I have a string that encrypted in java by "AES", Now i need decrypt in my C# program (I have the key)
Now i need decrypt in C#.How do I decode it into the C#?
my Encrypte and Decrypt in java :
public class AES {
public static String encrypt(String seed, String cleartext) throws Exception {
byte[] rawKey = getRawKey(seed.getBytes());
byte[] result = encrypt(rawKey, cleartext.getBytes());
return toHex(result);
}
public static String decrypt(String seed, String encrypted) throws Exception {
byte[] rawKey = getRawKey(seed.getBytes());
byte[] enc = toByte(encrypted);
//ggggg
byte[] result = decrypt(rawKey, enc);
return new String(result);
}
private static byte[] getRawKey(byte[] seed) throws Exception {
KeyGenerator keygen = KeyGenerator.getInstance("AES");
SecureRandom secrand = SecureRandom.getInstance("SHA1PRNG", "Crypto");
secrand.setSeed(seed);
keygen.init(128, secrand);
SecretKey seckey = keygen.generateKey();
byte[] rawKey = seckey.getEncoded();
return rawKey;
}
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);
//0000
byte[] decrypted = cipher.doFinal(encrypted);
return decrypted;
}
public static String toHex(String txt) {
return toHex(txt.getBytes());
}
public static String fromHex(String hex) {
return new String(toByte(hex));
}
public static 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 static 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 static String HEX = "0123456789ABCDEF";
private static void appendHex(StringBuffer sb, byte b) {
sb.append(HEX.charAt((b>>4)&0x0f)).append(HEX.charAt(b&0x0f));
}
and
try {
String plaintext = "Hello world", key = "111";
String ciphertext = AES.encrypt(key, plaintext);
Log.i("ddddddd",ciphertext);
String plaintext2 = AES.decrypt(key, ciphertext);
Log.i("ddddddd","Encrypting '" + plaintext +
"' yields: (" + ciphertext.length() + ") " + ciphertext);
Log.i("ddddddd","Decrypting it yields: " + plaintext2);
}
catch (Exception ex) {
ex.printStackTrace();
}
Now i need decrypt in C#.How do I decode it into the C#?
the best way would be to use the RijndaelManaged Class to perform your task in C#.
Here you can find an excellent example on encryption/decryption:
https://stackoverflow.com/a/212707/282649
Let me know...
Related
I referred to the below link
AES Encryption .net to swift,
But, applying the same for ANDROID, I am not able to get the correct AES encryption with version(PBKDF2) conversion for my code. NEED HELP.
public static String Encrypt(String PlainText) throws Exception {
try {
byte[] salt = new byte[] { 0x49, 0x76, 0x61, 0x6E, 0x20, 0x4D,
0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76 };
System.out.println("Exception setting up cipher: "+pbkdf2("<keyname>",salt.toString(),1024,128));
Cipher _aesCipher = Cipher.getInstance("AES/CBC/PKCS7Padding");
byte[] keyBytes =pbkdf2("<keyname>",salt.toString(),1024,128).getBytes();
SecretKeySpec keySpec = new SecretKeySpec(keyBytes, "AES");
byte[] iv ="OFRna73m*aze01xY".getBytes();//pbkdf2("<keyname>",salt.toString(),2,64).getBytes();
IvParameterSpec ivSpec = new IvParameterSpec(iv);
_aesCipher.init(1, keySpec, ivSpec);
byte[] plainText = PlainText.getBytes();
byte[] result = _aesCipher.doFinal(plainText);
return Base64.encodeToString(result, Base64.DEFAULT);//Base64.encode(result,1));
} catch (Exception ex1) {
System.out.println("Exception setting up cipher: "
+ ex1.getMessage() + "\r\n");
ex1.printStackTrace();
return "";
}
}
public static String pbkdf2(String password, String salt, int iterations, int keyLength) throws NoSuchAlgorithmException, InvalidKeySpecException {
char[] chars = password.toCharArray();
PBEKeySpec spec = new PBEKeySpec(chars, salt.getBytes(), iterations, keyLength);
SecretKeyFactory skf = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
byte[] hash = skf.generateSecret(spec).getEncoded();
return toHex(hash);
}
// Converts byte array to a hexadecimal string
private static String toHex(byte[] array) {
StringBuffer sb = new StringBuffer();
for (int i = 0; i < array.length; i++) {
sb.append(Integer.toString((array[i] & 0xff) + 0x100, 16).substring(1));
}
return sb.toString();
}
Please check below code .
I have created Singletone class for the same so that i can access it anywhere in app.
Below Points Should be same like .net or swift
Important Points are IV , SALT and PASSWORD
Please check this too PBKDF2WithHmacSHA1
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
to generate key we used this
KeySpec spec = new PBEKeySpec(password, salt, 2, 256);
Importnant points are (password, salt,iterantion,bytes) this must be same like other platform which you are using with like .net or swift
public class AesBase64Wrapper {
private static String IV = "it should be same like server or other platform";
private static String PASSWORD = "it should be same like server or other platform";
private static String SALT = "it should be same like server or other platform";
private static volatile AesBase64Wrapper sSoleInstance = new AesBase64Wrapper();
//private constructor.
private AesBase64Wrapper() {
}
public static AesBase64Wrapper getInstance() {
return sSoleInstance;
}
// For Encryption
public String encryptAndEncode(String raw) {
try {
Cipher c = getCipher(Cipher.ENCRYPT_MODE);
byte[] encryptedVal = c.doFinal(getBytes(raw));
//String retVal = Base64.encodeToString(encryptedVal, Base64.DEFAULT);
String retVal = Base64.encodeToString(encryptedVal, Base64.NO_WRAP);
return retVal;
}catch (Throwable t) {
throw new RuntimeException(t);
}
}
public String decodeAndDecrypt(String encrypted) throws Exception {
// byte[] decodedValue = Base64.decode(getBytes(encrypted),Base64.DEFAULT);
byte[] decodedValue = Base64.decode(getBytes(encrypted), Base64.NO_WRAP);
Cipher c = getCipher(Cipher.DECRYPT_MODE);
byte[] decValue = c.doFinal(decodedValue);
return new String(decValue);
}
private String getString(byte[] bytes) throws UnsupportedEncodingException {
return new String(bytes, "UTF-8");
}
private byte[] getBytes(String str) throws UnsupportedEncodingException {
return str.getBytes("UTF-8");
}
private Cipher getCipher(int mode) throws Exception {
Cipher c = Cipher.getInstance("AES/CBC/PKCS5Padding");
byte[] iv = getBytes(IV);
String xyz = String.valueOf(generateKey());
Log.i("generateKey", xyz);
c.init(mode, generateKey(), new IvParameterSpec(iv));
return c;
}
private Key generateKey() throws Exception {
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
char[] password = PASSWORD.toCharArray();
byte[] salt = getBytes(SALT);
KeySpec spec = new PBEKeySpec(password, salt, 2, 256);
SecretKey tmp = factory.generateSecret(spec);
byte[] encoded = tmp.getEncoded();
byte b = encoded[1];
Log.e("Secrete Key", String.valueOf(encoded));
return new SecretKeySpec(encoded, "CBC");
}
}
In Activity you can use it like
String EncryptString = AesBase64Wrapper.getInstance().encryptAndEncode("hello");
String DecryptString = AesBase64Wrapper.getInstance().encryptAndEncode(EncryptString);
// You will Get Output in Decrypted String
I need to encrypt and decrypt a text using AES. I can call both method locally and it works, however when I run it outside the class I get javax.crypto.BadPaddingException error. I think I am losing data somewhere but U cannot find where.
Here is the code:
public class AES {
public String encryptAES(String seed, String cleartext) throws Exception {
byte[] rawKey = getRawKey(seed.getBytes());
byte[] result = encrypt(rawKey, cleartext.getBytes());
return toHex(result);
}
public String decryptAES(String seed, String encrypted) throws Exception {
byte[] rawKey = getRawKey(seed.getBytes());
byte[] enc = toByte(encrypted);
byte[] result = decrypt(rawKey, enc);
return new String(result);
}
private byte[] getRawKey(byte[] seed) throws Exception {
KeyGenerator kgen = KeyGenerator.getInstance("AES");
SecureRandom sr = SecureRandom.getInstance("SHA1PRNG");
sr.setSeed(seed);
kgen.init(128, sr);
SecretKey skey = kgen.generateKey();
byte[] raw = skey.getEncoded();
return raw;
}
private byte[] encrypt(byte[] raw, byte[] clear) throws Exception {
SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, skeySpec);
byte[] encrypted = cipher.doFinal(clear);
return encrypted;
}
private 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;
}
private 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;
}
private String toHex(byte[] buf) {
if (buf == null)
return "";
StringBuffer result = new StringBuffer(2 * buf.length);
String HEX = "0123456789ABCDEF";
for (int i = 0; i < buf.length; i++) {
result.append(HEX.charAt((buf[i] >> 4) & 0x0f)).append(HEX.charAt(buf[i] & 0x0f));
}
return result.toString();
}
the error points to
byte[] decrypted = cipher.doFinal(encrypted);
I see several things that need fixing ..
Firstly the seed to SecureRandom won't make it produce the same output. So if you try to create the same key by specifying the same seed, it wont work.
Secondly .. you should make sure to instantiate your encrypt and decrypt cipher with the same properties .. currently you don't.
Also, when you specify CBC mode you need to handle the initialization vector. If you don't specify one on the encrypt, the cipher makes one for you .. this you need to grab and provide when you decrypt.
Fixing these things don't necessarily fix everything, but should lead you in the right direction. Take a look at some of the related question at the right side .. StackOverflow have numerous working AES examples.
I am trying to encrypt data in my android app. I am having following exception.
javax.crypto.BadPaddingException: pad block corrupted
at this line
byte[] decrypted = cipher.doFinal(encrypted);
My code is as follows
private final static String HEX = "0123456789ABCDEF";
public static String encryptString(String str) throws Exception {
return encrypt("KeY123", str);
}
public static String decryptString(String str) throws Exception {
return decrypt("KeY123", str);
}
public static String encrypt(String seed, String cleartext) throws Exception {
byte[] rawKey = getRawKey(seed.getBytes());
byte[] result = encrypt(rawKey, cleartext.getBytes());
return toHex(result);
}
public static String decrypt(String seed, String encrypted) throws Exception {
byte[] rawKey = getRawKey(seed.getBytes());
byte[] enc = toByte(encrypted);
byte[] result = decrypt(rawKey, enc);
return new String(result);
}
private static byte[] getRawKey(byte[] seed) throws Exception {
KeyGenerator kgen = KeyGenerator.getInstance("AES");
SecureRandom sr = SecureRandom.getInstance("SHA1PRNG", "Crypto");
sr.setSeed(seed);
kgen.init(128, sr); // 192 and 256 bits may not be available
SecretKey skey = kgen.generateKey();
byte[] raw = skey.getEncoded();
return raw;
}
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;
}
public static String toHex(String txt) {
return toHex(txt.getBytes());
}
public static String fromHex(String hex) {
return new String(toByte(hex));
}
public static 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 static 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 static void appendHex(StringBuffer sb, byte b) {
sb.append(HEX.charAt((b >> 4) & 0x0f)).append(HEX.charAt(b & 0x0f));
}
I am using encryptString and encryptString methods throughout the app to encrypt and decrypt data, I already tried converting
SecureRandom sr = SecureRandom.getInstance("SHA1PRNG", "Crypto"); to
SecureRandom sr = SecureRandom.getInstance("SHA1PRNG"); and vice versa but nothing helped me.
Are there any other techniques i can use apart from above technique?
Update:-
Added HEX
And if you don't know the solution or answer, there is no need to downvote just mind your own business and move ahead.
Can you please show me how can I use AES with CFB mode (so that the size of input (plain text) and out (encrypted text) remains same. I've tried replacing AES with AES/CFB/NoPadding but its not working. The Application crashes.
I am using the following code. Please help me to make it work for AES with CFB. Thanks
public class SimpleCrypto {
public static String encrypt(String seed, String cleartext) throws Exception {
byte[] rawKey = getRawKey(seed.getBytes());
byte[] result = encrypt(rawKey, cleartext.getBytes());
return toHex(result);
}
public static String decrypt(String seed, String encrypted) throws Exception {
byte[] rawKey = getRawKey(seed.getBytes());
byte[] enc = toByte(encrypted);
byte[] result = decrypt(rawKey, enc);
return new String(result);
}
private static byte[] getRawKey(byte[] seed) throws Exception {
KeyGenerator kgen = KeyGenerator.getInstance("AES");
SecureRandom sr = SecureRandom.getInstance("SHA1PRNG");
sr.setSeed(seed);
kgen.init(128, sr); // 192 and 256 bits may not be available
SecretKey skey = kgen.generateKey();
byte[] raw = skey.getEncoded();
return raw;
}
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;
}
public static String toHex(String txt) {
return toHex(txt.getBytes());
}
public static String fromHex(String hex) {
return new String(toByte(hex));
}
public static 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 static 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 static String HEX = "0123456789ABCDEF";
private static void appendHex(StringBuffer sb, byte b) {
sb.append(HEX.charAt((b>>4)&0x0f)).append(HEX.charAt(b&0x0f));
}
}
If you want to use AES/CFB/NoPadding algorithm, you should initialize your cipher instance with IvParameterSpec like this:
byte[] iv = new byte[] { 0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8, 0x9, 0xA, 0xB, 0xC, 0xD, 0xE, 0xF };
IvParameterSpec ivSpec = new IvParameterSpec(iv);
SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
Cipher cipher = Cipher.getInstance("AES/CFB/NoPadding");
cipher.init(Cipher.ENCRYPT_MODE, skeySpec, ivSpec);
I believe this is a snippet from androidsnippets.org - why this isn't funcioning on Android 2.3? How to fix it?
Error
03-05 23:19:17.479: WARN/System.err(3598): javax.crypto.BadPaddingException: pad block corrupted
03-05 23:19:17.518: WARN/System.err(3598): at org.bouncycastle.jce.provider.JCEBlockCipher.engineDoFinal(JCEBlockCipher.java:715)
03-05 23:19:17.518: WARN/System.err(3598): at javax.crypto.Cipher.doFinal(Cipher.java:1090)
I found several answers on this topic but I couldn't find a decent way how to fix this, add NoPadding parameter or different algorithm or..?
public static String code(String stringToCode) {
try {
stringToCode = encrypt("somekey",stringToCode);
} catch (Exception e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
return stringToCode;
}
public static String decode(String stringToDecode) {
try {
stringToDecode = decrypt("somekey",stringToDecode);
} catch (Exception e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
return stringToDecode;
}
public static String encrypt(String seed, String cleartext) throws Exception {
byte[] rawKey = getRawKey(seed.getBytes());
byte[] result = encrypt(rawKey, cleartext.getBytes());
return toHex(result);
}
public static String decrypt(String seed, String encrypted) throws Exception {
byte[] rawKey = getRawKey(seed.getBytes());
byte[] enc = toByte(encrypted);
byte[] result = decrypt(rawKey, enc);
return new String(result);
}
private static byte[] getRawKey(byte[] seed) throws Exception {
KeyGenerator kgen = KeyGenerator.getInstance("AES");
SecureRandom sr = SecureRandom.getInstance("SHA1PRNG");
sr.setSeed(seed);
kgen.init(128, sr); // 192 and 256 bits may not be available
SecretKey skey = kgen.generateKey();
byte[] raw = skey.getEncoded();
return raw;
}
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;
}
public static String toHex(String txt) {
return toHex(txt.getBytes());
}
public static String fromHex(String hex) {
return new String(toByte(hex));
}
public static 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 static 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 static String HEX = "0123456789ABCDEF";
private static void appendHex(StringBuffer sb, byte b) {
sb.append(HEX.charAt((b>>4)&0x0f)).append(HEX.charAt(b&0x0f));
}
Two points:
1) The toByte() method isn't clear what it's trying to do, but I'll bet it's wrong, as the line
int len = hexString.length()/2;
is going to give the same result of 3 for strings of length 6 and 7 (say)
2) You can't rely on converting stings to byte arrays without specifying the Charset to use. Different locales and different run machines may have different default Charsets. You should probably use str.getBytes("UTF8") in the algorithm.
NickT says: "is going to give the same result of 3 for strings of length 6 and 7 (say)"
I suppose that length of HEX string in that case is always EVEN number (see function appendHex)
It's problem with BouncyCastle (BouncyCastle AES error when upgrading to 1.45).
What I have found is that this
results in two different values for BC
1.34 vs 1.45.
I couldn't find the solution, yet...