I am using AES as an encryption technique. While decrypting my encrypted string I am facing this StringIndexOutOfBoundsException String index out of range : -3. Can you tell me why am I facing this? is it related BASE64 encoding that I used?
Code for decryption:
Key key = generateKey();
Cipher c = Cipher.getInstance(ALGO);
c.init(Cipher.DECRYPT_MODE, key);
String salt = "some salt";
String dValue = null;
String valueToDecrypt = encryptedData;
for (int i = 0; i < 2; i++) {
byte[] decordedValue = Base64.decodeBase64(valueToDecrypt);
byte[] decValue = c.doFinal(decordedValue);
dValue = new String(decValue).substring(salt.length());
valueToDecrypt = dValue;
}
Code for Encryption :
Key key = generateKey();
Cipher c = Cipher.getInstance(ALGO);
c.init(Cipher.ENCRYPT_MODE, key);
String salt = "some salt";
String valueToEnc = null;
String eValue = Data;
for (int i = 0; i < 2; i++) {
valueToEnc = salt + eValue;
byte[] encValue = c.doFinal(valueToEnc.getBytes(UNICODE_FORMAT));
eValue =new String(Base64.encodeBase64(encValue));
}
Reference : http://www.digizol.com/2009/10/java-encrypt-decrypt-jce-salt.html
Related
I am trying to covert a c# encryption method to java. It is Triple DES with MD5 hash in ECB mode and I am having a hard time finding the java equivalent. The hashes do not match when I try to run them
Below is the c# code
public string Encrypt(string value, string key)
{
string encrypted;
var hashmd5 = new MD5CryptoServiceProvider();
var des = new TripleDESCryptoServiceProvider();
des.Key = hashmd5.ComputeHash(ASCIIEncoding.ASCII.GetBytes(key));
des.Mode = CipherMode.ECB; //CBC, CFB
var buff = ASCIIEncoding.ASCII.GetBytes(value);
encrypted = Convert.ToBase64String(des.CreateEncryptor().TransformFinalBlock(buff, 0, buff.Length));
return encrypted;
}
Here is the Java Code
public String encryptSession (String session, String sessionEncryptionKey) throws Exception {
MessageDigest md = MessageDigest.getInstance("MD5");
byte[] hash = EncodingUtils.getAsciiBytes(sessionEncryptionKey);
byte[] digestOfPassword = md.digest(hash);
byte[] keyBytes = Arrays.copyOf(digestOfPassword, 24);
for (int j = 0, k = 16; j < 8;) {
keyBytes[k++] = keyBytes[j++];
}
SecretKey key = new SecretKeySpec(keyBytes, "DESede");
Cipher cipher = Cipher.getInstance("DESede/ECB/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, key);
byte[] sessionBytes = EncodingUtils.getAsciiBytes(session);
byte[] buf = cipher.doFinal(sessionBytes);
byte[] base64Bytes = Base64.getEncoder().encode(buf);
String base64EncryptedString = new String(base64Bytes);
return base64EncryptedString;
}
I have got this code from Server guys:
public string Encryption(string PlainText)
{
string key = "twelve_digit_key";
TripleDES des = CreateDES(key);
ICryptoTransform ct = des.CreateEncryptor();
byte[] input = Encoding.Unicode.GetBytes(PlainText);
byte[] buffer = ct.TransformFinalBlock(input, 0, input.Length);
return Convert.ToBase64String(buffer);
}
static TripleDES CreateDES(string key)
{
MD5 md5 = new MD5CryptoServiceProvider();
TripleDES des = new TripleDESCryptoServiceProvider();
des.Key = md5.ComputeHash(Encoding.Unicode.GetBytes(key));
des.IV = new byte[des.BlockSize / 8];
return des;
}
This is my code against above :
public String encryptDES(String message) throws Exception {
final MessageDigest md = MessageDigest.getInstance("md5");
final byte[] digestOfPassword = md.digest(getNativeKey3().getBytes("utf-8"));
final byte[] keyBytes = Arrays.copyOf(digestOfPassword, 24);
for (int j = 0, k = 16; j < 8; ) {
keyBytes[k++] = keyBytes[j++];
}
final SecretKey key = new SecretKeySpec(digestOfPassword, "DESede");
final IvParameterSpec iv = new IvParameterSpec(new byte[8]);
final Cipher cipher = Cipher.getInstance("DESede/CBC/PKCS7Padding");
cipher.init(Cipher.ENCRYPT_MODE, key, iv);
final byte[] plainTextBytes = message.getBytes("utf-8");
final byte[] cipherText = cipher.doFinal(plainTextBytes);
return Base64.encodeToString(cipherText, Base64.DEFAULT)
.replace("\n", "")
.replace("\r", "");
}
Problem :
First Code gives below result :
Encrypted Text for 121212 is VvRQkSUj5SQ69mGXsL+h6w==
But Second Code returns this :
Encrypted Text for 121212 is 2STVJSd1mnw=
Observations :
When I increase the plainttext to 10 digits I am getting 24 digit cipher text
Can any one help me in this:
Thanks in Advance
You've been fooled by the badly named Unicode class, which actually specifies UTF-16LE rather than UTF-8.
You can use StandardCharsets.UTF_16LE for specifying the encoding rather than the string; this saves you from one exception to handle.
If there are still issues with the length (test!) then you may have to deal with the Byte Order Mark or BOM - but I don't think so.
I received an encrypted string from Java, and I can see the Java encrypted source code.
I wrote the decryption code in C#. But always report an error at "FlushFinalBlock". Error message: "System.Security.Cryptography.CryptographicException. Additional information: Incorrect data."
Can any body point out where the problem is in my C# code?
this is java code:
private static byte[] coderByDES(byte[] plainText, String key, int mode)
throws InvalidKeyException, InvalidKeySpecException,
NoSuchAlgorithmException, NoSuchPaddingException,
BadPaddingException, IllegalBlockSizeException,
UnsupportedEncodingException {
SecureRandom sr = new SecureRandom();
byte[] resultKey = makeKey(key);
DESKeySpec desSpec = new DESKeySpec(resultKey);
SecretKey secretKey = SecretKeyFactory.getInstance("DES").generateSecret(desSpec);
Cipher cipher = Cipher.getInstance("DES");
cipher.init(mode, secretKey, sr);
return cipher.doFinal(plainText);
}
private static byte[] makeKey(String key)
throws UnsupportedEncodingException {
byte[] keyByte = new byte[8];
byte[] keyResult = key.getBytes("UTF-8");
for (int i = 0; i < keyResult.length && i < keyByte.length; i++) {
keyByte[i] = keyResult[i];
}
return keyByte;
}
private static String byteArr2HexStr(byte[] arrB) {
int iLen = arrB.length;
StringBuilder sb = new StringBuilder(iLen * 2);
for (int i = 0; i < iLen; i++) {
int intTmp = arrB[i];
while (intTmp < 0) {
intTmp = intTmp + 256;
}
if (intTmp < 16) {
sb.append("0");
}
sb.append(Integer.toString(intTmp, 16));
}
return sb.toString();
}
this is C# code:
public static string DecryptForDES(string input, string key)
{
byte[] inputByteArray = HexStr2ByteArr(input);
byte[] buffArray = null;
using (DESCryptoServiceProvider des = new DESCryptoServiceProvider())
{
des.Key = Encoding.UTF8.GetBytes(key);
des.IV = Encoding.UTF8.GetBytes(key);
des.Mode = System.Security.Cryptography.CipherMode.ECB;
des.Padding = PaddingMode.PKCS7;
System.IO.MemoryStream ms = new System.IO.MemoryStream();
using (CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write))
{
cs.Write(inputByteArray, 0, inputByteArray.Length);
cs.FlushFinalBlock();//
cs.Close();
}
buffArray = ms.ToArray();
ms.Close();
}
string str = string.Empty;
if (buffArray != null)
{
str = Encoding.UTF8.GetString(buffArray);
}
return str;
}
public static byte[] HexStr2ByteArr(string strIn)
{
byte[] arrB = Encoding.UTF8.GetBytes(strIn);
int iLen = arrB.Length;
byte[] arrOut = new byte[iLen / 2];
byte[] arrTmp = new byte[2];
for (int i = 0; i < iLen; i = i + 2)
{
string strTmp = Encoding.UTF8.GetString(arrB, i, 2);
arrOut[i / 2] = (byte)Convert.ToInt32(strTmp, 16);
}
return arrOut;
}
Both, the Java encryption part and the C# decryption part work on my machine if the passwords match. Otherwise a System.Security.Cryptography.CryptographicException: 'Bad Data' is thrown. To get the password match replace in the C#-method DecryptForDES
des.Key = Encoding.UTF8.GetBytes(key);
with
des.Key = MakeKey(key);
with the C#-method:
private static byte[] MakeKey(String key)
{
byte[] keyByte = new byte[8];
byte[] keyResult = Encoding.UTF8.GetBytes(key);
for (int i = 0; i<keyResult.Length && i<keyByte.Length; i++) {
keyByte[i] = keyResult[i];
}
return keyByte;
}
corresponding to the Java-method makeKey(String key).
Moreover, remove in the C#-method DecryptForDES
des.IV = Encoding.UTF8.GetBytes(key);
since the ECB-mode doesn't use an IV.
In the following testcase
coderByDES("This is a plain text that needs to be encrypted...", "This is the key used for encryption...", Cipher.ENCRYPT_MODE);
returns the byte-array
a47b1b2c90fb3b7a0ab1f51f328ff55aae3c1eb7789c31c28346696a8b1f27c7413c14e68fe977d3235b5a6f63c07d7a95d912ff22f17ad6
and
DecryptForDES("a47b1b2c90fb3b7a0ab1f51f328ff55aae3c1eb7789c31c28346696a8b1f27c7413c14e68fe977d3235b5a6f63c07d7a95d912ff22f17ad6", "This is the key used for encryption...");
returns the correct plain text.
By the way: As Flydog57 already stated DES is insecure (https://en.wikipedia.org/wiki/Data_Encryption_Standard). And also the ECB mode is not secure (https://crypto.stackexchange.com/questions/20941/why-shouldnt-i-use-ecb-encryption).
Better choices are AES (https://en.wikipedia.org/wiki/Advanced_Encryption_Standard) with CBC or GCM mode (https://crypto.stackexchange.com/questions/2310/what-is-the-difference-between-cbc-and-gcm-mode).
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 have a PHP servor which decrypt data in 3DES with the CFB Mode
I encrypt in PHP :
$montant = "500";
$message_crypte = mcrypt_encrypt(MCRYPT_3DES, "N4y1FRDRJ7wn7eJNnWaahCIS", $montant, ,CRYPT_MODE_CFB, "NCNPJDcR");
$montant = base64_encode($message_crypte);
This script in PHP is OK with other system.
And I want to encrypt in Java :
public class CryptData {
private KeySpec keySpec;
private SecretKey key;
private IvParameterSpec iv;
public CryptData(String keyString, String ivString) {
try {
final MessageDigest md = MessageDigest.getInstance("md5");
final byte[] digestOfPassword = md.digest(Base64
.decodeBase64(keyString.getBytes("ISO-8859-1")));
final byte[] keyBytes = Arrays.copyOf(digestOfPassword, 24);
for (int j = 0, k = 16; j < 8;) {
keyBytes[k++] = keyBytes[j++];
}
//keySpec = new DESedeKeySpec(keyBytes);
keySpec = new DESedeKeySpec(keyString.getBytes());
key = SecretKeyFactory.getInstance("DESede")
.generateSecret(keySpec);
iv = new IvParameterSpec(ivString.getBytes());
} catch (Exception e) {
e.printStackTrace();
}
}
public String encrypt(String value) {
try {
Cipher ecipher = Cipher.getInstance("DESede/CFB/NoPadding");
//"SunJCE");
ecipher.init(Cipher.ENCRYPT_MODE, key, iv);
if (value == null)
return null;
// Encode the string into bytes using utf-8
byte[] valeur = value.getBytes("ISO-8859-1");
//byte[] utf8 = value.getBytes();
// Encrypt
byte[] enc = ecipher.doFinal(valeur);
// Encode bytes to base64 to get a string
return new String(Base64.encodeBase64(enc), "ISO-8859-1");
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
}
I have not the same result in PHP and in Java
How modify Java treatment to obtain the same result as PHP?
The answer is:
Cipher ecipher = Cipher.getInstance("DESede/CFB8/NoPadding");
I need to use "CFB8"