I have spent some time to make this Encryption Algorithm work. Firstly I tried to convert the java code into vb, but have several problems with Usigned Int bit calculations. Even using long numbers gave problems. So, I decided to embed java code inside a class file. Follows the code:
The class name should be: JXXTEA (or change the value in sub Initialize)
The calling code:
The JJXTEA class code:
The class name should be: JXXTEA (or change the value in sub Initialize)
The calling code:
B4X:
Dim XX As JXXTEA
Dim SU As StringUtils
XX.Initialize
XX.SetKey("The Encryption K") '16 chars
Dim R As String="MyMessage"
Dim B() As Byte=XX.Encrypt(R)
Dim S As String=SU.EncodeBase64(B)
Msgbox(S,"ENCRYPTED")
S=XX.Decrypt(B)
Msgbox(S,"DECRYPTED")The JJXTEA class code:
B4X:
Sub Class_Globals
Dim jo As JavaObject
Private Key() As Byte
End Sub
Public Sub Initialize
jo.InitializeStatic(Application.PackageName & ".jxxtea.XXTEA")
End Sub
public Sub SetKey (K As String)
Key=K.GetBytes("UTF8")
End Sub
public Sub Encrypt(S As String) As Byte()
Dim R() As Byte=jo.RunMethod("encrypt",Array(S.GetBytes("UTF8"),Key))
Return R
End Sub
public Sub Decrypt(S() As Byte) As String
Dim R() As Byte=jo.RunMethod("decrypt",Array(S,Key))
Return BytesToString(R,0,R.Length,"UTF8")
End Sub
#If JAVA
import java.io.UnsupportedEncodingException;
public final static class XXTEA {
private static final int DELTA = 0x9E3779B9;
private static int MX(int sum, int y, int z, int p, int e, int[] k) {
return (z >>> 5 ^ y << 2) + (y >>> 3 ^ z << 4) ^ (sum ^ y) + (k[p & 3 ^ e] ^ z);
}
private XXTEA() {}
public static final byte[] encrypt(byte[] data, byte[] key) {
if (data.length == 0) {
return data;
}
return toByteArray(
encrypt(toIntArray(data, true), toIntArray(fixKey(key), false)), false);
}
public static final byte[] encrypt(String data, byte[] key) {
try {
return encrypt(data.getBytes("UTF-8"), key);
}
catch (UnsupportedEncodingException e) {
return null;
}
}
public static final byte[] encrypt(byte[] data, String key) {
try {
return encrypt(data, key.getBytes("UTF-8"));
}
catch (UnsupportedEncodingException e) {
return null;
}
}
public static final byte[] encrypt(String data, String key) {
try {
return encrypt(data.getBytes("UTF-8"), key.getBytes("UTF-8"));
}
catch (UnsupportedEncodingException e) {
return null;
}
}
public static final byte[] decrypt(byte[] data, byte[] key) {
if (data.length == 0) {
return data;
}
return toByteArray(
decrypt(toIntArray(data, false), toIntArray(fixKey(key), false)), true);
}
public static final byte[] decrypt(byte[] data, String key) {
try {
return decrypt(data, key.getBytes("UTF-8"));
}
catch (UnsupportedEncodingException e) {
return null;
}
}
public static final String decryptToString(byte[] data, byte[] key) {
try {
byte[] bytes = decrypt(data, key);
if (bytes == null) return null;
return new String(bytes, "UTF-8");
}
catch (UnsupportedEncodingException ex) {
return null;
}
}
public static final String decryptToString(byte[] data, String key) {
try {
byte[] bytes = decrypt(data, key);
if (bytes == null) return null;
return new String(bytes, "UTF-8");
}
catch (UnsupportedEncodingException ex) {
return null;
}
}
private static int[] encrypt(int[] v, int[] k) {
int n = v.length - 1;
if (n < 1) {
return v;
}
int p, q = 6 + 52 / (n + 1);
int z = v[n], y, sum = 0, e;
while (q-- > 0) {
sum = sum + DELTA;
e = sum >>> 2 & 3;
for (p = 0; p < n; p++) {
y = v[p + 1];
z = v[p] += MX(sum, y, z, p, e, k);
}
y = v[0];
z = v[n] += MX(sum, y, z, p, e, k);
}
return v;
}
private static int[] decrypt(int[] v, int[] k) {
int n = v.length - 1;
if (n < 1) {
return v;
}
int p, q = 6 + 52 / (n + 1);
int z, y = v[0], sum = q * DELTA, e;
while (sum != 0) {
e = sum >>> 2 & 3;
for (p = n; p > 0; p--) {
z = v[p - 1];
y = v[p] -= MX(sum, y, z, p, e, k);
}
z = v[n];
y = v[0] -= MX(sum, y, z, p, e, k);
sum = sum - DELTA;
}
return v;
}
private static byte[] fixKey(byte[] key) {
if (key.length == 16) return key;
byte[] fixedkey = new byte[16];
if (key.length < 16) {
System.arraycopy(key, 0, fixedkey, 0, key.length);
}
else {
System.arraycopy(key, 0, fixedkey, 0, 16);
}
return fixedkey;
}
private static int[] toIntArray(byte[] data, boolean includeLength) {
int n = (((data.length & 3) == 0)
? (data.length >>> 2)
: ((data.length >>> 2) + 1));
int[] result;
if (includeLength) {
result = new int[n + 1];
result[n] = data.length;
}
else {
result = new int[n];
}
n = data.length;
for (int i = 0; i < n; ++i) {
result[i >>> 2] |= (0x000000ff & data[i]) << ((i & 3) << 3);
}
return result;
}
private static byte[] toByteArray(int[] data, boolean includeLength) {
int n = data.length << 2;
if (includeLength) {
int m = data[data.length - 1];
n -= 4;
if ((m < n - 3) || (m > n)) {
return null;
}
n = m;
}
byte[] result = new byte[n];
for (int i = 0; i < n; ++i) {
result[i] = (byte) (data[i >>> 2] >>> ((i & 3) << 3));
}
return result;
}
}
#End If
