RSA用私钥签名的时候发现报错，删除以下内容即可
-----BEGIN PRIVATE KEY-----
-----END PRIVATE KEY-----
import org.apache.commons.codec.binary.Base64; 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 :cza * @date :2021/4/14 9:52 * @description : * @modyified By: */ public class RSAEncrypt { 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 + " 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，保存在keyPair中 KeyPair keyPair = keyPairGen.generateKeyPair(); RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate(); // 得到私钥 RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic(); // 得到公钥 String publicKeyString = new String(Base64.encodeBase64(publicKey.getEncoded())); // 得到私钥字符串 String privateKeyString = new String(Base64.encodeBase64((privateKey.getEncoded()))); // 将公钥和私钥保存到Map keyMap.put(0,publicKeyString); //0表示公钥 keyMap.put(1,privateKeyString); //1表示私钥 } /** * RSA公钥加密 * * @param str * 加密字符串 * @param publicKey * 公钥 * @return 密文 * @throws Exception * 加密过程中的异常信息 */ public static String encrypt(String str, String publicKey ) 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 * @param privateKey * 私钥 * @return 铭文 * @throws Exception * 解密过程中的异常信息 */ public static String decrypt(String str, String privateKey) 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; } /** * 签名 * * @param data 待签名数据 * @param privateKey 私钥 * @return 签名 */ public static String sign(String data, PrivateKey privateKey) throws Exception { byte[] keyBytes = privateKey.getEncoded(); PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(keyBytes); KeyFactory keyFactory = KeyFactory.getInstance("RSA"); PrivateKey key = keyFactory.generatePrivate(keySpec); Signature signature = Signature.getInstance("MD5withRSA"); signature.initSign(key); signature.update(data.getBytes()); return new String(Base64.encodeBase64(signature.sign())); } /** * rsa签名 * * @param content * 待签名的字符串 * @param privateKey * rsa私钥字符串 * @param charset * 字符编码 * @return 签名结果 * @throws Exception * 签名失败则抛出异常 */ public static String sign(String content, String privateKey) throws Exception { //base64编码的私钥 byte[] decoded = Base64.decodeBase64(privateKey); try { //RSAPrivateKey priKey = (RSAPrivateKey) KeyFactory.getInstance("RSA").generatePrivate(new PKCS8EncodedKeySpec(decoded)); // 取得私钥 byte[] pri_key_bytes = Base64.decodeBase64(privateKey); PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(pri_key_bytes); KeyFactory keyFactory = KeyFactory.getInstance("RSA"); // 生成私钥 PrivateKey priKey = keyFactory.generatePrivate(pkcs8KeySpec); return sign(content,priKey); } catch (Exception e) { e.printStackTrace(); throw e; } } /** * 验签 * * @param srcData 原始字符串 * @param publicKey 公钥 * @param sign 签名 * @return 是否验签通过 */ public static boolean verify(String srcData, PublicKey publicKey, String sign) throws Exception { byte[] keyBytes = publicKey.getEncoded(); X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes); KeyFactory keyFactory = KeyFactory.getInstance("RSA"); PublicKey key = keyFactory.generatePublic(keySpec); Signature signature = Signature.getInstance("MD5withRSA"); signature.initVerify(key); signature.update(srcData.getBytes()); return signature.verify(Base64.decodeBase64(sign.getBytes())); } /** * 验签 * * @param srcData 原始字符串 * @param publicKey 公钥 * @param sign 签名 * @return 是否验签通过 */ public static boolean verify(String srcData, String publicKey, String sign) throws Exception { byte[] publicBytes = Base64.decodeBase64(publicKey); X509EncodedKeySpec keySpec = new X509EncodedKeySpec(publicBytes); KeyFactory keyFactory = KeyFactory.getInstance("RSA"); PublicKey pubKey = keyFactory.generatePublic(keySpec); return verify(srcData,pubKey,sign); }