Develop Reference

How to decrypt ByteArrayOutputStream in Java.?

I am trying to decrypt a file downloaded as ByteArrayOutputStream from Azure Storage.
I have a stream of type ByteArrayOutputStream.
How can I decrypt it and return decrypted ByteArrayOutputStream.?
I have tried using CipherOutputStream, but I'm not sure how to use it.
Below is the code (snippet) I am using to encrypt the file before uploading
cipher.init(Cipher.ENCRYPT_MODE, key,new IvParameterSpec(INITIALIZATIO_VECTOR.getBytes("UTF-8")));
blob.upload(new CipherInputStream(file.getInputStream(), cipher), file.getSize());
Below is my code:
public ByteArrayOutputStream download(String fileName, Long id) {
ByteArrayOutputStream os = new ByteArrayOutputStream();
try {
Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding", "SunJCE");
SecretKeySpec key = new SecretKeySpec(encrypkey.getBytes("UTF-8"), "AES");
cipher.init(Cipher.DECRYPT_MODE, key,new IvParameterSpec(INITIALIZATIO_VECTOR.getBytes("UTF-8")));
CipherOutputStream output = null;
container = getBlobClient().getContainerReference("container" + id.toString());
CloudBlockBlob blob = container.getBlockBlobReference(fileName);
if (blob.exists()) {
blob.download(os);
//output = new CipherOutputStream(outputStream, cipher);
} else {
logger.info("File does not exists on azure container");
}
} catch (StorageException e) {
logger.error("StorageException : {}" + e.getLocalizedMessage(), e);
} catch (Exception e) {
logger.error("Exception : {}" + e.getLocalizedMessage(), e);
}
return os;
}

First create the CipherOutputStream, then download the blob into that output:
output = new CipherOutputStream(os, cipher);
blob.download(output);

How to fix No such file or directory in Android

In my application i have Decrypt file with AES256 and CBC .
i have written below codes, to check if file exists.
But when run application it shows me an error and not can open my file!
I used Log.e to show files's path and it shows me this path. but it says can not open file!
My code :
private SecureRandom r;
private byte[] _iv;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
r = new SecureRandom();
_iv = new byte[16];
r.nextBytes(_iv);
String inputFile = getRootDirPath(context) + "/"+bookName;
String outPutFile = getRootDirPath(context) + "/BookFile_716798_decrypt3.html";
File file = new File(inputFile);
if (file.exists()) {
try {
decrypt(inputFile, encryptionPassword, outPutFile, "");
Log.e("DecryptLog", "0");
} catch (IOException e) {
e.printStackTrace();
Log.e("DecryptLog", "1 : " + e.getMessage());
Log.e("DecryptLog", "\nPath : " + inputFile);
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
Log.e("DecryptLog", "2 : " + e.getMessage());
} catch (NoSuchPaddingException e) {
e.printStackTrace();
Log.e("DecryptLog", "3 : " + e.getMessage());
} catch (InvalidKeyException e) {
e.printStackTrace();
Log.e("DecryptLog", "4 : " + e.getMessage());
}
} else {
Toast.makeText(context, "Not", Toast.LENGTH_SHORT).show();
}
}
public String getRootDirPath(Context context) {
if (Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState())) {
File file = ContextCompat.getExternalFilesDirs(context.getApplicationContext(),
null)[0];
return file.getAbsolutePath();
} else {
return context.getApplicationContext().getFilesDir().getAbsolutePath();
}
}
private void decrypt(String path, String password, String _initVector, String outPath)
throws IOException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException {
FileInputStream fis = new FileInputStream(path);
FileOutputStream fos = new FileOutputStream(outPath);
byte[] key = (password).getBytes("UTF-8");
MessageDigest sha = MessageDigest.getInstance("SHA-1");
key = sha.digest(key);
key = Arrays.copyOf(key, 16);
SecretKeySpec sks = new SecretKeySpec(key, "AES");
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding");
try {
cipher.init(Cipher.DECRYPT_MODE, sks, new IvParameterSpec(_iv));
} catch (InvalidAlgorithmParameterException e) {
e.printStackTrace();
}
CipherInputStream cis = new CipherInputStream(fis, cipher);
int b;
byte[] d = new byte[8];
while ((b = cis.read(d)) != -1) {
fos.write(d, 0, b);
}
fos.flush();
fos.close();
cis.close();
}
After run application show me this error :
2020-08-01 08:03:59.324 28560-28560/com.app.appE/DecryptLog: 1 : : open failed: ENOENT (No such file or directory)
2020-08-01 08:03:59.324 28560-28560/com.app.app E/DecryptLog: Path : /storage/emulated/0/Android/data/com.app.app/files/BookFile_716798.html

Why does encrypting in one Java class and decrypting in another causes BadPaddingError?

I have a test function that returns a byte[] in one Java class, FirstClass:
public static byte[] testA(){
CipherClass crypto = new CipherClass();
byte[] a = crypto.encrypt("helloWorld");
return a;
}
Where CipherClass contains my java.crypto.Cipher methods to encrypt and decrypt inputs.
In another Java class, SecondClass, I instantiate my previous FirstClass and call its testA() method which I save to a byte[] variable and then try to decrypt it:
FirstClass fc = new FirstClass();
byte[] b = fc.testA();
System.out.println(crypto.decrypt(b)); //Outputs BadPaddingError
Why does encrypting a String in one Java file and then passing the resulting byte[] into another Java file to decrypt it causes a BadPaddingError?
What can be done to fix a way around this?
Why does the Cipher only work if both encryption and decryption are in the same class as follows?:
CipherClass crypto = new CipherClass();
byte[] a = crypto.encrypt("helloWorld"); //Outputs [B#5474c6c
byte[] b = a;
System.out.println(crypto.decrypt(b)); //Outputs "helloWorld"
EDIT: My CipherClass code as requested below.
SecretKey and IVParameterSpec generator:
public List<KeyGenerator> getKeyGenerator(){
List<KeyGenerator> list = new ArrayList<KeyGenerator>();
KeyGenerator keyGenerator;
int keyBitSize = 128;
try
{
SecureRandom secureRandom = new SecureRandom();
keyGenerator = KeyGenerator.getInstance("AES");
keyGenerator.init(keyBitSize, secureRandom);
list.add(keyGenerator);
return list;
}
catch (NoSuchAlgorithmException e)
{
e.printStackTrace();
}
return list;
}
public List<SecretKey> getSecretKey(List<KeyGenerator> keygen) {
List<SecretKey> list = new ArrayList<SecretKey>();
KeyGenerator keyGenerator;
SecretKey secretKey;
keyGenerator = keygen.get(0);
secretKey = keyGenerator.generateKey();
list.add(secretKey);
return list;
}
public List<IvParameterSpec> getIvSpec(List<SecretKey> secretKey) {
List<IvParameterSpec> list = new ArrayList<IvParameterSpec>();
Cipher cipher;
byte[] iv;
try
{
cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
iv = new byte[cipher.getBlockSize()];
IvParameterSpec ivSpec = new IvParameterSpec(iv);
list.add(ivSpec);
}
catch (NoSuchAlgorithmException e)
{
e.printStackTrace();
}
catch (NoSuchPaddingException e)
{
e.printStackTrace();
}
return list;
}
List<KeyGenerator> kgList = getKeyGenerator();
List<SecretKey> skList = getSecretKey(kgList); //skList.get(0) is the SecretKey
List<IvParameterSpec> ivList = getIvSpec(skList); //ivList.get(0) is the IVParameterSpec
My encrypt() method:
public byte[] encrypt(String inputStr) {
Cipher cipher;
SecretKey secretKey = skList.get(0);
IvParameterSpec ivSpec = ivList.get(0);
byte[] plainText;
byte[] cipherText = new byte[]{};
try
{
cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
try
{
secretKey = skList.get(0);
ivSpec = ivList.get(0);
cipher.init(Cipher.ENCRYPT_MODE, secretKey, ivSpec);
try
{
plainText = inputStr.getBytes("UTF-8");
cipherText = cipher.doFinal(plainText);
return cipherText;
}
catch (IllegalBlockSizeException e)
{
e.printStackTrace();
}
catch (BadPaddingException e)
{
e.printStackTrace();
}
catch (UnsupportedEncodingException e)
{
e.printStackTrace();
}
}
catch (InvalidKeyException e)
{
e.printStackTrace();
}
catch (InvalidAlgorithmParameterException e1)
{
e1.printStackTrace();
}
}
catch (NoSuchAlgorithmException e)
{
e.printStackTrace();
}
catch (NoSuchPaddingException e)
{
e.printStackTrace();
}
return cipherText;
}
My decrypt() method:
public String decrypt(byte[] cipherText){
Cipher cipherDe;
SecretKey secretKey = skList.get(0);
IvParameterSpec ivSpec = ivList.get(0);
byte[] deciByte;
String decryptText = "";
try
{
cipherDe = Cipher.getInstance("AES/CBC/PKCS5Padding");
try
{
secretKey = skList.get(0);
ivSpec = ivList.get(0);
cipherDe.init(Cipher.DECRYPT_MODE, secretKey, ivSpec);
try
{
//De-cryption
deciByte = cipherDe.doFinal(cipherText);
decryptText = new String(deciByte);
return decryptText;
}
catch (IllegalBlockSizeException e)
{
e.printStackTrace();
}
catch (BadPaddingException e)
{
e.printStackTrace();
}
}
catch (InvalidKeyException e)
{
e.printStackTrace();
}
//De-cryption
catch (InvalidAlgorithmParameterException e1)
{
e1.printStackTrace();
}
}
catch (NoSuchAlgorithmException e)
{
e.printStackTrace();
}
catch (NoSuchPaddingException e)
{
e.printStackTrace();
}
return decryptText;
}

Im getting a RSA bad padding exception

I cannot seem to find a awnser to why my program wont work
I have already checked the keys and they are the same
here is my error
javax.crypto.BadPaddingException: Decryption error null 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.thatmadhacker.finlaybot.client.FinlayBot.rsadecrypt(FinlayBot.java:234)
at
com.thatmadhacker.finlaybot.client.MainThread.run(MainThread.java:16)
at java.lang.Thread.run(Thread.java:745)
here is mv key generator code
KeyPairGenerator kpg = null;
try {
kpg = KeyPairGenerator.getInstance("RSA");
kpg.initialize(2048);
KeyPair kp = kpg.genKeyPair();
publicKey = kp.getPublic();
privateKey = kp.getPrivate();
KeyFactory fact = KeyFactory.getInstance("RSA");
pub = fact.getKeySpec(kp.getPublic(),
RSAPublicKeySpec.class);
priv = fact.getKeySpec(kp.getPrivate(),
RSAPrivateKeySpec.class);
saveToFile("public.key", pub.getModulus(),
pub.getPublicExponent());
saveToFile("private.key", priv.getModulus(),
priv.getPrivateExponent());
} catch (Exception e1) {
e1.printStackTrace();
}
here are my decryption and encryption methods
public static String rsadecrypt(byte[] text) {
try {
// get an RSA cipher object and print the provider
final Cipher cipher = Cipher.getInstance("RSA");
// decrypt the text using the private key
cipher.init(Cipher.DECRYPT_MODE, privateKey);
byte[] dectyptedText = cipher.doFinal(text);
return new String(dectyptedText);
} catch (Exception ex) {
ex.printStackTrace();
}
return null;
}
public static byte[] rsaencrypt(String text) {
try {
// get an RSA cipher object and print the provider
final Cipher cipher = Cipher.getInstance("RSA");
// encrypt the plain text using the public key
cipher.init(Cipher.ENCRYPT_MODE, clientKey);
byte[] cipherText = cipher.doFinal(text.getBytes());
return cipherText;
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
and then here is my server thread that performing a key exchange
Scanner in = new Scanner(s.getInputStream());
PrintWriter out = new PrintWriter(s.getOutputStream(), true);
java.io.PrintWriter unEncryptOut = new java.io.PrintWriter(s.getOutputStream(), true);
unEncryptOut.println(FinlayBot.pub.getModulus());
unEncryptOut.println(FinlayBot.pub.getPublicExponent());
unEncryptOut.flush();
BigInteger modulus = new BigInteger(in.nextLine());
BigInteger exponent = new BigInteger(in.nextLine());
RSAPublicKeySpec pub = new RSAPublicKeySpec(modulus,exponent);
try {
FinlayBot.clientKey = KeyFactory.getInstance("RSA").generatePublic(pub);
//System.out.println(modulus +" "+exponent);
} catch (InvalidKeySpecException e) {
e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
and the client
System.out.println("Waiting For KeyPair!");
pubKeyModulus = new BigInteger(in.nextLine().trim());
pubKeyExponent = new BigInteger(in.nextLine().trim());
//System.out.println(pubKeyModulus+" "+pubKeyExponent);
System.out.println("Recieved KeyPair!");
RSAPublicKeySpec pub = new RSAPublicKeySpec(pubKeyModulus, pubKeyExponent);
try {
serverPublicKey = KeyFactory.getInstance("RSA").generatePublic(pub);
System.out.println(pub.getModulus()+" "+pub.getPublicExponent());
writer.println(pub.getModulus());
writer.println(pub.getPublicExponent());
writer.flush();
} catch (InvalidKeySpecException e) {
e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}

java Aes encryption using key file

How can we store the KEY in a key file for AES encryption using java so that the key file can be used for decryption purpose.
private static void storeKey(SecretKey key){
byte[] keyb = key.getEncoded();
FileOutputStream keyfos;
try {
File file = new File(generateKeyFilesPath);
if (!file.exists()) {
file.createNewFile();
}
keyfos = new FileOutputStream(file);
keyfos.write(keyb);
keyfos.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
private static SecretKeySpec getKey(String generateKeyFilesPath){
SecretKeySpec key = null;
try {
File keyFile = new File(path);
FileInputStream stream = new FileInputStream(keyFile);
byte[] bytesArray = new byte[(int) keyFile.length()];
stream.read(bytesArray);
stream.close();
key = new SecretKeySpec(bytesArray, "AES");
} catch (Exception e) {
e.printStackTrace();
}
return key;
}
Unable to decrypt the cipher using the stored key(file),