AES128bit暗号化/復号化を文字列で行なってみる

import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.SecretKeySpec;

import org.apache.commons.codec.binary.Base64;

/**
 * 文字列のAES暗号化/復号化ユーティリティ
 * 
 * @author bose999
 *
 */
public class AESUtil {

    /**
     * AES
     */
    private static final String AES = "AES";

    public static void main(String[] args) {

        try {
            String secretKey = "12345678901$3456"; // キーは16文字で
            String original = "この文字列を暗号化したいの！"; // 元の文字列

            String encryptBytesBase64String = AESUtil.encrypt(original, secretKey);
            System.out.println("暗号化文字列：" + encryptBytesBase64String);

            String returnString = AESUtil.decrypt(encryptBytesBase64String, secretKey);
            System.out.println("復号化文字列：" + returnString);
            
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * 文字列を16文字の秘密鍵でAES暗号化してBase64した文字列で返す
     * 
     * @param originalString String
     * @param secretKey String
     * @return String
     * @throws NoSuchAlgorithmException
     * @throws NoSuchPaddingException
     * @throws InvalidKeyException
     * @throws IllegalBlockSizeException
     * @throws BadPaddingException
     */
    public static String encrypt(String originalString, String secretKey) throws NoSuchAlgorithmException,
            NoSuchPaddingException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException {

        byte[] originalBytes = originalString.getBytes();
        byte[] secretKeyBytes = secretKey.getBytes();

        SecretKeySpec secretKeySpec = new SecretKeySpec(secretKeyBytes, AES);
        Cipher cipher = Cipher.getInstance(AES);
        cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec);
        byte[] encryptBytes = cipher.doFinal(originalBytes);
        byte[] encryptBytesBase64 = Base64.encodeBase64(encryptBytes, false);
        return new String(encryptBytesBase64);
    }

    /**
     * Base64されたAES暗号化文字列を元の文字列に復元する
     * 
     * @param encryptBytesBase64String String
     * @param secretKey String
     * @return String
     * @throws NoSuchAlgorithmException
     * @throws NoSuchPaddingException
     * @throws InvalidKeyException
     * @throws IllegalBlockSizeException
     * @throws BadPaddingException
     */
    public static String decrypt(String encryptBytesBase64String, String secretKey)
            throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException,
            IllegalBlockSizeException, BadPaddingException {

        byte[] encryptBytes = Base64.decodeBase64(encryptBytesBase64String);
        byte[] secretKeyBytes = secretKey.getBytes();

        SecretKeySpec secretKeySpec = new SecretKeySpec(secretKeyBytes, AES);
        Cipher cipher = Cipher.getInstance(AES);
        cipher.init(Cipher.DECRYPT_MODE, secretKeySpec);
        byte[] originalBytes = cipher.doFinal(encryptBytes);
        return new String(originalBytes);
    }
}

コンソールへの出力結果

暗号化文字列：dtA6UNsMnahxCkfGdrc8AFhisnFZg8FnKTl7Sk4Wg9J8gYK8+Dv6Io7Ssef7ZPTo
復号化文字列：この文字列を暗号化したいの！