import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.security.Security;
import java.security.spec.AlgorithmParameterSpec;
import javax.crypto.Cipher;
import javax.crypto.CipherInputStream;
import javax.crypto.CipherOutputStream;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
public class MainClass {
static Cipher m_encrypter;
static Cipher m_decrypter;
public static void main(String args[]) throws Exception {
Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
SecretKey key = KeyGenerator.getInstance("DES").generateKey();
// for CBC; must be 8 bytes
byte[] initVector = new byte[] { 0x10, 0x10, 0x01, 0x04, 0x01, 0x01, 0x01, 0x02 };
AlgorithmParameterSpec algParamSpec = new IvParameterSpec(initVector);
Cipher m_encrypter = Cipher.getInstance("DES/CBC/PKCS5Padding");
Cipher m_decrypter = Cipher.getInstance("DES/CBC/PKCS5Padding");
m_encrypter.init(Cipher.ENCRYPT_MODE, key, algParamSpec);
m_decrypter.init(Cipher.DECRYPT_MODE, key, algParamSpec);
FileInputStream fis = new FileInputStream("cipherTest.in");
FileOutputStream fos = new FileOutputStream("cipherTest.out");
int dataInputSize = fis.available();
byte[] inputBytes = new byte[dataInputSize];
fis.read(inputBytes);
write(inputBytes, fos);
fos.flush();
fis.close();
fos.close();
String inputFileAsString = new String(inputBytes);
System.out.println("INPUT FILE CONTENTS\n" + inputFileAsString + "\n");
System.out.println("File encrypted and saved to disk\n");
fis = new FileInputStream("cipherTest.out");
byte[] decrypted = new byte[dataInputSize];
read(decrypted, fis);
fis.close();
String decryptedAsString = new String(decrypted);
System.out.println("DECRYPTED FILE:\n" + decryptedAsString + "\n");
}
public static void write(byte[] bytes, OutputStream out) throws Exception {
CipherOutputStream cos = new CipherOutputStream(out, m_encrypter);
cos.write(bytes, 0, bytes.length);
cos.close();
}
public static void read(byte[] bytes, InputStream in) throws Exception {
CipherInputStream cis = new CipherInputStream(in, m_decrypter);
int pos = 0, intValue;
while ((intValue = cis.read()) != -1) {
bytes[pos] = (byte) intValue;
pos++;
}
}
}
DESCrypterAndDecryperFile.zip( 1,199 k)