(hopefully) last version

AESEncryption.java

@@ -1,25 +1,74 @@
 import java.lang.Object;
-import javax.crypto.Cipher;
-import java.security.GeneralSecurityException;
-import javax.crypto.NoSuchPaddingException;
-import java.security.NoSuchAlgorithmException;
+import javax.crypto.*;
+import java.security.*;
+import java.io.*;
+import javax.crypto.spec.SecretKeySpec;
+import java.util.Scanner;
 public class AESEncryption
 {
    public static void main(String[] args)
    {
-  
-   }
-   public void encrypt()
-   {
-  
+      Scanner input = new Scanner(System.in);
+      System.out.print("Enter E for encyrption or D for decryption: ");
+      String a = input.nextLine();
+
+      if(a.equals("E"))
+      {
+         encrypt();
+      }
+      else
+      {
+         decrypt();
+      }
    }
-   public static final Cipher getInstance(String transformation)
+   public static void encrypt()
    {
+
+      Scanner input = new Scanner(System.in);
+      System.out.print("Enter the file name: ");
+      String fileName = input.nextLine();
+      File file = new File(fileName);
       try
       {
+
          KeyGenerator keyGen = KeyGenerator.getInstance("AES");
          keyGen.init(128);
-         SecretKey key = keyGen.generateKey(); 
+         SecretKey key = keyGen.generateKey();
+
+         Cipher cipher = Cipher.getInstance("AES");
+         cipher.init(Cipher.ENCRYPT_MODE, key);
+
+         FileInputStream fis = new FileInputStream(file);
+         byte[] byteArray = new byte[(int)file.length()];
+         int buffer = fis.read(byteArray);
+         byte[] bArray = cipher.doFinal(byteArray);
+
+         FileOutputStream fos = new FileOutputStream(file);
+         fos.write(bArray);
+
+         FileOutputStream encodedKey = new FileOutputStream("key.txt");
+         byte[] keys = key.getEncoded();
+         encodedKey.write(keys);
+
+         fis.close();
+         fos.close();
+         encodedKey.close();
+      }
+      catch(FileNotFoundException fnfe)
+      {
+         System.out.println("File Not Found");
+      }
+      catch(IOException ioe)
+      {
+         System.out.println("Signals that an I/O exception of some sort has occurred.");
+      }
+      catch(IllegalBlockSizeException ibse)
+      {
+         System.out.println(" no padding has been requested (only in encryption mode), and the total input length of the data processed by this cipher is not a multiple of block size; or if this encryption algorithm is unable to process the input data provided");
+      }
+      catch(BadPaddingException bpe)
+      {
+         System.out.println("if this cipher is in decryption mode, and (un)padding has been requested, but the decrypted data is not bounded by the appropriate padding bytes");
       }
       catch(NoSuchPaddingException nspe)
       {
@@ -29,6 +78,83 @@ public class AESEncryption
       {
          System.out.println("cryptographic algorithm is requested but is not available in the environment");
       }
-   }
-}
+      catch(InvalidKeyException ike)
+      {
+         System.out.println("the given key is inappropriate for initializing this cipher");
+      }
+   }//end of encrypt method
+   public static void decrypt()
+   {
+      Scanner input = new Scanner(System.in);
+      System.out.print("Enter the file name of whats to be decrypted: ");
+      String fileName = input.nextLine();
+
+      System.out.print("Enter the file name of the key: ");
+      String keyName = input.nextLine();
+
+      File encryptedFile = new File(fileName);
+      File encryptedKey = new File(keyName);
+
+      try
+      {
+
 
+         FileInputStream fisKey = new FileInputStream(encryptedKey);
+         FileInputStream fisFile = new FileInputStream(encryptedFile);
+         FileOutputStream fos = new FileOutputStream("decryptedFile.txt");
+
+         byte[] fileArray = new byte[(int)encryptedFile.length()];
+         int buffer2 = fisFile.read(fileArray);
+
+         byte[] keyBytes = new byte[(int)encryptedKey.length()];
+         int buffer = fisKey.read(keyBytes);
+
+         SecretKeySpec key = new SecretKeySpec(keyBytes, "AES");
+
+         Cipher cipher = Cipher.getInstance("AES");
+         cipher.init(Cipher.DECRYPT_MODE, key);
+         byte[] cipherBytes = cipher.doFinal(fileArray);
+
+
+         fos.write(cipherBytes);
+
+         fisKey.close();
+         fos.close();
+         fisFile.close();
+
+      }
+      catch(FileNotFoundException fnfe)
+      {
+         System.out.println("File Not Found");
+      }
+      catch(IOException ioe)
+      {
+         System.out.println("Signals that an I/O exception of some sort has occurred.");
+      }
+      catch(IllegalBlockSizeException ibse)
+      {
+         System.out.println(" no padding has been requested (only in encryption mode), and the total input length of the data processed by this cipher is not a multiple of block size; or if this encryption algorithm is unable to process the input data provided");
+      }
+      catch(NoSuchPaddingException nspe)
+      {
+         System.out.println("a particular padding mechanism is requested but is not available in the environment");
+      }
+      catch(NoSuchAlgorithmException nsae)
+      {
+         System.out.println("cryptographic algorithm is requested but is not available in the environment");
+      }
+      catch(InvalidKeyException ike)
+      {
+         System.out.println("the given key is inappropriate for initializing this cipher");
+      }
+      catch(NullPointerException npe)
+      {
+         System.out.println("specified algorithm is null");
+      }
+      catch(GeneralSecurityException gse)
+      {
+         System.out.println("bad or invalid padding/block");
+      }
+
+   }
+}