1.RSA简介
RSA是目前使用最广泛的公钥密码体制之一,可以实现非对称加密。它是1977年由罗纳德·李维斯特（Ron Rivest）、阿迪·萨莫尔（Adi Shamir）和伦纳德·阿德曼（Leonard Adleman）一起提出的。当时他们三人都在麻省理工学院工作。RSA就是他们三人姓氏开头字母拼在一起组成的。RSA算法的安全性基于RSA问题的困难性，也就是基于大整数因子分解的困难性上。但是RSA问题不会比因子分解问题更加困难，也就是说，在没有解决因子分解问题的情况下可能解决RSA问题，因此RSA算法并不是完全基于大整数因子分解的困难性上的。
2.代码样例
a.RSAHelper.java工具类
import java.io.ByteArrayOutputStream;import java.io.IOException;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.interfaces.RSAPrivateKey;import java.security.interfaces.RSAPublicKey;import java.security.spec.InvalidKeySpecException;import java.security.spec.PKCS8EncodedKeySpec;import java.security.spec.X509EncodedKeySpec;import javax.crypto.BadPaddingException;import javax.crypto.Cipher;import javax.crypto.IllegalBlockSizeException;import mons.codec.binary.Base64;import org.springframework.util.Base64Utils;/*** RSA加解密工具类* @author shixiangcheng* -04-29*/public final class RSAHelper {public static final String PUBLIC_KEY_VALUES = "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA0bb7yxuvRIWOUxlTbTXE\n" +"cKX5f4Q6+BBOf1fYJKic9l6Wf1QPmyt6ML7PywaPH861D7eYoQl0bGNK2fKsgcAG\n" +"ZzObG5CpmP8ESnSzqcjltdAgx+neCZQy7yUmXUIhpBEQMN80CNYoasOxeZTdPh2w\n" +"zhlmwa27ubkvpINtKUfZbg8sQ5wiDGbLM32ej8z2Rl8DNY4vrusJaNXB7LWaRQm7\n" +"4lPhLN2B/hMv/Ktif4iNxUCYDY97Xws2kVVu7ffWkn4rnhiCrTw2XMZRjIJq3a4o\n" +"4zGWUhYm0usVOLz+yG22cLSCIDhM8tBXL2f3960l4OIQbSObfQkGnqlmi0Fe686p\n" +"gwIDAQAB";public static final String PRIVATE_KEY_VALUES = "MIIEvgIBADANBgkqhkiG9w0BAQEFAASCBKgwggSkAgEAAoIBAQDRtvvLG69EhY5T\n" +"GVNtNcRwpfl/hDr4EE5/V9gkqJz2XpZ/VA+bK3owvs/LBo8fzrUPt5ihCXRsY0rZ\n" +"8qyBwAZnM5sbkKmY/wRKdLOpyOW10CDH6d4JlDLvJSZdQiGkERAw3zQI1ihqw7F5\n" +"lN0+HbDOGWbBrbu5uS+kg20pR9luDyxDnCIMZsszfZ6PzPZGXwM1ji+u6wlo1cHs\n" +"tZpFCbviU+Es3YH+Ey/8q2J/iI3FQJgNj3tfCzaRVW7t99aSfiueGIKtPDZcxlGM\n" +"gmrdrijjMZZSFibS6xU4vP7IbbZwtIIgOEzy0FcvZ/f3rSXg4hBtI5t9CQaeqWaL\n" +"QV7rzqmDAgMBAAECggEBAIpVZ5Y8tso+RvmttQhO9TtRYFirArLrHryFV4Am8RLa\n" +"pe9rpbe3YCyTUUIdG3/hvDGX68geEnwEqzVFDGGyJwcgVWpDbHwNi+kJPhH7APuD\n" +"RHxaWip7ZXW2Ta4ql0JANyvlr888ZQC4AXOvrJjywNPSkaOkVDZYX4LnZrRaPqSH\n" +"j9iVGuKK4nbqbXP1tuLyto6bsn3L2KuwrBthtiDPaZ1cRm3aSu/XND030iSGloW/\n" +"/f6vHI3U//cPFPdi8p54nbpGTB0E66D2xbfK5+z9dZYoFDZUdMsloR1JgS4vQErr\n" +"17165RS7cpWx2HejiKat6qmNFXkHbREpcLDT+lq91LECgYEA7wqm+mIFIYyXEARc\n" +"lKKabCKaufKE+7kyBGpAEyon1lYZHw62dCYkGmuXULam4IAz7TesWsbG5SEgDx/A\n" +"jeFSoC6NTyyTzSh1I08UHdOJ4xhAa67GnlJG7WLNZFK+itl7v3VOOlGsAYAxaG5q\n" +"kQKQ1mKk6C6oGRpQ0aqKxVhoDc0CgYEA4Je2flPUYs33qy4m09UBFx6Xf91/5LvL\n" +"iTtEo+HGcMzxmfeV3sawUwtjHhyippN5lTR80JLbYoEvoUMyKt+N5Jnic206alSH\n" +"hujsQnO4LCRHz/XwkHnB8Ncd3J67Uaq9PUPY630NIA/ChBAQchsqntJSdVn65PZf\n" +"mw7+hO2WxI8CgYB4eX/qlVhMrlS8R9Z5OvJlKZOdv/LyA0aIHxyoDAkD52TF2F5w\n" +"b4CmqC8dCNFWOIbzOanuHlzDwkwsEy6y0ysXfB7QFoFvVsKixwo2dhT6lZByNSX5\n" +"STJiFfe6ZlGOHUpXFkIU9nCgWQGNxoiDCS4CPrkqI8mozTCKW0+RYpseyQKBgQCR\n" +"cK21UQQQl+Dy8YgjVaTHHABvxTi1HwfHbqIcnnCrS4yJcFOVWIWGwbEGJvUNeiMa\n" +"BEtvpip7t7zoaWNrcCmrCBwlM27IvMSnEN8uiVGTBEuc2F9YsABvvl6QKBqV4EN8\n" +"ERvAI9MEGDCW5PBBdGY9Q2YyqHpZG1L+Ts9ztYgU8QKBgB7bP9eNMrDzgZ6i9pFP\n" +"djlcJ+NE0veOLwTA1eQhiIZFSJTI5eyiePTYNIS3GwIyGauzePw5LeBb6rLVBt4Y\n" +"NAOgJDeHbPV2bnstONjE7FyUswJivIVD3n3UaVGgBTe6xc468Ws4rmeKZ8/Ph1Nq\n" +"ylaViyPWz486JAibF3Kudl5B";/*** RSA密钥长度必须是64的倍数，在512~65536之间。默认是1024*/public static final int KEY_SIZE = 2048;/*** 生成公钥、私钥对(keysize=1024)*/public static RSAHelper.KeyPairInfo getKeyPair() {return getKeyPair(KEY_SIZE);}private static final String src = "{\"OrderId\":\"HP124456\",\"PrepaymentDate\":\"-01-20\"}";//// public static void main(String[] args) throws Exception {// System.out.println("\n");// KeyPairInfo keyPair = getKeyPair();// System.out.println("构建RSA密钥对公钥：" + keyPair.getPublicKey());// System.out.println("构建RSA密钥对私钥：" + keyPair.getPrivateKey());// // 公钥、私钥生成一次后，调用方、被调用方都要保存// // 调用方用公钥加密，被调用方用私钥解密// // 返回值 被调用方公钥加密，调用方用私钥解密// System.out.println("\n");// String data1 = encipher(src,keyPair.getPublicKey());// String data2 = decipher(data1,keyPair.getPrivateKey());// System.out.println("加密前：" + src);// System.out.println("加密后HTTP传输内容：" + data1);// System.out.println("解密后：" + data2);// System.out.println("***************** 公钥加密私钥解密结束 *****************");// }/*** 生成公钥、私钥对** @param keySize* @return*/public static RSAHelper.KeyPairInfo getKeyPair(int keySize) {try {KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA");keyPairGen.initialize(keySize);// 生成一个密钥对，保存在keyPair中KeyPair keyPair = keyPairGen.generateKeyPair();// 得到私钥RSAPrivateKey oraprivateKey = (RSAPrivateKey) keyPair.getPrivate();// 得到公钥RSAPublicKey orapublicKey = (RSAPublicKey) keyPair.getPublic();RSAHelper.KeyPairInfo pairInfo = new RSAHelper.KeyPairInfo(keySize);//公钥byte[] publicKeybyte = orapublicKey.getEncoded();String publicKeyString = Base64.encodeBase64String(publicKeybyte);pairInfo.setPublicKey(publicKeyString);//私钥byte[] privateKeybyte = oraprivateKey.getEncoded();String privateKeyString = Base64.encodeBase64String(privateKeybyte);pairInfo.setPrivateKey(privateKeyString);return pairInfo;} catch (Exception e) {e.printStackTrace();return null;}}/*** 获取公钥对象* @param publicKeyBase64* @return* @throws InvalidKeySpecException* @throws NoSuchAlgorithmException*/public static PublicKey getPublicKey(String publicKeyBase64)throws InvalidKeySpecException, NoSuchAlgorithmException {KeyFactory keyFactory = KeyFactory.getInstance("RSA");X509EncodedKeySpec publicpkcs8KeySpec =new X509EncodedKeySpec(Base64.decodeBase64(publicKeyBase64));PublicKey publicKey = keyFactory.generatePublic(publicpkcs8KeySpec);return publicKey;}/*** 获取私钥对象* @param privateKeyBase64* @return* @throws NoSuchAlgorithmException* @throws InvalidKeySpecException*/public static PrivateKey getPrivateKey(String privateKeyBase64)throws NoSuchAlgorithmException, InvalidKeySpecException {KeyFactory keyFactory = KeyFactory.getInstance("RSA");PKCS8EncodedKeySpec privatekcs8KeySpec =new PKCS8EncodedKeySpec(Base64.decodeBase64(privateKeyBase64));PrivateKey privateKey = keyFactory.generatePrivate(privatekcs8KeySpec);return privateKey;}/*** 使用工钥加密----分段加密* @param content 待加密内容* @param publicKeyBase64 公钥 base64 编码* @return 经过 base64 编码后的字符串*/public static String encipher(String content, String publicKeyBase64) {return encipher(content, publicKeyBase64, KEY_SIZE / 8 - 11);}/*** 使用公司钥加密（分段加密）* @param content 待加密内容* @param publicKeyBase64 公钥 base64 编码* @param segmentSize分段大小,一般小于 keySize/8（段小于等于0时，将不使用分段加密）* @return 经过 base64 编码后的字符串*/public static String encipher(String content, String publicKeyBase64, int segmentSize) {try {PublicKey publicKey = getPublicKey(publicKeyBase64);return encipher(content, publicKey, segmentSize);} catch (Exception e) {e.printStackTrace();return null;}}/*** 分段加密* @param ciphertext 密文* @param key 加密秘钥* @param segmentSize 分段大小，<=0 不分段* @return*/public static String encipher(String ciphertext, java.security.Key key, int segmentSize) {try {// 用公钥加密byte[] srcBytes = ciphertext.getBytes();// Cipher负责完成加密或解密工作，基于RSACipher cipher = Cipher.getInstance("RSA");// 根据公钥，对Cipher对象进行初始化cipher.init(Cipher.ENCRYPT_MODE, key);byte[] resultBytes = null;if (segmentSize > 0)resultBytes = cipherDoFinal(cipher, srcBytes, segmentSize); //分段加密elseresultBytes = cipher.doFinal(srcBytes);String base64Str = Base64Utils.encodeToString(resultBytes);return base64Str;} catch (Exception e) {e.printStackTrace();return null;}}/*** 分段大小* @param cipher* @param srcBytes* @param segmentSize* @return* @throws IllegalBlockSizeException* @throws BadPaddingException* @throws IOException*/public static byte[] cipherDoFinal(Cipher cipher, byte[] srcBytes, int segmentSize)throws IllegalBlockSizeException, BadPaddingException, IOException {if (segmentSize <= 0)throw new RuntimeException("分段大小必须大于0");ByteArrayOutputStream out = new ByteArrayOutputStream();int inputLen = srcBytes.length;int offSet = 0;byte[] cache;int i = 0;// 对数据分段解密while (inputLen - offSet > 0) {if (inputLen - offSet > segmentSize) {cache = cipher.doFinal(srcBytes, offSet, segmentSize);} else {cache = cipher.doFinal(srcBytes, offSet, inputLen - offSet);}out.write(cache, 0, cache.length);i++;offSet = i * segmentSize;}byte[] data = out.toByteArray();out.close();return data;}/*** 使用私钥解密* @param contentBase64 待加密内容,base64 编码* @param privateKeyBase64 私钥 base64 编码* @return* @segmentSize 分段大小*/public static String decipher(String contentBase64, String privateKeyBase64) {return decipher(contentBase64, privateKeyBase64, KEY_SIZE / 8);}/*** 使用私钥解密（分段解密）* @param contentBase64 待加密内容,base64 编码* @param privateKeyBase64 私钥 base64 编码* @return* @segmentSize 分段大小*/public static String decipher(String contentBase64, String privateKeyBase64, int segmentSize) {try {PrivateKey privateKey = getPrivateKey(privateKeyBase64);return decipher(contentBase64, privateKey, segmentSize);} catch (Exception e) {e.printStackTrace();return null;}}/*** 分段解密* @param contentBase64 密文* @param key 解密秘钥* @param segmentSize 分段大小（小于等于0不分段）* @return*/public static String decipher(String contentBase64, java.security.Key key, int segmentSize) {try {// 用私钥解密byte[] srcBytes = Base64Utils.decodeFromString(contentBase64);// Cipher负责完成加密或解密工作，基于RSACipher deCipher = Cipher.getInstance("RSA");// 根据公钥，对Cipher对象进行初始化deCipher.init(Cipher.DECRYPT_MODE, key);byte[] decBytes = null;//deCipher.doFinal(srcBytes);if (segmentSize > 0)decBytes = cipherDoFinal(deCipher, srcBytes, segmentSize); //分段加密elsedecBytes = deCipher.doFinal(srcBytes);String decrytStr = new String(decBytes);return decrytStr;} catch (Exception e) {e.printStackTrace();return null;}}/*** 秘钥对*/public static class KeyPairInfo {String privateKey;String publicKey;int keySize = 0;public KeyPairInfo(int keySize) {setKeySize(keySize);}public KeyPairInfo(String publicKey, String privateKey) {setPrivateKey(privateKey);setPublicKey(publicKey);}public String getPrivateKey() {return privateKey;}public void setPrivateKey(String privateKey) {this.privateKey = privateKey;}public String getPublicKey() {return publicKey;}public void setPublicKey(String publicKey) {this.publicKey = publicKey;}public int getKeySize() {return keySize;}public void setKeySize(int keySize) {this.keySize = keySize;}}}
b.RSAController.java控制类
import java.io.ByteArrayOutputStream;import java.io.InputStream;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import org.springframework.http.MediaType;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestMethod;import org.springframework.web.bind.annotation.RestController;import com.alibaba.fastjson.JSON;import com.anji.ajfes.bao.util.RSAHelper;import io.swagger.annotations.Api;import io.swagger.annotations.ApiOperation;/*** RSA非对称加密* @author shixiangcheng* -04-29*/@Api(value = "RSA非对称加密")@RestController@RequestMapping(value="/rsa",produces=MediaType.APPLICATION_JSON_UTF8_VALUE)public class RSAController {@RequestMapping(value="/testRsa",method = RequestMethod.POST,consumes=MediaType.APPLICATION_JSON_UTF8_VALUE)@ApiOperation("测试RSA非对称加密")public void testRsa(HttpServletRequest request,HttpServletResponse response) throws Exception{request.setCharacterEncoding("UTF-8");//取得请求报文ByteArrayOutputStream arrayOutputStream = new ByteArrayOutputStream();InputStream is = request.getInputStream();byte[] buffer = new byte[1024];while (true) {int size = is.read(buffer);if (size <= 0) {break;}arrayOutputStream.write(buffer, 0, size);}String inMsg=new String(arrayOutputStream.toByteArray());//私钥解密inMsg=RSAHelper.decipher(inMsg,RSAHelper.PRIVATE_KEY_VALUES);System.out.println("服务端入参解密后:"+inMsg);//将JSON报文转为对象DemoDTO demoDTO=JSON.parseObject(inMsg,DemoDTO.class);demoDTO.setName("服务端返回");String responseJSON=JSON.toJSONString(demoDTO);System.out.println("服务端出参加密前:"+responseJSON);//公钥加密responseJSON=RSAHelper.encipher(responseJSON,RSAHelper.PUBLIC_KEY_VALUES);//将结果报文推送response.setCharacterEncoding("UTF-8");response.setContentType("application/json; charset=UTF-8");response.getWriter().print(responseJSON);response.flushBuffer();}}
c.DemoDTO.java实体
package com.shi.anji.util;import java.io.Serializable;/*** 实体对象* @author shixiangcheng* -04-29*/public class DemoDTO implements Serializable{private static final long serialVersionUID = 1L;private int id;private String name="";public int getId() {return id;}public void setId(int id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}}
d.Test.java测试类
import com.alibaba.fastjson.JSON;import com.shi.anji.util.DemoDTO;import com.shi.anji.util.HttpUtil;import com.shi.anji.util.RSAHelper;/*** 测试RSA非对称加密* @author shixiangcheng* -04-29*/public class Test {public static void main(String [] args) throws Exception{DemoDTO d=new DemoDTO();d.setId(1);d.setName("RSA加密");String serviceUrl="http://localhost:8080/rsa/testRsa";//服务地址String inMsg=JSON.toJSONString(d);//入参(JSON格式)System.out.println("客户端调用接口参数加密前:"+inMsg);//公钥加密inMsg=RSAHelper.encipher(inMsg,RSAHelper.PUBLIC_KEY_VALUES);//调用接口String outMsg=HttpUtil.httpPost(serviceUrl,inMsg);//私钥解密outMsg=RSAHelper.decipher(outMsg,RSAHelper.PRIVATE_KEY_VALUES);System.out.println("客户端调用接口返回值解密后:"+outMsg);}}
PS.HttpUtil工具类参考链接
执行日志
--Test类日志客户端调用接口参数加密前:{"id":1,"name":"RSA加密"}客户端调用接口返回值解密后:{"id":1,"name":"服务端返回"}--controller日志服务端入参解密后:{"id":1,"name":"RSA加密"}服务端出参加密前:{"id":1,"name":"服务端返回"}
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