[android-developers] File encryption using AES

hi all,

i am trying the File encryption using AES on android but there is a
weird exception occured everytime,i am not able to find out the
solution for this exception.
my code for encryption is:

public void encrypt(File file,String aesKey) throws Exception
{
try
{
byte[] byteKey = aesKey.getBytes("UTF8");
KeySpec ks = new SecretKeySpec(byteKey,"AES");
SecretKeyFactory skf = SecretKeyFactory.getInstance("AES");
SecretKey sk = skf.generateSecret(ks);
aspec = new IvParameterSpec(ivector);
encCipher = Cipher.getInstance("AES/CBC/PKCS7Padding");
encCipher.init(Cipher.ENCRYPT_MODE, sk);
in = new FileInputStream(file);
AlertDialog.Builder builder = new AlertDialog.Builder(null);
builder.setMessage("you are in middle of encrypt function");
AlertDialog alert = builder.create();
FileOutputStream fout = new FileOutputStream("/mnt/sdcard/b.txt");
out = new CipherOutputStream(fout,encCipher);
int num = 0;
while((num = in.read(buffer)) >=0)
{
out.write(buffer, 0, num);

}

out.close();
}

--
You received this message because you are subscribed to the Google
Groups "Android Developers" group.
To post to this group, send email to android-developers@googlegroups.com
To unsubscribe from this group, send email to
android-developers+unsubscribe@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/android-developers?hl=en