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com.gitee.summer9102.develop.common.util.SignUtil Maven / Gradle / Ivy
package com.gitee.summer9102.develop.common.util;
import org.springframework.util.DigestUtils;
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;
public class SignUtil {
/**
* 加密算法RSA
*/
private static final String KEY_ALGORITHM = "RSA";
/**
* 签名算法
*/
private static final String SIGNATURE_ALGORITHM = "MD5withRSA";
/**
* RSA最大加密明文大小
*/
private static final int MAX_ENCRYPT_BLOCK = 117;
/**
* RSA最大解密密文大小
*/
private static final int MAX_DECRYPT_BLOCK = 128;
/**
* base64 decode
*/
private static Base64.Decoder decoder = Base64.getDecoder();
/**
* base64 encode
*/
private static Base64.Encoder encoder = Base64.getEncoder();
public static Base64.Decoder getDecoder() {
return decoder;
}
public static Base64.Encoder getEncoder() {
return encoder;
}
/**
* 生成密钥对(公钥和私钥)(BASE64编码)
*/
public static void genKeys() throws Exception {
KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance(KEY_ALGORITHM);
keyPairGen.initialize(1024);
KeyPair keyPair = keyPairGen.generateKeyPair();
RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
System.out.println("privateKey:" + encoder.encodeToString(privateKey.getEncoded()));
System.out.println("publicKey:" + encoder.encodeToString(publicKey.getEncoded()));
}
/**
* 用私钥对信息生成数字签名
*
* @param data 已加密数据
* @param privateKey 私钥(BASE64编码)
*/
public static String sign(String data, String privateKey) throws Exception {
byte[] keyBytes = decoder.decode(privateKey);
PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
PrivateKey privateK = keyFactory.generatePrivate(pkcs8KeySpec);
Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
signature.initSign(privateK);
signature.update(data.getBytes());
return encoder.encodeToString(signature.sign());
}
/**
* 校验数字签名
*
* @param data 已加密数据
* @param publicKey 公钥(BASE64编码)
* @param sign 数字签名
*/
public static boolean verify(String data, String publicKey, String sign) throws Exception {
byte[] keyBytes = decoder.decode(publicKey);
X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
PublicKey publicK = keyFactory.generatePublic(keySpec);
Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
signature.initVerify(publicK);
signature.update(data.getBytes());
return signature.verify(decoder.decode(sign));
}
/**
* 私钥解密
*
* @param data 已加密数据
* @param privateKey 私钥(BASE64编码)
*/
public static String decryptByPrivateKey(String data, String privateKey) throws Exception {
byte[] encryptedData = decoder.decode(data.getBytes(StandardCharsets.UTF_8));
byte[] keyBytes = decoder.decode(privateKey);
PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.DECRYPT_MODE, privateK);
int inputLen = encryptedData.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(encryptedData, offSet, MAX_DECRYPT_BLOCK);
} else {
cache = cipher.doFinal(encryptedData, offSet, inputLen - offSet);
}
out.write(cache, 0, cache.length);
i++;
offSet = i * MAX_DECRYPT_BLOCK;
}
byte[] decryptedData = out.toByteArray();
out.close();
return new String(decryptedData, StandardCharsets.UTF_8);
}
/**
* 公钥解密
*
* @param data 已加密数据
* @param publicKey 公钥(BASE64编码)
*/
public static String decryptByPublicKey(String data, String publicKey) throws Exception {
byte[] encryptedData = decoder.decode(data.getBytes(StandardCharsets.UTF_8));
byte[] keyBytes = decoder.decode(publicKey);
X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key publicK = keyFactory.generatePublic(x509KeySpec);
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.DECRYPT_MODE, publicK);
int inputLen = encryptedData.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(encryptedData, offSet, MAX_DECRYPT_BLOCK);
} else {
cache = cipher.doFinal(encryptedData, offSet, inputLen - offSet);
}
out.write(cache, 0, cache.length);
i++;
offSet = i * MAX_DECRYPT_BLOCK;
}
byte[] decryptedData = out.toByteArray();
out.close();
return new String(decryptedData, StandardCharsets.UTF_8);
}
/**
* 公钥加密
*
* @param dataStr 源数据
* @param publicKey 公钥(BASE64编码)
*/
public static String encryptByPublicKey(String dataStr, String publicKey) throws Exception {
byte[] data = dataStr.getBytes(StandardCharsets.UTF_8);
byte[] keyBytes = decoder.decode(publicKey);
X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key publicK = keyFactory.generatePublic(x509KeySpec);
// 对数据加密
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.ENCRYPT_MODE, publicK);
int inputLen = data.length;
ByteArrayOutputStream out = new ByteArrayOutputStream();
int offSet = 0;
byte[] cache;
int i = 0;
// 对数据分段加密
while (inputLen - offSet > 0) {
if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);
} else {
cache = cipher.doFinal(data, offSet, inputLen - offSet);
}
out.write(cache, 0, cache.length);
i++;
offSet = i * MAX_ENCRYPT_BLOCK;
}
byte[] encryptedData = out.toByteArray();
out.close();
return encoder.encodeToString(encryptedData);
}
/**
* 私钥加密
*
* @param dataStr 源数据
* @param privateKey 私钥(BASE64编码)
*/
public static String encryptByPrivateKey(String dataStr, String privateKey) throws Exception {
byte[] data = dataStr.getBytes(StandardCharsets.UTF_8);
byte[] keyBytes = decoder.decode(privateKey);
PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.ENCRYPT_MODE, privateK);
int inputLen = data.length;
ByteArrayOutputStream out = new ByteArrayOutputStream();
int offSet = 0;
byte[] cache;
int i = 0;
// 对数据分段加密
while (inputLen - offSet > 0) {
if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);
} else {
cache = cipher.doFinal(data, offSet, inputLen - offSet);
}
out.write(cache, 0, cache.length);
i++;
offSet = i * MAX_ENCRYPT_BLOCK;
}
byte[] encryptedData = out.toByteArray();
out.close();
return encoder.encodeToString(encryptedData);
}
/**
* SHA256签名
*
* @param str 参数
*/
public static String SHA256(String str) {
try {
MessageDigest digest = MessageDigest.getInstance("SHA-256");
digest.update(str.getBytes());
byte[] messageDigest = digest.digest();
// Create Hex String
StringBuilder hexString = new StringBuilder();
// 字节数组转换为 十六进制 数
for (byte b : messageDigest) {
String shaHex = Integer.toHexString(b & 0xFF);
if (shaHex.length() < 2) {
hexString.append(0);
}
hexString.append(shaHex);
}
return hexString.toString();
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
return "";
}
/**
* MD5 使用spring版本
*
* @param str
* @return
*/
public static String MD5(String str) {
return DigestUtils.md5DigestAsHex(str.getBytes(StandardCharsets.UTF_8));
}
}
