problem in encryption of ZIP files.

[Bala Raju Mandala]

Hi Folks,

I am facing a problem while encrypting and decrypting a ZIP file. The result file is corrupted.

If i encrypt .txt and .doc files, i am able to get them in decryption. But problem with ZIP files. What could be the reasone?

[Ulf Dittmer]

How are you doing the encryption/decryption?

[Bala Raju Mandala]

I am using AES algorithem.

    
Key Generator code is:
---------------------
KeyGenerator kgen = KeyGenerator.getInstance("AES");
kgen.init(128); //128 bits
key = kgen.generateKey();
 
Encryption:
----------
Cipher ecipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
//paramSpec is a Initialization Vector
ecipher.init(Cipher.ENCRYPT_MODE, skey, paramSpec);
FileInputStream in = new FileInputStream("c:\\encryption\\Source.zip");
FileOutputStream out = new FileOutputStream("c:\\cipher\\cipher.enc");
OutputStream cout = new CipherOutputStream(out, ecipher);
int numRead = 0;
while ((numRead = in.read(buf)) >= 0) {
cout.write(buf, 0, numRead);
}
 
Decryption:
-----------
Cipher dcipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
dcipher.init(Cipher.DECRYPT_MODE, skey, paramSpec);
FileInputStream fis = new FileInputStream("c:\\cipher\\cipher.enc");
InputStream in = new CipherInputStream(fis, dcipher);
FileOutputStream fos = new FileOutputStream("c:\\encryption\\Result.zip");
int numRead = 0;
while ((numRead = in.read(buf)) >= 0) {
     fos.write(buf, 0, numRead);
}

[ September 25, 2008: Message edited by: Bala Raju Mandala ]