title: BadPaddingException : Decryption error
body: <p>I'm writing a program which takes as input from the console - the name of a zip file, name of a zip file to be made containing the (de/en)crypted files generated from the first zip and a file containing the public key. I get the exception when decrypting:</p>
  
  <pre><code>exception 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:363) 
  at com.sun.crypto.provider.RSACipher.engineDoFinal(RSACipher.java:389) 
  at javax.crypto.Cipher.doFinal(Cipher.java:2165) 
  at com.Main.decrypt(Main.java:67) 
  at com.Main.main(Main.java:201)
  </code></pre>
  
  <p>Can't figure out why I get this exception?</p>
  
  <p>Public key:</p>
  
  <pre><code>MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCE3pA746UfpC8sFk8ZJp0yupyJqj5jy6cjdxUYoP7mCm7c0mqQDeCcDNBYW2eSozCioPrH/9L+CDQEPLYakoem+jFnUKDH5+pru/0PJTJJF8Xh/ZT9eJlvsYBr1/qSfICf6RTs7kzwq9IuSZBw7/tfNEF9i0A8FVox6HOopXod1QIDAQAB
  </code></pre>
  
  <p>Private key:</p>
  
  <pre><code>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
  </code></pre>
  
  <p>The code for the program is bellow . Any help is wellcomed :)</p>
  
  <pre><code>package com;
  
  import java.io.BufferedReader;
  import java.io.FileOutputStream;
  import java.io.FileReader;
  import java.io.IOException;
  import java.io.InputStream;
  import java.security.GeneralSecurityException;
  import java.security.KeyFactory;
  import java.security.PrivateKey;
  import java.security.PublicKey;
  import java.security.spec.PKCS8EncodedKeySpec;
  import java.security.spec.X509EncodedKeySpec;
  import java.util.Base64;
  import java.util.Enumeration;
  import java.util.Scanner;
  import java.util.zip.ZipEntry;
  import java.util.zip.ZipFile;
  import java.util.zip.ZipOutputStream;
  
  import javax.crypto.Cipher;
  import org.bouncycastle.asn1.ASN1EncodableVector;
  import org.bouncycastle.asn1.ASN1Integer;
  import org.bouncycastle.asn1.ASN1ObjectIdentifier;
  import org.bouncycastle.asn1.ASN1Sequence;
  import org.bouncycastle.asn1.DERNull;
  import org.bouncycastle.asn1.DEROctetString;
  import org.bouncycastle.asn1.DERSequence;
  import org.bouncycastle.asn1.pkcs.PKCSObjectIdentifiers;
  
  public class Main {
  
      public final static int BUFFER_SIZE = 117;
  
      public static void decrypt(String originalZipFileName, String newZipFileName, String privateKeyFileName) throws Exception {
          byte[] buffer = new byte[128];  
  
          ZipFile originalZipFile = new ZipFile(originalZipFileName); 
          ZipOutputStream newZipFile = new ZipOutputStream(new FileOutputStream(newZipFileName));
  
          Enumeration&lt;? extends ZipEntry&gt; zipEntries = originalZipFile.entries();
  
          String privateKey = getKeyString(privateKeyFileName);
          PrivateKey key = makePrivateKey(privateKey);
  
          Cipher cipher = Cipher.getInstance("RSA");
  
          cipher.init(Cipher.DECRYPT_MODE, key);
  
  
          while(zipEntries.hasMoreElements()){
  
              ZipEntry entry = zipEntries.nextElement();          
  
              ZipEntry copy = new ZipEntry(entry.getName());      
              newZipFile.putNextEntry(copy);          
  
              InputStream inputEntry = originalZipFile.getInputStream(entry);         
  
              while(inputEntry.read(buffer) != -1){   
                  newZipFile.write(cipher.doFinal(buffer));
              }
  
              newZipFile.closeEntry();
              inputEntry.close();
          }
          newZipFile.close();
          originalZipFile.close();
      }
  
      public static void encrypt(String originalZipFileName, String newZipFileName, String publicKeyFileName) throws Exception{
  
          byte[] buffer = new byte[BUFFER_SIZE];  
  
          ZipFile originalZipFile = new ZipFile(originalZipFileName); 
          ZipOutputStream newZipFile = new ZipOutputStream(new FileOutputStream(newZipFileName));
  
          Enumeration&lt;? extends ZipEntry&gt; zipEntries = originalZipFile.entries();
  
          String publicKey = getKeyString(publicKeyFileName);
          PublicKey key = makePublicKey(publicKey);
  
          Cipher cipher = Cipher.getInstance("RSA");
  
          cipher.init(Cipher.ENCRYPT_MODE, key);
  
  
          while(zipEntries.hasMoreElements()){
  
              ZipEntry entry = zipEntries.nextElement();          
  
              ZipEntry copy = new ZipEntry(entry.getName());      
              newZipFile.putNextEntry(copy);          
  
              InputStream inputEntry = originalZipFile.getInputStream(entry);         
  
              while(inputEntry.read(buffer) != -1){               
                  newZipFile.write(cipher.doFinal(buffer));
              }
  
              newZipFile.closeEntry();
              inputEntry.close();
          }
          newZipFile.close();
          originalZipFile.close();
      }   
  
      public static String getKeyString(String fileName){
  
          String key = new String();
          try {
              BufferedReader buf = new BufferedReader(new FileReader(fileName));
              key = buf.readLine();       
          } catch ( IOException e) {
              e.printStackTrace();
          }   
  
          return key.trim();
      }
  
      public static PublicKey makePublicKey(String stored) throws GeneralSecurityException {
          byte[] data = Base64.getDecoder().decode(stored);
          X509EncodedKeySpec spec = new  X509EncodedKeySpec(data);
          KeyFactory fact = KeyFactory.getInstance("RSA");
          return fact.generatePublic(spec);
      }
  
      public static PrivateKey makePrivateKey(String stored) throws GeneralSecurityException, Exception {
          /*byte[] data = Base64.getDecoder().decode(stored);
          PKCS8EncodedKeySpec spec = new  PKCS8EncodedKeySpec(data);
          KeyFactory fact = KeyFactory.getInstance("RSA");
          return fact.generatePrivate(spec);*/
  
          byte[] data = Base64.getDecoder().decode(stored);
  
          ASN1EncodableVector v = new ASN1EncodableVector();
          v.add(new ASN1Integer(0));
          ASN1EncodableVector v2 = new ASN1EncodableVector();
          v2.add(new ASN1ObjectIdentifier(PKCSObjectIdentifiers.rsaEncryption.getId()));
          v2.add(DERNull.INSTANCE);
          v.add(new DERSequence(v2));
          v.add(new DEROctetString(data));
          ASN1Sequence seq = new DERSequence(v);
          byte[] privKey = seq.getEncoded("DER");
  
          PKCS8EncodedKeySpec spec = new  PKCS8EncodedKeySpec(privKey);
          KeyFactory fact = KeyFactory.getInstance("RSA");
          PrivateKey key = fact.generatePrivate(spec);
  
          return key; 
  
      }
  
      public static void main(String[] args) throws Exception {
  
          Scanner scan = new Scanner(System.in);
  
          System.out.println("Enter type of operation:");
          String line = scan.nextLine();
  
          if(line.equals("encrypt")){
              System.out.println("Enter name of original ZIP file:");
              String originalZipFileName = scan.nextLine();
  
              System.out.println("Enter name of new ZIP file:");
              String newZipFileName = scan.nextLine();
  
              System.out.println("Enter name of file containg public key:");
              String publicKeyFileName = scan.nextLine();
  
              encrypt(originalZipFileName, newZipFileName, publicKeyFileName);        
          }
  
          if(line.equals("decrypt")){
              System.out.println("Enter name of original ZIP file:");
              String originalZipFileName = scan.nextLine();
  
              System.out.println("Enter name of new ZIP file:");
              String newZipFileName = scan.nextLine();
  
              System.out.println("Enter name of file containg private key:");
              String privateKeyFileName = scan.nextLine();
  
              decrypt(originalZipFileName, newZipFileName, privateKeyFileName);       
          }       
  
      }
  
  }
  </code></pre>
  
  <p>PS: Updated <code>decrypt</code> method. Still gives same error.</p>
  
  <pre><code>public static void decrypt(String originalZipFileName, String newZipFileName, String privateKeyFileName) throws Exception {
      byte[] buffer = new byte[128];  
  
      ZipFile originalZipFile = new ZipFile(originalZipFileName); 
      ZipOutputStream newZipFile = new ZipOutputStream(new FileOutputStream(newZipFileName));
  
      Enumeration&lt;? extends ZipEntry&gt; zipEntries = originalZipFile.entries();
  
      String privateKey = getKeyString(privateKeyFileName);
      PrivateKey key = makePrivateKey(privateKey);
  
      Cipher cipher = Cipher.getInstance("RSA");
  
      cipher.init(Cipher.DECRYPT_MODE, key);
  
  
      while(zipEntries.hasMoreElements()){
  
          ZipEntry entry = zipEntries.nextElement();          
  
          ZipEntry copy = new ZipEntry(entry.getName());      
          newZipFile.putNextEntry(copy);
  
  
          InputStream inputEntry = originalZipFile.getInputStream(entry);
  
  
          while(inputEntry.read(buffer) != -1){
              newZipFile.write(cipher.doFinal(buffer));
          }
  
          newZipFile.closeEntry();
          inputEntry.close();
      }
      newZipFile.close();
      originalZipFile.close();
  }
  </code></pre>