Java AES暗号解読例

コード:

package com.techzero.aes;

import java.io.UnsupportedEncodingException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;

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

/**
 * AESTest.java
 * 
 * @author Techzero
 * @Email [email protected]
 * @Time 2013-12-12   1:25:44
 */
public class AESTest {

	public static void main(String[] args) {
		String content = "AEStest";
		String password = "AEStest";
		System.out.println(" 　 ：" + password);
		System.out.println("   ：" + content);
		//   
		String encryptResult = encrypt(content, password);
		System.out.println("   ：" + encryptResult);
		//   
		String decryptResult = decrypt(encryptResult, password);
		System.out.println("   ：" + decryptResult);
	}

	/**
	 *   
	 * 
	 * @param content
	 *                 
	 * @param key
	 *                 
	 * @return
	 */
	public static String encrypt(String content, String key) {
		try {
			KeyGenerator kgen = KeyGenerator.getInstance("AES");
			kgen.init(128, new SecureRandom(key.getBytes()));
			SecretKey secretKey = kgen.generateKey();
			byte[] enCodeFormat = secretKey.getEncoded();
			SecretKeySpec secretKeySpec = new SecretKeySpec(enCodeFormat, "AES");
			Cipher cipher = Cipher.getInstance("AES");
			byte[] byteContent = content.getBytes("utf-8");
			cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec);
			byte[] byteRresult = cipher.doFinal(byteContent);
			StringBuffer sb = new StringBuffer();
			for (int i = 0; i < byteRresult.length; i++) {
				String hex = Integer.toHexString(byteRresult[i] & 0xFF);
				if (hex.length() == 1) {
					hex = '0' + hex;
				}
				sb.append(hex.toUpperCase());
			}
			return sb.toString();
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
		} catch (NoSuchPaddingException e) {
			e.printStackTrace();
		} catch (InvalidKeyException e) {
			e.printStackTrace();
		} catch (UnsupportedEncodingException e) {
			e.printStackTrace();
		} catch (IllegalBlockSizeException e) {
			e.printStackTrace();
		} catch (BadPaddingException e) {
			e.printStackTrace();
		}
		return null;
	}

	/**
	 *   
	 * 
	 * @param content
	 *                 
	 * @param key
	 *                 
	 * @return
	 */
	public static String decrypt(String content, String key) {
		if (content.length() < 1)
			return null;
		byte[] byteRresult = new byte[content.length() / 2];
		for (int i = 0; i < content.length() / 2; i++) {
			int high = Integer.parseInt(content.substring(i * 2, i * 2 + 1), 16);
			int low = Integer.parseInt(content.substring(i * 2 + 1, i * 2 + 2), 16);
			byteRresult[i] = (byte) (high * 16 + low);
		}
		try {
			KeyGenerator kgen = KeyGenerator.getInstance("AES");
			kgen.init(128, new SecureRandom(key.getBytes()));
			SecretKey secretKey = kgen.generateKey();
			byte[] enCodeFormat = secretKey.getEncoded();
			SecretKeySpec secretKeySpec = new SecretKeySpec(enCodeFormat, "AES");
			Cipher cipher = Cipher.getInstance("AES");
			cipher.init(Cipher.DECRYPT_MODE, secretKeySpec);
			byte[] result = cipher.doFinal(byteRresult);
			return new String(result);
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
		} catch (NoSuchPaddingException e) {
			e.printStackTrace();
		} catch (InvalidKeyException e) {
			e.printStackTrace();
		} catch (IllegalBlockSizeException e) {
			e.printStackTrace();
		} catch (BadPaddingException e) {
			e.printStackTrace();
		}
		return null;
	}

}

実行結果:
秘密鍵:AEStest暗号化前:AEStest暗号化後:24 C 2584138719 D 77 C 4 FEBDE 382 D 84648復号後:AEStest