最近项目组给了一个需要，须要我这边写一个接口，给第三方应用。过后就想，这不是很简略嘛，唰唰唰，就写好了。忽然想到，没有限度条件，那岂不是太不平安了，谁都能够调我这个接口了啊。而后就想了想，emmmm，ras如同能够用的啊，那就间接写写看吧。
RSA的加密过程如下：
（1）A生成一对密钥（公钥和私钥），私钥不公开，A本人保留。公钥为公开的，任何人能够获取。
（2）A传递本人的公钥给B，B用A的公钥对音讯进行加密。
（3）A接管到B加密的音讯，利用A本人的私钥对音讯进行解密。
先上代码:
public static void main(String[] args) throws Exception { //生成公钥和私钥 genKeyPair(); //加密字符串 String message = "df723820"; System.out.println("随机生成的公钥为:" + keyMap.get(0)); System.out.println("随机生成的私钥为:" + keyMap.get(1)); } /** * 随机生成密钥对 * @throws NoSuchAlgorithmException */ public static void genKeyPair() throws NoSuchAlgorithmException { // KeyPairGenerator类用于生成公钥和私钥对，基于RSA算法生成对象 KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA"); // 初始化密钥对生成器，密钥大小为96-1024位 keyPairGen.initialize(1024,new SecureRandom()); // 生成一个密钥对，保留在keyPair中 KeyPair keyPair = keyPairGen.generateKeyPair(); RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate(); // 失去私钥 RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic(); // 失去公钥 String publicKeyString = new String(Base64.encodeBase64(publicKey.getEncoded())); // 失去私钥字符串 String privateKeyString = new String(Base64.encodeBase64((privateKey.getEncoded()))); // 将公钥和私钥保留到Map keyMap.put(0,publicKeyString); //0示意公钥 keyMap.put(1,privateKeyString); //1示意私钥 }公钥，私钥生成后，公钥可对外公开，私钥需本人保留。
加密，解密办法：
/** * RSA公钥加密 * * @param str * 加密字符串 * 公钥 * @return 密文 * @throws Exception * 加密过程中的异样信息 */public String encrypt( String str ) throws Exception{ //base64编码的公钥 byte[] decoded = Base64.decodeBase64(publicKey); RSAPublicKey pubKey = (RSAPublicKey) KeyFactory.getInstance("RSA").generatePublic(new X509EncodedKeySpec(decoded)); //RSA加密 Cipher cipher = Cipher.getInstance("RSA"); cipher.init(Cipher.ENCRYPT_MODE, pubKey); String outStr = Base64.encodeBase64String(cipher.doFinal(str.getBytes("UTF-8"))); return outStr;}/** * RSA私钥解密 * * @param str * 加密字符串 * 私钥 * @return 铭文 * @throws Exception * 解密过程中的异样信息 */public String decrypt(String str) throws Exception{ //64位解码加密后的字符串 byte[] inputByte = Base64.decodeBase64(str.getBytes("UTF-8")); //base64编码的私钥 byte[] decoded = Base64.decodeBase64(privateKey); RSAPrivateKey priKey = (RSAPrivateKey) KeyFactory.getInstance("RSA").generatePrivate(new PKCS8EncodedKeySpec(decoded)); //RSA解密 Cipher cipher = Cipher.getInstance("RSA"); cipher.init(Cipher.DECRYPT_MODE, priKey); String outStr = new String(cipher.doFinal(inputByte)); return outStr;}这段代码中的 publicKey 和 privateKey,就是咱们上段代码中获取到的，只需生成一次。这个时候咱们就能够在咱们的接口里进行验证了。
附上本人应用时的代码：
我这边是把加密解密的办法放到了一个工具类里，应用的时候间接调用工具类的办法就能够了，残缺如下：
package com.pactera.rms.util;import org.apache.commons.codec.binary.Base64;import org.springframework.beans.factory.annotation.Value;import org.springframework.stereotype.Component;import javax.crypto.Cipher;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.HashMap;import java.util.Map;/** * @author qps * Date 2020/10/25 19:30 */@Componentpublic class RSAEncrypt { @Value("${rms.rsa.publicKey.key}") private String publicKey; @Value("${rms.rsa.privateKey.key}") private String privateKey; private static Map<Integer, String> keyMap = new HashMap<Integer, String>(); //用于封装随机产生的公钥与私钥 public static void main(String[] args) throws Exception { //生成公钥和私钥 genKeyPair(); //加密字符串 String message = "df723820"; System.out.println("随机生成的公钥为:" + keyMap.get(0)); System.out.println("随机生成的私钥为:" + keyMap.get(1));// String messageEn = encrypt(message,keyMap.get(0));// System.out.println(message + "t加密后的字符串为:" + messageEn);// String messageDe = decrypt(messageEn,keyMap.get(1));// System.out.println("还原后的字符串为:" + messageDe); } /** * 随机生成密钥对 * @throws NoSuchAlgorithmException */ public static void genKeyPair() throws NoSuchAlgorithmException { // KeyPairGenerator类用于生成公钥和私钥对，基于RSA算法生成对象 KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA"); // 初始化密钥对生成器，密钥大小为96-1024位 keyPairGen.initialize(1024,new SecureRandom()); // 生成一个密钥对，保留在keyPair中 KeyPair keyPair = keyPairGen.generateKeyPair(); RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate(); // 失去私钥 RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic(); // 失去公钥 String publicKeyString = new String(Base64.encodeBase64(publicKey.getEncoded())); // 失去私钥字符串 String privateKeyString = new String(Base64.encodeBase64((privateKey.getEncoded()))); // 将公钥和私钥保留到Map keyMap.put(0,publicKeyString); //0示意公钥 keyMap.put(1,privateKeyString); //1示意私钥 } /** * RSA公钥加密 * * @param str * 加密字符串 * 公钥 * @return 密文 * @throws Exception * 加密过程中的异样信息 */ public String encrypt( String str ) throws Exception{ //base64编码的公钥 byte[] decoded = Base64.decodeBase64(publicKey); RSAPublicKey pubKey = (RSAPublicKey) KeyFactory.getInstance("RSA").generatePublic(new X509EncodedKeySpec(decoded)); //RSA加密 Cipher cipher = Cipher.getInstance("RSA"); cipher.init(Cipher.ENCRYPT_MODE, pubKey); String outStr = Base64.encodeBase64String(cipher.doFinal(str.getBytes("UTF-8"))); return outStr; } /** * RSA私钥解密 * * @param str * 加密字符串 * 私钥 * @return 铭文 * @throws Exception * 解密过程中的异样信息 */ public String decrypt(String str) throws Exception{ //64位解码加密后的字符串 byte[] inputByte = Base64.decodeBase64(str.getBytes("UTF-8")); //base64编码的私钥 byte[] decoded = Base64.decodeBase64(privateKey); RSAPrivateKey priKey = (RSAPrivateKey) KeyFactory.getInstance("RSA").generatePrivate(new PKCS8EncodedKeySpec(decoded)); //RSA解密 Cipher cipher = Cipher.getInstance("RSA"); cipher.init(Cipher.DECRYPT_MODE, priKey); String outStr = new String(cipher.doFinal(inputByte)); return outStr; }}另外，还有一段代码，是我用来获取传过来的headers 中的key和value的：
package com.pactera.rms.util;import org.apache.commons.io.IOUtils;import javax.servlet.ReadListener;import javax.servlet.ServletInputStream;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletRequestWrapper;import java.io.BufferedReader;import java.io.ByteArrayInputStream;import java.io.IOException;import java.io.InputStreamReader;/** * @author qps */public class MultiReadHttpServletRequest extends HttpServletRequestWrapper { private final byte[] bytes; public MultiReadHttpServletRequest(HttpServletRequest request) throws IOException { super(request); bytes = IOUtils.toByteArray(request.getInputStream()); } @Override public ServletInputStream getInputStream() throws IOException { return new ServletInputStream() { private int lastIndexRetrieved = -1; private ReadListener readListener = null; @Override public boolean isFinished() { return (lastIndexRetrieved == bytes.length-1); } @Override public boolean isReady() { // This implementation will never block // We also never need to call the readListener from this method, as this method will never return false return isFinished(); } @Override public void setReadListener(ReadListener readListener) { this.readListener = readListener; if (!isFinished()) { try { readListener.onDataAvailable(); } catch (IOException e) { readListener.onError(e); } } else { try { readListener.onAllDataRead(); } catch (IOException e) { readListener.onError(e); } } } @Override public int read() throws IOException { int i; if (!isFinished()) { i = bytes[lastIndexRetrieved+1]; lastIndexRetrieved++; if (isFinished() && (readListener != null)) { try { readListener.onAllDataRead(); } catch (IOException ex) { readListener.onError(ex); throw ex; } } return i; } else { return -1; } } }; } @Override public BufferedReader getReader() throws IOException { ByteArrayInputStream is = new ByteArrayInputStream(bytes); BufferedReader temp = new BufferedReader(new InputStreamReader(is)); return temp; }}这两个文件放好之后，就能够在本人办法应用了：
@ApiOperation("简历解析")@ApiParam(name = "files", value = "files", required = true)@RequestMapping(value = "/resume", method = RequestMethod.POST, consumes = {"multipart/*"}, headers = {"content-type=multipart/form-data"})public ListOutput resumeAnalysis(@RequestParam("files") MultipartFile[] files, ServletRequest servletRequest) throws Exception { MultiReadHttpServletRequest request = new MultiReadHttpServletRequest((HttpServletRequest) servletRequest); String sign = request.getHeader("Authorization"); String decrypt = rsaEncrypt.decrypt(sign); StringBuilder params = new StringBuilder(); for (int i = 0; i < files.length; i++) { String originalFilename = files[i].getOriginalFilename(); int i1 = originalFilename.lastIndexOf("."); String substring = originalFilename.substring((i1 + 1), originalFilename.length()); params.append("&").append(substring); } //源数据 String data = params.toString().replaceFirst("&", "");// String encrypt = rsaEncrypt.encrypt(data);// System.out.println(encrypt); //校验 System.out.println(data.equals(decrypt)); if(data.equals(decrypt)){ logger.info("调用接口胜利，开始执行....." + files); String type = "Campus"; List jsonObject = service.resume(files, type); return new ListOutput(200, "胜利", null, jsonObject); }else { return new ListOutput(407, "身份验证失败，请从新提交", null, null); }}这时就功败垂成了。
PS:RSA加密对明文的长度有所限度，规定需加密的明文最大长度=密钥长度-11（单位是字节，即byte），所以在加密和解密的过程中须要分块进行。而密钥默认是1024位，即1024位/8位-11=128-11=117字节。所以默认加密前的明文最大长度117字节，解密密文最大长度为128字。那么为啥两者相差11字节呢？是因为RSA加密应用到了填充模式（padding），即内容有余117字节时会主动填满，用到填充模式天然会占用肯定的字节，而且这部分字节也是参加加密的。