AES加密实现

jar包：bcprov-jdk15-133.jar             

package aes256;

import java.io.UnsupportedEncodingException;
import java.security.Key;
import java.security.Security;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;

/**
 * @author 47475
 *
 */
public class AES256Encryption {

	/**
	 * 密钥算法
	 */
	private static final String KEY_ALGORITHM = "AES";
	/**
	 * 加解密算法/工作模式/填充方式
	 */
	private static final String CIPHER_ALGORITHM = "AES/ECB/PKCS5Padding";

	public static byte[] initkey() throws Exception {
		// 实例化密钥生成器
		Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
		KeyGenerator kg = KeyGenerator.getInstance(KEY_ALGORITHM, "BC");// BC是算法提供者
		kg.init(256);
//		kg.init(128);
		// 生成秘钥
		SecretKey secretKey = kg.generateKey();
		return secretKey.getEncoded();
	}

	/** 默认的秘钥key */
	public static byte[] initRootKey() throws Exception {
		return new byte[] { 0x08, 0x08, 0x04, 0x0b, 0x02, 0x0f, 0x0b, 0x0c, 0x01, 0x03, 0x09, 0x07, 0x0c, 0x03, 0x07,
				0x0a, 0x04, 0x0f, 0x06, 0x0f, 0x0e, 0x09, 0x05, 0x01, 0x0a, 0x0a, 0x01, 0x09, 0x06, 0x07, 0x09, 0x0d };
	}

	/** 根据给定的enCodeFormat字节数组构造一个用AES算法加密的密钥 */
	public static Key toKey(byte[] key) throws Exception {
		SecretKey secretKey = new SecretKeySpec(key, KEY_ALGORITHM);
		return secretKey;
	}

	/**
	 * 加密
	 * 
	 * @param data 要加密的数据
	 * @param key  秘钥
	 * @return
	 * @throws Exception
	 */
	public static byte[] encrypt(byte[] data, byte[] key) throws Exception {
		Key k = toKey(key);
		Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
		Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM, "BC");
		cipher.init(Cipher.ENCRYPT_MODE, k);// ENCRYPT_MODE,用于初始化cipher的加密模式的常量

		return cipher.doFinal(data);
	}

	public static byte[] decrypt(byte[] data, byte[] key) throws Exception {
		Key k = toKey(key);
		Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
		Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM, "BC");
		cipher.init(Cipher.DECRYPT_MODE, k);// DECRYPT_MODE,用于初始化cipher的解密模式的常量。
		return cipher.doFinal(data);
	}

	public static void main(String[] args) throws UnsupportedEncodingException {
		String str = "abc123@-_.:;   空格";
		// 打印原文
		System.out.println("原文：" + str);
		// 密钥
		byte[] key;
		try {
			// 生成随机密钥
			key = AES256Encryption.initkey();
			// 打印密钥
			System.out.print("密钥：");
			for (int i = 0; i < key.length; i++) {
				System.out.printf("%x", key[i]);// %x十六进制数形式输出整数
			}
			System.out.println();
			// 加密
			byte[] data = AES256Encryption.encrypt(str.getBytes(), key);
			// 打印密文
			System.out.print("加密后：");
			for (int i = 0; i < data.length; i++) {
				System.out.printf("%x", data[i]);
			}
			System.out.println();
			// 解密密文
			data = AES256Encryption.decrypt(data, key);
			// 打印原文
			System.out.println("解密后：" + new String(data));
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}