项目背景:要对打印地址进行加密,用公钥加密后会乱码需要base64 decode一下,但是在解密时报错:javax.crypto.BadPaddingException: Data must start with zero
解决办法:
1.加解密时KeyFactory keyFactory = KeyFactory.getInstance("RSA");
2.将加解密的Cipher cipher = Cipher.getInstance(“RSA”)改为Cipher cipher = Cipher.getInstance(“RSA/ECB/NoPadding”)
困扰了两天的问题解决了,代码如下,希望有次问题的同学不必再走此弯路。
- package resources.util.encryption;
-
- import java.io.FileInputStream;
- import java.io.FileOutputStream;
- import java.io.ObjectInputStream;
- import java.io.ObjectOutputStream;
- import java.security.Key;
- import java.security.KeyFactory;
- import java.security.KeyPair;
- import java.security.KeyPairGenerator;
- import java.security.PrivateKey;
- import java.security.PublicKey;
- import java.security.spec.PKCS8EncodedKeySpec;
- import java.security.spec.X509EncodedKeySpec;
-
- import javax.crypto.Cipher;
-
- import org.junit.Test;
-
- public class EncryptionUtil {
- private static final String RSA = "RSA";
- private static final String RSANOPADDING = "RSA/ECB/NoPadding";
- private static final String PUBLIC_KEY_PATH = "public.key";
- private static final String PRIVATE_KEY_PATH = "private.key";
- private static final String path = Thread.currentThread().getContextClassLoader().getResource("/").getPath();
- // private static final String path = "";
- @Test
- public void generateKey() throws Exception {
- //KeyPairGenerator引擎类用于产生密钥对,JDK(7)默认支持的算法有,DiffieHellman、DSA、RSA、EC
- KeyPairGenerator generator = KeyPairGenerator.getInstance(RSA);
- generator.initialize(512);
- //产生密钥对
- KeyPair keyPair = generator.generateKeyPair();
- //获取公钥
- PublicKey publicKey = keyPair.getPublic();
- //获取私钥
- PrivateKey privateKey = keyPair.getPrivate();
-
- //将公钥与私钥写入文件,以备后用
- writeKey(PUBLIC_KEY_PATH, publicKey);
- writeKey(PRIVATE_KEY_PATH, privateKey);
- }
-
- //公钥加密
- public byte[] SRAEncrypt(String src) throws Exception {
- PublicKey publicKey= (PublicKey)readKey(path + PUBLIC_KEY_PATH);
- X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(publicKey.getEncoded());
- KeyFactory keyFactory = KeyFactory.getInstance(RSA);
- publicKey = keyFactory.generatePublic(x509EncodedKeySpec);
- Cipher cipher = Cipher.getInstance(RSANOPADDING);
- cipher.init(Cipher.ENCRYPT_MODE, publicKey);
- byte[] data = src.getBytes();
- int blockSize = 53;//根据异常提示设的53
- //根据块大小分块,不足一块的部分为一块
- int blocksNum = (int)Math.ceil((1.0*data.length)/blockSize);
- //加密
- for (int i = 0; i < blocksNum; i++) {
- if (i < blocksNum - 1) {
- cipher.doFinal(data, i * blockSize, blockSize);
- } else {
- cipher.doFinal(data, i * blockSize, data.length - i * blockSize);
- }
- }
- return data;
- }
-
- //私钥解密
- public String SRADecrypt(byte[] data) throws Exception{
- PrivateKey privateKey= (PrivateKey)readKey(path + PRIVATE_KEY_PATH);
- PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(privateKey.getEncoded());
- KeyFactory keyFactory = KeyFactory.getInstance(RSA);
- privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec);
- Cipher cipher = Cipher.getInstance(RSANOPADDING);
- cipher.init(Cipher.DECRYPT_MODE, privateKey);
- int blockSize = 64;//根据异常提示设的64
- //根据块大小分块,不足一块的部分为一块
- int blocksNum = (int)Math.ceil((1.0*data.length)/blockSize);
- //解密
- for (int i = 0; i < blocksNum; i++) {
- if (i < blocksNum - 1) {
- cipher.doFinal(data, i * blockSize, blockSize);
- } else {
- cipher.doFinal(data, i * blockSize, data.length - i * blockSize);
- }
- }
- return new String(data);
- }
-
- public void writeKey(String path, Key key) throws Exception {
- FileOutputStream fos = new FileOutputStream(path);
- ObjectOutputStream oos = new ObjectOutputStream(fos);
- oos.writeObject(key);
- oos.close();
- }
-
- public Key readKey(String path) throws Exception {
- FileInputStream fis = new FileInputStream(path);
- ObjectInputStream bis = new ObjectInputStream(fis);
- Object object = bis.readObject();
- bis.close();
- return (Key)object;
- }
-
- @Test
- public void testEncryptAndDecrypt() throws Exception {
- Cipher cipher = Cipher.getInstance(RSA);
- //读取公钥,进行加密
- PublicKey publicKey= (PublicKey) readKey("component/"+PUBLIC_KEY_PATH);
- cipher.init(Cipher.ENCRYPT_MODE, publicKey);
- //加密
- String sendInfo = "我的明文";
- byte[] results = cipher.doFinal(sendInfo.getBytes());
-
- //读取私钥,进行解密
- PrivateKey privateKey = (PrivateKey) readKey("component/"+PRIVATE_KEY_PATH);
- cipher.init(Cipher.DECRYPT_MODE, privateKey);
- //解密
- byte[] deciphered = cipher.doFinal(results);
- //得到明文
- String recvInfo = new String(deciphered);
- System.out.println(recvInfo);
- }
-
- @Test
- public void testSRA() throws Exception{
- PublicKey publicKey= (PublicKey)readKey("component/" + PUBLIC_KEY_PATH);
- X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(publicKey.getEncoded());
- KeyFactory keyFactory = KeyFactory.getInstance(RSA);
- publicKey = keyFactory.generatePublic(x509EncodedKeySpec);
- Cipher cipher = Cipher.getInstance(RSA);
- cipher.init(Cipher.ENCRYPT_MODE, publicKey);
- byte[] result = cipher.doFinal("yuanyuan".getBytes());
-
- PrivateKey privateKey= (PrivateKey)readKey("component/" + PRIVATE_KEY_PATH);
- PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(privateKey.getEncoded());
- privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec);
- cipher = Cipher.getInstance(RSANOPADDING);
- cipher.init(Cipher.DECRYPT_MODE, privateKey);
- result = cipher.doFinal(result);
- System.out.println(new String(result));
- }
- }