Encryption-decryption loosing bytes in operation

[mandlar suurla]

Here is my encryption/decrypt code. But after decrypting file, it is some bytes bigger or smaller, i dont know how to get the exact bytes.

import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.spec.AlgorithmParameterSpec;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.KeySpec;
 
import javax.crypto.Cipher;
import javax.crypto.CipherInputStream;
import javax.crypto.CipherOutputStream;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.PBEParameterSpec;
 
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;
 
public class Crypt {
private final static int BUFFER_SIZE = 1024;
private Cipher ecipher;
private Cipher dcipher;
private byte[] buf = new byte[BUFFER_SIZE];

// 8-byte Salt
byte[] salt = { (byte) 0xA9, (byte) 0x9B, (byte) 0xC8, (byte) 0x32,
(byte) 0x56, (byte) 0x35, (byte) 0xE3, (byte) 0x03 };
 
// Iteration count
int iterationCount = 19;
 
Crypt(String passPhrase) throws NoSuchAlgorithmException, NoSuchPaddingException, 
InvalidKeyException, InvalidAlgorithmParameterException, InvalidKeySpecException {
// 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);
}

public void encrypt(InputStream in, OutputStream out) throws Exception {
out = new CipherOutputStream(out, ecipher);
buf = new byte[BUFFER_SIZE];
int countRead = 0;
while ((countRead = in.read(buf, 0, BUFFER_SIZE)) != -1) {
out.write(buf, 0, countRead);
//System.out.println(countRead);
}
}

public void decrypt(InputStream in, OutputStream out) throws Exception {
in = new CipherInputStream(in, dcipher);
buf = new byte[BUFFER_SIZE];

int countRead = 0;
while ((countRead = in.read(buf, 0, BUFFER_SIZE)) != -1)
out.write(buf, 0, countRead);
}
 
}
    

Simple use of it

 import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.spec.InvalidKeySpecException;
 
import javax.crypto.NoSuchPaddingException;
 
import junit.framework.TestCase;
 

public class TestCryption extends TestCase {
 
File file = new File("C:\\test.txt");

public void testEncryption() {
try {
Crypt c = new Crypt("kass");
c.encrypt(new FileInputStream("C:\\winhelp.exe"), new FileOutputStream("C:\\winhelp2.exe"));

c.decrypt(new FileInputStream("C:\\winhelp2.exe"), new FileOutputStream("c:\\decrypted.exe"));
} 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 (InvalidAlgorithmParameterException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvalidKeySpecException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}
}
   

[Paul Clapham]

You aren't closing your output stream after you finish writing to it.

[mandlar suurla]

Yeha it worked like charm .