Actually, I searched lot from internet and in stackoverflow too for this,
Initially I don't used padding in my encryption and decryption,
But Finally I got solution from here
https://stackoverflow.com/a/10775577/1115788
and I updated my code with padding as AES/CBC/PKCS5Padding
and the same error is coming, and last block is not decrypted...
I'm working on this for last two day, but no solution found
my Crypter Code:
package mani.droid.browsedropbox;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.math.BigInteger;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import javax.crypto.Cipher;
import javax.crypto.CipherInputStream;
import javax.crypto.CipherOutputStream;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
public class Crypter {
Cipher encipher;
Cipher decipher;
CipherInputStream cis;
CipherOutputStream cos;
FileInputStream fis;
byte[] ivbytes = new byte[]{(byte)'a', (byte)'b', (byte)'c', (byte)'d', (byte)'e', (byte)'f', (byte)'g', (byte)'h', (byte)'i', (byte)'j', (byte)'k', (byte)'l', (byte)'m', (byte)'n', (byte)'o', (byte)'p'};
IvParameterSpec iv = new IvParameterSpec(ivbytes);
public boolean enCrypt(String key, InputStream is, OutputStream os)
{
try {
byte[] encoded = new BigInteger(key, 16).toByteArray();
SecretKey seckey = new SecretKeySpec(encoded, "AES");
encipher = Cipher.getInstance("AES/CBC/PKCS7Padding");
encipher.init(Cipher.ENCRYPT_MODE, seckey, iv);
cis = new CipherInputStream(is, encipher);
copyByte(cis, os);
return true;
}
catch (InvalidKeyException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (NoSuchPaddingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvalidAlgorithmParameterException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return false;
}
public boolean deCrypt(String key, InputStream is, OutputStream os)
{
try {
byte[] encoded = new BigInteger(key, 16).toByteArray();
SecretKey seckey = new SecretKeySpec(encoded, "AES");
encipher = Cipher.getInstance("AES/CBC/PKCS7Padding");
encipher.init(Cipher.DECRYPT_MODE, seckey, iv);
cos = new CipherOutputStream(os, encipher);
copyByte(is, cos);
//cos.close();
return true;
}
catch (InvalidKeyException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (NoSuchPaddingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvalidAlgorithmParameterException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return false;
}
public void copyByte(InputStream is, OutputStream os) throws IOException
{
byte[] buf = new byte[8192];
int numbytes;
while((numbytes = is.read(buf)) != -1)
{
os.write(buf, 0, numbytes);
os.flush();
}
os.close();
is.close();
}
}
I've had exactly the same problem.
The accepted solution works because you've used cipher mode that does not require padding, but this is not a way crypto-related issues are fixed.
According to the CipherOutputStream documentation, you have to call close() method in order to finalize encryption properly (i.e., padding block is added).
This method invokes the doFinal method of the encapsulated cipher
object, which causes any bytes buffered by the encapsulated cipher to
be processed. The result is written out by calling the flush method of
this output stream.
This method resets the encapsulated cipher object to its initial state
and calls the close method of the underlying output stream.
If you want to preserve OutputStream open even after calling CipherOutputStream.close() method, you can wrap OutputStream to the stream that does not close it. For example:
public class NotClosingOutputStream extends OutputStream {
private final OutputStream os;
public NotClosingOutputStream(OutputStream os) {
this.os = os;
}
#Override
public void write(int b) throws IOException {
os.write(b);
}
#Override
public void close() throws IOException {
// not closing the stream.
}
#Override
public void flush() throws IOException {
os.flush();
}
#Override
public void write(byte[] buffer, int offset, int count) throws IOException {
os.write(buffer, offset, count);
}
#Override
public void write(byte[] buffer) throws IOException {
os.write(buffer);
}
}
Then you can use:
...
cos = new CipherOutputStream(new NotClosingOutputStream(os), encipher);
copyByte(is, cos);
cos.close();
...
Note the os stream does not get closed, you need to do it on your own when appropriate.
Finally I got answer for my own question, with trial and error
Actually here Conflict is I set Padding in encipher = Cipher.getInstance("AES/CBC/PKCS7Padding");
and Set IV with some values.....,
Finally I got Answer only just replaced the Algorithm
From:
AES/CBC/PKCS7Paddinng
To:
AES/CFB8/NoPadding
and its worked like charm...., So I suggest this answer for others who struggling with this problem, if you solved you problem, mention here for others...
I've seen CipherInputStream fail with padding problems too. This behaviour varied across different versions of the JVM. Eg 7u55 32 bit my code worked fine, 7u55 64 bit same code failed... and I also saw failures on later 32 bit JVMs. Workaround was to use byte array methods and avoid CipherInputStream.
Not sure if this is relevant to OP's problem, but this may help someone.
When you repeatedly get that java.io.IOException: last block incomplete in decryption regardless of what you change, check if you are still using the file from some previous run. If your read/write test code appends to that file, you will always get that exception -- unless you delete the corrupt file that you write to.
Using CipherInputStream with padding is possible, switching to NoPadding is a workaround but not a solution.
Padding is applied when CipherInputStream reaches the end of the stream. The important point is that you have to call the read() method of the CipherInputStream at least twice for getting all the data.
The following example demonstrates reading a CipherInputStream with padding:
public static void test() throws Exception {
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
SecureRandom rnd = new SecureRandom();
byte[] keyData = new byte[16];
byte[] iv = new byte[16];
rnd.nextBytes(keyData);
rnd.nextBytes(iv);
SecretKeySpec key = new SecretKeySpec(keyData, "AES");
cipher.init(Cipher.ENCRYPT_MODE, key, new IvParameterSpec(iv));
ByteArrayOutputStream buffer = new ByteArrayOutputStream();
CipherOutputStream out = new CipherOutputStream(buffer, cipher);
byte[] plain = "Test1234567890_ABCDEFG".getBytes();
out.write(plain);
out.flush();
out.close();
byte[] encrypted = buffer.toByteArray();
System.out.println("Plaintext length: " + plain.length);
System.out.println("Padding length : " + (cipher.getBlockSize() - (plain.length % cipher.getBlockSize())));
System.out.println("Cipher length : " + encrypted.length);
cipher.init(Cipher.DECRYPT_MODE, key, new IvParameterSpec(iv));
CipherInputStream in = new CipherInputStream(new ByteArrayInputStream(encrypted), cipher);
buffer = new ByteArrayOutputStream();
byte[] b = new byte[100];
int read;
while ((read = in.read(b)) >= 0) {
buffer.write(b, 0, read);
}
in.close();
// prints Test1234567890_ABCDEFG
System.out.println(new String(buffer.toByteArray()));
}
For those who are struggling with aes encryption / decryption with image file, here is my example, and it works like a charm.
public static String decrypt(String textToDecrypt) {
byte[] dataDecrypted = null;
try {
Cipher cipher = getCipher();
SecretKey key = getKey();
IvParameterSpec iv = getIV();
if(cipher == null) {
return null;
}
cipher.init(Cipher.DECRYPT_MODE, key, iv);
byte[] dataToDecrypt = Base64.decode(textToDecrypt, Base64.NO_WRAP);
ByteArrayInputStream bais = new ByteArrayInputStream(dataToDecrypt);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
// Wrap the output stream
CipherOutputStream cos = new CipherOutputStream(baos, cipher);
// Read bytes
int count = 0;
byte[] buffer = new byte[DEFAULT_BYTE_READ_WRITE_BLOCK_BUFFER_SIZE];
while ((count = bais.read(buffer)) != -1) {
cos.write(buffer, 0, count);
}
cos.close(); // manually do close for the last bit
dataDecrypted = baos.toByteArray();
// Close streams.
baos.close();
bais.close();
} catch (Exception e) {
e.printStackTrace();
}
return (dataDecrypted == null ? "" : Base64.encodeToString(dataDecrypted, Base64.NO_WRAP));
}
public static String encrypt(String textToEncrypt) {
byte[] dataEncrypted = null;
try {
Cipher cipher = getCipher();
SecretKey key = getKey();
IvParameterSpec iv = getIV();
if (cipher == null) {
return null;
}
cipher.init(Cipher.ENCRYPT_MODE, key, iv);
byte[] dataToEncrypt = Base64.decode(textToEncrypt, Base64.NO_WRAP);
ByteArrayInputStream bais = new ByteArrayInputStream(dataToEncrypt);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
// Wrap the output stream
CipherOutputStream cos = new CipherOutputStream(baos, cipher);
// Read bytes
int count = 0;
byte[] buffer = new byte[DEFAULT_BYTE_READ_WRITE_BLOCK_BUFFER_SIZE];
while ((count = bais.read(buffer)) != -1) {
cos.write(buffer, 0, count);
}
cos.close(); // manually do close for the last bit
dataEncrypted = baos.toByteArray();
// Close streams.
baos.close();
bais.close();
} catch (Exception e) {
e.printStackTrace();
}
return (dataEncrypted == null ? "" : Base64.encodeToString(dataEncrypted, Base64.NO_WRAP));
}
Related
I'm writing server/client system that uses AES.
The following method (server side) works fine:
public static byte[] encode(byte type, byte subType, String string, Cipher cipher)
throws NullPointerException, IOException {
Objects.requireNonNull(string);
Objects.requireNonNull(cipher);
byte[] data = null;
try {
data = string.getBytes(StandardCharsets.UTF_8.name());
} catch (UnsupportedEncodingException e1) {};
ByteArrayOutputStream bytesOutput = new ByteArrayOutputStream();
bytesOutput.write(type);
bytesOutput.write(subType);
bytesOutput.write(data);
byte[] plainBytes = bytesOutput.toByteArray();
byte[] bytes = null;
try {
bytes = cipher.doFinal(plainBytes);
} catch (Exception e) {
e.printStackTrace();
}
byte[] base64Bytes = Base64.getEncoder().encode(bytes);
return base64Bytes;
}
But when I replaced it with the following code I got IllegalBlockSizeException on client side.
public static byte[] encode(byte type, byte subType, String string, Cipher cipher)
throws NullPointerException, EncodingException {
Objects.requireNonNull(string);
Objects.requireNonNull(cipher);
byte[] data = null;
try {
data = string.getBytes(StandardCharsets.UTF_8.name());
} catch (UnsupportedEncodingException e1) {};
CipherOutputStream cipherOutput = null;
try {
ByteArrayOutputStream bytesOutput = new ByteArrayOutputStream();
OutputStream base64Output = Base64.getEncoder().wrap(bytesOutput);
cipherOutput = new CipherOutputStream(base64Output, cipher);
cipherOutput.write(type);
cipherOutput.write(subType);
cipherOutput.write(data);
cipherOutput.flush();
byte[] bytes = bytesOutput.toByteArray();
return bytes;
} catch (IllegalStateException | IOException e) {
throw new EncodingException(e);
} finally {
if (cipherOutput != null)
try {
cipherOutput.close();
} catch (IOException e) {};
}
}
}
What is wrong with second method? Both methods use the same cipher. Nothing changed on server excluding the encode method.
I am using below code for encryption & decryption in Spring boot project with conveter annotation on attributes which I want to encrypt & decrypt
import org.apache.commons.codec.binary.Base64;
import javax.crypto.*;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.SecretKeySpec;
import javax.persistence.AttributeConverter;
import javax.persistence.Converter;
import java.io.UnsupportedEncodingException;
import java.nio.ByteBuffer;
import java.security.*;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.InvalidParameterSpecException;
#Converter
public class CryptoConverter implements AttributeConverter<String, String> {
#Override
public String convertToDatabaseColumn(String attribute) {
if(attribute == null){
return null;
}
try {
byte[] ivBytes;
//String password="Hello";
String password = EncryptionUtil.key.get();
SecureRandom random = new SecureRandom();
byte bytes[] = new byte[20];
random.nextBytes(bytes);
byte[] saltBytes = bytes;
// Derive the key
SecretKeyFactory factory = null;
factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
PBEKeySpec spec = new PBEKeySpec(password.toCharArray(),saltBytes,65556,256);
SecretKey secretKey = factory.generateSecret(spec);
SecretKeySpec secret = new SecretKeySpec(secretKey.getEncoded(), "AES");
//encrypting the word
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, secret);
AlgorithmParameters params = cipher.getParameters();
ivBytes = params.getParameterSpec(IvParameterSpec.class).getIV();
byte[] encryptedTextBytes = cipher.doFinal(attribute.getBytes("UTF-8"));
//prepend salt and vi
byte[] buffer = new byte[saltBytes.length + ivBytes.length + encryptedTextBytes.length];
System.arraycopy(saltBytes, 0, buffer, 0, saltBytes.length);
System.arraycopy(ivBytes, 0, buffer, saltBytes.length, ivBytes.length);
System.arraycopy(encryptedTextBytes, 0, buffer, saltBytes.length + ivBytes.length, encryptedTextBytes.length);
return new Base64().encodeToString(buffer);
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (InvalidKeySpecException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (NoSuchPaddingException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (InvalidParameterSpecException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
}
return null;
}
#Override
public String convertToEntityAttribute(String dbData) {
if(dbData == null){
return null;
}
try {
String password = EncryptionUtil.key.get();
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
//strip off the salt and iv
ByteBuffer buffer = ByteBuffer.wrap(new Base64().decode(dbData));
byte[] saltBytes = new byte[20];
buffer.get(saltBytes, 0, saltBytes.length);
byte[] ivBytes1 = new byte[cipher.getBlockSize()];
buffer.get(ivBytes1, 0, ivBytes1.length);
byte[] encryptedTextBytes = new byte[buffer.capacity() - saltBytes.length - ivBytes1.length];
buffer.get(encryptedTextBytes);
// Deriving the key
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
PBEKeySpec spec = new PBEKeySpec(password.toCharArray(), saltBytes, 65556, 256);
SecretKey secretKey = factory.generateSecret(spec);
SecretKeySpec secret = new SecretKeySpec(secretKey.getEncoded(), "AES");
cipher.init(Cipher.DECRYPT_MODE, secret, new IvParameterSpec(ivBytes1));
byte[] decryptedTextBytes = null;
decryptedTextBytes = cipher.doFinal(encryptedTextBytes);
return new String(decryptedTextBytes);
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (InvalidAlgorithmParameterException e) {
e.printStackTrace();
} catch (NoSuchPaddingException e) {
e.printStackTrace();
} catch (InvalidKeySpecException e) {
e.printStackTrace();
}
return null;
}
}
The issue is this code takes a lot of time to encrypt & decrypt.
With this I am getting a serious performance hit.
If you want to encrypt faster than simply use an actual randomly generated key instead of a password. You can store that in a KeyStore instance that you protect with a password if you like.
You could also simply move the PBKDF2 key derivation out of the encryption method itself and store the resulting SecretKey instance in a field if and only if the password doesn't change in between calls. That way you only have to derive the key once.
PBKDF2 currently uses 65556 iterations each time you want to encrypt/decrypt anything. And PBKDF2 consists of a single hash - in this case SHA-1 - taking 64 bytes at a time. So even before you start encrypting you've hashed at least 65556 (or 64Ki + 20 for some reason) times 64 bytes. That's 4 MiB of hashing you're doing before starting to encrypt. Compared to that you won't even notice the AES encryption.
This question already has answers here:
What is a NullPointerException, and how do I fix it?
(12 answers)
Closed 7 years ago.
I have a program that encrypts and decrypts using the AES algorithm, but I have to specify the name of the encrypted file, and also specify the format of the original file as part of the name of the encrypted file. I will like to know how how to implement the following features into my code:
I want the name of the encrypted file to be in cipherText
I want the computer to be able to decide the file type(extension eg.txt) without me having to specify it, for example in my code if I am encrypting a .jpg file, I have to specify the name of the encrypted file as encrypt.jpg
Here is my code which i have tried to implement:
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.CipherOutputStream;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.ShortBufferException;
import javax.crypto.spec.SecretKeySpec;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.util.Scanner;
public class EncryptDecrypt {
static Cipher cipher;
static byte[] cipherText;
static byte[] input;
static byte k[]="2305ty6345663ty0".getBytes();
static SecretKeySpec key = new SecretKeySpec(k, "AES");
static int ctLength;
static String filePath = "C:/inddexfolder/casie.jpg";
static String encryptionPath = "C:/indexfolder1/encrypt.jpg";
public static void main(String[] args) {
EncryptDecrypt.encrypt();
EncryptDecrypt.decrypt();
}
public static void encrypt() {
try{
input = filePath.getBytes();
FileInputStream file = new FileInputStream(filePath);
FileOutputStream outStream = new FileOutputStream(encryptionPath);
cipher = Cipher.getInstance("AES/ECB/PKCS5Padding", "SunJCE");
cipher.init(Cipher.ENCRYPT_MODE, key);
cipherText = new byte[cipher.getOutputSize(input.length)];
ctLength = cipher.update(input, 0, input.length, cipherText, 0);
ctLength+= cipher.doFinal(cipherText, ctLength);
String encrypted = new String (cipherText);
CipherOutputStream cos = new CipherOutputStream(outStream, cipher);
byte[] buf = new byte[1024];
int read;
while((read=file.read(buf))!=-1){
cos.write(buf,0,read);
}
file.close();
outStream.flush();
cos.close();
}
catch(IOException e) {
e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (NoSuchPaddingException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (NoSuchProviderException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
} catch (ShortBufferException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
}
}
public static void decrypt() {
try {
FileInputStream file = new FileInputStream(encryptionPath);
FileOutputStream outStream = new FileOutputStream("casenc1.jpg");
byte k[]="2305ty6345663ty0".getBytes();
SecretKeySpec key = new SecretKeySpec(k, "AES");
cipher = Cipher.getInstance("AES");
cipher.init(Cipher.DECRYPT_MODE, key);
CipherOutputStream cos = new CipherOutputStream(outStream, cipher);
byte[] buf = new byte[1024];
int read;
while((read=file.read(buf))!=-1) {
cos.write(buf,0,read);
}
file.close();
outStream.flush();
cos.close();
Runtime.getRuntime().exec("rundll32 url.dll, FiProtocolHandler
"+"casenc1.jpg");
} catch(IOException e) {
System.out.println(" not decrypted Successfully");
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (NoSuchPaddingException e) {
e.printStackTrace();
}
}
}
For the FileOutputStream in the encrypt method , i tried:
FileOutputStream outStream
= new FileOutputStream(encryptionPath = new String(cipherText));
…to see if I could get the file name to be in cipher text but I got these errors:
Exception in thread "main" java.lang.NullPointerException
at java.lang.String.<init>(Unknown Source)
at EncryptDecrypt.encrypt(EncryptDecrypt.java:48)
at EncryptDecrypt.main(EncryptDecrypt.java:37)
Thanks!
Your cipherText is null. Please check whether you try assign it before encrypt it.
FileOutputStream outStream
= new FileOutputStream(encryptionPath = new String(cipherText));
Iam using TripleDes /cbc/pkcs7padding in C#.net to encrypt file.
and i need to decrypt in java.In java am using DESede/CBC/PKcs5padding
But the file is decrypted,but corrupted.
*In java is it possible to use pkcs7padding?
or any other solution to decrypt the file in java with encrypted using pkcs7 padding
C# code
namespace EncryptEpubFiles
{
public class Encryptor
{
public static bool EncryptBook(FileInfo fileToEncrypt,string outPathWithoutExtension,string keyString)
{
try
{
byte[] encryptedFileByteArray;
//Start Encryption service provider
TripleDESCryptoServiceProvider tDES = new TripleDESCryptoServiceProvider();
//Read all bytes from input file
byte[] _fileByteArray = File.ReadAllBytes(fileToEncrypt.FullName);
tDES.Key = GetBytes(keyString);
tDES.Mode = CipherMode.CBC;
//tDES.Padding = PaddingMode.PKCS7;
tDES.Padding = PaddingMode.PKCS7;
ICryptoTransform trans = tDES.CreateEncryptor();
//Create Encrypted file byte array
encryptedFileByteArray = (trans.TransformFinalBlock(_fileByteArray, 0, ((_fileByteArray).Length)));
//Write Encrypted file byte array to a filr with proper extension
System.IO.File.WriteAllBytes((outPathWithoutExtension + ".akr"), encryptedFileByteArray);
return true;
}
catch (Exception ex)
{
return false;
}
}
Java code
public class DecryptFinal {
private static Cipher dcipher;
private static byte[] iv = {
(byte)0xB2, (byte)0x12, (byte)0xD5, (byte)0xB2,
(byte)0x44, (byte)0x21, (byte)0xC3, (byte)0xC3
};
public static void main(String[] args){
try {
String s = "123456789123456789111234";
AlgorithmParameterSpec paramSpec = new IvParameterSpec(iv);
SecretKeyFactory keyfactory=SecretKeyFactory.getInstance("DESede");
byte[] encodedkey=s.getBytes();
System.out.println();
SecretKey key = keyfactory.generateSecret(new DESedeKeySpec(encodedkey));
System.out.println(new DESedeKeySpec(encodedkey));
SecretKeySpec(encodedKey,0,encodedKey.length,"DESede" );
dcipher = Cipher.getInstance("DESede/CBC/PKCS5Padding");
dcipher.init(Cipher.DECRYPT_MODE, key, paramSpec);
FileInputStream fs =new FileInputStream("E:\\Test1\\Test1\\Encrypted Files\\Wedding bells.akr");
FileOutputStream os= new FileOutputStream("E:\\Test1\\Test1\\Encrypted Files\\Encrypted Files\\E-pub Totorials");
byte[] buf = new byte[1024];// bytes read from stream will be decrypted
CipherInputStream cis = new CipherInputStream(fs, 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);
}
cis.close();// close all streams
fs.close();
os.close();
}
catch(FileNotFoundException e) {
System.out.println("File Not Found:" + e.getMessage());
return;
} catch (NoSuchAlgorithmException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (NoSuchPaddingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvalidKeyException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvalidAlgorithmParameterException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
catch (IOException e) {
System.out.println("I/O Error:" + e.getMessage());
}
catch (InvalidKeySpecException e) {
// TODO: handle exception
e.printStackTrace();
}
I have an application consisting of three services: Client, Server and TokenService. In order to access data on the Server, Client has to obtain SecurityToken object from TokenService. The communication between parties is encrypted using shared keys (Client and TokenService share a key 'A' and TokenService and Server share a different key 'B'). When Client sends request to TokenService then the communication is encrypted with 'A'. When TokenService returns SecurityToken object, this object is encrypted with B and A like this: ((SecurityToken)B)A). This doubly encrypted object first goes back to Client, Client decrypts it with A, puts it into another object, attaches some additional information (String with request) and sends it to the Server where SecurityToken gets decrypted with B.
Everything works fine until I'am decrypting SecurityToken object on the server side. I get Exception:
javax.crypto.IllegalBlockSizeException: Input length must be multiple of 16 when decrypting with padded cipher
at com.sun.crypto.provider.CipherCore.doFinal(CipherCore.java:749)
at com.sun.crypto.provider.CipherCore.doFinal(CipherCore.java:675)
at com.sun.crypto.provider.AESCipher.engineDoFinal(AESCipher.java:313)
at javax.crypto.Cipher.doFinal(Cipher.java:2087)
at mds.hm5.sharedclasses.Decryptor.decryptData(Decryptor.java:40)
at mds.hm5.tokenservice.Main2.main(Main2.java:28)
I was able to recreate this error (without remote communication between parties) like this:
public static void main(String[] args) {
SecurityToken s = new SecurityToken(false, "2");
try {
byte[] bytes = Encryptor.getBytesFromObject(s);
bytes = Encryptor.encryptData(bytes, "secretkey1");
bytes = Encryptor.encryptData(bytes, "secretkey2");
bytes = Base64.encodeBase64(bytes);
System.out.println(bytes);
bytes = Base64.decodeBase64(bytes);
bytes = Decryptor.decryptData(bytes, "secretkey2");
bytes = Decryptor.decryptData(bytes, "secretkey1");
SecurityToken s2 = (SecurityToken) Decryptor.getObjectFromBytes(bytes);
System.out.println(s2.getRole());
} catch (IOException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
I have no idea what I'am doing wrong here. Is it impossible to create two layers of encryption just like that? Am I missing something?
Additional information:
Here is my Encryptor class:
public class Encryptor {
public static byte[] encryptData(byte[] credentials, String key){
Cipher c;
SecretKeySpec k;
byte[] byteCredentials = null;
byte[] encryptedCredentials = null;
byte[] byteSharedKey = null;
try {
byteCredentials = getBytesFromObject(credentials);
byteSharedKey = getByteKey(key);
c = Cipher.getInstance("AES");
k = new SecretKeySpec(byteSharedKey, "AES");
c.init(Cipher.ENCRYPT_MODE, k);
encryptedCredentials = c.doFinal(byteCredentials);
} catch (NoSuchAlgorithmException | NoSuchPaddingException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
}
return encryptedCredentials;
}
public static byte[] getBytesFromObject(Object credentials) throws IOException{
//Hmmm.... now I'm thinking I should make generic type for both: Token and ITU_Credentials object, that would have this getBytes and getObject methods.
ByteArrayOutputStream bos = new ByteArrayOutputStream();
ObjectOutput out = null;
byte[] newBytes = null;
try {
out = new ObjectOutputStream(bos);
out.writeObject(credentials);
newBytes = bos.toByteArray();
} catch (IOException e) {
e.printStackTrace();
} finally {
out.close();
bos.close();
}
return newBytes;
}
private static byte[] getByteKey(String key) throws UnsupportedEncodingException, NoSuchAlgorithmException{
//Converting key to SHA-1 and trimming to mach maximum lenght of key
byte[] bkey = key.getBytes("UTF-8");
MessageDigest sha = MessageDigest.getInstance("SHA-1");
bkey = sha.digest(bkey);
bkey = Arrays.copyOf(bkey, 16);
return bkey;
}
And here is my Decryptor class:
public class Decryptor {
public static byte[] decryptData(byte[] encryptedCredentials, String key){
Cipher c;
SecretKeySpec k;
byte[] byteSharedKey = null;
byte[] byteObject = null;
try {
byteSharedKey = getByteKey(key);
c = Cipher.getInstance("AES");
k = new SecretKeySpec(byteSharedKey, "AES");
c.init(Cipher.DECRYPT_MODE, k);
byteObject = c.doFinal(encryptedCredentials);
} catch (NoSuchAlgorithmException | NoSuchPaddingException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
}
return byteObject;
}
public static Object getObjectFromBytes(byte[] credentials) throws IOException, ClassNotFoundException{
ByteArrayInputStream bis = new ByteArrayInputStream(credentials);
ObjectInput in = null;
ITU_Credentials credentialsObj = null;
try {
in = new ObjectInputStream(bis);
credentialsObj = (ITU_Credentials)in.readObject();
} finally {
bis.close();
in.close();
}
return credentialsObj;
}
private static byte[] getByteKey(String key) throws UnsupportedEncodingException, NoSuchAlgorithmException{
//Converting key to SHA-1 and trimming to mach maximum lenght of key
byte[] bkey = key.getBytes("UTF-8");
MessageDigest sha = MessageDigest.getInstance("SHA-1");
bkey = sha.digest(bkey);
bkey = Arrays.copyOf(bkey, 16);
return bkey;
}
public static void main(String[] args) {
new Encryptor();
}
}
EDIT:
As advised, I replaced all e.printStackTrace(); with throw new RuntimeException(e); in the Decriptor class to properly throw exceptions:
public class Decryptor {
public static byte[] decryptData(byte[] encryptedCredentials, String key){
Cipher c;
SecretKeySpec k;
byte[] byteSharedKey = null;
byte[] byteObject = null;
try {
byteSharedKey = getByteKey(key);
c = Cipher.getInstance("AES");
k = new SecretKeySpec(byteSharedKey, "AES");
c.init(Cipher.DECRYPT_MODE, k);
byteObject = c.doFinal(encryptedCredentials);
} catch (NoSuchAlgorithmException | NoSuchPaddingException e) {
throw new RuntimeException(e);
} catch (InvalidKeyException e) {
throw new RuntimeException(e);
} catch (IOException e) {
throw new RuntimeException(e);
} catch (IllegalBlockSizeException e) {
throw new RuntimeException(e);
} catch (BadPaddingException e) {
throw new RuntimeException(e);
}
return byteObject;
}
public static Object getObjectFromBytes(byte[] credentials) throws IOException, ClassNotFoundException{
ByteArrayInputStream bis = new ByteArrayInputStream(credentials);
ObjectInput in = null;
ITU_Credentials credentialsObj = null;
try {
in = new ObjectInputStream(bis);
credentialsObj = (ITU_Credentials)in.readObject();
} finally {
bis.close();
in.close();
}
return credentialsObj;
}
private static byte[] getByteKey(String key) throws UnsupportedEncodingException, NoSuchAlgorithmException{
//Converting key to SHA-1 and trimming to mach maximum lenght of key
byte[] bkey = key.getBytes("UTF-8");
MessageDigest sha = MessageDigest.getInstance("SHA-1");
bkey = sha.digest(bkey);
bkey = Arrays.copyOf(bkey, 16);
return bkey;
}
public static void main(String[] args) {
new Encryptor();
}
}
Now the exception looks as follows:
Exception in thread "main" java.lang.RuntimeException: javax.crypto.IllegalBlockSizeException: Input length must be multiple of 16 when decrypting with padded cipher
at mds.hm5.sharedclasses.Decryptor.decryptData(Decryptor.java:51)
at mds.hm5.tokenservice.Main2.main(Main2.java:28)
Caused by: javax.crypto.IllegalBlockSizeException: Input length must be multiple of 16 when decrypting with padded cipher
at com.sun.crypto.provider.CipherCore.doFinal(CipherCore.java:749)
at com.sun.crypto.provider.CipherCore.doFinal(CipherCore.java:675)
at com.sun.crypto.provider.AESCipher.engineDoFinal(AESCipher.java:313)
at javax.crypto.Cipher.doFinal(Cipher.java:2087)
at mds.hm5.sharedclasses.Decryptor.decryptData(Decryptor.java:40)
... 1 more
I think the root of your problem is:
byte[] bytes = Encryptor.getBytesFromObject(s);
bytes = Encryptor.encryptData(bytes, "secretkey1");
which goes to:
//etc.//
byte[] encryptedCredentials = null;
byte[] byteSharedKey = null;
try {
byteCredentials = getBytesFromObject(credentials);
//Whoops! credentials is already a byte array.
//etc.//
catch (and eat) exception.....
return encryptedCredentials;
And, since you eat the exception and just return null, as home has advised against in the comments, then it keeps moving until it gets to the decryption step, where it throws an exception you hadn't anticipated (when it fails to decrypt, an IllegalBlockSizeException which is none of the eight types of Exception that you catch there), and gives you something useful.
That's what I think is going on anyway.