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Encrypt and Decrypt data with Meteor and Java

I have my application's UI built in Meteor and it gets and send the data from REST API (Spring CXF). I would like to encrypt the data in Meteor, and decrypt the same in REST API code. I am using AES for encryption and Decryption. In Meteor i am using https://atmospherejs.com/jparker/crypto-aes package for encryption. I have written the below code in java for decryption the encryption key send by Meteor.
public class AESTest {
private static String AESStr = "<Encrypted KEY>";
public static void main(String[] args) throws Exception {
Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
System.out.println(decrypt(AESStr, "Test"));
}
public static String decrypt(String responseStr, String passPhrase) throws GeneralSecurityException {
String decryptedStr = "";
try {
Cipher cipher = getCipher(Cipher.DECRYPT_MODE, passPhrase);
byte[] decoded = Base64.decodeBase64(responseStr.getBytes());
byte[] decryptedWithKey = cipher.doFinal(decoded);
byte[] decrypted = Arrays.copyOfRange(decryptedWithKey, 16, decryptedWithKey.length);
decryptedStr = new String(decrypted, "UTF-8");
} catch (Exception e) {
e.printStackTrace();
}
return decryptedStr;
}
private static Cipher getCipher(int mode, String passPhrase) throws Exception {
SecretKeySpec secretKeySpec = new SecretKeySpec(passPhrase.getBytes(), "AES");
byte[] IV = new byte[16];
new Random().nextBytes(IV);
AlgorithmParameterSpec paramSpec = new IvParameterSpec(IV);
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding");
cipher.init(mode, secretKeySpec, paramSpec);
return cipher;
}
}
When I run the code i am getting below exception
javax.crypto.BadPaddingException: pad block corrupted
at org.bouncycastle.jce.provider.JCEBlockCipher.engineDoFinal(Unknown Source)
at javax.crypto.Cipher.doFinal(Cipher.java:2165)
at com.tph.r3.EncodeTest.decrypt(EncodeTest.java:37)
at com.tph.r3.EncodeTest.main(EncodeTest.java:26)
Can anyone guide me with the issue?

There is a problem with the decryption logic w.r.t IV. You are selecting an IV randomly to initialize decryption cipher which is wrong. You need to use the same IV that was used to encrypt the responseStr which forms its first 16 bytes usually.
In the current form your getCipher() can be used only for encryption where IV is selected randomly but not for decryption. Better write another method.
Psuedocode for decryption:
decCipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
SecretKeySpec keySpec = new SecretKeySpec(securityKey , "AES");
//IV + Cipher
byte [] cipherWithIV = Base64.decodeBase64(responseStr.getBytes()));
//Extract IV
byte [] iv = new byte [16];
byte [] cipherWithoutIV = new byte [cipherWithIV.length - 16 ];
//First 16 bytes
for(i < 16; i++) {
iv [i] = cipherWithIV [i];
}
//Rest of the cipher ie 16 -> cipherWithIV.length
for(i < cipherWithIV.length; i++) {
cipherWithoutIV [j] = cipherWithIV[i];
j++;
}
//
IvParameterSpec ivParamSpec = new IvParameterSpec(iv);
//
decCipher.init(Cipher.DECRYPT_MODE, keySpec, ivParamSpec);
//Decrypt cipher without IV
decText = decCipher.doFinal(cipherWithoutIV);
//Convert to string
decString = new String(decText,"UTF8");

Invalid Key exception while decrypting AES key

I have a few methods to encrypt and decrypt files. as far as I know, my encrypt function does its job great, while decrypt usually throws an InvalidKeyException, particularly on the Cipher.getInstance("AES"); bit. I have switch this around from RSA to "RSA/CBC/PKCS5Padding" but nothing has worked so far.
Main function:
static String inFile = "";
static String outFile = "";
static String hexKey="";
static String keyStore;
static String keyName;
public static void main(String[] args) {
if (args.length==5 && args[0].equals("-encRSA") ) {
keyStore = args[1];
keyName = args[2];
inFile = args[3];
outFile = args[4];
encryptRSA();
} else if (args.length==5 && args[0].equals("-decRSA") ) {
keyStore = args[1];
keyName = args[2];
inFile = args[3];
outFile = args[4];
decryptRSA();
} else {
System.out.println("This is a simple program to encrypt and decrypt files");
System.out.println("Usage: ");
System.out.println(" -encRSA <keyStore> <keyName> <inputFile> <outputFile> RSA encrypt");
System.out.println(" -decRSA <keyStore> <keyName> <inputFile> <outputFile> RSA decrypt");
}
Encrypt function
private static void encryptRSA() {
try {
//Get the public key from the keyStore and set up the Cipher object
PublicKey publicKey = getPubKey(keyStore,keyName);
Cipher rsaCipher = Cipher.getInstance("RSA");
rsaCipher.init(Cipher.ENCRYPT_MODE, publicKey);
//Read the plainText
System.out.println("Loading plaintext file: "+inFile);
RandomAccessFile rawDataFromFile = new RandomAccessFile(inFile, "r");
byte[] plainText = new byte[(int)rawDataFromFile.length()];
rawDataFromFile.read(plainText);
// Generate a symmetric key to encrypt the data and initiate the AES Cipher Object
System.out.println("Generating AES key");
KeyGenerator sKenGen = KeyGenerator.getInstance("AES"); //ECB is fine here
Key aesKey = sKenGen.generateKey();
Cipher aesCipher = Cipher.getInstance("AES");
aesCipher.init(Cipher.ENCRYPT_MODE, aesKey);
// Encrypt the symmetric AES key with the public RSA key
System.out.println("Encrypting Data");
byte[] encodedKey = rsaCipher.doFinal(aesKey.getEncoded());
// Encrypt the plaintext with the AES key
byte[] cipherText = aesCipher.doFinal(plainText);
//Write the encrypted AES key and Ciphertext to the file.
System.out.println("Writting to file: "+outFile);
FileOutputStream outToFile = new FileOutputStream(outFile);
outToFile.write(encodedKey);
outToFile.write(cipherText);
System.out.println("Closing Files");
rawDataFromFile.close();
outToFile.close();
}
catch (Exception e) {
System.out.println("Doh: "+e);
}
}
Decrypt function (so far):
private static void decryptRSA()
{
FileInputStream cipherfile;
try {
cipherfile = new FileInputStream(inFile);
byte[] ciphertext = new byte[cipherfile.available()];
PrivateKey privatekey = getKeyPair().getPrivate();
/* Create cipher for decryption. */
Cipher decrypt_cipher = Cipher.getInstance("AES");
decrypt_cipher.init(Cipher.DECRYPT_MODE, privatekey);
/* Reconstruct the plaintext message. */
byte[] plaintext = decrypt_cipher.doFinal(ciphertext);
FileOutputStream plainfile = new FileOutputStream(outFile);
plainfile.write(plaintext);
plainfile.close();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
private static KeyPair getKeyPair() throws Exception
{
KeyPair keypair = null;
FileInputStream is = new FileInputStream(keyStore);
KeyStore keystore = KeyStore.getInstance(KeyStore.getDefaultType());
keystore.load(is, password.toCharArray());
Key key = keystore.getKey(keyName, password.toCharArray());
if (key instanceof PrivateKey) {
Certificate cert = keystore.getCertificate(keyName);
PublicKey publicKey = cert.getPublicKey();
keypair = new KeyPair(publicKey, (PrivateKey) key);
}
return keypair;
}

You need to reverse the encryption process to code the decryption process. Currently you are encrypting an AES key using RSA and then encrypting the plaintext to ciphertext using AES.
In the decryption process you only try and decrypt the ciphertext using AES. You should first extract the encrypted AES key, decrypt that and then decrypt the (rest of the) ciphertext using AES to retrieve the plaintext.

javax.crypto.BadPaddingException: pad block corrupted

I'm trying to encrypt something, and decrypt it. I'm failing on the decryption - I get the exception above. I tried changing ctLength and ptLength, but to no avail. What am I doing wrong?
I'm trying to encrypt: 0 0 0 0 0 0 0 0
private Cipher encrypt(byte[] input)
{
try
{
SecretKeySpec key = new SecretKeySpec(keyBytes, "AES");
Cipher cipher = Cipher.getInstance("AES/ECB/PKCS7Padding", "BC");
// encryption pass
cipher.init(Cipher.ENCRYPT_MODE, key);
byte[] cipherText = new byte[cipher.getOutputSize(input.length)];
int ctLength = cipher.update(input, 0, input.length, cipherText, 0);
ctLength += cipher.doFinal(cipherText, ctLength);
FileOutputStream fs = new FileOutputStream(savedScoresFileName);
fs.write(cipherText);
return cipher;
}
catch (Exception e)
{
Log.e("encrtypt", "Exception", e);
}
return null;
}
private String decrypt()
{
try
{
Cipher cipher = Cipher.getInstance("AES/ECB/PKCS7Padding", "BC");
SecretKeySpec key = new SecretKeySpec(keyBytes, "AES");
byte[] cipherText = new byte[32];
FileInputStream fl = new FileInputStream(savedScoresFileName);
fl.read(cipherText);
cipher.init(Cipher.DECRYPT_MODE, key);
byte[] plainText = new byte[cipher.getOutputSize(32)];
int ptLength = cipher.update(cipherText, 0, 32, plainText, 0);
ptLength += cipher.doFinal(plainText, ptLength);
return new String(plainText).substring(0, ptLength);
}
catch (Exception e)
{
Log.e("decrypt", "Exception", e);
}
return null;
}
This code was copied from this, which worked.

Your code has a number of issues, but your problem is caused by your file reading code and your strange method of performing the encryption and decryption.
Don't use the update() method, just use doFinal() and correct your file writing/reading code. E.g. your decryption method should look something like:
try {
Cipher cipher = Cipher.getInstance("AES/ECB/PKCS7Padding", "BC");
SecretKeySpec key = new SecretKeySpec(keyBytes, "AES");
// Here you need to accurately and correctly read your file into a byte
// array. Either Google for a decent solution (there are many out there)
// or use an existing implementation, such as Apache Commons commons-io.
// Your existing effort is buggy and doesn't close its resources.
byte[] cipherText = FileUtils.readFileToByteArray(new File(savedScoresFileName));
cipher.init(Cipher.DECRYPT_MODE, key);
// Just one call to doFinal
byte[] plainText = cipher.doFinal(cipherText);
// Note: don't do this. If you create a string from a byte array,
// PLEASE pass a charset otherwise your result is platform dependent.
return new String(plainText);
} catch (Exception e) {
e.printStackTrace();
}

AES 128 encryption in Android and .Net with custom key and IV

I have a password string in my android application. I need to the send the password through the .net web service (i.e. end with .aspx) using the SOAP web service. Before sending the password i need to encrypt the password with AES 128 encryption with the custom key and IV.
They have a encrypt/decrypt tool in .net with the custom key and Iv. The tool ask a custom key with 16 digit and IV 8 digit. If give the string it generate the encrypting string. example
Example:
Key : 1234567812345678
IV : 12345678
String : android
Encrypted string : oZu5E7GgZ83Z3yoK4y8Utg==
I didn't have any idea how to do this in android. Need help.

A complete example may help you:
The encrypt/decrypt functions, using IV
public static byte[] encrypt(byte[] data, byte[] key, byte[] ivs) {
try {
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
SecretKeySpec secretKeySpec = new SecretKeySpec(key, "AES");
byte[] finalIvs = new byte[16];
int len = ivs.length > 16 ? 16 : ivs.length;
System.arraycopy(ivs, 0, finalIvs, 0, len);
IvParameterSpec ivps = new IvParameterSpec(finalIvs);
cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec, ivps);
return cipher.doFinal(data);
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
public static byte[] decrypt(byte[] data, byte[] key, byte[] ivs) {
try {
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
SecretKeySpec secretKeySpec = new SecretKeySpec(key, "AES");
byte[] finalIvs = new byte[16];
int len = ivs.length > 16 ? 16 : ivs.length;
System.arraycopy(ivs, 0, finalIvs, 0, len);
IvParameterSpec ivps = new IvParameterSpec(finalIvs);
cipher.init(Cipher.DECRYPT_MODE, secretKeySpec, ivps);
return cipher.doFinal(data);
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
You can use it as below :
String dataToEncryptDecrypt = "android";
String encryptionDecryptionKey = "1234567812345678";
String ivs = "12345678";
byte[] encryptedData = encrypt(dataToEncryptDecrypt.getBytes(), encryptionDecryptionKey.getBytes(),
ivs.getBytes());
// here you will get the encrypted bytes. Now you can use Base64 encoding on these bytes, before sending to your web-service
byte[] decryptedData = decrypt(encryptedData, encryptionDecryptionKey.getBytes(), ivs.getBytes());
System.out.println(new String(decryptedData));

I don't know the details of AES algorithm in use(ie mode & padding method), bit it should be roughly like this:
public static byte[] encrypt(byte[] data, byte[] key) {
try {
Cipher cipher = Cipher.getInstance("AES/CBC/ZeroBytePadding");
SecretKeySpec secretKeySpec = new SecretKeySpec(key, "AES");
byte[] empty = new byte[16]; // For better security you should use a random 16 byte key!!!
IvParameterSpec ivps = new IvParameterSpec(empty);
cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec, ivps);
return cipher.doFinal(data);
} catch (Exception e) {
// ...
}
return null;
}
Function above could be used like this:
String data = "android";
String key = "1234567812345678";
byte encrypted = encrypt(data.getbytes("UTF-8"), key.getbytes("UTF-8"));

RSA encryption in Android

I am writing a program which employs RSA in Android. I have the following problem:
I am getting the RSA keys:
KeyPair kp = kpg.genKeyPair();
publicKey = kp.getPublic();
privateKey = kp.getPrivate();
Using the encryption function to encrypt a test string:
String test ="test";
byte[] testbytes = test.getBytes();
Cipher cipher = Cipher.getInstance("RSA");
cipher.init(Cipher.ENCRYPT_MODE, publicKey);
byte[] cipherData = cipher.doFinal(testbytes);
String s = new String(cipherData);
Log.d("testbytes after encryption",s);
In the decryption function i am decrypting the data back to get the original string
Cipher cipher2 = Cipher.getInstance("RSA");
cipher2.init(Cipher.DECRYPT_MODE, privateKey);
byte[] plainData = cipher.doFinal(cipherData);
String p = new String(plainData);
Log.d("decrypted data is:",p);
The data in 'p' printed out in the log does not match the original string "test" . Where am I going wrong in this?

Here an example on how to do it, BUT in practice,
You can't really encrypt and decrypt whole files with just RSA. The
RSA algorithm can only encrypt a single block, and it is rather slow
for doing a whole file.
You can encrypt the file using
3DES or AES, and then encrypt the AES key using intended recipient's
RSA public key.
Some code:
public static void main(String[] args) throws Exception {
KeyPairGenerator kpg = KeyPairGenerator.getInstance("RSA");
Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
kpg.initialize(1024);
KeyPair keyPair = kpg.generateKeyPair();
PrivateKey privKey = keyPair.getPrivate();
PublicKey pubKey = keyPair.getPublic();
// Encrypt
cipher.init(Cipher.ENCRYPT_MODE, pubKey);
String test = "My test string";
String ciphertextFile = "ciphertextRSA.txt";
InputStream fis = new ByteArrayInputStream(test.getBytes("UTF-8"));
FileOutputStream fos = new FileOutputStream(ciphertextFile);
CipherOutputStream cos = new CipherOutputStream(fos, cipher);
byte[] block = new byte[32];
int i;
while ((i = fis.read(block)) != -1) {
cos.write(block, 0, i);
}
cos.close();
// Decrypt
String cleartextAgainFile = "cleartextAgainRSA.txt";
cipher.init(Cipher.DECRYPT_MODE, privKey);
fis = new FileInputStream(ciphertextFile);
CipherInputStream cis = new CipherInputStream(fis, cipher);
fos = new FileOutputStream(cleartextAgainFile);
while ((i = cis.read(block)) != -1) {
fos.write(block, 0, i);
}
fos.close();
}