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how to sent byte[ ] array in socket

I'm a newbie in Java, I'm trying to sent a byte [] array via socket, but it itself convert my array to string and then sends it. so far it's ok, but the problem is that I need to either receive the message in array type, OR I have to convert the string to array, in order to make the decrypt method be able to decrypt the array (the input of decrypt method must be byte array). how can I do that?
my serverside related code is:
private void IssuingTickets() throws Exception{
String socketUsername = reader.readLine();//rcv username
String socketPassword = reader.readLine();//rcv password
writer.println("Lemme Check!");
Properties prop = new Properties();
prop.load(new FileInputStream("input"));
String fileUsername = prop.getProperty("username");
String filePassword = null;
if (prop.getProperty("password") != null) {
filePassword = prop.getProperty("password");}
if (socketPassword.equals(filePassword)){
String sessionKeyBobKdc = new Scanner(new File("sBOBandKDC")).useDelimiter("\\Z").next();
byte[] ClientTicket = encrypt(sessionKeyBobKdc, filePassword);
System.out.println("clietn ticket = " + ClientTicket+" ArraytoString " + Arrays.toString(ClientTicket));
writer.println(ClientTicket);
String KDCkey = new Scanner(new File("KDCkey")).useDelimiter("\\Z").next();
String UnEncTGT= sessionKeyBobKdc.concat(socketUsername);
byte[] TGT = encrypt(UnEncTGT, KDCkey);
writer.println(TGT);
}else
{writer.println("Please try again later!");}
}
public static byte[] encrypt(String plainText1, String encryptionKey) throws Exception {
Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding", "SunJCE");
SecretKeySpec key = new SecretKeySpec(encryptionKey.getBytes("UTF-8"), "AES");
cipher.init(Cipher.ENCRYPT_MODE, key,new IvParameterSpec(IV.getBytes("UTF-8")));
return cipher.doFinal(plainText1.getBytes("UTF-8"));
}
public static String decrypt(byte[] cipherText, String encryptionKey) throws Exception{
Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding", "SunJCE");
SecretKeySpec key = new SecretKeySpec(encryptionKey.getBytes("UTF-8"), "AES");
cipher.init(Cipher.DECRYPT_MODE, key,new IvParameterSpec(IV.getBytes("UTF-8")));
return new String(cipher.doFinal(cipherText),"UTF-8");
}
}
the Clientside related code is:
private void recieveTickts() throws IOException, InterruptedException, Exception{
String msg = reader.readLine(); //Lemme check
System.out.println("Server :" + msg);
TimeUnit.SECONDS.sleep(3);
String Sth = reader.readLine(); //please try again
if(Sth.equals("Please try again later!")){
System.out.println(Sth);
System.exit(1);
}else{
ClientTicket = Sth;
String TGT = reader.readLine();
System.out.println("Encrypted key between Client and KDC is " + ClientTicket + " and the TGT is " + TGT);
TimeUnit.SECONDS.sleep(3);
System.out.println("SUCCESSFUL"); }
byte[] b = ClientTicket.getBytes();
System.out.println("b= " + b);
String sessionKeyBobKdc = decrypt(b, Password);
System.out.println(Password + "session key is "+ sessionKeyBobKdc);
}
thanx in advanced guys..

I documented the code to help you out but that is basically a quick and dirty way to never stop listening for data and then also return the received as byte[]. If you don't need to listen at all times just modify this code to stop listening once you received your message
You can make this more dynamic with using parameters for defining the sign that a message is finished etc.
I used a StringBuilder to act as a little buffer. And defined that a message is finished once I receive a LF. Everything else get's put into the "buffer". Additionally I filter out CR since I don't want them in my message.
Socket client;
StringBuilder sb = new StringBuilder();
String result = "";
int c;
try
{
InputStream inputStream = client.getInputStream();
while ( ( c = inputStream.read() ) >= 0 ) // Loop to listen for data until the connection is dead
{
if ( c == 0x0a ) // 0x0a is the hex for a LineFeed ( LF )
{
result = sb.toString(); // put everything you received so far as a final message
sb.delete( 0, sb.length() ); // clear your message "buffer"
}
else if ( c != 0x0d /* <CR> */ ) // Not necessary but it helps keeping the message clear
{
sb.append( (char) c ); // add the received integer as char to the message "buffer"
}
if ( !result.isEmpty() ) // Catch that a message is received
{
log.fine( "received message: " + result ); // just log for tracing
return result.getBytes(StandardCharsets.UTF_8); // return the byte[] of the message with the needed Charset.
}
}
}
catch ( Exception e )
{
log.warning( e.getMessage() );
}

Encoding/Decoding text in ORMLITE using Base64

I am working on android application in which i want to encrypt my text which is stored using ormlite, so if any one from outside get the DB file, he will not be able to read it with out decrypting it. My major concern is to encrypt the data using base64 and when i want to read the data it should decrypt it. I have read some sample code from a link for base64 please suggest me the way for encrypting my text before saving it to the DB and on retrieving time it should decrypt it.
// Sending side
byte[] data = text.getBytes("UTF-8");
String base64 = Base64.encodeToString(data, Base64.DEFAULT);
// Receiving side
byte[] data = Base64.decode(base64, Base64.DEFAULT);
String text = new String(data, "UTF-8");

You can use this code for encryption and decryption.
I am using 3DES encryption scheme here. I hope it will help you.
public PasswordEncryption_TrippleDES() throws Exception {
myEncryptionKey = //your encryption key
myEncryptionScheme = DESEDE_ENCRYPTION_SCHEME;
arrayBytes = myEncryptionKey.getBytes(UNICODE_FORMAT);
ks = new DESedeKeySpec(arrayBytes);
skf = SecretKeyFactory.getInstance(myEncryptionScheme);
cipher = Cipher.getInstance(myEncryptionScheme);
key = skf.generateSecret(ks);
}
public String encrypt(String unencryptedString) {
String encryptedString = null;
try {
cipher.init(Cipher.ENCRYPT_MODE, key);
byte[] plainText = unencryptedString.getBytes(UNICODE_FORMAT);
byte[] encryptedText = cipher.doFinal(plainText);
encryptedString = new String(Base64.encodeBase64(encryptedText));
} catch (Exception e) {
e.printStackTrace();
}
return encryptedString;
}
public String decrypt(String encryptedString) {
String decryptedText=null;
try {
cipher.init(Cipher.DECRYPT_MODE, key);
byte[] encryptedText = Base64.decodeBase64(encryptedString);
byte[] plainText = cipher.doFinal(encryptedText);
decryptedText= new String(plainText);
} catch (Exception e) {
e.printStackTrace();
}
return decryptedText;
}

how to decrypt in java (snippet of my code included)

I am wanting to create a functional Java chat application.
So I have a small application which allows users to connect via server classes and talk with each other via client classes and I have started to add Encryption. I am having trouble decrypting output from other clients in my Java chat application.
can someone help me please?
snippet of my code is included below:
THE CLIENTGUI.JAVA CLASS (encrypt is a button which is clicked)
if(o == encrypt) {
String change = null;
try{
change = tf.getText();
change = FileEncryption.encryptString(change);
tf.setText("" + change);
return;
} catch (Exception e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
finally{
}
THE FILEENCRYPTION.JAVA
public class FileEncryption {
//Initial Vector
public static final byte[] iv = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
//EncryptAndDecrypt String -> Input : PlainText + Return : CipherText+DecipherText
public static String encryptString(String src) throws Exception
{
String dst="";
//Not Input!
if(src == null || src.length()==0)
return "";
//Encryption Setting
byte[] k="Multimediaproces".getBytes();
SecretKeySpec Key = new SecretKeySpec(k,"AES");
IvParameterSpec ivspec = new IvParameterSpec(iv);
Cipher encryptCipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
encryptCipher.init(Cipher.ENCRYPT_MODE,Key,ivspec);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
CipherOutputStream cout = new CipherOutputStream(baos,encryptCipher);
cout.write(src.getBytes());
cout.flush(); //ByteOutputStream -> Write Encryption Text
cout.close();
// in encrypt method
dst = DatatypeConverter.printHexBinary(baos.toByteArray());
return dst;
}
//String src -> EncryptedData
public static String decryptString(String src) throws Exception
{
//src value is Encrypted Value!
//So, src value -> Not Byte!
String dst="";
byte[] encryptedBytes = DatatypeConverter.parseHexBinary(src);;
//Not Input!
if(src == null || src.length()==0)
return "";
//Decryption Setting
IvParameterSpec ivspec = new IvParameterSpec(iv);
byte[] k="Multimediaproces".getBytes();
SecretKeySpec Key = new SecretKeySpec(k,"AES");
Cipher decryptCipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
decryptCipher.init(Cipher.DECRYPT_MODE,Key,ivspec);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ByteArrayInputStream bais = new ByteArrayInputStream(encryptedBytes);
CipherInputStream cin = new CipherInputStream(bais,decryptCipher);
byte[] buf = new byte[1024];
int read;
while((read=cin.read(buf))>=0) //reading encrypted data!
{
baos.write(buf,0,read); //writing decrypted data!
}
// closing streams
cin.close();
dst = new String(baos.toByteArray());
return dst;
}
}
the problem is that when i try to decrypt the code entering the following code:
if(o == decrypt) {
try{
msg = tf.getText();
msg = FileEncryption.decryptString(msg);
fop.
} catch (Exception e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}finally{
}
Currently, it ALLOWS me to encrypt what I type into text field.
It does not allow me to decrypt the output of what the users have said in the chat. The current code I have included for the decrypt does not function.
Can anyone help me? or have any suggestions that I could make to my program to help it decrypt?
Thanks
EDIT:

Your best bet would probably be to simply use SSL sockets for your network communications, rather than writing the encryption code yourself. While your question isn't exactly a duplicate of this one, you'd likely be well served by the answers here:
Secret Key SSL Socket connections in Java

I suspect that the problem is not passing the encrypted status between the 2 clients.
If the "encrypt" object is a button then it is a button on only one side of the client-client connection. You will need to pass the encrypted state to the other client, so that it knows to decrypt the message.
A short cut to confirming this would be to automatically show the plaintext and decrypted message on the receiving end. One of them will always be gibberish but it should change depending on the use of the encrypt button.
Good luck :)

AES encryption, got extra trash characters in decrypted file

Im making a debug loggin function in an android app.
I have a simple class which is logging to .txt file using 128 bit AES encryption.
After the logging is done, i decrypt the logged file with a simple JAVA program.
The problem is when i decrypt the encrypted log i got some weird content in it, i also got the encrypted content, but there are some extra characters, see below.
Android app logging part:
public class FileLogger {
//file and folder name
public static String LOG_FILE_NAME = "my_log.txt";
public static String LOG_FOLDER_NAME = "my_log_folder";
static SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd_HH-mm-ss_SSS");
//My secret key, 16 bytes = 128 bit
static byte[] key = {1,2,3,4,5,6,7,8,9,0,1,2,3,4,5,6};
//Appends to a log file, using encryption
public static void appendToLog(Context context, Object msg) {
String msgStr;
String timestamp = "t:" + formatter.format(new java.util.Date());
msgStr = msg + "|" + timestamp + "\n";
File sdcard = Environment.getExternalStorageDirectory();
File dir = new File(sdcard.getAbsolutePath() + "/" + LOG_FOLDER_NAME);
if (!dir.exists()) {
dir.mkdir();
}
File encryptedFile = new File(dir, LOG_FILE_NAME);
try {
//Encryption using my key above defined
Key secretKey = new SecretKeySpec(key, "AES");
Cipher cipher = Cipher.getInstance("AES");
cipher.init(Cipher.ENCRYPT_MODE, secretKey);
byte[] outputBytes = cipher.doFinal(msgStr.getBytes());
//Writing to the file using append mode
FileOutputStream outputStream = new FileOutputStream(encryptedFile, true);
outputStream.write(outputBytes);
outputStream.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (NoSuchPaddingException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
}
}
}
And this is the decrypter JAVA program:
public class Main {
//output file name after decryption
private static String decryptedFileName;
//input encrypted file
private static String fileSource;
//a prefix tag for output file name
private static String outputFilePrefix = "decrypted_";
//My key for decryption, its the same as in the encrypter program.
static byte[] key = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6 };
//Decrypting function
public static void decrypt(byte[] key, File inputFile, File outputFile) throws Exception {
try {
Key secretKey = new SecretKeySpec(key, "AES");
Cipher cipher = Cipher.getInstance("AES");
cipher.init(Cipher.DECRYPT_MODE, secretKey);
FileInputStream inputStream = new FileInputStream(inputFile);
byte[] inputBytes = new byte[(int) inputFile.length()];
inputStream.read(inputBytes);
byte[] outputBytes = cipher.doFinal(inputBytes);
FileOutputStream outputStream = new FileOutputStream(outputFile, true);
outputStream.write(outputBytes);
inputStream.close();
outputStream.close();
} catch (Exception ex) {
ex.printStackTrace();
}
}
//first argument is the intput file source
public static void main(String[] args) {
if (args.length != 1) {
System.out.println("Add log file name as a parameter.");
} else {
fileSource = args[0];
try {
File sourceFile = new File(fileSource);
if (sourceFile.exists()) {
//Decrption
decryptedFileName = outputFilePrefix + sourceFile.getName();
File decryptedFile = new File(decryptedFileName);
decrypt(key, sourceFile, decryptedFile);
} else {
System.out.println("Log file not found: " + fileSource);
}
} catch (Exception e) {
e.printStackTrace();
}
System.out.println("Decryption done, output file: " + decryptedFileName);
}
}
}
Output decrypted log (Opened with notepad++):
There is the valid content, but you also can see the extra thrash characters. If I open with the default windows text editor i also got thrash charaters, but different ones.
This is my first try with encrypt -decrypt, what m i doing wrong?
Any ideas?

AES is a block cipher which only works on blocks. The plaintext that you want to encrypt can be of any length, so the cipher must always pad the plaintext to fill it up to a multiple of the block size (or add a complete block when it already is a multiple of the block size). In this PKCS#5/PKCS#7 padding each padding byte denotes the number of padded bytes.
The easy fix would be to iterate over outputBytes during decryption and remove those padding bytes which are always on the next line. This will break as soon as you use multiline log messages or use a semantically secure mode (more on that later).
The better fix would be to write the number of bytes for each log message before the message, read that and decrypt only that many bytes. This also probably easier to implement with file streams.
You currently use Cipher.getInstance("AES"); which is a non-fully qualified version of Cipher.getInstance("AES/ECB/PKCS5Padding");. ECB mode is not semantically secure. It simply encrypts each block (16 bytes) with AES and the key. So blocks that are the same will be the same in ciphertext. This is particularly bad, because some log messages start the same and an attacker might be able to distinguish them. This is also the reason why the decryption of the whole file worked despite being encrypted in chunks. You should use CBC mode with a random IV.
Here is some sample code for proper use of AES in CBC mode with a random IV using streams:
private static SecretKey key = generateAESkey();
private static String cipherString = "AES/CBC/PKCS5Padding";
public static void main(String[] args) throws Exception {
ByteArrayOutputStream log = new ByteArrayOutputStream();
appendToLog("Test1", log);
appendToLog("Test2 is longer", log);
appendToLog("Test3 is multiple of block size!", log);
appendToLog("Test4 is shorter.", log);
byte[] encLog = log.toByteArray();
List<String> logs = decryptLog(new ByteArrayInputStream(encLog));
for(String logLine : logs) {
System.out.println(logLine);
}
}
private static SecretKey generateAESkey() {
try {
return KeyGenerator.getInstance("AES").generateKey();
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
return null;
}
private static byte[] generateIV() {
SecureRandom random = new SecureRandom();
byte[] iv = new byte[16];
random.nextBytes(iv);
return iv;
}
public static void appendToLog(String s, OutputStream os) throws Exception {
Cipher cipher = Cipher.getInstance(cipherString);
byte[] iv = generateIV();
cipher.init(Cipher.ENCRYPT_MODE, key, new IvParameterSpec(iv));
byte[] data = cipher.doFinal(s.getBytes("UTF-8"));
os.write(data.length);
os.write(iv);
os.write(data);
}
public static List<String> decryptLog(InputStream is) throws Exception{
ArrayList<String> logs = new ArrayList<String>();
while(is.available() > 0) {
int len = is.read();
byte[] encLogLine = new byte[len];
byte[] iv = new byte[16];
is.read(iv);
is.read(encLogLine);
Cipher cipher = Cipher.getInstance(cipherString);
cipher.init(Cipher.DECRYPT_MODE, key, new IvParameterSpec(iv));
byte[] data = cipher.doFinal(encLogLine);
logs.add(new String(data, "UTF-8"));
}
return logs;
}

You've encrypted each log message with a distinct encryption context. When you call the doFinal method on the cipher object the plaintext is padded out to a multiple of 16. Effectively, your log file is sequence of many small encrypted messages. However on decryption you are ignoring these message boundaries and treating the file as a single encrypted message. The result is that the padding characters are not being properly stripped. What you are seeing as 'trash' characters are likely these padding bytes. You will need to redesign your logfile format, either to preserve the message boundaries so the decryptor can discover them or to eliminate them altogether.
Also, don't use defaults in Java cryptography: they're not portable. For example, Cipher.getInstance() takes a string of the form alg/mode/padding. Always specify all three. I notice you also use the default no-args String.getBytes() method. Always specify a Charset, and almost always "UTF8" is the best choice.

Android exception java.io.IOException: last block incomplete

I am working on decrypting a binary file encrypted in C# using Rijndael encryption method. The file is copied to an android device. The decryption logic works fine when run in a java based desktop test program. But it throws java.io.IOException: last block incomplete when run in android. I am using the code below.
public static void Decrypt(String fileIn, String fileOut, byte[] key, byte[] IV, long offset)
{
// First we are going to open the file streams
FileInputStream fsIn;
try
{
fsIn = new FileInputStream(fileIn);,,
FileOutputStream fsOut = new FileOutputStream(fileOut);
// create cipher object
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(key, "AES"), new IvParameterSpec(IV));
// create the encryption stream
CipherInputStream cis = new CipherInputStream(fsIn, cipher);
// set a buffer and keep writing to the stream
int bufferLen = KiloByte;
byte[] buffer = new byte[bufferLen];
int bytesRead = 0;
// read a chunk of data from the input file
while ( (bytesRead = cis.read(buffer, 0, bufferLen)) != -1)
{
// write to file
fsOut.write(buffer, 0, bytesRead);
}
fsOut.flush();
// close streams
fsOut.close();
cis.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (NoSuchPaddingException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (InvalidAlgorithmParameterException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
The key is generated by using the function
public static byte[] GetKey(String password, byte[] IV, int length)
throws NoSuchAlgorithmException, InvalidKeySpecException
{
// Length is kept 16 to make it compatible with all platforms
SecretKeyFactory f = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
KeySpec ks = new PBEKeySpec(password.toCharArray(), IV, 1000, length*8);
SecretKey s = f.generateSecret(ks);
Key k = new SecretKeySpec(s.getEncoded(),"AES");
return k.getEncoded();
}
I have gone through many posts on internet related to the topic. Based on that, I have made sure that I use byte array rather String. But still getting this issue.