the code for both encryption and decryption for now...
http://qaru.site/questions/19874/java-equivalent-of-an-openssl-aes-cbc-encryption
import java.net.URLEncoder;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.util.Arrays;
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 org.apache.commons.codec.binary.Base64;
import static java.nio.charset.StandardCharsets.*;
/**
* Mimics the OpenSSL AES Cipher options for encrypting and decrypting messages using a
* shared key (aka password) with symetric ciphers.
*/
public class OpenSslAesQu {
/** OpenSSL magic initial bytes. */
private static final String SALTED_STR = "Salted__";
private static final byte[] SALTED_MAGIC = SALTED_STR.getBytes(US_ASCII);
public static String encryptAndURLEncode(String password, String clearText) {
String encrypted = null;
try {
encrypted = URLEncoder.encode(encrypt(password, clearText),UTF_8.name());
} catch (Exception e) {e.printStackTrace();}
return encrypted;
}
/**
*
* #param password The password / key to encrypt with.
* #param data The data to encrypt
* #return A base64 encoded string containing the encrypted data.
*/
public static String encrypt(String password, String clearText) {
String encryptedMsg = null;
final byte[] pass = password.getBytes(US_ASCII);
final byte[] salt = (new SecureRandom()).generateSeed(8);
final byte[] inBytes = clearText.getBytes(UTF_8);
final byte[] passAndSalt = array_concat(pass, salt);
byte[] hash = new byte[0];
byte[] keyAndIv = new byte[0];
try {
for (int i = 0; i < 3 && keyAndIv.length < 48; i++) {
final byte[] hashData = array_concat(hash, passAndSalt);
final MessageDigest md = MessageDigest.getInstance("MD5");
hash = md.digest(hashData);
keyAndIv = array_concat(keyAndIv, hash);
}
final byte[] keyValue = Arrays.copyOfRange(keyAndIv, 0, 32);
final byte[] iv = Arrays.copyOfRange(keyAndIv, 32, 48);
final SecretKeySpec key = new SecretKeySpec(keyValue, "AES");
final Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, key, new IvParameterSpec(iv));
byte[] data = cipher.doFinal(inBytes);
data = array_concat(array_concat(SALTED_MAGIC, salt), data);
//return Base64.getEncoder().encodeToString( data );
encryptedMsg = org.apache.commons.codec.binary.Base64.encodeBase64String(data);
} catch(Exception e) {e.printStackTrace();}
return encryptedMsg;
}
/**
* #see http://stackoverflow.com/questions/32508961/java-equivalent-of-an-openssl-aes-cbc-encryption for what looks like a useful answer. The not-yet-commons-ssl also has an implementation
* #param password
* #param source The encrypted data
*/
public static String decrypt(String password, String source) {
String decryptedMsg = null;
final byte[] pass = password.getBytes(US_ASCII);
//final byte[] inBytes = Base64.getDecoder().decode(source);
final byte[] inBytes = Base64.decodeBase64(source);
final byte[] shouldBeMagic = Arrays.copyOfRange(inBytes, 0, SALTED_MAGIC.length);
if (!Arrays.equals(shouldBeMagic, SALTED_MAGIC)) {
throw new IllegalArgumentException("Initial bytes from input do not match OpenSSL SALTED_MAGIC salt value.");
}
final byte[] salt = Arrays.copyOfRange(inBytes, SALTED_MAGIC.length, SALTED_MAGIC.length + 8);
final byte[] passAndSalt = array_concat(pass, salt);
byte[] hash = new byte[0];
byte[] keyAndIv = new byte[0];
try {
for (int i = 0; i < 3 && keyAndIv.length < 48; i++) {
final byte[] hashData = array_concat(hash, passAndSalt);
final MessageDigest md = MessageDigest.getInstance("MD5");
hash = md.digest(hashData);
keyAndIv = array_concat(keyAndIv, hash);
}
final byte[] keyValue = Arrays.copyOfRange(keyAndIv, 0, 32);
final SecretKeySpec key = new SecretKeySpec(keyValue, "AES");
final byte[] iv = Arrays.copyOfRange(keyAndIv, 32, 48);
final Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
cipher.init(Cipher.DECRYPT_MODE, key, new IvParameterSpec(iv));
final byte[] clear = cipher.doFinal(inBytes, 16, inBytes.length - 16);
decryptedMsg = new String(clear, UTF_8);
} catch (Exception e) {e.printStackTrace();}
return decryptedMsg;
}
private static byte[] array_concat(final byte[] a, final byte[] b) {
final byte[] c = new byte[a.length + b.length];
System.arraycopy(a, 0, c, 0, a.length);
System.arraycopy(b, 0, c, a.length, b.length);
return c;
}
public static void main(String[] args) throws InvalidKeyException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException {
String msg = "the decrypted message is this";
String password = "pass";
System.out.println(">> "+encrypt(password,msg));
//System.out.println("<< "+decrypt(encrypt(msg, password), password));
String encryptedMsg = "U2FsdGVkX190A5FsNTanwTKBdex29SpnH4zWkZN+Ld+MmbJgK4BH1whGIRRSpOJT";
String encryptedMsg2 = "U2FsdGVkX1/B6oOznz5+nd7W/qXwXI7G7rhj5o9pjx8MS0TXp9SNxO3AhM9HBJ/z";
System.out.println(decrypt(password,encryptedMsg));
System.out.println(decrypt(password,encryptedMsg2));
System.out.println(decrypt(password,encrypt(password,msg)));
}
}

Encryption and decryption using RC4 [closed]

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I am trying to write a code for encryption and decryption input text with RC4 in Java. Does anyone know how to fix it?
My code:
import java.util.Arrays;
public class RC4 {
private static final int SBOX_LEN = 256;
private static final int MIN_KEY_LEN = 5;
private byte[] key = new byte[SBOX_LEN - 1];
private int[] sbox = new int[SBOX_LEN];
public RC4() {
initialize();
}
public RC4(String key) {
this();
setKey(key);
}
public static void main(String[] args) {
RC4 rc4 = new RC4();
byte[] cipherText = rc4.encryptMessage(args[0], args[1]);
System.out.println(Arrays.toString(cipherText));
String plainText = rc4.decryptMessage(cipherText, args[1]);
System.out.println(plainText);
}
private void initialize() {
Arrays.fill(key, (byte) 0);
Arrays.fill(sbox, 0);
}
public byte[] encryptMessage(String message, String key) {
initialize();
setKey(key);
byte[] crypt = crypt(message.getBytes());
initialize();
return crypt;
}
public String decryptMessage(byte[] message, String key) {
initialize();
setKey(key);
byte[] msg = crypt(message);
initialize();
return new String(msg);
}
public byte[] crypt(final byte[] msg) {
sbox = initializeSBox(key);
byte[] code = new byte[msg.length];
int i = 0;
int j = 0;
for (int n = 0; n < msg.length; n++) {
i = (i + 1) % SBOX_LEN;
j = (j + sbox[i]) % SBOX_LEN;
swap(i, j, sbox);
int rand = sbox[(sbox[i] + sbox[j]) % SBOX_LEN];
code[n] = (byte) (rand ^ msg[n]);
}
return code;
}
private int[] initializeSBox(byte[] key) {
int[] sbox = new int[SBOX_LEN];
int j = 0;
for (int i = 0; i < SBOX_LEN; i++) {
sbox[i] = i;
}
for (int i = 0; i < SBOX_LEN; i++) {
j = ((j + sbox[i] + (key[i % key.length])) & 0xFF) % SBOX_LEN;
swap(i, j, sbox);
}
return sbox;
}
private void swap(int i, int j, int[] sbox) {
int temp = sbox[i];
sbox[i] = sbox[j];
sbox[j] = temp;
}
public void setKey(String key) {
if (!((key.length() >= MIN_KEY_LEN) && (key.length() < SBOX_LEN))) {
throw new RuntimeException(String.format("Key length must be between %d and %d", MIN_KEY_LEN, SBOX_LEN - 1));
}
this.key = key.getBytes();
}
}

RC4 is a broken algorithm and recommendation is to not use the same anymore if the data is to be kept highly secure.
If you still need a working implementation, you don't need to recreate the algorithm in your code. Java API javax.crypto can do it for you. Just generate a key and call the init method with mode set to encryption/decryption.
static String decryptRC4() throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException, InvalidAlgorithmParameterException{
byte[] testDataBytes = "testString".getBytes();
KeyGenerator rc4KeyGenerator = KeyGenerator.getInstance("RC4");
SecretKey key = rc4KeyGenerator.generateKey();
// Create Cipher instance and initialize it to encrytion mode
Cipher cipher = Cipher.getInstance("RC4"); // Transformation of the algorithm
cipher.init(Cipher.ENCRYPT_MODE, key);
byte[] cipherBytes = cipher.doFinal(testDataBytes);
// Reinitialize the Cipher to decryption mode
cipher.init(Cipher.DECRYPT_MODE,key, cipher.getParameters());
byte[] testDataBytesDecrypted = cipher.doFinal(cipherBytes);
System.out.println("Decrypted Data : "+new String(testDataBytesDecrypted));
return new String(testDataBytesDecrypted);
}
Output:
If you need to send the encrypted data as part of a url then use Base64Encoding and then send.
e.g.
static String decryptRC4() throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException, InvalidAlgorithmParameterException{
byte[] plainBytes = "testString".getBytes();
KeyGenerator rc4KeyGenerator = KeyGenerator.getInstance("RC4");
SecretKey key = rc4KeyGenerator.generateKey();
// Create Cipher instance and initialize it to encrytion mode
Cipher cipher = Cipher.getInstance("RC4"); // Transformation of the algorithm
cipher.init(Cipher.ENCRYPT_MODE, key);
byte[] cipherBytes = cipher.doFinal(plainBytes);
String encoded = encodeBase64(cipherBytes);
String decoded = decodeBase64(encoded);
// Reinitialize the Cipher to decryption mode
cipher.init(Cipher.DECRYPT_MODE,key, cipher.getParameters());
byte[] plainBytesDecrypted = cipher.doFinal(Hex.decode(decoded));
System.out.println("Decrypted Data : "+new String(plainBytesDecrypted));
return new String(plainBytesDecrypted);
}
static String decodeBase64(String encodedData){
byte[] b = Base64.getDecoder().decode(encodedData);
String decodedData = DatatypeConverter.printHexBinary(b);
return decodedData;
}
static String encodeBase64(byte[] data){
byte[] b = Base64.getEncoder().encode(data);
String encodedData = new String(b);
/*String encodedData = DatatypeConverter.printHexBinary(b);*/
return encodedData;
}
** Tip: ** Use Hex.decode as shown above to get bytes from the base64 decoded string or else you will get encoding issues. As much as possible do the conversions using Hex and convert to bytes array using bouncycastle methods.
Imports needed:
import java.io.IOException;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Base64;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.xml.bind.DatatypeConverter;
import org.apache.commons.codec.DecoderException;
import org.bouncycastle.util.encoders.Hex;
Also if you are generating a key from your own string you can use MD5Hashing for the same.

RC4 Encryption/Decryption with C# and Java

I even use the AES algorithm to encrypt and decrypt files, but according to my research, the performance of this algorithm is slower than the RC4 algorithm in Java.
I'm use this code for encrypt files in C#
public static class RC4
{
public static byte[] Encrypt(byte[] key, byte[] data)
{
return EncryptOutput(key, data).ToArray();
}
private static byte[] EncryptInitalize(byte[] key)
{
byte[] s = Enumerable.Range(0, 256)
.Select(i => (byte)i)
.ToArray();
for (int i = 0, j = 0; i < 256; i++)
{
j = (j + key[i % key.Length] + s[i]) & 255;
Swap(s, i, j);
}
return s;
}
private static IEnumerable<byte> EncryptOutput(byte[] key, IEnumerable<byte> data)
{
byte[] s = EncryptInitalize(key);
int i = 0;
int j = 0;
return data.Select((b) =>
{
i = (i + 1) & 255;
j = (j + s[i]) & 255;
Swap(s, i, j);
return (byte)(b ^ s[(s[i] + s[j]) & 255]);
});
}
private static void Swap(byte[] s, int i, int j)
{
byte c = s[i];
s[i] = s[j];
s[j] = c;
}
}
I need to encrypt a file in C # and decrypt this file with java, but found no implementation for both languages.

This solution implemented by Michael Remijan showed better performance to decrypt files using AES. Encrypt and Decrypt files for I implemented just a string conversion to byte array.
Java Code
package org.ferris.aes.crypto;
import java.io.UnsupportedEncodingException;
import java.security.Key;
import java.security.spec.KeySpec;
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;
import org.apache.commons.codec.binary.Base64;
/**
*
* #author Michael Remijan mjremijan#yahoo.com #mjremijan
*/
public class AesBase64Wrapper {
private static String IV = "IV_VALUE_16_BYTE";
private static String PASSWORD = "PASSWORD_VALUE";
private static String SALT = "SALT_VALUE";
public String encryptAndEncode(String raw) {
try {
Cipher c = getCipher(Cipher.ENCRYPT_MODE);
byte[] encryptedVal = c.doFinal(getBytes(raw));
String s = getString(Base64.encodeBase64(encryptedVal));
return s;
} catch (Throwable t) {
throw new RuntimeException(t);
}
}
public String decodeAndDecrypt(String encrypted) throws Exception {
byte[] decodedValue = Base64.decodeBase64(getBytes(encrypted));
Cipher c = getCipher(Cipher.DECRYPT_MODE);
byte[] decValue = c.doFinal(decodedValue);
return new String(decValue);
}
private String getString(byte[] bytes) throws UnsupportedEncodingException {
return new String(bytes, "UTF-8");
}
private byte[] getBytes(String str) throws UnsupportedEncodingException {
return str.getBytes("UTF-8");
}
private Cipher getCipher(int mode) throws Exception {
Cipher c = Cipher.getInstance("AES/CBC/PKCS5Padding");
byte[] iv = getBytes(IV);
c.init(mode, generateKey(), new IvParameterSpec(iv));
return c;
}
private Key generateKey() throws Exception {
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
char[] password = PASSWORD.toCharArray();
byte[] salt = getBytes(SALT);
KeySpec spec = new PBEKeySpec(password, salt, 65536, 128);
SecretKey tmp = factory.generateSecret(spec);
byte[] encoded = tmp.getEncoded();
return new SecretKeySpec(encoded, "AES");
}
}
C# Code
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Security.Cryptography;
namespace EncryptDecryptTest
{
class Program
{
class AesBase64Wrapper
{
private static string IV = "IV_VALUE_16_BYTE";
private static string PASSWORD = "PASSWORD_VALUE";
private static string SALT = "SALT_VALUE";
public static string EncryptAndEncode(string raw)
{
using (var csp = new AesCryptoServiceProvider())
{
ICryptoTransform e = GetCryptoTransform(csp, true);
byte[] inputBuffer = Encoding.UTF8.GetBytes(raw);
byte[] output = e.TransformFinalBlock(inputBuffer, 0, inputBuffer.Length);
string encrypted = Convert.ToBase64String(output);
return encrypted;
}
}
public static string DecodeAndDecrypt(string encrypted)
{
using (var csp = new AesCryptoServiceProvider())
{
var d = GetCryptoTransform(csp, false);
byte[] output = Convert.FromBase64String(encrypted);
byte[] decryptedOutput = d.TransformFinalBlock(output, 0, output.Length);
string decypted = Encoding.UTF8.GetString(decryptedOutput);
return decypted;
}
}
private static ICryptoTransform GetCryptoTransform(AesCryptoServiceProvider csp, bool encrypting)
{
csp.Mode = CipherMode.CBC;
csp.Padding = PaddingMode.PKCS7;
var spec = new Rfc2898DeriveBytes(Encoding.UTF8.GetBytes(PASSWORD), Encoding.UTF8.GetBytes(SALT), 65536);
byte[] key = spec.GetBytes(16);
csp.IV = Encoding.UTF8.GetBytes(IV);
csp.Key = key;
if (encrypting)
{
return csp.CreateEncryptor();
}
return csp.CreateDecryptor();
}
}
static void Main(string[] args)
{
string encryptMe;
string encrypted;
string decrypted;
encryptMe = "please encrypt me";
Console.WriteLine("encryptMe = " + encryptMe);
encrypted = AesBase64Wrapper.EncryptAndEncode(encryptMe);
Console.WriteLine("encypted: " + encrypted);
decrypted = AesBase64Wrapper.DecodeAndDecrypt(encrypted);
Console.WriteLine("decrypted: " + decrypted);
Console.WriteLine("press any key to exit....");
Console.ReadKey();
}
}
}

Based on your comments, I am assuming you want to know how to speed up your encryption / decryption process, and changing the main algorithm is not mandatory.
You could look at different modes for AES. For example, AES in counter (CTR) mode is significantly faster than cipher block chaining (CBC) which is often used.
Try creating your cipher like
Cipher myCipher = Cipher.getInstance("AES/CTR/NoPadding");
and you should see a performance increase. Additionally, using NoPadding will keep the size the same as the plaintext.
(Yes, I know that CTR mode turn AES into a stream cipher, never mind my comment)
UPDATE
I have used this in the past along these lines:
Key key = new SecretKeySpec(yourKeyValue, "AES");
Cipher enc = Cipher.getInstance("AES/CTR/NoPadding");
enc.init(Cipher.ENCRYPT_MODE, key);
// Get the IV that was generated
byte[] iv = enc.getIV();
// Encrypt your data
...
Cipher dec = Cipher.getInstance("AES/CTR/NoPadding");
dec.init(Cipher.DECRYPT_MODE, key, new IvParameterSpec(iv));
// Decrypt your data
...

HMAC in Ruby from Java

I am trying to write have the following java function in ruby:
public static byte[] hmac_sha1(byte[] keyBytes, byte[] text)
throws NoSuchAlgorithmException, InvalidKeyException
{
// try {
Mac hmacSha1;
try {
hmacSha1 = Mac.getInstance("HmacSHA1");
} catch (NoSuchAlgorithmException nsae) {
hmacSha1 = Mac.getInstance("HMAC-SHA-1");
}
SecretKeySpec macKey = new SecretKeySpec(keyBytes, "RAW");
hmacSha1.init(macKey);
System.out.println("Algorithm [" + macKey.getAlgorithm() + "] key [" + Helper.bytesToString(macKey.getEncoded()) + "]");
System.out.println("Final text: " + Helper.bytesToString(text));
byte[] hash = hmacSha1.doFinal(text);
System.out.println("Hash: " + Helper.bytesToString(hash));
return hash;
}
I added the System.out.println, here is the output:
Algorithm [RAW] key [3132333435363738393031323334353637383930]
Final text: 0000000000000000
Hash: cc93cf18508d94934c64b65d8ba7667fb7cde4b0
Now in ruby I try
require 'openssl'
#
# text: 0000000000000000
# Key bytes: 3132333435363738393031323334353637383930
# Wanted hash = cc93cf18508d94934c64b65d8ba7667fb7cde4b0
digest = OpenSSL::Digest::Digest.new('sha1')
secret = "12345678901234567890"
secret2 = "3132333435363738393031323334353637383930"
text = "0000000000000000"
puts OpenSSL::HMAC.hexdigest(digest, secret, text)
puts OpenSSL::HMAC.hexdigest(digest, secret, "0")
puts OpenSSL::HMAC.hexdigest(digest, secret2, "0")
puts OpenSSL::HMAC.hexdigest(digest, secret2, text)
puts "Wanted hash: cc93cf18508d94934c64b65d8ba7667fb7cde4b0"
None of the hashes match, I know it's something to do with encodings etc. How can I match the java HMAC ?

Actually, I ended up using an utility class from from commons-codec-1.5.jar, as follows:
import org.apache.commons.codec.binary.Hex;
// (...)
Hex.encodeHexString(rawBytes);

Java code:
import java.io.IOException;
import java.io.File;
import java.io.DataInputStream;
import java.io.FileInputStream ;
import java.lang.reflect.UndeclaredThrowableException;
import java.security.GeneralSecurityException;
import java.security.NoSuchAlgorithmException;
import java.security.InvalidKeyException;
import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
public class Stack
{
public static String hashToHexString(byte[] hash)
{
StringBuffer hexString = new StringBuffer();
for (int i = 0; i 0) {
hexString.append('0');
}
hexString.append(hexByte);
}
return hexString.toString();
}
public static void main(String[] args)
throws NoSuchAlgorithmException, InvalidKeyException
{
String secret = "12345678901234567890";
byte[] keyBytes = secret.getBytes();
String movingFact = "0";
byte[] text = movingFact.getBytes();
Mac hmacSha1;
try {
hmacSha1 = Mac.getInstance("HmacSHA1");
} catch (Exception nsae) {
hmacSha1 = Mac.getInstance("HMAC-SHA-1");
}
SecretKeySpec macKey = new SecretKeySpec(keyBytes, "RAW");
hmacSha1.init(macKey);
byte[] hash = hmacSha1.doFinal(text);
String hexString = hashToHexString(hash);
System.out.println(hexString);
}
}
Ruby code:
require 'openssl'
digest = OpenSSL::Digest::Digest.new('sha1')
secret = "12345678901234567890"
movingFactor = "0"
hash = OpenSSL::HMAC.hexdigest(digest, secret, movingFactor)
puts "Hash: #{hash}"
output:
Java:
DANIELs-MacBook-Air:del dani$ javac Stack.java
DANIELs-MacBook-Air:del dani$ java Stack
32a67f374525d32d0ce13e3db42b5b4a3f370cce
Ruby:
DANIELs-MacBook-Air:del dani$ ruby Stack.rb
Hash: 32a67f374525d32d0ce13e3db42b5b4a3f370cce
Done, the problem was that the java version was not translated into hexstrings properly.

Just a compiling version of the accepted answer if anybody else needs it.
public static void main(String[] args) throws InvalidKeyException, NoSuchAlgorithmException {
String secret = "12345678901234567890";
byte[] text = "0".getBytes();
Mac hmacSha1 = Mac.getInstance("HmacSHA1");
SecretKeySpec macKey = new SecretKeySpec(secret.getBytes(), "HmacSHA1");
hmacSha1.init(macKey);
byte[] hash = hmacSha1.doFinal(text);
String hexString = toHexString(hash);
System.out.println(hexString);
}
private static String toHexString(final byte[] hash) {
Formatter formatter = new Formatter();
for (byte b : hash) {
formatter.format("%02x", b);
}
return formatter.toString();
}