Develop Reference

Java - Decryption : javax.crypto.BadPaddingException

I get this warning:
javax.crypto.BadPaddingException: Given final block not properly padded. Such issues can arise if a bad key is used during decryption.
Any ideas what causes this? Here are my encryption and decryption code. I have looked at a variety of different answers on StackOverflow but I was unable to find one that actually works.
private static Cipher ecipher;
private static Cipher dcipher;
private static SecretKey key;
public static void Menu() {
try {
// generate secret key using DES algorithm
key = KeyGenerator.getInstance("DES").generateKey();
ecipher = Cipher.getInstance("DES");
dcipher = Cipher.getInstance("DES");
// initialize the ciphers with the given key
ecipher.init(Cipher.ENCRYPT_MODE, key);
dcipher.init(Cipher.DECRYPT_MODE, key);
} catch (NoSuchAlgorithmException e) {
System.out.println("No Such Algorithm:" + e.getMessage());
return;
} catch (NoSuchPaddingException e) {
System.out.println("No Such Padding:" + e.getMessage());
return;
} catch (InvalidKeyException e) {
System.out.println("Invalid Key:" + e.getMessage());
return;
}
}
public static String encrypt(String WordToEncrypt) {
Menu();
try {
// encode the string into a sequence of bytes using the named charset
// storing the result into a new byte array.
byte[] utf8 = WordToEncrypt.getBytes("UTF8");
byte[] enc = ecipher.doFinal(utf8);
// encode to base64
enc = BASE64EncoderStream.encode(enc);
System.out.println(new String(enc));
return new String(enc);
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
public static String decrypt(String WordToDecrypt) {
Menu();
try {
// decode with base64 to get bytes
byte[] dec = BASE64DecoderStream.decode(WordToDecrypt.getBytes());
byte[] utf8 = dcipher.doFinal(dec);
return new String(utf8, "UTF8");
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
}

You call Menu once in the encryption code and once in the decryption code. Since you generate the key randomly for both encryption and decryption, the key will differ and your code will fail.
Don't keep Cipher instances around, preferably not even in fields, but certainly not in class fields. DES is old; too old. Use AES - using DES isn't any easier than AES.

How can we do Triple Decryption in java?

I am using a MOL API for VOUCHER recharges. Which returns a PIN number in response is successful. That PIN number will be an encrypted text and I need to triple decrypt it!
I contacted the API support, They provided with the code below:
byte[] PinBytes = Base64.decodeBase64(encryptedText.getBytes("utf-8"));
byte[] VectorBytes = Base64.decodeBase64(vectorKey.getBytes("utf-8"));
byte[] SecretKeyBytes = Base64.decodeBase64(secretKey.getBytes("utf-8"));
TripleDESProvider = CreateTripleDESCryptographicProvider(VectorBytes, SecretKeyBytes)
DecryptedBytes = TripleDESProvider.Decrypt(PinBytes)
Here VectorBytes and SecretKeyBytes are security keys provided by them and PinBytes are the response PIN number which is encrypted.
I googled while I was not able to get a correct solution with these three parameters. Any help, please?
I tried this:
try
{
String encryptedText = "FN0hbSrVzkqhe+w2rQefAQ==";
String vectorKey = "7EsBtzAJjMg=";
//32 bit key
String secretKey = "08061052989102040806105298910204";
byte[] PinBytes = Base64.decodeBase64(encryptedText.getBytes("utf-8"));
byte[] VectorBytes = Base64.decodeBase64(vectorKey.getBytes("utf-8"));
byte[] SecretKeyBytes = Base64.decodeBase64(secretKey.getBytes("utf-8"));
final MessageDigest md = MessageDigest.getInstance("md5");
final byte[] digestOfPassword = md.digest(SecretKeyBytes);
final byte[] keyBytes = Arrays.copyOf(digestOfPassword, 24);
for (int j = 0, k = 16; j < 8;)
{
keyBytes[k++] = keyBytes[j++];
}
final SecretKey key = new SecretKeySpec(keyBytes, "DESede");
final IvParameterSpec iv = new IvParameterSpec(VectorBytes);
final Cipher decipher = Cipher.getInstance("DESede/CBC/PKCS5Padding");
decipher.init(Cipher.DECRYPT_MODE, key, iv);
//final byte[] encData = new sun.misc.BASE64Decoder().decodeBuffer(message);
final byte[] plainText = decipher.doFinal(PinBytes);
System.out.println(plainText.toString());
}
catch (java.security.InvalidAlgorithmParameterException e) { System.out.println("Invalid Algorithm"); }
catch (javax.crypto.NoSuchPaddingException e) { System.out.println("No Such Padding"); }
catch (java.security.NoSuchAlgorithmException e) { System.out.println("No Such Algorithm"); }
catch (java.security.InvalidKeyException e) { System.out.println("Invalid Key"); }
catch (BadPaddingException e) { System.out.println("Invalid Key");}
catch (IllegalBlockSizeException e) { System.out.println("Invalid Key");}
catch (UnsupportedEncodingException e) { System.out.println("Invalid Key");}
catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Error is Invalid KEY
The document they provide is;
Convert Encrypted Pin into Byte Array from Base64 format
PinBytes = ConvertFromBase64String ("FN0hbSrVzkqhe+w2rQefAQ==")
As Vector Key and Secret Key are provided in Base64 format, thus we need to convert both data into Byte Array as well
VectorBytes = ConvertFromBase64String ("xxxxxxxxx")
SecretKeyBytes = ConvertFromBase64String ("xxxxxxxxxxxx")
Please create your Triple DES Cryptographic Provider and set your IV byte array and Secret Key byte array into your Provider.
TripleDESProvider = CreateTripleDESCryptographicProvider(VectorBytes, SecretKeyBytes)
Please invokes Triple DES Provider decrypt method.
DecryptedBytes = TripleDESProvider.Decrypt(PinBytes)
Finally convert back decrypted bytes back to string.
ConvertToString(DecryptedBytes)
The result should be 8157151550.

I am not sure if this is the right approach but with AES encryption it works. They provided you the vector, use it to initialize the IVParameterSpec, then create Key object and Cipher instance:
// this is the encripted text
byte[] PinBytes = Base64.decodeBase64(encryptedText.getBytes("utf-8"));
byte[] VectorBytes = Base64.decodeBase64(vectorKey.getBytes("utf-8"));
byte[] SecretKeyBytes = Base64.decodeBase64(secretKey.getBytes("utf-8"));
// initialize the vector with the one you receive
IvParameterSpec spec = new IvParameterSpec(VectorBytes);
// create the key. DESede should be correct, but if it doesn't work try also with DES
Key key = new SecretKeySpec(SecretKeyBytes, "DESede");
// Initialize the cipher
Cipher c = Cipher.getInstance("DESede/CBC/PKCS5Padding");
// decrypt the string
c.init(Cipher.DECRYPT_MODE, key, spec);
byte[] decodedDecryptedBytes = c.doFinal(PinBytes);
Base64 object i use is from apache common codec library, but you can use the library you want.

Finally, I Got this answer with same provided secretKey!!
try
{
byte[] PinBytes = Base64.decodeBase64(encryptedText);
byte[] VectorBytes = Base64.decodeBase64(vectorKey);
byte[] SecretKeyBytes = Base64.decodeBase64(secretKey);
// initialize the vector with the one you receive
IvParameterSpec spec = new IvParameterSpec(VectorBytes);
// create the key. DESede should be correct, but if it doesn't work try also with DES
Key key = new SecretKeySpec(SecretKeyBytes, "DESede");
// Initialize the cipher
Cipher c = Cipher.getInstance("DESede/CBC/PKCS5Padding");
// decrypt the string
c.init(Cipher.DECRYPT_MODE, key, spec);
byte[] decodedDecryptedBytes = c.doFinal(PinBytes);
return new String(decodedDecryptedBytes, "UTF-8");
}
catch (java.security.InvalidAlgorithmParameterException e) { System.out.println("Invalid Algorithm"); }
catch (javax.crypto.NoSuchPaddingException e) { System.out.println("No Such Padding"); }
catch (java.security.NoSuchAlgorithmException e) { System.out.println("No Such Algorithm"); }
catch (java.security.InvalidKeyException e) { System.out.println("InvalidKeyException : Invalid Key"); }
catch (BadPaddingException e) { System.out.println("BadPaddingException : Invalid Key");}
catch (IllegalBlockSizeException e) { System.out.println("IllegalBlockSizeException : Invalid Key");}
catch (UnsupportedEncodingException e) { System.out.println("UnsupportedEncodingException : Invalid Key");}
catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
The Mistake was doing this:
byte[] SecretKeyBytes = Base64.decodeBase64(secretKey.getBytes("utf-8"));
I don't know why this happens! But by removing that I got the answer!!

Decrypt a string with DES in PHP that's been encrypted by Java

I've been banging my head against the wall trying to figure out exactly how to format everything to decrypt this string in PHP that's been encrypted in a custom Java class.
Here's the relevent functions from the Java class. The "salt" variable is a class variable byte array set earlier:
public DesEncrypter(String passPhrase) {
try {
// Create the key
KeySpec keySpec = new PBEKeySpec(passPhrase.toCharArray(), salt,
iterationCount);
SecretKey key = SecretKeyFactory.getInstance("PBEWithMD5AndDES")
.generateSecret(keySpec);
ecipher = Cipher.getInstance(key.getAlgorithm());
dcipher = Cipher.getInstance(key.getAlgorithm());
// Prepare the parameter to the ciphers
AlgorithmParameterSpec paramSpec = new PBEParameterSpec(salt,
iterationCount);
// Create the ciphers
ecipher.init(Cipher.ENCRYPT_MODE, key, paramSpec);
dcipher.init(Cipher.DECRYPT_MODE, key, paramSpec);
} catch (java.security.InvalidAlgorithmParameterException e) {
} catch (java.security.spec.InvalidKeySpecException e) {
} catch (javax.crypto.NoSuchPaddingException e) {
} catch (java.security.NoSuchAlgorithmException e) {
} catch (java.security.InvalidKeyException e) {
}
}
public String encrypt(String str) {
try {
// Encode the string into bytes using utf-8
byte[] utf8 = str.getBytes("UTF8");
// Encrypt
byte[] enc = ecipher.doFinal(utf8);
// Encode bytes to base64 to get a string
return new sun.misc.BASE64Encoder().encode(enc);
} catch (javax.crypto.BadPaddingException e) {
} catch (IllegalBlockSizeException e) {
} catch (UnsupportedEncodingException e) {
}
return null;
}
public String decrypt(String str) {
try {
// Decode base64 to get bytes
byte[] dec = new sun.misc.BASE64Decoder().decodeBuffer(str);
// Decrypt
byte[] utf8 = dcipher.doFinal(dec);
// Decode using utf-8
return new String(utf8, "UTF8");
} catch( Exception ex) {
ex.printStackTrace(System.err);
}
return null;
}
And here's what I have so far in PHP (FYI, I'm using this encryption library in PHP https://github.com/phpseclib/phpseclib):
$app->get('/decrypt', function () use ($app) {
$data = '3aCRLRd3srA/QF4MQb0D+P==';
$salt = pack('nvc*', 0xB7, 0x9A, 0xC1, 0x34, 0x26, 0x89, 0xW3, 0x30);
$secret = "secret";
$keyLength = 16;
$cipher = new Crypt_DES(CRYPT_DES_MODE_CBC);
$cipher->setPassword($secret, 'pbkdf2', 'md5', $salt, $keyLength);
var_dump($cipher->decrypt($data));
});
Right now it's dumping out a bunch of binary, which I've tried base64_decoding, but that doesn't do anything either.

If key.getAlgorithm() is "DES" then you need to provide a fully specified Cipher name like "DES/CBC/PKCS5Padding".
You will also need to provide the IV if it is non-null. Usually the IV is prepended to the ciphertext.
You can get the IV with cipher.getIV() and set with $cipher->setIV('...');.

InvalidKeyException java.security.InvalidKeyException: No installed provider supports this key: (null)

I have two classes, one is main class and another is the implementation of AES.
However, in my AES class i have a method to decrypt a string, but whenever i run it, it gives an exception
My encryption method works just fine but my decryption method doesn't work as expected.
The code
private Cipher aesCipherForDecryption;
String strDecryptedText = new String();
public String decryptAES(final String ciphertext) {
try {
aesCipherForDecryption = Cipher.getInstance("AES/CBC/PKCS5PADDING");
aesCipherForDecryption.init(Cipher.DECRYPT_MODE, secretKey, new IvParameterSpec(iV));
byte[] byteDecryptedText = aesCipherForDecryption.doFinal(byteCipherText);
strDecryptedText = new String(byteDecryptedText);
} catch (IllegalBlockSizeException e) {
System.out.print("IllegalBlockSizeException " +e);
} catch (BadPaddingException e) {
System.out.print("BadPaddingException "+e);
} catch (NoSuchAlgorithmException e) {
System.out.print("NoSuchAlgorithmException "+ e);
} catch (NoSuchPaddingException e) {
System.out.print("NoSuchPaddingException "+e);
} catch (InvalidKeyException e) {
System.out.print("InvalidKeyException "+e);
} catch (InvalidAlgorithmParameterException e) {
System.out.print("InvalidAlgorithmParameterException "+e);
}
System.out.println("\nDecrypted Text message is " + strDecryptedText);
return strDecryptedText;
}
The error this method outputs is
InvalidKeyException java.security.InvalidKeyException: No installed provider supports this key: (null)
UPDATE #1:
So i have updated the code as the following
public String decryptAES(byte[] ciphertext) {
String strDecryptedText = new String();
try {
byte[] byteDecryptedText = aesCipherForDecryption.doFinal(ciphertext);
strDecryptedText = new String(byteDecryptedText);
} catch (IllegalBlockSizeException e) {
System.out.print("IllegalBlockSizeException "+e);
e.printStackTrace();
} catch (BadPaddingException e) {
System.out.print("BadPaddingException "+e);
e.printStackTrace();
}
System.out.println("\nDecrypted Text message is " + strDecryptedText);
return strDecryptedText;
}
and in the main class i have this line
byte [] byteciphertext = ciphertext.getBytes();
just to convert the string to bytes
is it correct? i'm still having
IllegalBlockSizeException javax.crypto.IllegalBlockSizeException: Input length must be multiple of 16 when decrypting with padded cipherjavax.crypto.IllegalBlockSizeException: Input length must be multiple of 16 when decrypting with padded cipher
Could someone help me fix this issue?
Thank you.

secretKey is clearly null.
Other problems:
You aren't using the input parameter cipherText.
The input parameter cipherText should be a byte[], not a String: cipher text is binary, and String is not a container for binary data.
The result string strDecryptedText should be a local variable, not a member variable.

Encrypting and decrypting a zip file in Android?

I am using this code: http://examples.javacodegeeks.com/core-java/crypto/encrypt-decrypt-file-stream-with-des for encrypting my zip files used in android app .It is working really fine with the zip files when I tried it using java code ,But when I tried same methods in Android app - It decrypts the file but file I get is corrupted and unable to open it.
Log:
04-19 10:58:25.711: W/System.err(6752): net.lingala.zip4j.exception.ZipException: zip headers not found. probably not a zip file
04-19 10:58:25.721: W/System.err(6752): at net.lingala.zip4j.core.HeaderReader.readEndOfCentralDirectoryRecord(HeaderReader.java:122)
And when I try to open the same file on Windows with winzip it displays:
Does not appear to be a valid archive file.
Update::
public class EncryptDecryptFileStreamWithDES {
private static Cipher ecipher;
private static Cipher dcipher;
// 8-byte initialization vector
private static byte[] iv = {
(byte)0xB2, (byte)0x12, (byte)0xD5, (byte)0xB2,
(byte)0x44, (byte)0x21, (byte)0xC3, (byte)0xC3
};
public static void call() {
try {
SecretKey key = KeyGenerator.getInstance("DES").generateKey();
AlgorithmParameterSpec paramSpec = new IvParameterSpec(iv);
ecipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
dcipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
ecipher.init(Cipher.ENCRYPT_MODE, key, paramSpec);
dcipher.init(Cipher.DECRYPT_MODE, key, paramSpec);
// encrypt(new FileInputStream("C:\\Users\\Admin\\Desktop\\zipped\\4.zip"), new FileOutputStream("C:\\Users\\Admin\\Desktop\\zipped\\4.dat"));
// decrypt(new FileInputStream("C:\\Users\\Admin\\Desktop\\zipped\\4.dat"), new FileOutputStream("C:\\Users\\Admin\\Desktop\\zipped\\4new.zip"));
//}
//catch (FileNotFoundException e) {
//System.out.println("File Not Found:" + e.getMessage());
//return;
}
catch (InvalidAlgorithmParameterException e) {
System.out.println("Invalid Alogorithm Parameter:" + e.getMessage());
return;
}
catch (NoSuchAlgorithmException e) {
System.out.println("No Such Algorithm:" + e.getMessage());
return;
}
catch (NoSuchPaddingException e) {
System.out.println("No Such Padding:" + e.getMessage());
return;
}
catch (InvalidKeyException e) {
System.out.println("Invalid Key:" + e.getMessage());
return;
}
}
public static void encrypt(InputStream is, OutputStream os) {
try {
call();
byte[] buf = new byte[1024];
// bytes at this stream are first encoded
os = new CipherOutputStream(os, ecipher);
// read in the clear text and write to out to encrypt
int numRead = 0;
while ((numRead = is.read(buf)) >= 0) {
os.write(buf, 0, numRead);
}
// close all streams
os.close();
}
catch (IOException e) {
System.out.println("I/O Error:" + e.getMessage());
}
}
public static void decrypt(InputStream is, OutputStream os) {
try {
call();
byte[] buf = new byte[1024];
// bytes read from stream will be decrypted
CipherInputStream cis = new CipherInputStream(is, dcipher);
// read in the decrypted bytes and write the clear text to out
int numRead = 0;
while ((numRead = cis.read(buf)) > 0) {
os.write(buf, 0, numRead);
}
// close all streams
cis.close();
is.close();
os.close();
}
catch (IOException e) {
System.out.println("I/O Error:" + e.getMessage());
}
}
}
This is the Class which I am using:

The problem is that you use different keys to encrypt and decrypt the file:
1) You call encrypt(..) from somewhere outside the EncryptDecryptFileStreamWithDES, which in its turn calls your call() method, which initializes new key:
SecretKey key = KeyGenerator.getInstance("DES").generateKey();
2) Then you call decrypt(..), which calls your call() method again and you get new SecretKey.
There is no such a problem in the example you used, there is an opposite order of these methods invocations.
To extend this example you need to hold the key between invocation of encrypt(..) and decrypt(..) and then initialize SecretKeySpec with the key stored:
byte[] keyBytes = KeyGenerator.getInstance("AES").getEncoded();
...
SecretKeySpec skeySpec = new SecretKeySpec(keyBytes, "AES");
Cipher cipher = Cipher.getInstance("AES");
cipher.init(Cipher.DECRYPT_MODE, skeySpec);
Here is a little bit more real-life example.
P.S. As it was mentioned, using DES algorithm is not the best idea, use AES instead.