概述
高级加密标准(AES,Advanced Encryption Standard)为最常见的对称加密算法，对称加密算法即加密和解密的过程使用同一个秘钥进行加密。本文从实用的角度去描述前后端使用AES对称加密。
需求分析
前端请求数据传递参数时，需要对其进行加密，而不是使用明文进行传输，防止http请求被人截获而获取到信息，AES对称加密就是一种方式，前端对密码进行加密，传输给后端，后端获取之后使用和前端约定好的秘钥进行解密。
前端AES加解密
前端加密需要引入crypto-js的js文件，crypto-js是加密标准的JavaScript库，实现了各种加密算法，下载地址： # 《前后端加密crypto-js.js文件》
实操，demo如下
前端AES加解密代码：
// 密钥
var key = '38373134313330303030333134313738';
key = CryptoJS.enc.Hex.parse(key)
var iv = CryptoJS.enc.Hex.parse("303132333435233454243444546")
var src = mobile_phone;
console.log('原 字符串 ：', src);
var enc = CryptoJS.AES.encrypt(src ,key,{
iv:iv,
mode: CryptoJS.mode.CBC,
padding: CryptoJS.pad.Pkcs7
})
console.log('加密:',enc. toString ());
var enced = enc.ciphertext.toString()
console.log("加密：", enced);
var dec = CryptoJS.AES.decrypt(CryptoJS.format.Hex.parse(enced), key,{
iv:iv,
mode: CryptoJS.mode.CBC,
padding: CryptoJS.pad.Pkcs7
})
console.log('解密:',CryptoJS.enc.Utf8.stringify(dec));
其中key和iv的值并不是随意填写的，这个是需要后端加解密生成后给到前端使用
后端AES加解密：
package unis.cloud.data.tool;
import java.io.UnsupportedEncodingException;
import java.nio.charset.Charset;
import java.security.InvalidAlgorithmParameterException;
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.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
public class AesTool {
private static String iv = "0123456789ABCDEF";// 偏移量 字符串必须是16位 当模式是CBC的时候必须设置偏移量
private static String Algorithm = "AES";
private static String AlgorithmProvider = "AES/CBC/PKCS5Padding"; //算法/模式/补码方式
public static byte[] generatorKey() throws NoSuchAlgorithmException {
KeyGenerator keyGenerator = KeyGenerator. getInstance (Algorithm);
keyGenerator.init(256);//默认128，获得无政策权限后可为192或256
SecretKey secretKey = keyGenerator.generateKey();
return secretKey.getEncoded();
}
public static IvParameterSpec getIv() throws UnsupportedEncodingException {
IvParameterSpec ivParameterSpec = new IvParameterSpec(iv.get byte s("utf-8"));
System.out.println("偏移量："+byteToHexString(ivParameterSpec.getIV()));
return ivParameterSpec;
}
public static byte[] encrypt(String src) throws NoSuchAlgorithmException, NoSuchPaddingException,
InvalidKeyException, IllegalBlockSizeException, BadPaddingException, UnsupportedEncodingException, InvalidAlgorithmParameterException {
byte key[] = "87000078".getBytes("utf-8");
SecretKey secretKey = new SecretKeySpec(key, Algorithm);
IvParameterSpec ivParameterSpec = getIv();
Cipher cipher = Cipher.getInstance(AlgorithmProvider);
cipher.init(Cipher.ENCRYPT_MODE, secretKey, ivParameterSpec);
byte[] cipherBytes = cipher.doFinal(src.getBytes(Charset.forName("utf-8")));
return cipherBytes;
}
public static byte[] decrypt(String src) throws Exception {
byte key[] = "87000078".getBytes("utf-8");
SecretKey secretKey = new SecretKeySpec(key, Algorithm);
IvParameterSpec ivParameterSpec = getIv();
Cipher cipher = Cipher.getInstance(AlgorithmProvider);
cipher.init(Cipher.DECRYPT_MODE, secretKey, ivParameterSpec);
byte[] hexBytes = hexStringToBytes(src);
byte[] plainBytes = cipher.doFinal(hexBytes);
return plainBytes;
}
/**
* 将byte转换为16进制字符串
* @param src
* @return
*/
public static String byteToHexString(byte[] src) {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < src.length; i++) {
int v = src[i] & 0xff;
String hv = Integer.toHexString(v);
if (hv.length() < 2) {
sb.append("0");
}
sb.append(hv);
}
return sb.toString();
}
/**
* 将16进制字符串装换为byte数组
* @param hexString
* @return
*/
public static byte[] hexStringToBytes(String hexString) {
hexString = hexString.toUpperCase();
int length = hexString.length() / 2;
char[] hexChars = hexString.toCharArray();
byte[] b = new byte[length];
for (int i = 0; i < length; i++) {
int pos = i * 2;
b[i] = (byte) (charToByte(hexChars[pos]) << 4 | charToByte(hexChars[pos + 1]));
}
return b;
}
private static byte charToByte(char c) {
return (byte) "0123456789ABCDEF".indexOf(c);
}
public static void main(String[] args) {
try {
// 密钥必须是16的倍数
byte key[] = "8711110000222278".getBytes("utf-8");
String src = "183222222222";
System.out.println("密钥:"+byteToHexString(key));
System.out.println("原字符串:"+src);
String enc = byteToHexString(encrypt(src));
System.out.println("加密："+enc);
System.out.println("解密："+new String(decrypt(enc), "utf-8"));
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (NoSuchPaddingException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
}
}
后端输出结果：
密钥:38373134313330303030333134313738
原字符串:你好
偏移量：30313233343536373839414243444546
加密：08e56adf28a16558631aa0914d04bd0c
偏移量：30313233343536373839414243444546
解密：你好
需要注意，后端输出的密钥和偏移量都要给前端，这样解析出来的参数才是一致的，其中后端打印出的密钥对应前端的key，后端打印出的便宜量对应前端的iv中的值！
表达可能不太清楚，调试中有问题可私信我！
