AES加密

package test;

/*****************************************************
*
* @author wuzhenzhong
*
* @since May 8, 2009
*
*****************************************************/
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;

public class AES {

/**
* AES
*/

private final static String algorithm = "AES";
/*
* 转为十六进制
*/
private static String asHex(byte buf[]) {
StringBuffer strbuf = new StringBuffer(buf.length * 2);
int i;

for (i = 0; i < buf.length; i++) {
if (((int) buf[i] & 0xff) < 0x10)
strbuf.append("0");

strbuf.append(Long.toString((int) buf[i] & 0xff, 16));
}
System.out.println(strbuf.toString());
return strbuf.toString();
}
/*
* 转为二进制
*/
private static byte[] asBin(String src) {
if (src.length() < 1)
return null;
byte[] encrypted = new byte[src.length() / 2];
for (int i = 0; i < src.length() / 2; i++) {
int high = Integer.parseInt(src.substring(i * 2, i * 2 + 1), 16);
int low = Integer.parseInt(src.substring(i * 2 + 1, i * 2 + 2), 16);

encrypted[i] = (byte) (high * 16 + low);
}
return encrypted;
}
/*
* 得到密钥key
*/
public static String getRawKey() {

try {
KeyGenerator kgen = KeyGenerator.getInstance(algorithm);// 获取密匙生成器
kgen.init(128); // 192 and 256 bits may not be available

SecretKey skey = kgen.generateKey();// 生成密匙，可用多种方法来保存密匙
byte[] raw = skey.getEncoded();
return asHex(raw);
} catch (Exception e) {
return "";
}

}
/*
* 加密
*/
public static String getEncrypt(String message, String rawKey) {
byte[] key = asBin(rawKey);
try {
SecretKeySpec skeySpec = new SecretKeySpec(key, algorithm);

Cipher cipher = Cipher.getInstance(algorithm);// 创建密码器

cipher.init(Cipher.ENCRYPT_MODE, skeySpec);

byte[] encrypted = cipher.doFinal(message.getBytes());

return asHex(encrypted);
} catch (Exception e) {
return "";
}

}
/*
* 解密
*/
public static String getDecrypt(String encrypted, String rawKey) {
byte[] tmp = asBin(encrypted);
byte[] key = asBin(rawKey);

try {
SecretKeySpec skeySpec = new SecretKeySpec(key, algorithm);

Cipher cipher = Cipher.getInstance(algorithm);

cipher.init(Cipher.DECRYPT_MODE, skeySpec);

byte[] decrypted = cipher.doFinal(tmp);

return new String(decrypted);
} catch (Exception e) {
return "";
}

}

public static void main(String[] args) throws Exception {

String message = "1";

String rawKey = getRawKey(); // 得到钥匙
System.out.println("Key = " + rawKey);

String encrypted = getEncrypt(message, rawKey);
System.out.println("org text = " + message);// 原数据
System.out.println("encrypted = " + encrypted);// 加密以后

String decrypted = getDecrypt(encrypted, rawKey);// 解密串

System.out.println("decrypted = " + decrypted);

}
}