aes加解密

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;

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;

/**
 * 2010年9月1日
 * @author 张守磊
 */
public class DigicanAES {

	public static void main(String[] args) throws Exception {
		//getAutoCreateAESKey("e:/aes.txt");
		//加密
		byte[] text = "hello world中国".getBytes("utf-8");
		byte[] bm = getAESEncode("e:/aes.txt", text);
		String encryptResultStr = parseByte2HexStr(bm);  
		System.out.println(encryptResultStr);
		byte[] decryptFrom = parseHexStr2Byte(encryptResultStr); 
		//解密
		/*File file = new File("d:\\testAESjiamji");
		byte[] bm = new byte[(int) file.length()];
		FileInputStream fis = new FileInputStream(file);
		fis.read(bm);*/
				byte[] b = getAESDecode("e:/aes.txt", decryptFrom);
				System.out.println(b);
				System.out.println(new String(b));
	}

	/**
	 * 生成密钥
	 * 自动生成AES128位密钥
	 * 传入保存密钥文件路径
	 * filePath 表示文件存储路径加文件名；例如d:\aes.txt
	 * @throws NoSuchAlgorithmException 
	 * @throws IOException 
	 */
	public static void getAutoCreateAESKey(String filePath)
			throws NoSuchAlgorithmException, IOException {
		KeyGenerator kg = KeyGenerator.getInstance("AES");
		kg.init(128);//要生成多少位，只需要修改这里即可128, 192或256
		SecretKey sk = kg.generateKey();
		byte[] b = sk.getEncoded();
		FileOutputStream fos = new FileOutputStream(filePath);
		fos.write(b);
		fos.flush();
		fos.close();
	}

	/**
	 * 加密
	 * 使用对称密钥进行加密
	 * keyFilePath 密钥存放路径
	 * text 要加密的字节数组
	 * 加密后返回一个字节数组
	 * @throws IOException 
	 * @throws NoSuchPaddingException 
	 * @throws NoSuchAlgorithmException 
	 * @throws InvalidKeyException 
	 * @throws BadPaddingException 
	 * @throws IllegalBlockSizeException 
	 */
	public static byte[] getAESEncode(String keyFilePath, byte[] text)
			throws IOException, NoSuchAlgorithmException,
			NoSuchPaddingException, InvalidKeyException,
			IllegalBlockSizeException, BadPaddingException {
		File file = new File(keyFilePath);
		byte[] key = new byte[(int) file.length()];
		FileInputStream fis = new FileInputStream(file);
		fis.read(key);
		SecretKeySpec sKeySpec = new SecretKeySpec(key, "AES");
		Cipher cipher = Cipher.getInstance("AES");
		cipher.init(Cipher.ENCRYPT_MODE, sKeySpec);
		byte[] bjiamihou = cipher.doFinal(text);
		return bjiamihou;
	}

	/**
	 * 解密
	 * 使用对称密钥进行解密
	 * keyFilePath 密钥存放路径
	 * text 要解密的字节数组
	 * 解密后返回一个字节数组
	 * @throws IOException 
	 * @throws NoSuchPaddingException 
	 * @throws NoSuchAlgorithmException 
	 * @throws InvalidKeyException 
	 * @throws BadPaddingException 
	 * @throws IllegalBlockSizeException 
	 */
	public static byte[] getAESDecode(String keyFilePath, byte[] text)
			throws IOException, NoSuchAlgorithmException,
			NoSuchPaddingException, InvalidKeyException,
			IllegalBlockSizeException, BadPaddingException {
		File file = new File(keyFilePath);
		byte[] key = new byte[(int) file.length()];
		FileInputStream fis = new FileInputStream(file);
		fis.read(key);
		SecretKeySpec sKeySpec = new SecretKeySpec(key, "AES");
		Cipher cipher = Cipher.getInstance("AES");
		cipher.init(Cipher.DECRYPT_MODE, sKeySpec);
		byte[] bjiemihou = cipher.doFinal(text);
		return bjiemihou;
	}

	/**将二进制转换成16进制 
	 * @param buf 
	 * @return 
	 */
	public static String parseByte2HexStr(byte buf[]) {
		StringBuffer sb = new StringBuffer();
		for (int i = 0; i < buf.length; i++) {
			String hex = Integer.toHexString(buf[i] & 0xFF);
			if (hex.length() == 1) {
				hex = '0' + hex;
			}
			sb.append(hex.toUpperCase());
		}
		return sb.toString();
	}

	/**将16进制转换为二进制 
	 * @param hexStr 
	 * @return 
	 */
	public static byte[] parseHexStr2Byte(String hexStr) {
		if (hexStr.length() < 1)
			return null;
		byte[] result = new byte[hexStr.length() / 2];
		for (int i = 0; i < hexStr.length() / 2; i++) {
			int high = Integer.parseInt(hexStr.substring(i * 2, i * 2 + 1), 16);
			int low = Integer.parseInt(hexStr.substring(i * 2 + 1, i * 2 + 2),
					16);
			result[i] = (byte) (high * 16 + low);
		}
		return result;
	}
}
//解密C语言的AES加密后数据，要把JAVA中的AES改成AES/ECB/NoPadding