java：AES加密和解密
1 前言
對稱加密，即單秘鑰加密，指加密和解密的過程中，使用相同的秘鑰，相比于非對稱加密，因僅有一把鑰匙，故而速度更快，更適合解密大文件（常見于如視頻文件的加密解密中）。AES算法就屬于對稱加密中的一種。
2 使用
依賴引入：
<dependency>
<groupId>commons-codec</groupId>
<artifactId>commons-codec</artifactId>
<version>1.6</version>
</dependency>
<!-- spring-boot 3.12.0 -->
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
</dependency>
AES加密與解密的工具類封裝：
package com.xiaoxu.crawler.utils;
import org.apache.commons.codec.binary.Base64;
import org.apache.commons.lang3.ArrayUtils;
import org.springframework.util.StringUtils;
import javax.crypto.*;
import javax.crypto.spec.SecretKeySpec;
import java.io.UnsupportedEncodingException;
import java.nio.charset.StandardCharsets;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
/**
* @author xiaoxu
* @date 2022-11-06 21:24
* crawlerJ:com.xiaoxu.crawler.utils.AESUtils
*/
public class AESUtils {
private static final String AES_ALGORITHM = "AES";
private static final String UTF8 = StandardCharsets.UTF_8.name();
/* AES加密 String */
public static String encryptStrAES(String text, String key){
if(!StringUtils.hasLength(text)){
ExcpUtils.throwExp("encode text should not be null or empty.");
}
byte[] encodeBytes = encryptByteAES(text.getBytes(StandardCharsets.UTF_8), key);
return Base64.encodeBase64String(encodeBytes);
}
/* AES解密 String*/
public static String decryptStrAES(String text, String key){
if(!StringUtils.hasLength(text)){
ExcpUtils.throwExp("decode text should not be null or empty.");
}
byte[] decodeBytes = decryptByteAES(Base64.decodeBase64(text.getBytes(StandardCharsets.UTF_8)), key);
return new String(decodeBytes, StandardCharsets.UTF_8);
}
/* AES加密 originalBytes */
public static byte[] encryptByteAES(byte[] originalBytes, String key){
if(ArrayUtils.isEmpty(originalBytes)){
ExcpUtils.throwExp("encode originalBytes should not be empty.");
}
if(!StringUtils.hasLength(key)){
ExcpUtils.throwExp("key :" + key + ", encode key should not be null or empty.");
}
Cipher cipher = getAESCipher(key, Cipher.ENCRYPT_MODE);
byte[] encodeBytes = null;
try {
encodeBytes = cipher.doFinal(originalBytes);
} catch (IllegalBlockSizeException | BadPaddingException e) {
ExcpUtils.throwExp(e.getClass().getName()+": encode byte fail. "+e.getMessage());
}
return encodeBytes;
}
/* AES解密 encryptedBytes */
public static byte[] decryptByteAES(byte[] encryptedBytes, String key){
if(ArrayUtils.isEmpty(encryptedBytes)){
ExcpUtils.throwExp("decode encryptedBytes should not be empty.");
}
if(!StringUtils.hasLength(key)){
ExcpUtils.throwExp("key :" + key + ", decode key should not be null or empty.");
}
Cipher cipher = getAESCipher(key, Cipher.DECRYPT_MODE);
byte[] decodeBytes = null;
try {
decodeBytes = cipher.doFinal(encryptedBytes);
} catch (IllegalBlockSizeException | BadPaddingException e) {
ExcpUtils.throwExp(e.getClass().getName()+": decode byte fail. "+e.getMessage());
}
return decodeBytes;
}
public static Cipher getAESCipher(String key, int mode){
if(!StringUtils.hasLength(key)){
ExcpUtils.throwExp("key :" + key + ", should not be null or empty.");
}
Cipher cipher = null;
SecretKey secretKey;
try {
cipher = Cipher.getInstance(AES_ALGORITHM);
byte[] keyBytes = key.getBytes(UTF8);
secretKey = new SecretKeySpec(keyBytes, AES_ALGORITHM);
cipher.init(mode, secretKey);
} catch (NoSuchAlgorithmException | NoSuchPaddingException e) {
ExcpUtils.throwExp(e.getClass().getName()+": get cipher instance wrong. "+e.getMessage());
} catch (UnsupportedEncodingException u){
ExcpUtils.throwExp(u.getClass().getName()+": key transfer bytes fail. "+u.getMessage());
} catch (InvalidKeyException i) {
ExcpUtils.throwExp(i.getClass().getName()+": key is invalid. "+i.getMessage());
}
return cipher;
}
public static void main(String[] args) {
String msg = "小徐123testAes!!!";
String key = "0382f2bcbacfa8be";
// String key = "0382f2bcbacfa8b";
System.out.println("AES秘鑰長度只能為16、24、32:"+key.getBytes(StandardCharsets.UTF_8).length);
String s = encryptStrAES(msg, key);
System.out.println("加密后:"+s);
String s1 = decryptStrAES(s, key);
System.out.println("解密后:"+s1);
}
}
執(zhí)行如下：
AES秘鑰長度只能為16、24、32:16
加密后:ZfZYz9Pk4RcA3QQcv+rKnjM54AQV4s/LjsRiGbkpzw8=
解密后:小徐123testAes!!!
AES的秘鑰字節(jié)數(shù)組長度僅能為16、24、32，修改秘鑰長度為15再次執(zhí)行：
public static void main(String[] args) {
String msg = "小徐123testAes!!!";
// String key = "0382f2bcbacfa8be";
String key = "0382f2bcbacfa8b";
System.out.println("AES秘鑰長度只能為16、24、32:"+key.getBytes(StandardCharsets.UTF_8).length);
String s = encryptStrAES(msg, key);
System.out.println("加密后:"+s);
String s1 = decryptStrAES(s, key);
System.out.println("解密后:"+s1);
}
結(jié)果如下，出現(xiàn)了Invalid AES key length異常：
AES秘鑰長度只能為16、24、32:15
Exception in thread "main" com.xiaoxu.crawler.excp.CrawlerForJException: java.security.InvalidKeyException: key is invalid. Invalid AES key length: 15 bytes
at com.xiaoxu.crawler.utils.ExcpUtils.throwExp(ExcpUtils.java:28)
at com.xiaoxu.crawler.utils.AESUtils.getAESCipher(AESUtils.java:94)
at com.xiaoxu.crawler.utils.AESUtils.encryptByteAES(AESUtils.java:50)
at com.xiaoxu.crawler.utils.AESUtils.encryptStrAES(AESUtils.java:29)
at com.xiaoxu.crawler.utils.AESUtils.main(AESUtils.java:104)
debug源碼可見：
AES使用的秘鑰key參數(shù)有長度限制，如下可見ElectronicCodeBook的部分源碼：
var2為傳入的加密的算法，為AES；var3就是秘鑰key轉(zhuǎn)換的字節(jié)數(shù)組，總共長度為15；調(diào)用的是AESCrypt的init方法，如下可見AESCrypt的init源碼：
void init(boolean var1, String var2, byte[] var3) throws InvalidKeyException {
if (!var2.equalsIgnoreCase("AES") && !var2.equalsIgnoreCase("Rijndael")) {
throw new InvalidKeyException("Wrong algorithm: AES or Rijndael required");
} else if (!isKeySizeValid(var3.length)) {
throw new InvalidKeyException("Invalid AES key length: " + var3.length + " bytes");
} else {
if (!MessageDigest.isEqual(var3, this.lastKey)) {
this.makeSessionKey(var3);
this.lastKey = (byte[])var3.clone();
}
this.K = this.sessionK[var1 ? 1 : 0];
}
}
可見，isKeySizeValid(var3.length)返回false時，即拋出Invalid AES key length異常，如下為isKeySizeValid源碼：
AESCrypt部分源碼如下：
static final boolean isKeySizeValid(int var0) {
for(int var1 = 0; var1 < AES_KEYSIZES.length; ++var1) {
if (var0 == AES_KEYSIZES[var1]) {
return true;
}
}
return false;
}
其中AES_KEYSIZES為接口中的常量：
interface AESConstants {
int AES_BLOCK_SIZE = 16;
int[] AES_KEYSIZES = new int[]{16, 24, 32};
}
即AES的秘鑰字節(jié)數(shù)組長度如果不為16、24、32，將拋出Invalid AES key length異常。
由此可見，AES的秘鑰字節(jié)數(shù)組長度需限制在16、24、32內(nèi)。文章來源：http://www.zghlxwxcb.cn/news/detail-500731.html
package com.xiaoxu.crawler.utils;
import org.apache.commons.codec.binary.Base64;
import org.apache.commons.lang3.ArrayUtils;
import org.springframework.util.StringUtils;
import javax.crypto.*;
import javax.crypto.spec.SecretKeySpec;
import java.io.UnsupportedEncodingException;
import java.nio.charset.StandardCharsets;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;
import java.util.Comparator;
import java.util.List;
import java.util.stream.Collectors;
/**
* @author xiaoxu
* @date 2022-11-06 21:24
* crawlerJ:com.xiaoxu.crawler.utils.AESUtils
*/
public class AESUtils {
private static final String AES_ALGORITHM = "AES";
private static final String UTF8 = StandardCharsets.UTF_8.name();
private static final List<Integer> AES_KEYSIZES = Arrays.asList(16, 24, 32);
public static String newKey(String key){
if(!StringUtils.hasLength(key)){
ExcpUtils.throwExp("new key should not be empty");
}
boolean fl = false;
int len = key.getBytes(StandardCharsets.UTF_8).length;
for (int keySize : AES_KEYSIZES) {
if(len == keySize){
fl = true;
break;
}
}
String newKey = key;
if(!fl){
/* 32、24、16倒序排序 */
List<Integer> new_sizes = AES_KEYSIZES.stream().sorted(new Comparator<Integer>() {
@Override
public int compare(Integer o1, Integer o2) {
return o2-o1;
}
}).collect(Collectors.toList());
int length = 0;
for (int var0 = 0; var0 < new_sizes.size(); var0++) {
if(len > 0 && len < new_sizes.get(new_sizes.size()-1) && var0 == new_sizes.size()-1){
length = len;
}else if(new_sizes.get(var0) <= len){
length = new_sizes.get(var0);
}
if(new_sizes.get(var0) <= len || (len > 0 && len < new_sizes.get(new_sizes.size()-1)&& var0 == new_sizes.size()-1 ) ){
byte[] nKey = new byte[new_sizes.get(var0)];
for (int f = 0; f < new_sizes.get(var0); f++) {
/* 不足16位的末尾補0 */
nKey[f] = (byte)48;
}
System.arraycopy(key.getBytes(StandardCharsets.UTF_8),0,nKey,0,length);
newKey = new String(nKey, StandardCharsets.UTF_8);
break;
}
}
}
return newKey;
}
/* AES加密 String */
public static String encryptStrAES(String text, String key){
if(!StringUtils.hasLength(text)){
ExcpUtils.throwExp("encode text should not be null or empty.");
}
byte[] encodeBytes = encryptByteAES(text.getBytes(StandardCharsets.UTF_8), key);
return Base64.encodeBase64String(encodeBytes);
}
/* AES解密 String*/
public static String decryptStrAES(String text, String key){
if(!StringUtils.hasLength(text)){
ExcpUtils.throwExp("decode text should not be null or empty.");
}
byte[] decodeBytes = decryptByteAES(Base64.decodeBase64(text.getBytes(StandardCharsets.UTF_8)), key);
return new String(decodeBytes, StandardCharsets.UTF_8);
}
/* AES加密 originalBytes */
public static byte[] encryptByteAES(byte[] originalBytes, String key){
if(ArrayUtils.isEmpty(originalBytes)){
ExcpUtils.throwExp("encode originalBytes should not be empty.");
}
if(!StringUtils.hasLength(key)){
ExcpUtils.throwExp("key :" + key + ", encode key should not be null or empty.");
}
Cipher cipher = getAESCipher(key, Cipher.ENCRYPT_MODE);
byte[] encodeBytes = null;
try {
encodeBytes = cipher.doFinal(originalBytes);
} catch (IllegalBlockSizeException | BadPaddingException e) {
ExcpUtils.throwExp(e.getClass().getName()+": encode byte fail. "+e.getMessage());
}
return encodeBytes;
}
/* AES解密 encryptedBytes */
public static byte[] decryptByteAES(byte[] encryptedBytes, String key){
if(ArrayUtils.isEmpty(encryptedBytes)){
ExcpUtils.throwExp("decode encryptedBytes should not be empty.");
}
if(!StringUtils.hasLength(key)){
ExcpUtils.throwExp("key :" + key + ", decode key should not be null or empty.");
}
Cipher cipher = getAESCipher(key, Cipher.DECRYPT_MODE);
byte[] decodeBytes = null;
try {
decodeBytes = cipher.doFinal(encryptedBytes);
} catch (IllegalBlockSizeException | BadPaddingException e) {
ExcpUtils.throwExp(e.getClass().getName()+": decode byte fail. "+e.getMessage());
}
return decodeBytes;
}
public static Cipher getAESCipher(String key, int mode){
if(!StringUtils.hasLength(key)){
ExcpUtils.throwExp("key :" + key + ", should not be null or empty.");
}
Cipher cipher = null;
SecretKey secretKey;
try {
cipher = Cipher.getInstance(AES_ALGORITHM);
byte[] keyBytes = key.getBytes(UTF8);
secretKey = new SecretKeySpec(keyBytes, AES_ALGORITHM);
cipher.init(mode, secretKey);
} catch (NoSuchAlgorithmException | NoSuchPaddingException e) {
ExcpUtils.throwExp(e.getClass().getName()+": get cipher instance wrong. "+e.getMessage());
} catch (UnsupportedEncodingException u){
ExcpUtils.throwExp(u.getClass().getName()+": key transfer bytes fail. "+u.getMessage());
} catch (InvalidKeyException i) {
ExcpUtils.throwExp(i.getClass().getName()+": key is invalid. "+i.getMessage());
}
return cipher;
}
public static void main(String[] args) {
String msg = "小徐123testAes!!!";
// String key = "0382f2bcbacfa8be";
String key = "0382f2bcbacfa8b";
System.out.println("轉(zhuǎn)換前的秘鑰長度:" + key.getBytes(StandardCharsets.UTF_8).length);
System.out.println("轉(zhuǎn)換后秘鑰:"+newKey(key)+";長度:"+newKey(key).getBytes(StandardCharsets.UTF_8).length);
System.out.println("AES秘鑰長度只能為16、24、32:"+newKey(key).getBytes(StandardCharsets.UTF_8).length);
String s = encryptStrAES(msg, newKey(key));
System.out.println("加密后:"+s);
String s1 = decryptStrAES(s, newKey(key));
System.out.println("解密后:"+s1);
}
}
可如上簡單對秘鑰長度作出填充，執(zhí)行結(jié)果如下：文章來源地址http://www.zghlxwxcb.cn/news/detail-500731.html
轉(zhuǎn)換前的秘鑰長度:15
轉(zhuǎn)換后秘鑰:0382f2bcbacfa8b0;長度:16
AES秘鑰長度只能為16、24、32:16
加密后:AAz4gPXlduN+l1OX0BV9nWXqJqhXRS3ThRQXJsU0lWM=
解密后:小徐123testAes!!!
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