Java实现AES ECP PKCS5Padding加解密工具类
Java实现AES ECP PKCS5Padding加解密工具类
一灰灰blog
发布于 2020-05-09 16:36:16
发布于 2020-05-09 16:36:16
Java 实现一个AES/ECB/PKCS5Padding 加解密算法工具类
- 加密算法： AES
- 模式： ECB
- 补码方式： PKCS5Padding
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1. 工具类
import lombok.Getter;
import lombok.Setter;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.Base64Utils;
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.io.BufferedInputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.security.MessageDigest;
/**
* Created by @author yihui in 19:12 20/1/2.
*/
@Slf4j
public class EncryptUtil {
private static final String KEY_ALGORITHM = "AES";
/**
* 算法/模式/补码方式
*/
private static final String DEFAULT_CIPHER_ALGORITHM = "AES/ECB/PKCS5Padding";
private static final String CODE = "utf-8";
@Setter
@Getter
public static String encryptKey;
public static String encrypt(String content) {
return encrypt(content, encryptKey);
}
/**
* 加密
*
* @param content
* @param key
* @return
* @throws Exception
*/
public static String encrypt(String content, String key) {
try {
byte[] encrypted = encrypt2bytes(content, key);
return Base64Utils.encodeToString(encrypted);
} catch (Exception e) {
log.error("failed to encrypt: {} of {}", content, e);
return null;
}
}
public static byte[] encrypt2bytes(String content, String key) {
try {
byte[] raw = key.getBytes(CODE);
SecretKeySpec secretKeySpec = new SecretKeySpec(raw, KEY_ALGORITHM);
Cipher cipher = Cipher.getInstance(DEFAULT_CIPHER_ALGORITHM);
cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec);
return cipher.doFinal(content.getBytes(CODE));
} catch (Exception e) {
log.error("failed to encrypt: {} of {}", content, e);
return null;
}
}
public static String decrypt(String content) {
try {
return decrypt(content, encryptKey);
} catch (Exception e) {
log.error("failed to decrypt: {}, e: {}", content, e);
return null;
}
}
/**
* 解密
*
* @param content
* @param key
* @return
* @throws Exception
*/
public static String decrypt(String content, String key) throws Exception {
return decrypt(Base64Utils.decodeFromString(content), key);
}
public static String decrypt(byte[] content, String key) throws Exception {
if (key == null) {
log.error("AES key should not be null");
return null;
}
byte[] raw = key.getBytes(CODE);
SecretKeySpec keySpec = new SecretKeySpec(raw, KEY_ALGORITHM);
Cipher cipher = Cipher.getInstance(DEFAULT_CIPHER_ALGORITHM);
cipher.init(Cipher.DECRYPT_MODE, keySpec);
try {
byte[] original = cipher.doFinal(content);
return new String(original, CqODE);
} catch (Exception e) {
log.error("failed to decrypt content: {}/ key: {}, e: {}", content, key, e);
return null;
}
}
}请注意上面的实现，提供了两种方式
- 一个是AES加密之后使用base64编码输出，对应的是解密base64编码的数据
- 一个是AES加密之后，直接返回字节数组；也是直接解码字节数组
2. 测试case
我们提供了两个加密的文件，用于解密使用；
base64加解密
@Test
public void testEncrypt() throws Exception {
String abc = "Hello, 一灰灰Blog!";
String key = "JC66fRd3wj85k8Hr";
String out = EncryptUtil.encrypt(abc, key);
System.out.println(out);
System.out.println(EncryptUtil.decrypt(out, key));
}输出结果如:
TKrN7VKrqsAQ4JqygeHOlG21Sd3IRJ3Y11k4kOdOG4s=
Hello, 一灰灰Blog!字节数组加解密
@Test
public void testEncryptByte() throws Exception {
String abc = "Hello, 一灰灰Blog!";
String key = "JC66fRd3wj85k8Hr";
byte[] out = EncryptUtil.encrypt2bytes(abc, key);
System.out.println(new String(out));
System.out.println(EncryptUtil.decrypt(out, key));
}输出结果如:
// 加密的字节数组，就是乱码... 你没看错
L���R��������Δm�I��D���Y8��N�
Hello, 一灰灰Blog!为什么有上面两种区别？
如果我们将加密后的字节数组，直接 new String() 获得一个字符串，然后解密这个字符串，会发现解密失败哦
简单修改一下上面的测试用例
@Test
public void testEncryptByte() throws Exception {
String abc = "Hello, 一灰灰Blog!";
String key = "JC66fRd3wj85k8Hr";
byte[] out = EncryptUtil.encrypt2bytes(abc, key);
String enc = new String(out, "utf-8");
System.out.println(enc);
System.out.println(EncryptUtil.decrypt(enc.getBytes("utf-8"), key));
}执行之后，发现解密失败
为啥会出现这样情况呢？
enc = new String(out, "utf-8")与enc.getBytes("utf-8")字节数组转字符串； 字符串转字节数组这两个过程会导致最终生成的字节数组，与原始的不一致!!!
解密远程资源的case
最后给一个解密远程加密的二进制文件的实例case
private void binKey(String uri, String key) throws Exception {
// 这个文件是没有base64编码，直接上传的二进制
URL url = new URL(uri);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
InputStream stream = connection.getInputStream();
int lenth = connection.getContentLength();
byte[] out = new byte[lenth];
stream.read(out);
stream.close();
String ans = decrypt(out, key);
System.out.println(ans);
}
public void testDe() throws Exception {
String key = "5JRHMJn8xHnMDRXa";
binKey("http://q8rnsprw0.bkt.clouddn.com/mwzz/b0001", key);
}本文参与 腾讯云自媒体分享计划，分享自作者个人站点/博客。
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