package com.fzzy.api.utils;
|
|
|
import lombok.extern.slf4j.Slf4j;
|
import org.apache.commons.lang.ArrayUtils;
|
|
import javax.crypto.Cipher;
|
import java.io.ByteArrayOutputStream;
|
import java.nio.charset.StandardCharsets;
|
import java.security.*;
|
import java.security.interfaces.RSAPrivateKey;
|
import java.security.interfaces.RSAPublicKey;
|
import java.security.spec.PKCS8EncodedKeySpec;
|
import java.security.spec.X509EncodedKeySpec;
|
import java.util.Base64;
|
import java.util.HashMap;
|
import java.util.Map;
|
|
@Slf4j
|
public class RSAUtils {
|
public static final String KEY_ALGORITHM = "RSA";
|
|
private static final String PUBLIC_KEY = "RSAPublicKey";
|
|
private static final String PRIVATE_KEY = "RSAPrivateKey";
|
|
private static final String CHARSET = "utf-8";
|
|
private static final int KEYSIZE = 2048;// 密钥位数
|
private static final int RESERVE_BYTES = 11;
|
private static final String ECB_PADDING = "RSA/ECB/PKCS1Padding";
|
|
// 2048 bits 的 RSA 密钥对，最大解密密文大小
|
private static final int MAX_DECRYPT_BLOCK = KEYSIZE / 8;
|
|
// 2048 bits 的 RSA 密钥对，最大加密明文大小
|
private static final int MAX_ENCRYPT_BLOCK = MAX_DECRYPT_BLOCK - RESERVE_BYTES;
|
|
public static void main(String[] args) throws Exception {
|
Map<String, Object> map = initKey(1024);
|
|
String privateKeyStr = getPrivateKeyStr(map);
|
log.info("-----私钥={}", privateKeyStr);
|
|
String publicKeyStr = getPublicKeyStr(map);
|
log.info("-----公钥={}", publicKeyStr);
|
}
|
|
// 生成密钥对
|
public static Map<String, Object> initKey(int keysize) throws Exception {
|
KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance(KEY_ALGORITHM);
|
// 设置密钥对的 bit 数，越大越安全
|
keyPairGen.initialize(keysize);
|
KeyPair keyPair = keyPairGen.generateKeyPair();
|
|
// 获取公钥
|
RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
|
// 获取私钥
|
RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
|
Map<String, Object> keyMap = new HashMap<>(2);
|
keyMap.put(PUBLIC_KEY, publicKey);
|
keyMap.put(PRIVATE_KEY, privateKey);
|
return keyMap;
|
}
|
|
// 获取公钥字符串
|
public static String getPublicKeyStr(Map<String, Object> keyMap) {
|
// 获得 map 中的公钥对象，转为 key 对象
|
Key key = (Key) keyMap.get(PUBLIC_KEY);
|
// 编码返回字符串
|
return encryptBASE64(key.getEncoded());
|
}
|
|
// 获取私钥字符串
|
public static String getPrivateKeyStr(Map<String, Object> keyMap) {
|
// 获得 map 中的私钥对象，转为 key 对象
|
Key key = (Key) keyMap.get(PRIVATE_KEY);
|
// 编码返回字符串
|
return encryptBASE64(key.getEncoded());
|
}
|
|
// 获取公钥
|
public static PublicKey getPublicKey(String publicKeyString) throws Exception {
|
byte[] publicKeyByte = Base64.getDecoder().decode(publicKeyString);
|
X509EncodedKeySpec keySpec = new X509EncodedKeySpec(publicKeyByte);
|
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
|
return keyFactory.generatePublic(keySpec);
|
}
|
|
// 获取私钥
|
public static PrivateKey getPrivateKey(String privateKeyString) throws Exception {
|
byte[] privateKeyByte = Base64.getDecoder().decode(privateKeyString);
|
PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(privateKeyByte);
|
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
|
return keyFactory.generatePrivate(keySpec);
|
}
|
|
/**
|
* BASE64 编码返回加密字符串
|
*
|
* @param key 需要编码的字节数组
|
* @return 编码后的字符串
|
*/
|
public static String encryptBASE64(byte[] key) {
|
return new String(Base64.getEncoder().encode(key));
|
}
|
|
/**
|
* BASE64 解码，返回字节数组
|
*
|
* @param key 待解码的字符串
|
* @return 解码后的字节数组
|
*/
|
public static byte[] decryptBASE64(String key) {
|
return Base64.getDecoder().decode(key);
|
}
|
|
/**
|
* 公钥加密
|
*
|
* @param text 待加密的明文字符串
|
* @param publicKeyStr 公钥
|
* @return 加密后的密文
|
*/
|
public static String encrypt(String text, String publicKeyStr) {
|
try {
|
log.info("明文字符串为:[{}]", text);
|
Cipher cipher = Cipher.getInstance(KEY_ALGORITHM);
|
cipher.init(Cipher.ENCRYPT_MODE, getPublicKey(publicKeyStr));
|
|
// URLEncoder编码解决中文乱码问题
|
byte[] data = text.getBytes(StandardCharsets.UTF_8);
|
// 加密时超过117字节就报错。为此采用分段加密的办法来加密
|
byte[] enBytes = null;
|
for (int i = 0; i < data.length; i += MAX_ENCRYPT_BLOCK) {
|
// 注意要使用2的倍数，否则会出现加密后的内容再解密时为乱码
|
byte[] doFinal = cipher.doFinal(ArrayUtils.subarray(data, i, i + MAX_ENCRYPT_BLOCK));
|
enBytes = ArrayUtils.addAll(enBytes, doFinal);
|
}
|
return Base64.getEncoder().encodeToString(enBytes);
|
} catch (Exception e) {
|
throw new RuntimeException("加密字符串[" + text + "]时遇到异常", e);
|
}
|
}
|
|
/**
|
* 私钥解密
|
*
|
* @param secretText 待解密的密文字符串
|
* @param privateKeyStr 私钥
|
* @return 解密后的明文
|
*/
|
public static String decrypt(String secretText, String privateKeyStr) {
|
try {
|
// 生成私钥
|
Cipher cipher = Cipher.getInstance(KEY_ALGORITHM);
|
cipher.init(Cipher.DECRYPT_MODE, getPrivateKey(privateKeyStr));
|
// 密文解码
|
byte[] data = Base64.getDecoder().decode(secretText);
|
|
// 返回UTF-8编码的解密信息
|
int inputLen = data.length;
|
ByteArrayOutputStream out = new ByteArrayOutputStream();
|
int offSet = 0;
|
byte[] cache;
|
int i = 0;
|
// 对数据分段解密
|
while (inputLen - offSet > 0) {
|
if (inputLen - offSet > MAX_DECRYPT_BLOCK) {
|
cache = cipher.doFinal(data, offSet, MAX_DECRYPT_BLOCK);
|
} else {
|
cache = cipher.doFinal(data, offSet, inputLen - offSet);
|
}
|
out.write(cache, 0, cache.length);
|
i++;
|
offSet = i * MAX_DECRYPT_BLOCK;
|
}
|
out.close();
|
return out.toString(CHARSET);
|
} catch (Exception e) {
|
throw new RuntimeException("解密字符串[" + secretText + "]时遇到异常", e);
|
}
|
}
|
|
/**
|
* 私钥加密
|
*
|
* @param text
|
* @param privateInfoStr
|
* @return
|
*/
|
public static String encryptData(String text, String privateInfoStr) {
|
try {
|
log.info("明文字符串为:[{}]", text);
|
Cipher cipher = Cipher.getInstance(ECB_PADDING);
|
cipher.init(Cipher.ENCRYPT_MODE, getPrivateKey(privateInfoStr));
|
|
// URLEncoder编码解决中文乱码问题
|
byte[] data = text.getBytes(StandardCharsets.UTF_8);
|
byte[] enBytes = null;
|
for (int i = 0; i < data.length; i += MAX_ENCRYPT_BLOCK) {
|
// 注意要使用2的倍数，否则会出现加密后的内容再解密时为乱码
|
byte[] doFinal = cipher.doFinal(ArrayUtils.subarray(data, i, i + MAX_ENCRYPT_BLOCK));
|
enBytes = ArrayUtils.addAll(enBytes, doFinal);
|
}
|
return Base64.getEncoder().encodeToString(enBytes);
|
} catch (Exception e) {
|
throw new RuntimeException("加密字符串[" + text + "]时遇到异常", e);
|
}
|
}
|
|
/**
|
* 公钥解密
|
*
|
* @param secretText
|
* @param publicInfoStr
|
* @return
|
*/
|
public static String decryptData(String secretText, String publicInfoStr) {
|
try {
|
//解密
|
Cipher cipher = Cipher.getInstance(ECB_PADDING);
|
cipher.init(Cipher.DECRYPT_MODE, getPublicKey(publicInfoStr));
|
|
// 密文解码
|
byte[] data = Base64.getDecoder().decode(secretText);
|
|
// 返回UTF-8编码的解密信息
|
int inputLen = data.length;
|
ByteArrayOutputStream out = new ByteArrayOutputStream();
|
int offSet = 0;
|
byte[] cache;
|
int i = 0;
|
// 对数据分段解密
|
while (inputLen - offSet > 0) {
|
if (inputLen - offSet > MAX_DECRYPT_BLOCK) {
|
cache = cipher.doFinal(data, offSet, MAX_DECRYPT_BLOCK);
|
} else {
|
cache = cipher.doFinal(data, offSet, inputLen - offSet);
|
}
|
out.write(cache, 0, cache.length);
|
i++;
|
offSet = i * MAX_DECRYPT_BLOCK;
|
}
|
out.close();
|
return out.toString(CHARSET);
|
} catch (Exception e) {
|
throw new RuntimeException("解密字符串[" + secretText + "]时遇到异常", e);
|
}
|
}
|
|
}
|
