D4LjBnvf

1import java.io.File;
2import java.io.FileInputStream;
3import java.io.FileOutputStream;
4import java.io.IOException;
5import java.security.InvalidKeyException;
6import java.security.Key;
7import java.security.NoSuchAlgorithmException;
8 
9import javax.crypto.BadPaddingException;
10import javax.crypto.Cipher;
11import javax.crypto.IllegalBlockSizeException;
12import javax.crypto.NoSuchPaddingException;
13import javax.crypto.spec.SecretKeySpec;
14 
15/**
16 * A utility class that encrypts or decrypts a file.
17 * @author www.codejava.net
18 *
19 */
20public class CryptoUtils {
21    private static final String ALGORITHM = "AES";
22    private static final String TRANSFORMATION = "AES";
23 
24    public static void encrypt(String key, File inputFile, File outputFile)
25            throws CryptoException {
26        doCrypto(Cipher.ENCRYPT_MODE, key, inputFile, outputFile);
27    }
28 
29    public static void decrypt(String key, File inputFile, File outputFile)
30            throws CryptoException {
31        doCrypto(Cipher.DECRYPT_MODE, key, inputFile, outputFile);
32    }
33 
34    private static void doCrypto(int cipherMode, String key, File inputFile,
35            File outputFile) throws CryptoException {
36        try {
37            Key secretKey = new SecretKeySpec(key.getBytes(), ALGORITHM);
38            Cipher cipher = Cipher.getInstance(TRANSFORMATION);
39            cipher.init(cipherMode, secretKey);
40             
41            FileInputStream inputStream = new FileInputStream(inputFile);
42            byte[] inputBytes = new byte[(int) inputFile.length()];
43            inputStream.read(inputBytes);
44             
45            byte[] outputBytes = cipher.doFinal(inputBytes);
46             
47            FileOutputStream outputStream = new FileOutputStream(outputFile);
48            outputStream.write(outputBytes);
49             
50            inputStream.close();
51            outputStream.close();
52             
53        } catch (NoSuchPaddingException | NoSuchAlgorithmException
54                | InvalidKeyException | BadPaddingException
55                | IllegalBlockSizeException | IOException ex) {
56            throw new CryptoException("Error encrypting/decrypting file", ex);
57        }
58    }
59}