I have already use below library for encryption and decryption in iOS.
https://github.com/dev5tec/FBEncryptor
Now I want same functionality in Android. Is there any support for Android also? If not then how can I use this library to fulfil my need in Android also or please suggest another other encryption library that work same as FBEncryptor.
I have implemented the following code.
public class AESHelper {
private final Cipher cipher;
private final SecretKeySpec key;
private AlgorithmParameterSpec spec;
private static final String KEY = "VHJFTFRGJHGHJDhkhjhd/dhfdh=";
public AESHelper() throws Exception {
byte[] keyBytes = KEY.getBytes("UTF-8");
Arrays.fill(keyBytes, (byte) 0x00);
cipher = Cipher.getInstance("AES/CBC/PKCS7Padding");
key = new SecretKeySpec(keyBytes, "AES");
spec = getIV();
}
public AlgorithmParameterSpec getIV() {
final byte[] iv = new byte[16];
Arrays.fill(iv, (byte) 0x00);
return new IvParameterSpec(iv);
}
public String encrypt(String plainText) throws Exception {
cipher.init(Cipher.ENCRYPT_MODE, key, spec);
byte[] encrypted = cipher.doFinal(plainText.getBytes("UTF-8"));
String encryptedText = new String(Base64.encode(encrypted, Base64.DEFAULT), "UTF-8");
return encryptedText;
}
public String decrypt(String cryptedText) throws Exception {
cipher.init(Cipher.DECRYPT_MODE, key, spec);
byte[] bytes = Base64.decode(cryptedText, Base64.DEFAULT);
byte[] decrypted = cipher.doFinal(bytes);
String decryptedText = new String(decrypted, "UTF-8");
return decryptedText;
}
}
But it throw javax.crypto.BadPaddingException: Pad Block Corrupted
finally i have found solution for my own question.
For encryption in android you can use https://gist.github.com/m1entus/f70d4d1465b90d9ee024.
This class work same as like https://github.com/dev5tec/FBEncryptor in ios.
Related
I'm attempting to encrypt and encrypt strings (passwords). I'm trying to encrypt I've tried all Base64 encoding options and it continues to return bad base-64.
private String encrypt(String password) throws Exception {
SecretKeySpec key = generatePasswordKey(databaseSetup.getAES());
#SuppressLint("GetInstance") Cipher c = Cipher.getInstance("AES");
c.init(Cipher.ENCRYPT_MODE, key);
byte[] encodeBytes = c.doFinal(password.getBytes());
return Base64.encodeToString(encodeBytes, Base64.NO_WRAP);
}
private String decrypt(String password) throws Exception {
SecretKeySpec key = generatePasswordKey(databaseSetup.getAES());
Cipher c = Cipher.getInstance("AES");
c.init(Cipher.DECRYPT_MODE, key);
byte[] decodedBytes = Base64.decode(password, Base64.NO_WRAP);
byte[] decryptedVal = c.doFinal(decodedBytes);
String decryptedPassword = new String(decryptedVal);
return decryptedPassword;
}
private SecretKeySpec generatePasswordKey(String password) throws NoSuchAlgorithmException {
final MessageDigest messageDigest = MessageDigest.getInstance("SHA-256");
byte[] bytes = password.getBytes();
messageDigest.update(bytes, 0, bytes.length);
byte[] key = messageDigest.digest();
return new SecretKeySpec(key, "AES");
}
I am using below class for generating AES 256 key, initialization vector, encryption and decryption in android. There are few issues, that I am facing
1) When I call getInitializationVector() it return 24 characters instead of 16.(ex: WoiUFsQpizjG705OXja1Jw==)
2) When I call generateKey(), it returns 44 characters instead of 32.(ex:tEf+dcrzI4x+kSMS8UZxjwziGySMMkDxO0aVgsj0oBs=)
3) The below class is symmetric approach, How to make it asymmetric.
You can see textKey and testIV for default ones. But I am unable to create it. I have searched in stack overflow for solutions but, All are returning me same length text. Does anyone know how to do this? Am I doing wrong?
Thanks for your valuable time in advance.
public class CryptoDataHandler {
//32 characters
String testKey = "82a645babc5cd41c9a2cb4d0d3ba17ad";
//16 characters
String testIV = "acf30ad32b693849";
String edType = "AES";
String chiperInstanceType = "AES/CBC/PKCS5PADDING";
private static CryptoDataHandler instance = null;
public static CryptoDataHandler getInstance() {
if (instance == null) {
Security.setProperty("crypto.policy", "unlimited");
instance = new CryptoDataHandler();
}
return instance;
}
public String encrypt(String message) throws NoSuchAlgorithmException,
NoSuchPaddingException, IllegalBlockSizeException,
BadPaddingException, InvalidKeyException,
UnsupportedEncodingException, InvalidAlgorithmParameterException {
byte[] srcBuff = message.getBytes(StandardCharsets.UTF_8);
//here using substring because AES takes only 16 or 24 or 32 byte of key
SecretKeySpec skeySpec = new
SecretKeySpec(testKey.substring(0, 32).getBytes(), edType);
IvParameterSpec ivSpec = new
IvParameterSpec(testIV.substring(0, 16).getBytes());
Cipher ecipher = Cipher.getInstance(chiperInstanceType);
ecipher.init(Cipher.ENCRYPT_MODE, skeySpec, ivSpec);
byte[] dstBuff = ecipher.doFinal(srcBuff);
return Base64.encodeToString(dstBuff, Base64.DEFAULT);
}
public String decrypt(String encrypted) throws NoSuchAlgorithmException,
NoSuchPaddingException, InvalidKeyException,
InvalidAlgorithmParameterException, IllegalBlockSizeException,
BadPaddingException, UnsupportedEncodingException {
SecretKeySpec skeySpec = new
SecretKeySpec(testKey.substring(0, 32).getBytes(), edType);
IvParameterSpec ivSpec = new
IvParameterSpec(testIV.substring(0, 16).getBytes());
Cipher ecipher = Cipher.getInstance(chiperInstanceType);
ecipher.init(Cipher.DECRYPT_MODE, skeySpec, ivSpec);
byte[] raw = Base64.decode(encrypted, Base64.DEFAULT);
byte[] originalBytes = ecipher.doFinal(raw);
return new String(originalBytes, StandardCharsets.UTF_8);
}
public String generateKey() {
try {
Key key;
SecureRandom rand = new SecureRandom();
KeyGenerator generator = KeyGenerator.getInstance(edType);
generator.init(256, rand);
key = generator.generateKey();
return Base64.encodeToString(key.getEncoded(), Base64.DEFAULT);
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
return null;
}
public String getInitializationVector() {
byte[] IV = new byte[16];
SecureRandom random = new SecureRandom();
random.nextBytes(IV);
return Base64.encodeToString(IV, Base64.DEFAULT);
}
}
Well, I have found a solution. Posting it here. If it's helpful for someone else.
I just modified my KEY and IV generation method, for exact 32 and 16 characters. And I have tested the encryption and decryption and it's working fine.
public String generateKey() {
try {
Key key;
SecureRandom rand = new SecureRandom();
KeyGenerator generator = KeyGenerator.getInstance(edType);
generator.init(256, rand);
key = generator.generateKey();
return Base64.encodeToString(key.getEncoded(), Base64.DEFAULT).subString(0,32);
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
return null;
}
public String getInitializationVector() {
byte[] IV = new byte[16];
SecureRandom random = new SecureRandom();
random.nextBytes(IV);
return Base64.encodeToString(IV, Base64.DEFAULT).subString(0,16);
}
I need to encrypt a message using a key in Android.
How can I convert the below code to work with Android
public static String EncryptData(byte[] key, byte[] msg)
throws Exception {
String encryptedData = "";
AESKey key = new AESKey(keyData);
NoCopyByteArrayOutputStream out = new NoCopyByteArrayOutputStream();
AESEncryptorEngine engine = new AESEncryptorEngine(key);
BlockEncryptor encryptor = new BlockEncryptor(engine, out);
encryptor.write(data, 0, data.length);
int finalLength = out.size();
byte[] cbytes = new byte[finalLength];
System.arraycopy(out.getByteArray(), 0, cbytes, 0, finalLength);
encryptedData = getHexString(cbytes);
return encryptedData;
}
as this is java code for encryption you can use this code as it is in your class . this is AES algorithm encryption so you just need to create methods for encryption and decryption
private static byte[] encrypt(byte[] raw, byte[] clear) throws Exception {
SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
Cipher cipher = Cipher.getInstance("AES");
cipher.init(Cipher.ENCRYPT_MODE, skeySpec);
byte[] encrypted = cipher.doFinal(clear);
return encrypted;
}
private static byte[] decrypt(byte[] raw, byte[] encrypted) throws
Exception {
SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
Cipher cipher = Cipher.getInstance("AES");
cipher.init(Cipher.DECRYPT_MODE, skeySpec);
byte[] decrypted = cipher.doFinal(encrypted);
return decrypted;
}
... for reference you can follow the example given-
Aes encryption example
I have to encrypt and decrypt text on android devices. I have found some solution, but when I encrypt the text again, the result is different. Can anyone tell me why?
Here is my code:
public class AESDemo {
private static final String password = "test";
private static String salt;
private static int pswdIterations = 65536;
private static int keySize = 256;
private byte[] ivBytes;
public String encrypt(String plainText) throws Exception {
//get salt
salt = generateSalt();
byte[] saltBytes = salt.getBytes("UTF-8");
// Derive the key
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
PBEKeySpec spec = new PBEKeySpec(
password.toCharArray(),
saltBytes,
//null,
pswdIterations,
keySize
);
SecretKey secretKey = factory.generateSecret(spec);
SecretKeySpec secret = new SecretKeySpec(secretKey.getEncoded(), "AES");
//encrypt the message
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, secret);
AlgorithmParameters params = cipher.getParameters();
ivBytes = params.getParameterSpec(IvParameterSpec.class).getIV();
byte[] encryptedTextBytes = cipher.doFinal(plainText.getBytes("UTF-8"));
//return new Base64().encodeAsString(encryptedTextBytes);
return Base64.encodeToString(encryptedTextBytes, Base64.DEFAULT);
}
#SuppressWarnings("static-access")
public String decrypt(String encryptedText) throws Exception {
byte[] saltBytes = salt.getBytes("UTF-8");
//byte[] encryptedTextBytes = new Base64().decodeBase64(encryptedText);
byte[] encryptedTextBytes= Base64.decode(encryptedText, Base64.DEFAULT);
// Derive the key
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
PBEKeySpec spec = new PBEKeySpec(
password.toCharArray(),
saltBytes,
pswdIterations,
keySize
);
SecretKey secretKey = factory.generateSecret(spec);
SecretKeySpec secret = new SecretKeySpec(secretKey.getEncoded(), "AES");
// Decrypt the message
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
cipher.init(Cipher.DECRYPT_MODE, secret, new IvParameterSpec(ivBytes));
byte[] decryptedTextBytes = null;
try {
decryptedTextBytes = cipher.doFinal(encryptedTextBytes);
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
}
return new String(decryptedTextBytes);
}
public String generateSalt() {
SecureRandom random = new SecureRandom();
byte bytes[] = new byte[20];
String ss = "";
random.nextBytes(bytes);
String s = new String(bytes);
return "sare";
}
}
I've hardcoded the salt to be the same, but the result is different every time. Can anyone tell me why?
Your IV handling puzzles me. You call getIV() but where do you actually set the IV for the encryption? It seems to me you are using a random IV which might explain why you get a different encrypted data each time.
I would suggest to try create a dynamic IvParameterSpec class and fill it with a preset IV.
I'm a newbie to android dev, right now I implemented an AES on Android and it could encrypt strings with user input passwords. The encryption seems fine and it could omit Base64/Hex encoded strings.
But When I try to decrypt it, the problem comes: With the decryption, the omission always showing me a load of messy characters.
In order to get rid of it, I've tried debugging it by define a charset (Like UTF-8) while casting from string to byte[], but no hit, and also tried to encode the omit with base 64 or Hex, but both of them failed.
I've also tried to define AES/CBC/PKCS5Padding or just AES while using cipher.getInstance method, but still no go.
It is quite irritating, could you guys help me please?
Forgot to mention that I once asked a similar question https://stackoverflow.com/questions/6727255/aes-decryption-on-android-not-correct , the grammer problem there have been corrected.
And Here's the code:
For Encryption
public String AESEncrypt(String sKey, String PlainMsg)
throws Exception {
//Try use some Android based alert dialog to catch this exception.
if (sKey == null) {
Log.e("SecureChat", "IllegalArgumentException Catched");
throw new IllegalArgumentException ("NULL Secret NOT ALLOWED!");
}
/*Old Method
//byte[] rawKey = getRawKey(sKey.getBytes("UTF-8"));
byte[] rawKey = getRawKey(sKey.getBytes());
//Encrypt start
SecretKeySpec keySpec = new SecretKeySpec(rawKey, "AES");
Cipher cipher = Cipher.getInstance("AES");
cipher.init(Cipher.ENCRYPT_MODE, keySpec);
//byte[] cipherText = cipher.doFinal(PlainMsg.getBytes("UTF-8"));
byte[] cipherText = cipher.doFinal(PlainMsg.getBytes());
return Base64Encoded(cipherText);
*/
//New Method
byte[] salt = getSalt();
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBEWITHSHA256AND256BITAES-CBC-BC");
KeySpec spec = new PBEKeySpec(sKey.toCharArray(), salt, 1024, 256);
SecretKey tmp = factory.generateSecret(spec);
SecretKey secret = new SecretKeySpec(tmp.getEncoded(), "AES");
//Encryption Process
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, secret);
byte[] cipherText = cipher.doFinal(PlainMsg.getBytes());
//return Base64Encoded(cipherText);
//Hex
return toHex(cipherText);
}
For Decryption
public String AESDecrypt(String sKey, String EncryptMsg)
throws Exception {
/*Old Method
//byte[] rawKey = getRawKey(sKey.getBytes("UTF-8"));
byte[] rawKey = getRawKey(sKey.getBytes());
SecretKeySpec keySpec = new SecretKeySpec(rawKey, "AES");
Cipher cipher = Cipher.getInstance("AES");
cipher.init(Cipher.DECRYPT_MODE, keySpec);
//byte[] plainText = Base64Decoded(EncryptMsg.getBytes("UTF-8"));
byte[] plainText = Base64Decoded(EncryptMsg);
cipher.doFinal(plainText);
return new String(plainText, "UTF-8");
*/
//New Method
byte[] salt = getSalt();
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBEWITHSHA256AND256BITAES-CBC-BC");
KeySpec spec = new PBEKeySpec(sKey.toCharArray(), salt, 1024, 256);
SecretKey tmp = factory.generateSecret(spec);
SecretKey secret = new SecretKeySpec(tmp.getEncoded(), "AES");
//byte[] bCipherText = Base64Decoded(EncryptMsg);
//Hex
byte[] bCipherText = toByte(EncryptMsg);
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, secret);
cipher.doFinal(bCipherText);
return new String(bCipherText);
}
private byte[] getSalt() throws NoSuchAlgorithmException {
/*Mark for old key method
//Initialize the KeyGenerator
KeyGenerator kgen = KeyGenerator.getInstance("AES");
SecureRandom sr = SecureRandom.getInstance("SHA1PRNG");
sr.setSeed(seed);
//Init for 256bit AES key
kgen.init(Constants.AES_KEY_SIZE, sr);;
SecretKey secret = kgen.generateKey();
//Get secret raw key
byte[] rawKey = secret.getEncoded();
return rawKey;
*/
//New key method with some salt
SecureRandom random = SecureRandom.getInstance("SHA1PRNG");
byte[] ransalt = new byte[20];
random.nextBytes(ransalt);
return ransalt;
}
#Override
public byte[] getRawKey(byte[] seed) throws Exception {
/*Old Method
//Initialize the KeyGenerator
KeyGenerator kgen = KeyGenerator.getInstance("AES");
SecureRandom sr = SecureRandom.getInstance("SHA1PRNG");
sr.setSeed(seed);
//Init for 256bit AES key
kgen.init(Constants.AES_KEY_SIZE, sr);
SecretKey secret = kgen.generateKey();
//Get secret raw key
byte[] rawKey = secret.getEncoded();
return rawKey;
*/
return null;
}
/**
*
* #param toBeDecoded
* #return
*/
public byte[] Base64Decoded(String toBeDecoded) {
byte[] decoded = Base64.decode(toBeDecoded, 0);
return decoded;
}
//Hex Mode
public String toHex(String txt) {
return toHex(txt.getBytes());
}
public String fromHex(String hex) {
return new String(toByte(hex));
}
public byte[] toByte(String hexString) {
int len = hexString.length()/2;
byte[] result = new byte[len];
for (int i = 0; i < len; i++)
result[i] = Integer.valueOf(hexString.substring(2*i, 2*i+2), 16).byteValue();
return result;
}
public String toHex(byte[] buf) {
if (buf == null)
return "";
StringBuffer result = new StringBuffer(2*buf.length);
for (int i = 0; i < buf.length; i++) {
appendHex(result, buf[i]);
}
return result.toString();
}
private final String HEX = "0123456789ABCDEF";
private void appendHex(StringBuffer sb, byte b) {
sb.append(HEX.charAt((b>>4)&0x0f)).append(HEX.charAt(b&0x0f));
}
}
I've referenced/compared with these code on Stackoverflow:
Android aes encryption pad block corrupted
and
incorrect decryption using AES/CBC/PKCS5Padding in Android
Seems that my problem lies on the charset encoding, but I cannot find out where the problem is.
Any comments/answers are very appreciated!
Thank you for helping me!
This code I wrote works flawlessly. Look at this link below:
http://pocket-for-android.1047292.n5.nabble.com/Encryption-method-and-reading-the-Dropbox-backup-td4344194.html#a4454327
Without looking too carefully at your code I would suggest you should specify the encoding here though I'm not sure if this is the cause of your problems:
byte[] cipherText = cipher.doFinal(PlainMsg.getBytes());
and here:
return new String(bCipherText);