Using IDEA I need to encrypt a block (8 bytes). some example in net like https://github.com/LexBritvin/IdeaCipher are for entire files, I just need a block.
So far I have this code but the encrypt result is wrong:
when encrypt above data the result must be B93A652F011657A1
anyone can help?
So far I have this code but the encrypt result is wrong:
C#:
byte[] data = new byte[8] { 0x50,0x5E,0xAF,0x43,0xA0,0xDF,0x32,0x29};
string charKey = "3BD1955BEAA4428ADCC576F4DB752D00";
bool encrypt = true;
private static int blockSize = 8;
private void button1_Click(object sender, EventArgs e)
{
Idea idea = new Idea(charKey, encrypt);
BlockStreamCrypter bsc = new BlockStreamCrypter(idea, encrypt);
bsc.crypt(data,0);
}
private class BlockStreamCrypter
{
Idea idea;
bool encrypt;
// data of the previous ciphertext block
byte[] prev;
byte[] newPrev;
public BlockStreamCrypter(Idea idea, bool encrypt)
{
this.idea = idea;
this.encrypt = encrypt;
prev = new byte[blockSize];
newPrev = new byte[blockSize];
}
public void crypt(byte[] data, int pos)
{
if (encrypt)
{
xor(data, pos, prev);
idea.crypt(data, pos);
Array.Copy(data, pos, prev, 0, blockSize);
}
else
{
Array.Copy(data, pos, newPrev, 0, blockSize);
idea.crypt(data, pos);
xor(data, pos, prev);
byte[] temp = prev;
prev = newPrev;
newPrev = temp;
}
string fff = BitConverter.ToString(data);
MessageBox.Show(fff);
}
}
private static void xor(byte[] a, int pos, byte[] b)
{
for (int p = 0; p < blockSize; p++)
{
a[pos + p] ^= b[p];
}
}[/XCODE]
Also the namespace:
[XCODE]
namespace Idea_crypt
{
class Idea
{
// Number of rounds.
internal static int rounds = 8;
// Internal encryption sub-keys.
internal int[] subKey;
public Idea(String charKey, bool encrypt)
{
byte[] key = generateUserKeyFromCharKey(charKey);
// Expands a 16-byte user key to the internal encryption sub-keys.
int[] tempSubKey = expandUserKey(key);
if (encrypt)
{
subKey = tempSubKey;
}
else
{
subKey = invertSubKey(tempSubKey);
}
}
/**
* Encrypts or decrypts a block of 8 data bytes.
*
* @param data
* Buffer containing the 8 data bytes to be encrypted/decrypted.
*/
public void crypt(byte[] data)
{
crypt(data, 0);
}
/**
* Encrypts or decrypts a block of 8 data bytes.
*
* @param data
* Data buffer containing the bytes to be encrypted/decrypted.
* @param dataPos
* Start position of the 8 bytes within the buffer.
*/
public void crypt(byte[] data, int dataPos)
{
int x0 = ((data[dataPos + 0] & 0xFF) << 8) | (data[dataPos + 1] & 0xFF);
int x1 = ((data[dataPos + 2] & 0xFF) << 8) | (data[dataPos + 3] & 0xFF);
int x2 = ((data[dataPos + 4] & 0xFF) << 8) | (data[dataPos + 5] & 0xFF);
int x3 = ((data[dataPos + 6] & 0xFF) << 8) | (data[dataPos + 7] & 0xFF);
//
int p = 0;
for (int round = 0; round < rounds; round++)
{
int y0 = mul(x0, subKey[p++]);
int y1 = add(x1, subKey[p++]);
int y2 = add(x2, subKey[p++]);
int y3 = mul(x3, subKey[p++]);
//
int t0 = mul(y0 ^ y2, subKey[p++]);
int t1 = add(y1 ^ y3, t0);
int t2 = mul(t1, subKey[p++]);
int t3 = add(t0, t2);
//
x0 = y0 ^ t2;
x1 = y2 ^ t2;
x2 = y1 ^ t3;
x3 = y3 ^ t3;
}
//
int r0 = mul(x0, subKey[p++]);
int r1 = add(x2, subKey[p++]);
int r2 = add(x1, subKey[p++]);
int r3 = mul(x3, subKey[p++]);
//
data[dataPos + 0] = (byte)(r0 >> 8);
data[dataPos + 1] = (byte)r0;
data[dataPos + 2] = (byte)(r1 >> 8);
data[dataPos + 3] = (byte)r1;
data[dataPos + 4] = (byte)(r2 >> 8);
data[dataPos + 5] = (byte)r2;
data[dataPos + 6] = (byte)(r3 >> 8);
data[dataPos + 7] = (byte)r3;
}
// Expands a 16-byte user key to the internal encryption sub-keys.
private static int[] expandUserKey(byte[] userKey)
{
if (userKey.Length != 16)
{
throw new ArgumentException("Key length must be 128 bit", "key");
}
int[] key = new int[rounds * 6 + 4];
for (int i = 0; i < userKey.Length / 2; i++)
{
key[i] = ((userKey[2 * i] & 0xFF) << 8) | (userKey[2 * i + 1] & 0xFF);
}
for (int i = userKey.Length / 2; i < key.Length; i++)
{
key[i] = ((key[(i + 1) % 8 != 0 ? i - 7 : i - 15] << 9) | (key[(i + 2) % 8 < 2 ? i - 14 : i - 6] >> 7)) & 0xFFFF;
}
return key;
}
// Inverts decryption/encrytion sub-keys to encrytion/decryption sub-keys.
private static int[] invertSubKey(int[] key)
{
int[] invKey = new int[key.Length];
int p = 0;
int i = rounds * 6;
invKey[i + 0] = mulInv(key[p++]);
invKey[i + 1] = addInv(key[p++]);
invKey[i + 2] = addInv(key[p++]);
invKey[i + 3] = mulInv(key[p++]);
for (int r = rounds - 1; r >= 0; r--)
{
i = r * 6;
int m = r > 0 ? 2 : 1;
int n = r > 0 ? 1 : 2;
invKey[i + 4] = key[p++];
invKey[i + 5] = key[p++];
invKey[i + 0] = mulInv(key[p++]);
invKey[i + m] = addInv(key[p++]);
invKey[i + n] = addInv(key[p++]);
invKey[i + 3] = mulInv(key[p++]);
}
return invKey;
}
// Addition in the additive group.
// The arguments and the result are within the range 0 .. 0xFFFF.
private static int add(int a, int b)
{
return (a + b) & 0xFFFF;
}
// Multiplication in the multiplicative group.
// The arguments and the result are within the range 0 .. 0xFFFF.
private static int mul(int a, int b)
{
long r = (long)a * b;
if (r != 0)
{
return (int)(r % 0x10001) & 0xFFFF;
}
else
{
return (1 - a - b) & 0xFFFF;
}
}
// Additive Inverse.
// The argument and the result are within the range 0 .. 0xFFFF.
private static int addInv(int x)
{
return (0x10000 - x) & 0xFFFF;
}
// Multiplicative inverse.
// The argument and the result are within the range 0 .. 0xFFFF.
// The following condition is met for all values of x: mul(x, mulInv(x)) == 1
private static int mulInv(int x)
{
if (x <= 1)
{
return x;
}
int y = 0x10001;
int t0 = 1;
int t1 = 0;
while (true)
{
t1 += y / x * t0;
y %= x;
if (y == 1)
{
return 0x10001 - t1;
}
t0 += x / y * t1;
x %= y;
if (x == 1)
{
return t0;
}
}
}
// Generates a 16-byte binary user key from a character string key.
private static byte[] generateUserKeyFromCharKey(String charKey)
{
int nofChar = 0x7E - 0x21 + 1; // Number of different valid characters
int[] a = new int[8];
for (int p = 0; p < charKey.Length; p++)
{
int c = charKey[p];
for (int i = a.Length - 1; i >= 0; i--)
{
c += a[i] * nofChar;
a[i] = c & 0xFFFF;
c >>= 16;
}
}
byte[] key = new byte[16];
for (int i = 0; i < 8; i++)
{
key[i * 2] = (byte)(a[i] >> 8);
key[i * 2 + 1] = (byte)a[i];
}
return key;
}
}
}when encrypt above data the result must be B93A652F011657A1
anyone can help?
