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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)));
}
}
I have a Java AES 256 encryption code like this :
public class EncryptDecryptTwo {
static {
try {
Field field = Class.forName("javax.crypto.JceSecurity").getDeclaredField("isRestricted");
field.setAccessible(true);
field.set(null, java.lang.Boolean.FALSE);
} catch (Exception ex) {
}
}
private static String keyEnc = "BtDMQ7RfNVoRzJ7GYE32";
// Performs Encryption
public static String encrypt(String plainText) throws Exception {
String passphrase = keyEnc;
byte[] iv = DatatypeConverter.parseHexBinary("2aba86027a6f79dd463b81b0539bacb5");
byte[] salt = DatatypeConverter.parseHexBinary("0f3d1b0d514ca313");
IvParameterSpec ivParameterSpec = new IvParameterSpec(iv);
SecretKeySpec sKey = (SecretKeySpec) generateKeyFromPassword(passphrase, salt);
Cipher c = Cipher.getInstance("AES/CBC/PKCS5Padding");
c.init(Cipher.ENCRYPT_MODE, sKey, ivParameterSpec);
byte[] encryptedData = c.doFinal(plainText.getBytes());
return DatatypeConverter.printBase64Binary(encryptedData);
}
public static SecretKey generateKeyFromPassword(String password, byte[] saltBytes) throws GeneralSecurityException {
KeySpec keySpec = new PBEKeySpec(password.toCharArray(), saltBytes, 1, 256);
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
SecretKey secretKey = keyFactory.generateSecret(keySpec);
return new SecretKeySpec(secretKey.getEncoded(), "AES");
}
public static byte[] hexStringToByteArray(String s) {
int len = s.length();
byte[] data = new byte[len / 2];
for (int i = 0; i < len; i += 2) {
data[i / 2] = (byte) ((Character.digit(s.charAt(i), 16) << 4) + Character.digit(s.charAt(i + 1), 16));
}
return data;
}
}
In this case, I hardcoded the salt bytes and iv bytes just to make sure my coding is encrypt the message right, so it can be read by cryptoJS in another server. But when I send the encrypted text by calling the encrypt method, it is always rejected by the cryptoJS, saying that my encrypted message is not correct
The CryptoJS is in another server and it is like this :
var CryptoJSAesJson = {
stringify: function (cipherParams) {
var j = {ct: cipherParams.cipherText.toString(CryptoJS.enc.Base64)};
if (cipherParams.iv) j.iv = cipherParams.iv.toString();
if (cipherParams.salt) j.s = cipherParams.salt.toString();
return JSON.stringify(j);
},
parse: function (jsonStr) {
var j = JSON.parse(jsonStr);
var cipherParams = CryptoJS.lib.CipherParams.create({ciphertext: CryptoJS.enc.Base64.parse(j.ct)});
if (j.iv) cipherParams.iv = CryptoJS.enc.Hex.parse(j.iv)
if (j.s) cipherParams.salt = CryptoJS.enc.Hex.parse(j.s)
return cipherParams;
}
}
var encrypted = CryptoJS.AES.encrypt(JSON.stringify($scope.loginData.password), __ENV.AES_KEY, { format: CryptoJSAesJson}).toString();
Can anybody help me finding what's wrong in my java code? Thank you very much
Edited :
According to Artjom.B's comment and advise, I tried this :
static {
try {
Field field = Class.forName("javax.crypto.JceSecurity").getDeclaredField("isRestricted");
field.setAccessible(true);
field.set(null, java.lang.Boolean.FALSE);
} catch (Exception ex) {
}
}
public static void main(String[] args) throws UnsupportedEncodingException, GeneralSecurityException {
String plaintext = "someplaintext";
String password = "BtDMQ7RfNVoRzWGjS2DK";
int keySize = 256;
int ivSize = 128;
byte[] salt = DatatypeConverter.parseHexBinary("5ba2b0e0bb968f47"); // yes, for testing, I use a fixed salt
byte[] key = new byte[keySize/8];
byte[] iv = new byte[ivSize/8];
EvpKDF(password.getBytes("UTF-8"), keySize, ivSize, salt, key, iv);
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(key, "AES"), new IvParameterSpec(iv));
byte[] encryptedText = cipher.doFinal((plaintext).getBytes());
System.out.println("SALT : " + DatatypeConverter.printHexBinary(salt));
System.out.println("IV : " + DatatypeConverter.printHexBinary(iv));
System.out.println("CT : " + DatatypeConverter.printBase64Binary(encryptedText));
// I sent salt, IV, and ciphertext to CryptoJS
}
public static byte[] EvpKDF(byte[] password, int keySize, int ivSize, byte[] salt, byte[] resultKey, byte[] resultIv) throws NoSuchAlgorithmException {
return EvpKDF(password, keySize, ivSize, salt, 1, "MD5", resultKey, resultIv);
}
public static byte[] EvpKDF(byte[] password, int keySize, int ivSize, byte[] salt, int iterations, String hashAlgorithm, byte[] resultKey, byte[] resultIv) throws NoSuchAlgorithmException {
keySize = keySize / 32;
ivSize = ivSize / 32;
int targetKeySize = keySize + ivSize;
byte[] derivedBytes = new byte[targetKeySize * 4];
int numberOfDerivedWords = 0;
byte[] block = null;
MessageDigest hasher = MessageDigest.getInstance(hashAlgorithm);
while (numberOfDerivedWords < targetKeySize) {
if (block != null) {
hasher.update(block);
}
hasher.update(password);
block = hasher.digest(salt);
hasher.reset();
// Iterations
for (int i = 1; i < iterations; i++) {
block = hasher.digest(block);
hasher.reset();
}
System.arraycopy(block, 0, derivedBytes, numberOfDerivedWords * 4,
Math.min(block.length, (targetKeySize - numberOfDerivedWords) * 4));
numberOfDerivedWords += block.length/4;
}
System.arraycopy(derivedBytes, 0, resultKey, 0, keySize * 4);
System.arraycopy(derivedBytes, keySize * 4, resultIv, 0, ivSize * 4);
return derivedBytes; // key + iv
}
/**
* Copied from http://stackoverflow.com/a/140861
* */
public static byte[] hexStringToByteArray(String s) {
int len = s.length();
byte[] data = new byte[len / 2];
for (int i = 0; i < len; i += 2) {
data[i / 2] = (byte) ((Character.digit(s.charAt(i), 16) << 4)
+ Character.digit(s.charAt(i+1), 16));
}
return data;
}
But still no avail. The CryptoJS keep saying that I pass an incorrect password.
Can anybody help? Thank you very much
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
...
I searched a lot but I haven't found a good solution how to solve this. I have an app which has to decrypt a long hex string with AES 256.
In order to test it, I created a test method which encrypts a long text into a hex and then convert it back and decrypt it.
If I run this method, I always get the following error: Given final block not properly padded. I receive this error in the decryption method.
The test method looks like so:
#Test
public void testEncAndDecRequestWithHexString() throws UnsupportedEncodingException {
CryptoHelper cryptoHelper = new CryptoHelper("AES256");
String paramStr = "ABCB28BCEE5947B8AECE3386871EC0DF&{D5CA99D2-506B-4864-8971-E87821D6B105}&7523429";
//encrypt the param string
byte[] paramByteEnc = cryptoHelper.encryptBytesToBytes(paramStr.getBytes("ASCII"), PARAM_KEY, PARAM_IV);
//convert it to hex
String encryptedHexStr = cryptoHelper.byteArrayToHexStr(paramByteEnc);
//convert it back to a byte array
byte[] encryptedHexBytes = cryptoHelper.hexStrToByteArray(encryptedHexStr);
// decrypt it
byte[] paramByteDecrypted = cryptoHelper.decryptBytesToBytes(encryptedHexBytes, encryptedHexBytes.length, PARAM_KEY, PARAM_IV);
String decryptedStr = new String(paramByteDecrypted);
assertEquals("ABCB28BCEE5947B8AECE3386871EC0DF&{D5CA99D2-506B-4864-8971-E87821D6B105}&7523429", decryptedStr);
}
The CryptHelper class has following methods:
#Override
public byte[] encryptBytesToBytes(byte[] plainData, byte[] key, byte[] iv) {
try {
initCipher(Cipher.ENCRYPT_MODE, key, iv);
return aesCipher.doFinal(plainData);
} catch (IllegalBlockSizeException | BadPaddingException e) {
log.severe(e.getMessage());
}
return null;
}
#Override
public byte[] decryptBytesToBytes(byte[] encryptedBytes, int length,
byte[] key, byte[] iv) {
try {
initCipher(Cipher.DECRYPT_MODE, key, iv);
return aesCipher.doFinal(encryptedBytes, 0, length);
} catch (IllegalBlockSizeException | BadPaddingException e) {
e.printStackTrace();
}
return null;
}
private void initCipher(int mode, byte[] keyBytes, byte[] ivBytes) {
try {
// create shared secret and init cipher mode
SecretKeySpec secretKeySpec = new SecretKeySpec(keyBytes, "AES");
aesCipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
aesCipher.init(mode == Cipher.ENCRYPT_MODE ? Cipher.ENCRYPT_MODE : Cipher.DECRYPT_MODE, secretKeySpec, new IvParameterSpec(ivBytes));
} catch (InvalidAlgorithmParameterException | NoSuchAlgorithmException | NoSuchPaddingException | InvalidKeyException e) {
e.printStackTrace();
}
}
public String byteArrayToHexStr(byte[] encrypted) {
StringBuilder hex = new StringBuilder();
for (byte b : encrypted) {
hex.append(String.format("%02X", b));
}
return new String(hex.toString());
}
public byte[] hexStrToByteArray(String hex) {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < hex.length() - 1; i += 2) {
String output = hex.substring(i, (i + 2));
int decimal = Integer.parseInt(output, 16);
sb.append((char) decimal);
}
String temp = sb.toString();
return temp.getBytes();
}
I used the same key and initialization vector for the decryption process so the problem is not the wrong key or initialization vector. I am also sure that every function here is doing their job correctly. If you don't use the functions hexStrToByteArray() and byteArrayToHexStr() and just use the encrypted byte for decrypting, it works no problem. I think there is a encoding/decoding problem but I have no idea how to handle it in java. If I use getBytes("UTF-8") and new String(byte[], "UTF-8") I get an IllegalBlockSizeException.
I hope you can help me finding out if I am on the right way and what I did wrong.
This is a clear indication that you shouldn't write library functions if they have already been defined. Use a hex codec from Bouncy Castle, Guava or Apache codec instead (until Oracle finally sees the light and provides one in a java.util package).
If you do implement it yourself, please don't mistake characters for bytes:
public byte[] hexStrToByteArray(String hex) {
ByteArrayOutputStream baos = new ByteArrayOutputStream(hex.length() / 2);
for (int i = 0; i < hex.length(); i += 2) {
String output = hex.substring(i, i + 2);
int decimal = Integer.parseInt(output, 16);
baos.write(decimal);
}
return baos.toByteArray();
}
I am working on AES algorithm, and I have this exception which I couldn't solve.
javax.crypto.BadPaddingException: Given final block not properly padded
at com.sun.crypto.provider.SunJCE_f.b(DashoA13*..)
at com.sun.crypto.provider.SunJCE_f.b(DashoA13*..)
at com.sun.crypto.provider.AESCipher.engineDoFinal(DashoA13*..)
at javax.crypto.Cipher.doFinal(DashoA13*..)
the exception happens in the decryption part.
I initialize the key in a different place from where the decryption algorithm is
KeyGenerator kgen = KeyGenerator.getInstance("AES");//key generation for AES
kgen.init(128); // 192 and 256 bits may not be available
then I pass it with the cipher text which I read from file to the following method
public String decrypt(String message, SecretKey skey) {
byte[] raw = skey.getEncoded();
SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
// Instantiate the cipher
Cipher cipher;
byte[] original = null;
try {
cipher = Cipher.getInstance("AES");
cipher.init(Cipher.DECRYPT_MODE, skeySpec);
System.out.println("Original string: "
+ message);
original = cipher.doFinal(message.trim().getBytes()); //here where I got the exception
String originalString = new String(original);
}
//catches
EDIT
here's the encryption method.
public String encrypt(String message, SecretKey skey) {
byte[] raw = skey.getEncoded();
SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
// Instantiate the cipher
Cipher cipher;
byte[] encrypted = null;
try {
cipher = Cipher.getInstance("AES");
cipher.init(Cipher.ENCRYPT_MODE, skeySpec);
encrypted = cipher.doFinal(message.getBytes());
System.out.println("raw is " + encrypted);
} catches
return asHex(encrypted);
}
and here's the asHex method
public static String asHex(byte buf[]) {
StringBuffer strbuf = new StringBuffer(buf.length * 2);
int i;
for (i = 0; i < buf.length; i++) {
if (((int) buf[i] & 0xff) < 0x10) {
strbuf.append("0");
}
strbuf.append(Long.toString((int) buf[i] & 0xff, 16));
}
return strbuf.toString();
}
Here's where I read the cipher text form the file
static public String readFile(String filePath) {
StringBuilder file = new StringBuilder();
String line = null;
try {
FileReader reader = new FileReader(filePath);
BufferedReader br = new BufferedReader(reader);
if (br != null) {
line = br.readLine();
while (line != null) {
file.append(line);
// System.out.println("line is " + line);
line = br.readLine();
}
}
br.close();
reader.close();
} catch (IOException ex) {
Logger.getLogger(FileManagement.class.getName()).log(Level.SEVERE, null, ex);
}
System.out.println("line is " + file.toString());
return String.valueOf(file);
}
can someone help?
Ok, so the problem is that you are converting the encrypted bytes to a hex string (using the asHex method) but are not converting the hex string back to a byte array correctly for decryption. You can't use getBytes.
You can use the following method to convert a hex string to a byte array:
public static byte[] fromHexString(String s) {
int len = s.length();
byte[] data = new byte[len / 2];
for (int i = 0; i < len; i += 2) {
data[i / 2] = (byte) ((Character.digit(s.charAt(i), 16) << 4)
+ Character.digit(s.charAt(i+1), 16));
}
return data;
}
and then change your decrypt method to use:
original = cipher.doFinal(fromHexString(message));
I did have a Bad Padding Exception and have not been able to find on the internet a solution to my problem. Since I found it after some hard-working hours, I give it here.
My problem was, I was reading a file on my hard drive, and encrypting it through a buffer, always calling the doFinal() method instead of update() method. So when decrypting it, I had padding errors
input = new FileInputStream(file);
output = new FileOutputStream(newFile);
Cipher cipher = Cipher.getInstance("DES");
cipher.init(Cipher.ENCRYPT_MODE, mySecretKey);
byte[] buf = new byte[1024];
count = input.read(buf);
while (count >= 0) {
output.write(cipher.update(buf, 0, count)); // HERE I WAS DOING doFinal() method
count = input.read(buf);
}
output.write(cipher.doFinal()); // AND I DID NOT HAD THIS LINE BEFORE
output.flush();
And when decrypting, with the same method, but with a Cipher init with DECRYPT_MODE
input = new FileInputStream(file);
output = new FileOutputStream(newFile);
Cipher cipher = Cipher.getInstance("DES");
cipher.init(Cipher.DECRYPT_MODE, mySecretKey);
byte[] buf = new byte[1024];
count = input.read(buf);
while (count >= 0) {
output.write(cipher.update(buf, 0, count)); // HERE I WAS DOING doFinal() method
//AND HERE WAS THE BadPaddingExceotion -- the first pass in the while structure
count = input.read(buf);
}
output.write(cipher.doFinal()); // AND I DID NOT HAD THIS LINE BEFORE
output.flush();
With the code written, I no longer have any BadPaddingException.
I may precise that this exception only appears when the original clear file length (obtained through file.length()) is bigger than the buffer. Else, we do not need to pass several times in the while structure, and we can encrypt in one pass with a doFinal() call. That justify the random character of the exception following the size of the file you try to encrypt.
I hope you had a good reading!
I guess the expression message.trim().getBytes() does not return the same bytes which are generated when you encrypted the message. Specially the trim() method could delete the bytes which were added as padding in the encrypted message.
Verify that both the returned array of the doFinal() method during the encryption and the returned array of message.trim().getBytes():
got the same number of bytes (array length)
got the same bytes in the array
KeyPairGenerator kpg = KeyPairGenerator.getInstance("RSA");
kpg.initialize(512);
KeyPair rsaKeyPair = kpg.genKeyPair();
byte[] txt = "This is a secret message.".getBytes();
System.out.println("Original clear message: " + new String(txt));
// encrypt
Cipher cipher;
try
{
cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
cipher.init(Cipher.ENCRYPT_MODE, rsaKeyPair.getPublic());
txt = cipher.doFinal(txt);
}
catch (Throwable e)
{
e.printStackTrace();
return;
}
System.out.println("Encrypted message: " + new String(txt));
// decrypt
try
{
cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
cipher.init(Cipher.DECRYPT_MODE, rsaKeyPair.getPrivate());
txt = cipher.doFinal(txt);
}
catch (Throwable e)
{
e.printStackTrace();
return;
}
System.out.println("Decrypted message: " + new String(txt));
Here is a solution I was able to piece together using a jks keystore with RSA encryption
import javax.crypto.Cipher;
import javax.xml.bind.DatatypeConverter;
import java.security.Key;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.KeyStore;
import java.security.cert.Certificate;
public class Main {
public static void main(String[] args) {
byte[] txt = "This is a secret message for your own eyes only".getBytes();
byte[] encText;
try{
// Load the keystore
KeyStore ks = KeyStore.getInstance(KeyStore.getDefaultType());
char[] password = "keystorePassword".toCharArray();
java.io.FileInputStream fis = new java.io.FileInputStream("/path/to/keystore/myKeyStore.jks");
ks.load(fis, password);
fis.close();
Key rsakey = ks.getKey("mykeyalias", password);
Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
// Encrypt
Certificate cert = ks.getCertificate("mykeyalias");
try
{
cipher.init(Cipher.ENCRYPT_MODE, cert.getPublicKey());
encText = cipher.doFinal(txt);
System.out.println(encText.toString());
}
catch (Throwable e)
{
e.printStackTrace();
return;
}
// Decrypt
cipher.init(Cipher.DECRYPT_MODE, rsakey);
String decrypted = new String(cipher.doFinal(encText));
System.out.println(decrypted);
} catch (Exception e) {
System.out.println("error" + e);
}
}