Encryption-decryption file problem

[mandlar suurla]

Mostly this class is put to together from internet examples, k this class should do some doc, xls, and some picture encryption and then decryption, but problem is like when i decrypt file, in that process decryption misses bytes so file is smaller then original.

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 {
Cipher ecipher;
Cipher dcipher;
byte[] buf = new byte[1024];

// 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);

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

out.close();
in.close();
}
 
public void decrypt(InputStream in, OutputStream out) throws Exception {
in = new CipherInputStream(in, dcipher);

int numRead = 0;
while ((numRead = in.read(buf)) != -1)
out.write(buf, 0, numRead);
out.close();
in.close();
}
 
public String encrypt(String str) throws Exception {
// 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 BASE64Encoder().encode(enc);
}
 
public String decrypt(String str) throws Exception {
// Decode base64 to get bytes
byte[] dec = new BASE64Decoder().decodeBuffer(str);
 
// Decrypt
byte[] utf8 = dcipher.doFinal(dec);
 
// Decode using utf-8
return new String(utf8, "UTF8");
}
}

:roll:

[Campbell Ritchie]

Why are you using sun. classes? They are not officially supported and might be altered or even withdrawn in future.

I don't think this is a "beginner's" topic, and I think it would sit better in the security forum, so I shall move it.

[mandlar suurla]

Don't look the encrypt and decrypt with String parameters i dont use them. Main thing is the file encrypt and decrypt