本文记录使用java生成公钥私钥，将公钥私钥转换成字符串，验证公钥私钥是否匹配。
验证公钥私钥是否匹配的思想：使用公钥对字符串进行加密，再使用私钥进行解密，若解密生成的字符串与原字符串一致，则说明公钥私钥匹配。
引入第三方依赖bouncycastle：
<dependency><groupId>org.bouncycastle</groupId><artifactId>bcprov-jdk15on</artifactId><version>1.68</version></dependency>
实现代码：
import java.security.InvalidKeyException;import java.security.KeyFactory;import java.security.KeyPair;import java.security.KeyPairGenerator;import java.security.NoSuchAlgorithmException;import java.security.SecureRandom;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 javax.crypto.NoSuchPaddingException;import org.bouncycastle.jce.provider.BouncyCastleProvider;import java.util.Base64;import java.util.Random;/*** 该类用于生成公钥私钥，并且验证公钥私钥是否匹配* 使用方法：* 1.生成公钥私钥： 使用new RSAEncrypt()创建对象，之后调用get方法即可获取生成的公钥私钥（字符串）* 2.验证公钥私钥是否匹配： 调用静态方法verifyPublicAndPrivateKey()，传入公钥私钥字符串，返回boolean判断是否匹配*/public class RSAEncrypt {private RSAPrivateKey privateKey;private RSAPublicKey publicKey;public RSAEncrypt() {genKeyPair();}/*** 获取私钥字符串** @return 当前的私钥字符串*/public String getPrivateKeyStr() {KeyFactory keyFactory = null;String privateKeyStr = null;try {//将私钥对象转换为字符串keyFactory = KeyFactory.getInstance("RSA");PKCS8EncodedKeySpec keySpec = keyFactory.getKeySpec(privateKey, PKCS8EncodedKeySpec.class);byte[] buffer = keySpec.getEncoded();privateKeyStr = Base64.getEncoder().encodeToString(buffer);} catch (NoSuchAlgorithmException e) {System.err.println("无此算法");} catch (InvalidKeySpecException e) {System.err.println("私钥非法");}return privateKeyStr;}/*** 获取公钥字符串** @return 当前的公钥字符串*/public String getPublicKeyStr() {KeyFactory keyFactory = null;String publicKeyStr = null;try {//将公钥对象转换为字符串keyFactory = KeyFactory.getInstance("RSA");X509EncodedKeySpec keySpec = keyFactory.getKeySpec(publicKey, X509EncodedKeySpec.class);byte[] buffer = keySpec.getEncoded();publicKeyStr = Base64.getEncoder().encodeToString(buffer);} catch (NoSuchAlgorithmException e) {System.err.println("无此算法");} catch (InvalidKeySpecException e) {System.err.println("公钥非法");}return publicKeyStr;}/*** 随机生成公钥-私钥*/private void genKeyPair() {KeyPairGenerator keyPairGen = null;try {keyPairGen = KeyPairGenerator.getInstance("RSA");} catch (NoSuchAlgorithmException e) {e.printStackTrace();}keyPairGen.initialize(1024, new SecureRandom());KeyPair keyPair = keyPairGen.generateKeyPair();this.privateKey = (RSAPrivateKey) keyPair.getPrivate();this.publicKey = (RSAPublicKey) keyPair.getPublic();}/*** @param publicKeyStr 公钥* @param privateKeyStr 私钥* @return boolean值判断是否匹配*/public static boolean verifyPublicAndPrivateKey(String publicKeyStr, String privateKeyStr) {RSAPublicKey publicKeyToVerify = null;RSAPrivateKey privateKeyToVerify = null;try {publicKeyToVerify = loadPublicKey(publicKeyStr);} catch (Exception e) {System.err.println("加载公钥失败-公钥非法");return false;}try {privateKeyToVerify = loadPrivateKey(privateKeyStr);} catch (Exception e) {System.err.println("加载私钥失败-私钥非法");return false;}if (publicKeyToVerify == null || privateKeyToVerify == null) {return false;}//生成随机数字符串用于验证公钥私钥是否匹配Random seed = new Random();int randomNum = seed.nextInt(1000) + 1;String randomStr = String.valueOf(randomNum);byte[] cipher = null;byte[] plainText = null;try {cipher = encrypt(publicKeyToVerify, randomStr.getBytes());plainText = decrypt(privateKeyToVerify, cipher);} catch (Exception e) {e.printStackTrace();return false;}String plainStr = new String(plainText);return plainStr.equals(randomStr);}/*** 从字符串中加载公钥** @param publicKeyStr 公钥数据字符串* @throws Exception 加载公钥时产生的异常*/private static RSAPublicKey loadPublicKey(String publicKeyStr) throws Exception {RSAPublicKey loadedPublicKey = null;try {byte[] buffer = Base64.getDecoder().decode(publicKeyStr);KeyFactory keyFactory = KeyFactory.getInstance("RSA");X509EncodedKeySpec keySpec = new X509EncodedKeySpec(buffer);loadedPublicKey = (RSAPublicKey) keyFactory.generatePublic(keySpec);} catch (NoSuchAlgorithmException e) {throw new Exception(e);} catch (InvalidKeySpecException e) {throw new Exception(e);} catch (NullPointerException e) {throw new Exception(e);}return loadedPublicKey;}/*** 从字符串中加载私钥** @param privateKeyStr 私钥数据字符串* @throws Exception 加载私钥时产生的异常*/private static RSAPrivateKey loadPrivateKey(String privateKeyStr) throws Exception {RSAPrivateKey loadedPrivateKey = null;try {byte[] buffer = Base64.getDecoder().decode(privateKeyStr);PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(buffer);KeyFactory keyFactory = KeyFactory.getInstance("RSA");loadedPrivateKey = (RSAPrivateKey) keyFactory.generatePrivate(keySpec);} catch (NoSuchAlgorithmException e) {throw new Exception("无此算法");} catch (InvalidKeySpecException e) {throw new Exception("私钥非法");} catch (NullPointerException e) {throw new Exception("私钥数据为空");}return loadedPrivateKey;}/*** 加密过程** @param publicKey公钥* @param plainTextData 明文数据* @return 加密后的数据* @throws Exception 加密过程中的异常信息*/private static byte[] encrypt(RSAPublicKey publicKey, byte[] plainTextData) throws Exception {if (publicKey == null) {throw new Exception("加密公钥为空, 请设置");}Cipher cipher = null;try {cipher = Cipher.getInstance("RSA", new BouncyCastleProvider());cipher.init(Cipher.ENCRYPT_MODE, publicKey);byte[] output = cipher.doFinal(plainTextData);return output;} catch (NoSuchAlgorithmException e) {throw new Exception("无此加密算法");} catch (NoSuchPaddingException e) {e.printStackTrace();return null;} catch (InvalidKeyException e) {throw new Exception("加密公钥非法,请检查");} catch (IllegalBlockSizeException e) {throw new Exception("明文长度非法");} catch (BadPaddingException e) {throw new Exception("明文数据已损坏");}}/*** 解密过程** @param privateKey 私钥* @param cipherData 密文数据* @return 明文* @throws Exception 解密过程中的异常信息*/private static byte[] decrypt(RSAPrivateKey privateKey, byte[] cipherData) throws Exception {if (privateKey == null) {throw new Exception("解密私钥为空, 请设置");}Cipher cipher = null;try {cipher = Cipher.getInstance("RSA", new BouncyCastleProvider());cipher.init(Cipher.DECRYPT_MODE, privateKey);byte[] output = cipher.doFinal(cipherData);return output;} catch (NoSuchAlgorithmException e) {throw new Exception("无此解密算法");} catch (NoSuchPaddingException e) {e.printStackTrace();return null;} catch (InvalidKeyException e) {throw new Exception("解密私钥非法,请检查");} catch (IllegalBlockSizeException e) {throw new Exception("密文长度非法");} catch (BadPaddingException e) {throw new Exception("密文数据已损坏");}}public static void main(String[] args) {RSAEncrypt rsaEncrypt = new RSAEncrypt();System.out.println("公钥：" + rsaEncrypt.getPublicKeyStr());System.out.println("私钥：" + rsaEncrypt.getPrivateKeyStr());boolean res = RSAEncrypt.verifyPublicAndPrivateKey(rsaEncrypt.getPublicKeyStr(), rsaEncrypt.getPrivateKeyStr());System.out.println("是否匹配：" + res);}}
运行结果：
参考文章：Java中使用OpenSSL生成的RSA公私钥进行数据加解密
