Exception in thread “main” javax.crypto.BadPaddingException: Decryption error

    at sun.security.rsa.RSAPadding.unpadV15(RSAPadding.java:380)

    at sun.security.rsa.RSAPadding.unpad(RSAPadding.java:291)

    at com.sun.crypto.provider.RSACipher.doFinal(RSACipher.java:356)

    at com.sun.crypto.provider.RSACipher.engineDoFinal(RSACipher.java:389)

    at javax.crypto.Cipher.doFinal(Cipher.java:2223)

    at com.asymmetric.rsa.TestRSA.testDecrypt(TestRSA.java:115)

    at com.asymmetric.rsa.TestRSA.main(TestRSA.java:34)

简单解释:

字面意思就是解密的时候填充错误,rsa 加解密都是把数据必须满足一定的长度,如果  不满足就要进行填充(一般是补0)直到满足特定的长度

测试代码

   
  
 
   
      package com.asymmetric.rsa;  
 
   
       
 
   
      import java.io.ByteArrayOutputStream;  
 
   
      import java.io.IOException;  
 
   
      import java.security.InvalidKeyException;  
 
   
      import java.security.KeyFactory;  
 
   
      import java.security.NoSuchAlgorithmException;  
 
   
      import java.security.PrivateKey;  
 
   
      import java.security.PublicKey;  
 
   
      import java.security.spec.InvalidKeySpecException;  
 
   
      import java.security.spec.PKCS8EncodedKeySpec;  
 
   
      import java.security.spec.X509EncodedKeySpec;  
 
   
      import java.util.Base64;  
 
   
       
 
   
      import javax.crypto.BadPaddingException;  
 
   
      import javax.crypto.Cipher;  
 
   
      import javax.crypto.IllegalBlockSizeException;  
 
   
      import javax.crypto.NoSuchPaddingException;  
 
   
       
 
   
       
 
   
       
 
   
      public class TestRSA {  
 
   
       
 
   
      public static String publicKey = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDQgEoj3z9JrdPNI23DbMQkl3gkGuDke7iBr5yrYyqolkTyxuBLWFwHNuGv4VKOj9fXg61QxpaJ/fxDBvMvmkBSRowHBloGFceVTx8wV/8u0DcjvTCu0IZ1zp6wjG6xBn5j66Sg/q+9hvaY2p7fkKmsvcW6VoNPgQHU1Cf01DLZmQIDAQAB+oXcINOiE3AsuZ4VJmwNZg9Y/7fY+OFRS2JAh5YMsrv2qyoGP+Z9ksre26NYR+Lt91B2lhdwJHLpQpziaANZm/ONb31fj/lwIDAQAB";  
 
   
      public static String privateKey = "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";  
 
   
       
 
   
      private static String algorithm = "RSA"; //$NON-NLS-1$  
 
   
      private static final int MAX_ENCRYPT_BLOCK = 117;  
 
   
      private static final int MAX_DECRYPT_BLOCK = 128;  
 
   
      private static String data = "test jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihg"; //$NON-NLS-1$  
 
   
       
 
   
      public static void main(String[] args) throws NoSuchAlgorithmException, InvalidKeySpecException, NoSuchPaddingException, IllegalBlockSizeException, BadPaddingException, InvalidKeyException, IOException {  
 
   
      String test = testEncrypt(privateKey,data);  
 
   
      String testDecrypt = testDecrypt(publicKey, test);  
 
   
      System.out.println(testDecrypt);  
 
   
       
 
   
      }  
 
   
       
 
   
       
 
   
      /**  
 
   
       * 加密  
 
   
       * @param key  
 
   
       * @param data  
 
   
       * @return  
 
   
       * @throws NoSuchAlgorithmException  
 
   
       * @throws InvalidKeySpecException  
 
   
       * @throws NoSuchPaddingException  
 
   
       * @throws IllegalBlockSizeException  
 
   
       * @throws BadPaddingException  
 
   
       * @throws InvalidKeyException  
 
   
       * @throws IOException   
 
   
       */  
 
   
      public static String testEncrypt(String key,String data) throws NoSuchAlgorithmException, InvalidKeySpecException, NoSuchPaddingException, IllegalBlockSizeException, BadPaddingException, InvalidKeyException, IOException{  
 
   
      byte[] decode = Base64.getDecoder().decode(key);  
 
   
      PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(decode);  
 
   
      KeyFactory kf = KeyFactory.getInstance(algorithm);  
 
   
      PrivateKey generatePrivate = kf.generatePrivate(pkcs8EncodedKeySpec);  
 
   
      Cipher ci = Cipher.getInstance(algorithm);  
 
   
      ci.init(Cipher.ENCRYPT_MODE, generatePrivate);  
 
   
       
 
   
      byte[] bytes = data.getBytes();  
 
   
      int inputLen = bytes.length;  
 
   
      int offLen = 0; //偏移量  
 
   
      int i = 0;  
 
   
      ByteArrayOutputStream bops = new ByteArrayOutputStream();  
 
   
      while(inputLen - offLen > 0){  
 
   
      byte [] cache;  
 
   
      if(inputLen - offLen > 117){  
 
   
      cache = ci.doFinal(bytes, offLen, 117);  
 
   
      } else{  
 
   
      cache = ci.doFinal(bytes, offLen,inputLen - offLen);  
 
   
      }  
 
   
      bops.write(cache);  
 
   
      i++;  
 
   
      offLen = 117 * i;  
 
   
      }  
 
   
      bops.close();  
 
   
      byte[] encryptedData = bops.toByteArray();  
 
   
      String encodeToString = Base64.getEncoder().encodeToString(encryptedData);  
 
   
      return encodeToString;  
 
   
      }  
 
   
       
 
   
       
 
   
       
 
   
       
 
   
      /**  
 
   
       * 解密  
 
   
       * @param key  
 
   
       * @param data  
 
   
       * @return  
 
   
       * @throws NoSuchAlgorithmException  
 
   
       * @throws InvalidKeyException   
 
   
       * @throws NoSuchPaddingException   
 
   
       * @throws InvalidKeySpecException   
 
   
       * @throws BadPaddingException   
 
   
       * @throws IllegalBlockSizeException   
 
   
       * @throws IOException   
 
   
       */  
 
   
      public static String testDecrypt(String key,String data) throws NoSuchAlgorithmException, InvalidKeyException, NoSuchPaddingException, InvalidKeySpecException, IllegalBlockSizeException, BadPaddingException, IOException{  
 
   
      byte[] decode = Base64.getDecoder().decode(key);  
 
   
      // PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(decode); //java底层 RSA公钥只支持X509EncodedKeySpec这种格式  
 
   
      X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(decode);  
 
   
      KeyFactory kf = KeyFactory.getInstance(algorithm);  
 
   
      PublicKey generatePublic = kf.generatePublic(x509EncodedKeySpec);  
 
   
      Cipher ci = Cipher.getInstance(algorithm);  
 
   
      ci.init(Cipher.DECRYPT_MODE,generatePublic);  
 
   
       
 
   
      int inputLen = data.getBytes().length;  
 
   
      byte[] bytes = data.getBytes();  
 
   
      int offLen = 0;  
 
   
      int i = 0;  
 
   
      ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();  
 
   
      while(inputLen - offLen > 0){  
 
   
      byte[] cache;  
 
   
      if(inputLen - offLen > 128){  
 
   
      cache = ci.doFinal(bytes,offLen, 128);  
 
   
      } else{  
 
   
      cache = ci.doFinal(bytes,offLen,inputLen - offLen);  
 
   
      }  
 
   
      byteArrayOutputStream.write(cache);  
 
   
      i++;  
 
   
      offLen = 128 * i;  
 
   
       
 
   
      }  
 
   
      byteArrayOutputStream.close();  
 
   
      byte[] byteArray = byteArrayOutputStream.toByteArray();  
 
   
      return new String(byteArray);  
 
   
      }  
 
   
       
 
   
       
 
   
       
 
   
      }  
 
  
  

问题点:

后来发现确实是我自己的错误,rsa 加密后返回的字符串使用Base64编码的,忘了解密直接getBytes()就出错了

api 指出:BadPaddingException – 如果此 Cipher 为解密模式，并且未请求填充（或不填充），但解密的数据没有用适当的填充字节进行限制

只要是cipher.doFinal()解密时报 BadPaddingException 肯定是传入的字节数组有问题,传的不是加密时生成的数组

修正后的代码:

   
  
 
   
      package com.asymmetric.rsa;  
 
   
       
 
   
      import java.io.ByteArrayOutputStream;  
 
   
      import java.io.IOException;  
 
   
      import java.security.InvalidKeyException;  
 
   
      import java.security.KeyFactory;  
 
   
      import java.security.NoSuchAlgorithmException;  
 
   
      import java.security.PrivateKey;  
 
   
      import java.security.PublicKey;  
 
   
      import java.security.spec.InvalidKeySpecException;  
 
   
      import java.security.spec.PKCS8EncodedKeySpec;  
 
   
      import java.security.spec.X509EncodedKeySpec;  
 
   
      import java.util.Base64;  
 
   
       
 
   
      import javax.crypto.BadPaddingException;  
 
   
      import javax.crypto.Cipher;  
 
   
      import javax.crypto.IllegalBlockSizeException;  
 
   
      import javax.crypto.NoSuchPaddingException;  
 
   
       
 
   
       
 
   
       
 
   
      public class TestRSA {  
 
   
       
 
   
      public static String publicKey = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDQgEoj3z9JrdPNI23DbMQkl3gkGuDke7iBr5yrYyqolkTyxuBLWFwHNuGv4VKOj9fXg61QxpaJ/fxDBvMvmkBSRowHBloGFceVTx8wV/8u0DcjvTCu0IZ1zp6wjG6xBn5j66Sg/q+9hvaY2p7fkKmsvcW6VoNPgQHU1Cf01DLZmQIDAQAB+oXcINOiE3AsuZ4VJmwNZg9Y/7fY+OFRS2JAh5YMsrv2qyoGP+Z9ksre26NYR+Lt91B2lhdwJHLpQpziaANZm/ONb31fj/lwIDAQAB";  
 
   
      public static String privateKey = "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";  
 
   
       
 
   
      private static String algorithm = "RSA"; //$NON-NLS-1$  
 
   
      private static final int MAX_ENCRYPT_BLOCK = 117;  
 
   
      private static final int MAX_DECRYPT_BLOCK = 128;  
 
   
      private static String data = "test jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihg"; //$NON-NLS-1$  
 
   
       
 
   
      public static void main(String[] args) throws NoSuchAlgorithmException, InvalidKeySpecException, NoSuchPaddingException, IllegalBlockSizeException, BadPaddingException, InvalidKeyException, IOException {  
 
   
      String test = testEncrypt(privateKey,data);  
 
   
      String testDecrypt = testDecrypt(publicKey, test);  
 
   
      System.out.println(testDecrypt);  
 
   
       
 
   
      }  
 
   
       
 
   
       
 
   
      /**  
 
   
       * 加密  
 
   
       * @param key  
 
   
       * @param data  
 
   
       * @return  
 
   
       * @throws NoSuchAlgorithmException  
 
   
       * @throws InvalidKeySpecException  
 
   
       * @throws NoSuchPaddingException  
 
   
       * @throws IllegalBlockSizeException  
 
   
       * @throws BadPaddingException  
 
   
       * @throws InvalidKeyException  
 
   
       * @throws IOException   
 
   
       */  
 
   
      public static String testEncrypt(String key,String data) throws NoSuchAlgorithmException, InvalidKeySpecException, NoSuchPaddingException, IllegalBlockSizeException, BadPaddingException, InvalidKeyException, IOException{  
 
   
      byte[] decode = Base64.getDecoder().decode(key);  
 
   
      PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(decode);  
 
   
      KeyFactory kf = KeyFactory.getInstance(algorithm);  
 
   
      PrivateKey generatePrivate = kf.generatePrivate(pkcs8EncodedKeySpec);  
 
   
      Cipher ci = Cipher.getInstance(algorithm);  
 
   
      ci.init(Cipher.ENCRYPT_MODE, generatePrivate);  
 
   
       
 
   
      byte[] bytes = data.getBytes();  
 
   
      int inputLen = bytes.length;  
 
   
      int offLen = 0; //偏移量  
 
   
      int i = 0;  
 
   
      ByteArrayOutputStream bops = new ByteArrayOutputStream();  
 
   
      while(inputLen - offLen > 0){  
 
   
      byte [] cache;  
 
   
      if(inputLen - offLen > 117){  
 
   
      cache = ci.doFinal(bytes, offLen, 117);  
 
   
      } else{  
 
   
      cache = ci.doFinal(bytes, offLen,inputLen - offLen);  
 
   
      }  
 
   
      bops.write(cache);  
 
   
      i++;  
 
   
      offLen = 117 * i;  
 
   
      }  
 
   
      bops.close();  
 
   
      byte[] encryptedData = bops.toByteArray();  
 
   
      String encodeToString = Base64.getEncoder().encodeToString(encryptedData);  
 
   
      return encodeToString;  
 
   
      }  
 
   
       
 
   
       
 
   
       
 
   
       
 
   
      /**  
 
   
       * 解密  
 
   
       * @param key  
 
   
       * @param data  
 
   
       * @return  
 
   
       * @throws NoSuchAlgorithmException  
 
   
       * @throws InvalidKeyException   
 
   
       * @throws NoSuchPaddingException   
 
   
       * @throws InvalidKeySpecException   
 
   
       * @throws BadPaddingException   
 
   
       * @throws IllegalBlockSizeException   
 
   
       * @throws IOException   
 
   
       */  
 
   
      public static String testDecrypt(String key,String data) throws NoSuchAlgorithmException, InvalidKeyException, NoSuchPaddingException, InvalidKeySpecException, IllegalBlockSizeException, BadPaddingException, IOException{  
 
   
      byte[] decode = Base64.getDecoder().decode(key);  
 
   
      // PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(decode); //java底层 RSA公钥只支持X509EncodedKeySpec这种格式  
 
   
      X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(decode);  
 
   
      KeyFactory kf = KeyFactory.getInstance(algorithm);  
 
   
      PublicKey generatePublic = kf.generatePublic(x509EncodedKeySpec);  
 
   
      Cipher ci = Cipher.getInstance(algorithm);  
 
   
      ci.init(Cipher.DECRYPT_MODE,generatePublic);  
 
   
       
 
   
      byte[] bytes = Base64.getDecoder().decode(data);  
 
   
      int inputLen = bytes.length;  
 
   
      int offLen = 0;  
 
   
      int i = 0;  
 
   
      ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();  
 
   
      while(inputLen - offLen > 0){  
 
   
      byte[] cache;  
 
   
      if(inputLen - offLen > 128){  
 
   
      cache = ci.doFinal(bytes,offLen, 128);  
 
   
      } else{  
 
   
      cache = ci.doFinal(bytes,offLen,inputLen - offLen);  
 
   
      }  
 
   
      byteArrayOutputStream.write(cache);  
 
   
      i++;  
 
   
      offLen = 128 * i;  
 
   
       
 
   
      }  
 
   
      byteArrayOutputStream.close();  
 
   
      byte[] byteArray = byteArrayOutputStream.toByteArray();  
 
   
      return new String(byteArray);  
 
   
      }  
 
   
       
 
   
       
 
   
       
 
   
      }