RSA签名加密工具类

电玩女神 2023-10-18 21:56 99阅读 0赞

**目录**

一、工具类demo1

二、工具类demo2

三、工具类demo3

--------------------

### 一、工具类demo1 ###

package com.ykx.transfer.contorller;
    
    import java.security.KeyFactory;
    import java.security.NoSuchAlgorithmException;
    import java.security.PrivateKey;
    import java.security.PublicKey;
    import java.security.Signature;
    import java.security.spec.InvalidKeySpecException;
    import java.security.spec.PKCS8EncodedKeySpec;
    import java.security.spec.X509EncodedKeySpec;
    import javax.crypto.Cipher;
    
    import org.apache.commons.codec.binary.Base64;
    import org.apache.http.HttpEntity;
    import org.apache.http.HttpResponse;
    import org.apache.http.client.HttpClient;
    import org.apache.http.client.methods.HttpPost;
    import org.apache.http.entity.StringEntity;
    import org.apache.http.impl.client.HttpClients;
    import org.apache.http.util.EntityUtils;
    
    import net.sf.json.JSONObject;
    
    public class RSADemo {
        public static final String ALGORITHM = "RSA";
        public static final String SIGNATURE_ALGORITHM="MD5withRSA";
        private static String publickey = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDazJE8JgkL4hXA5pJwuBu9skcCrA6cQBGws3G0rmIp/K51sqGVCradW8ait03/5/sUKoHDF2tu89dcuhTYBxgidMDmyBlAznU8WRt9FrgCtlhq4evcq+ZeUAPyXtvBMU18gNJq0EctJbszjTBkGvHuEuJes5lPs3nT+eHG1edwfQIDAQAB";
        private static String privatekey = ;
    
        public void Test() throws Exception {}
        public static PublicKey getPublicKey(String key) throws Exception {
            X509EncodedKeySpec keySpec = new X509EncodedKeySpec(
                    Base64.decodeBase64(key));
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            PublicKey publicKey = keyFactory.generatePublic(keySpec);
            return publicKey;
        }
    
        public static PrivateKey getPrivateKey(String key)
                throws NoSuchAlgorithmException, InvalidKeySpecException {
            PKCS8EncodedKeySpec privatekeySpec = new PKCS8EncodedKeySpec(
                    Base64.decodeBase64(key));
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            return keyFactory.generatePrivate(privatekeySpec);
        }
    
        public static byte[] encrypt(String text, PublicKey key) {
            byte[] cipherText = null;
            try {
                final Cipher cipher = Cipher.getInstance(ALGORITHM);
                cipher.init(Cipher.ENCRYPT_MODE, key);
                cipherText = cipher.doFinal(text.getBytes());
            } catch (Exception e) {
                e.printStackTrace();
            }
            return cipherText;
        }
        
        /**
         * RSA算法使用公钥校验数字签名
         *
         * @param data 参与签名的明文字符串
         * @param key  RSA公钥字符串
         * @param sign RSA签名得到的经过Base64编码的字符串
         * @return true--验签通过,false--验签未通过
         */
        public static boolean buildRSAverifyByPublicKey(String data, String key, String sign) {
            try {
                //通过X509编码的Key指令获得公钥对象
                X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(java.util.Base64.getDecoder().decode(key));
                KeyFactory keyFactory = KeyFactory.getInstance("RSA");
                PublicKey publicKey = keyFactory.generatePublic(x509KeySpec);
                Signature signature = Signature.getInstance("MD5withRSA");
                signature.initVerify(publicKey);
                signature.update(data.getBytes("utf-8"));
                return signature.verify(java.util.Base64.getDecoder().decode(sign));
            } catch (Exception e) {
                throw new RuntimeException("验签字符串[" + data + "]时遇到异常", e);
            }
        }
        
        public static void main(String[] args) throws Exception{
    
            HttpPost post = new HttpPost("http://127.0.0.1:8081/transfer/placeorder");
            //获取securityKey
            PublicKey publicKey = getPublicKey(publickey);
            PrivateKey privateKey = getPrivateKey(privatekey);
            //拼装查询条件xxx=xxx&yyy=yyy&zzz=zzz
            String param = "startStationCode=8001qj&pathPoint=綦江";
          
            //签名
             Signature sig = Signature.getInstance(SIGNATURE_ALGORITHM);        
             sig.initSign(privateKey);
             sig.update(param.getBytes());
             byte[] sign = sig.sign();
             String signature = Base64.encodeBase64String(sign);
             
            //加密
            byte[] encrypt = encrypt(param, publicKey);
            String encodeBase64String = Base64.encodeBase64String(encrypt);
            //拼装json格式请求参数
            JSONObject json = new JSONObject();
            json.put("data", encodeBase64String);
            json.put("signature",signature);
            StringEntity entity = new StringEntity(json.toString(),"UTF-8");
            //设置content编码及类型
            entity.setContentEncoding("UTF-8");
            entity.setContentType("application/json");
            post.setEntity(entity);
            //模拟http post请求发送信息
            HttpClient client = HttpClients.createDefault();
            HttpResponse response = client.execute(post);
            System.out.println(response.getStatusLine().getStatusCode());
            if(response.getStatusLine().getStatusCode() ==200){
                HttpEntity entity_r = response.getEntity();
                String personal = EntityUtils.toString(entity_r);
                System.out.println(personal);
            }
        
    	}
    }

### 二、工具类demo2 ###

import java.io.ByteArrayInputStream;
    import java.io.InputStream;
    import java.io.InputStreamReader;
    import java.io.StringWriter;
    import java.security.Key;
    import java.security.KeyFactory;
    import java.security.KeyPair;
    import java.security.KeyPairGenerator;
    import java.security.NoSuchAlgorithmException;
    import java.security.PrivateKey;
    import java.security.PublicKey;
    import java.security.Signature;
    import java.security.spec.PKCS8EncodedKeySpec;
    import java.security.spec.X509EncodedKeySpec;
    import java.util.ArrayList;
    import java.util.Collections;
    import java.util.HashMap;
    import java.util.List;
    import java.util.Map;
    import org.apache.commons.codec.binary.Base64;
    import org.apache.commons.lang3.StringUtils;
    import com.ykx.orderCenter.dubbo.security.StreamUtil;
    import sun.misc.BASE64Decoder;
    
    /**   
     * 类名称：util   
     * 类描述：   
     * 创建人：Administrator
     * 创建时间：2019年7月23日 下午4:22:13   
     * 修改人：Administrator
     * 修改时间：2019年7月23日 下午4:22:13   
     * 修改备注：   
     * @version       
     */
    
    public class RSASignUtil {
    	/**	签名算法 */
        private static final String SIGN_SHA256RSA_ALGORITHMS = "SHA256WithRSA";
        
        /**	签名类型*/
        private static final String SIGN_TYPE_RSA = "RSA";
        
        /**	算法长度，默认2048*/
        public static final int KEY_SIZE = 2048;
        
        /**
         *	 初始化RSA算法密钥对
         *
         * @param keysize RSA1024已经不安全了,建议2048
         * @return 经过Base64编码后的公私钥Map, 键名分别为publicKey和privateKey
         */
        public static Map<String, String> initRSAKey(int keysize) {
            if (keysize != KEY_SIZE) {
                throw new IllegalArgumentException("RSA1024已经不安全了,请使用" + KEY_SIZE + "初始化RSA密钥对");
            }
            //为RSA算法创建一个KeyPairGenerator对象
            KeyPairGenerator kpg;
            try {
                kpg = KeyPairGenerator.getInstance(SIGN_TYPE_RSA);
            } catch (NoSuchAlgorithmException e) {
                throw new IllegalArgumentException("No such algorithm-->[" + SIGN_TYPE_RSA + "]");
            }
            //初始化KeyPairGenerator对象,不要被initialize()源码表面上欺骗,其实这里声明的size是生效的
            kpg.initialize(KEY_SIZE);
            //生成密匙对
            KeyPair keyPair = kpg.generateKeyPair();
            //得到公钥
            Key publicKey = keyPair.getPublic();
            String publicKeyStr = java.util.Base64.getEncoder().encodeToString(publicKey.getEncoded());
            //得到私钥
            Key privateKey = keyPair.getPrivate();
            String privateKeyStr = java.util.Base64.getEncoder().encodeToString(privateKey.getEncoded());
            Map<String, String> keyPairMap = new HashMap<String, String>();
            keyPairMap.put("publicKey", publicKeyStr);
            keyPairMap.put("privateKey", privateKeyStr);
            return keyPairMap;
        }
       
        
       
        /**
         * 
         * @Description: 字符串转公钥方法1
         * @param:@param key
         * @param:@return
         * @param:@throws Exception
         * @return：PublicKey
         * @throws：
         *
         * @version: v1.0.0
         * @author: Administrator
         * @date: 2019年7月24日 上午11:06:36 
         */
        public static PublicKey getPublicKeyFromX509(String key) throws Exception {
        	InputStream ins=new ByteArrayInputStream(key.getBytes());
            KeyFactory keyFactory = KeyFactory.getInstance(SIGN_TYPE_RSA);
            StringWriter writer = new StringWriter();
            StreamUtil.io(new InputStreamReader(ins), writer);
            byte[] encodedKey = writer.toString().getBytes();
            encodedKey = Base64.decodeBase64(encodedKey);
            return keyFactory.generatePublic(new X509EncodedKeySpec(encodedKey));
        }
        
        
        /**
         * 
         * @Description: 字符串转公钥方法2
         * @param:@param key
         * @param:@return
         * @param:@throws Exception
         * @return：PublicKey
         * @throws：
         *
         * @version: v1.0.0
         * @author: Administrator
         * @date: 2019年7月24日 上午11:06:36 
         */
        public static PublicKey getPublicKey(String key) throws Exception {
            byte[] keyBytes;
            keyBytes = (new BASE64Decoder()).decodeBuffer(key);
            X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
            KeyFactory keyFactory = KeyFactory.getInstance(SIGN_TYPE_RSA);
            PublicKey publicKey = keyFactory.generatePublic(keySpec);
            return publicKey;
      }
    
        /**
         * 
         * @Description: 字符串转私钥方法1
         * @param:@param key
         * @param:@return
         * @param:@throws Exception
         * @return：PrivateKey
         * @throws：
         *
         * @version: v1.0.0
         * @author: Administrator
         * @date: 2019年7月24日 上午11:06:39 
         */
        public static PrivateKey getPrivateKey(String key) throws Exception {
            byte[] keyBytes;
            keyBytes = (new BASE64Decoder()).decodeBuffer(key);
            //	通过PKCS#8编码的Key指令获得私钥对象
            PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(keyBytes);
            KeyFactory keyFactory = KeyFactory.getInstance(SIGN_TYPE_RSA);
            PrivateKey privateKey = keyFactory.generatePrivate(keySpec);
            return privateKey;
      }
        
        /**
         * 
         * @Description: TODO字符串转私钥方法2
         * @param:@param key
         * @param:@return
         * @param:@throws Exception
         * @return：PrivateKey
         * @throws：
         * @version: v1.0.0
         * @author: Administrator
         * @date: 2019年11月12日 下午4:56:50
         */
        public static PrivateKey getPrivateKeyFromPKCS8(String key) throws Exception {
        	InputStream ins=new ByteArrayInputStream(key.getBytes());
        	if (ins == null || StringUtils.isEmpty(SIGN_TYPE_RSA)) {
                return null;
            }
            KeyFactory keyFactory = KeyFactory.getInstance(SIGN_TYPE_RSA);
            byte[] encodedKey = StreamUtil.readText(ins).getBytes();
            encodedKey = Base64.decodeBase64(encodedKey);
            return keyFactory.generatePrivate(new PKCS8EncodedKeySpec(encodedKey));
        }
        /**
         * 
         * @Description: 处理待加密数据处理为URL键值对的格式（即key1=value1&key2=value2…）拼接成字符串stringA。
         * 	特别注意以下重要规则：
    	 *	  	◆ 参数名ASCII码从小到大排序（字典序）；
    	 *  	◆ 如果参数的值为空不参与签名； 
    	 *  	◆ 参数名区分大小写； 
         * @param:@param params
         * @param:@return
         * @return：String
         * @throws：
         * @version: v1.0.0
         * @author: Administrator
         * @date: 2019年11月12日 下午2:09:36
         */
        public static String getSignCheckContent(Map<String, String> params) {
            if (params == null) {
                return null;
            }
            StringBuffer content = new StringBuffer();
            List<String> keys = new ArrayList<String>(params.keySet());
            Collections.sort(keys);
            for (int i = 0; i < keys.size(); i++) {
                String key = keys.get(i);
                String value = params.get(key);
                content.append((i == 0 ? "" : "&") + key + "=" + value);
            }
            return content.toString();
        }
        
    	/**
    	 * 	 私钥签名
         * 
         * @param data 待签名的明文字符串
         * @param privateKey RSA私钥字符串
         * @return RSA私钥签名后的经过Base64编码的字符串
    	 * @throws Exception 
         */
    	@SuppressWarnings("unused")
    	private static String sign(String data, String privateKey,String charset){
    	    	  try {
    	    		PrivateKey priKey =getPrivateKey(privateKey);
    		        Signature signature = Signature.getInstance(SIGN_SHA256RSA_ALGORITHMS);
    		        signature.initSign(priKey);
    		        if (StringUtils.isEmpty(charset)) {
    		            signature.update(data.getBytes());
    		        } else {
    		            signature.update(data.getBytes(charset));
    		        }
    			 return new String(Base64.encodeBase64(signature.sign()));
    //			 return Base64.getEncoder().encodeToString(signature.sign());
    	    } catch (Exception e) {
    	    	throw new RuntimeException("签名字符串[" + data + " ]时遇到异常", e);
    	    }
        }
        
     
        
        /**
                   * 公钥 验签
         * @param srcData 原始字符串
         * @param publicKey 公钥
         * @param sign 签名
         * @return 是否验签通过
         */
        @SuppressWarnings("unused")
    	private static boolean verify(String data, String publicKey, String sign,String charset){
    	    try {
    	    	PublicKey pubKey = getPublicKey(publicKey);
    	        Signature signature = Signature.getInstance(SIGN_SHA256RSA_ALGORITHMS);
    	        signature.initVerify(pubKey);
    	        if (StringUtils.isEmpty(charset)) {
    	            signature.update(data.getBytes());
    	        } else {
    	            signature.update(data.getBytes(charset));
    	        }
    	        return signature.verify(Base64.decodeBase64(sign.getBytes()));
    	    } catch (Exception e) {
    	    	 throw new RuntimeException("验签字符串[" + data + "	]时遇到异常", e);
    	    }
        }
        
        /**
         * 
         * @Description: 公钥验签
         * @param:@param params
         * @param:@param publicKey
         * @param:@param charset
         * @param:@param sign
         * @param:@return
         * @return：boolean
         * @throws：
         * @version: v1.0.0
         * @author: Administrator
         * @date: 2019年11月12日 下午2:12:38
         */
        public static boolean rsa256Check(Map<String, String> params, String publicKey, String charset,String sign) {
            String content = getSignCheckContent(params);
            return verify(content, sign, publicKey, charset);
        }
        
        
       
        
    }

### 三、工具类demo3 ###

import java.io.ByteArrayOutputStream;
    import java.security.Key;
    import java.security.KeyFactory;
    import java.security.KeyPair;
    import java.security.KeyPairGenerator;
    import java.security.NoSuchAlgorithmException;
    import java.security.PrivateKey;
    import java.security.PublicKey;
    import java.security.Signature;
    import java.security.spec.PKCS8EncodedKeySpec;
    import java.security.spec.X509EncodedKeySpec;
    import java.util.Base64;
    import java.util.HashMap;
    import java.util.Map;
    
    import javax.crypto.Cipher;
    
    import org.apache.commons.io.IOUtils;
    
    /**
     * 加解密工具类
     */
    public final class EncryptDecryptUtil {
    	public static final String CHARSET = "UTF-8";
        //密钥算法
        public static final String ALGORITHM_RSA = "RSA";
        //RSA 签名算法
        public static final String ALGORITHM_RSA_SIGN = "SHA256WithRSA";
        public static final int ALGORITHM_RSA_PRIVATE_KEY_LENGTH = 2048;
        
        private EncryptDecryptUtil() {
        }
        
        /**
         * 初始化RSA算法密钥对
         *
         * @param keysize RSA1024已经不安全了,建议2048
         * @return 经过Base64编码后的公私钥Map, 键名分别为publicKey和privateKey
         */
        public static Map<String, String> initRSAKey(int keysize) {
            if (keysize != ALGORITHM_RSA_PRIVATE_KEY_LENGTH) {
                throw new IllegalArgumentException("RSA1024已经不安全了,请使用" + ALGORITHM_RSA_PRIVATE_KEY_LENGTH + "初始化RSA密钥对");
            }
            //为RSA算法创建一个KeyPairGenerator对象
            KeyPairGenerator kpg;
            try {
                kpg = KeyPairGenerator.getInstance(ALGORITHM_RSA);
            } catch (NoSuchAlgorithmException e) {
                throw new IllegalArgumentException("No such algorithm-->[" + ALGORITHM_RSA + "]");
            }
            //初始化KeyPairGenerator对象,不要被initialize()源码表面上欺骗,其实这里声明的size是生效的
            kpg.initialize(ALGORITHM_RSA_PRIVATE_KEY_LENGTH);
            //生成密匙对
            KeyPair keyPair = kpg.generateKeyPair();
            //得到公钥
            Key publicKey = keyPair.getPublic();
            String publicKeyStr = Base64.getEncoder().encodeToString(publicKey.getEncoded());
            //得到私钥
            Key privateKey = keyPair.getPrivate();
            String privateKeyStr = Base64.getEncoder().encodeToString(privateKey.getEncoded());
            Map<String, String> keyPairMap = new HashMap<String, String>();
            keyPairMap.put("publicKey", publicKeyStr);
            keyPairMap.put("privateKey", privateKeyStr);
            return keyPairMap;
        }
    
        /**
         * RSA算法公钥加密数据
         *
         * @param data 待加密的明文字符串
         * @param key  RSA公钥字符串
         * @return RSA公钥加密后的经过Base64编码的密文字符串
         */
        public static String buildRSAEncryptByPublicKey(String data, String key) {
            try {
                //通过X509编码的Key指令获得公钥对象
                X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(Base64.getDecoder().decode(key));
                KeyFactory keyFactory = KeyFactory.getInstance(ALGORITHM_RSA);
                Key publicKey = keyFactory.generatePublic(x509KeySpec);
                Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
                cipher.init(Cipher.ENCRYPT_MODE, publicKey);
                return Base64.getEncoder().encodeToString(rsaSplitCodec(cipher, Cipher.ENCRYPT_MODE, data.getBytes(CHARSET)));
            } catch (Exception e) {
                throw new RuntimeException("加密字符串[" + data + "]时遇到异常", e);
            }
        }
        /**
         * RSA算法公钥解密数据
         *
         * @param data 待解密的经过Base64编码的密文字符串
         * @param key  RSA公钥字符串
         * @return RSA公钥解密后的明文字符串
         */
        public static String buildRSADecryptByPublicKey(String data, String key) {
            try {
                //通过X509编码的Key指令获得公钥对象
                X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(Base64.getDecoder().decode(key));
                KeyFactory keyFactory = KeyFactory.getInstance(ALGORITHM_RSA);
                Key publicKey = keyFactory.generatePublic(x509KeySpec);
                Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
                cipher.init(Cipher.DECRYPT_MODE, publicKey);
                return new String(rsaSplitCodec(cipher, Cipher.DECRYPT_MODE, Base64.getDecoder().decode(data)), CHARSET);
            } catch (Exception e) {
                throw new RuntimeException("解密字符串[" + data + "]时遇到异常", e);
            }
        }
        /**
         * RSA算法私钥加密数据
         *
         * @param data 待加密的明文字符串
         * @param key  RSA私钥字符串
         * @return RSA私钥加密后的经过Base64编码的密文字符串
         */
        public static String buildRSAEncryptByPrivateKey(String data, String key) {
            try {
                //通过PKCS#8编码的Key指令获得私钥对象
                PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(Base64.getDecoder().decode(key));
                KeyFactory keyFactory = KeyFactory.getInstance(ALGORITHM_RSA);
                Key privateKey = keyFactory.generatePrivate(pkcs8KeySpec);
                Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
                cipher.init(Cipher.ENCRYPT_MODE, privateKey);
                return Base64.getEncoder().encodeToString(rsaSplitCodec(cipher, Cipher.ENCRYPT_MODE, data.getBytes(CHARSET)));
            } catch (Exception e) {
                throw new RuntimeException("加密字符串[" + data + "]时遇到异常", e);
            }
        }
        /**
         * RSA算法私钥解密数据
         * @param data 待解密的经过Base64编码的密文字符串
         * @param key  RSA私钥字符串
         * @return RSA私钥解密后的明文字符串
         */
        public static String buildRSADecryptByPrivateKey(String data, String key) {
            try {
                //通过PKCS#8编码的Key指令获得私钥对象
                PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(Base64.getDecoder().decode(key));
                KeyFactory keyFactory = KeyFactory.getInstance(ALGORITHM_RSA);
                Key privateKey = keyFactory.generatePrivate(pkcs8KeySpec);
                Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
                cipher.init(Cipher.DECRYPT_MODE, privateKey);
                return new String(rsaSplitCodec(cipher, Cipher.DECRYPT_MODE, Base64.getDecoder().decode(data)), CHARSET);
            } catch (Exception e) {
                throw new RuntimeException("解密字符串[" + data + "]时遇到异常", e);
            }
        }
        /**
         * RSA算法使用私钥对数据生成数字签名
         *
         * @param data 待签名的明文字符串
         * @param key  RSA私钥字符串
         * @return RSA私钥签名后的经过Base64编码的字符串
         */
        public static String buildRSASignByPrivateKey(String data, String key) {
            try {
                //通过PKCS#8编码的Key指令获得私钥对象
                PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(Base64.getDecoder().decode(key));
                KeyFactory keyFactory = KeyFactory.getInstance(ALGORITHM_RSA);
                PrivateKey privateKey = keyFactory.generatePrivate(pkcs8KeySpec);
                Signature signature = Signature.getInstance(ALGORITHM_RSA_SIGN);
                signature.initSign(privateKey);
                signature.update(data.getBytes(CHARSET));
                return Base64.getEncoder().encodeToString(signature.sign());
            } catch (Exception e) {
                throw new RuntimeException("签名字符串[" + data + "]时遇到异常", e);
            }
        }
        
        /**
         * RSA算法使用公钥校验数字签名
         *
         * @param data 参与签名的明文字符串
         * @param key  RSA公钥字符串
         * @param sign RSA签名得到的经过Base64编码的字符串
         * @return true--验签通过,false--验签未通过
         */
        public static boolean buildRSAverifyByPublicKey(String data, String key, String sign) {
            try {
                //通过X509编码的Key指令获得公钥对象
                X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(Base64.getDecoder().decode(key));
                KeyFactory keyFactory = KeyFactory.getInstance(ALGORITHM_RSA);
                PublicKey publicKey = keyFactory.generatePublic(x509KeySpec);
                Signature signature = Signature.getInstance(ALGORITHM_RSA_SIGN);
                signature.initVerify(publicKey);
                signature.update(data.getBytes(CHARSET));
                return signature.verify(Base64.getDecoder().decode(sign));
            } catch (Exception e) {
                throw new RuntimeException("验签字符串[" + data + "]时遇到异常", e);
            }
        }
    
        /**
         * RSA算法分段加解密数据
         *
         * @param cipher 初始化了加解密工作模式后的javax.crypto.Cipher对象
         * @param opmode 加解密模式,值为javax.crypto.Cipher.ENCRYPT_MODE/DECRYPT_MODE
         * @return 加密或解密后得到的数据的字节数组
         */
        private static byte[] rsaSplitCodec(Cipher cipher, int opmode, byte[] datas) {
            int maxBlock = 0;
            if (opmode == Cipher.DECRYPT_MODE) {
                maxBlock = ALGORITHM_RSA_PRIVATE_KEY_LENGTH / 8;
            } else {
                maxBlock = ALGORITHM_RSA_PRIVATE_KEY_LENGTH / 8 - 11;
            }
            ByteArrayOutputStream out = new ByteArrayOutputStream();
            int offSet = 0;
            byte[] buff;
            int i = 0;
            try {
                while (datas.length > offSet) {
                    if (datas.length - offSet > maxBlock) {
                        buff = cipher.doFinal(datas, offSet, maxBlock);
                    } else {
                        buff = cipher.doFinal(datas, offSet, datas.length - offSet);
                    }
                    out.write(buff, 0, buff.length);
                    i++;
                    offSet = i * maxBlock;
                }
            } catch (Exception e) {
                throw new RuntimeException("加解密阀值为[" + maxBlock + "]的数据时发生异常", e);
            }
            byte[] resultDatas = out.toByteArray();
            IOUtils.closeQuietly(out);
            return resultDatas;
        }
        
        public static void main(String[] args) {
            String privateKey="秘钥";
            String publicKey="公钥";
            System.out.println("签名:"+buildRSASignByPrivateKey("ABCabc123测试", privateKey));
            System.out.println("校验:"+buildRSAverifyByPublicKey("ABCabc123测试",publicKey,buildRSASignByPrivateKey("ABCabc123测试", privateKey)));
          
        }
    
    }