/*
 * EncryptHandler.java
 * Karl-Adam Karlsson
 * 06-10-04
 *
 * EncryptHandler, krypterar fil enligt given nyckel.
 * Använder Blowfish.
 * Usage: java EncryptHandler <data> <secretKey> <encryptedData>
 *
 * Där <data> är filen som skall krypterasz
 * <secretKey> är nyckeln som används vid krypteringen,
 * <encryptedData> är namnet på den resulterande krypterade filen.
 */
import javax.crypto.*;
import java.security.*;
import java.io.*;


public class EncryptHandler{

	/*
	* Konstruktor
	* Anrapar allt.
	* Klart!
	*/
	public EncryptHandler(String data, String secretKey, String encData){
		saveAndEncrypt(getInS(data), loadKey(secretKey), encData);
	}//end of constructor
		
	/*
	* loadKey
	* Loads a SecretKey Object from the file named <keyFileName>
	* @param keyFileName Name of file to load key from
	* @return SecretKey the loaded key.
	*/
	private SecretKey loadKey(String keyFileName){
		ObjectInputStream oInStr = null;
		SecretKey theKey = null;
		
		try{
			FileInputStream inFstream = new FileInputStream(keyFileName);
			oInStr = new ObjectInputStream(inFstream);
		}catch(FileNotFoundException fEx){
			System.err.print(fEx);
			System.exit(1);
		}catch(IOException ioe){
			System.err.print(ioe);
			System.exit(1);
		}
		
		try{
			theKey = (SecretKey)oInStr.readObject();
			oInStr.close();
		}catch(IOException io2){
			System.err.print(io2);
			System.exit(1);	
		}catch(ClassNotFoundException cNf){
			System.err.print(cNf);
			System.exit(1);
		}
	
	return theKey;
	}//end of loadKey
	

	/*
	* saveAndEncrypt
	* Krypterar till filen outname givet nyckeln akey och inströmmen inStream
	*
	*/
	private void saveAndEncrypt(FileInputStream inStream, SecretKey akey, String outName){
		Cipher myCipher = null;
		File outFile  = new File(outName);                    
		FileOutputStream outStream=null;;
		
		
		// CREATING CIPHER
		try{
			myCipher = Cipher.getInstance("Blowfish/ECB/PKCS5Padding");
			myCipher.init(Cipher.ENCRYPT_MODE, akey);
		}catch(NoSuchAlgorithmException alEx){
			System.err.print(alEx);
			System.exit(1);	
		}catch(InvalidKeyException iKe){
			System.err.print(iKe);
			System.exit(1);
		}catch(NoSuchPaddingException  padEx){
			System.err.print("NO SUCH PADDING");
			System.exit(1);
		}
		// DONE CREATING CIPHER
		
		try{
			outStream = new FileOutputStream(outFile);
		}catch(FileNotFoundException fnf){
			System.err.print(fnf);
			System.exit(1);
		}
		
		CipherOutputStream cStream = new CipherOutputStream(outStream, myCipher);
		int aLen;
		byte[] buffLn = new byte[1024];
		
		try{
			//Encrypt and save
        	while ((aLen = inStream.read(buffLn)) != -1) {
        	              cStream.write(buffLn, 0, aLen);
        	}
        	inStream.close();
			cStream.close();
			outStream.close();
			
		}catch(IOException ioe){
			System.err.print(ioe);
			System.exit(1);	
		}
		
		
	}//end of saveAndEncrypt


	/*
	* getInS
	* Returns a FileInputStream connected to a file
	* @param String fimeName The name of the file to connect the stream to.
	* @return FileInputStream A stream connected to the file.
	*/
	private FileInputStream getInS(String fileName){
		FileInputStream inFstream = null;
		
		try{
			inFstream = new FileInputStream(fileName);
		}catch(FileNotFoundException fEx){
			System.err.print(fEx);
			System.exit(1);
		}
	return inFstream;	
	}//end of getInS



	/*
	* main
	* Kollar att args e ok, skapar sedan ny instans av EncryptHandler.
	*/
	public static void main (String[] args) {
		if(args==null || args.length != 3){
			System.out.println("Usage: java EncryptHandler <data> <secretKey> <encryptedData>");
			System.out.println("Where <data> is the file to be encrypted.");
			System.out.println("Where <secretKey> is the file containing the key.");
			System.out.println("Where <encryptedData> is the name of the output file.");
		}
		else if(args.length==3 && args[0]!=null && args[1]!=null && args[2]!=null){
			new EncryptHandler(args[0], args[1], args[2]);
		}
		else if(args[0]==null||args[1]==null||args[2]==null){
			System.out.println("Null is not a valid argument.");
			System.out.println("Usage: java EncryptHandler <data> <secretKey> <encryptedData>");
			System.out.println("Where <data> is the file to be encrypted.");
			System.out.println("Where <secretKey> is the file containing the key.");
			System.out.println("Where <encryptedData> is the name of the output file.");
		}
  		
  	}//end of main
}//end of class