public void BlowfishEncrypt(BlowfishContext context, ref UInt32 left, ref UInt32 right)
{
for (int i = 0; i < 16; i++)
{
left ^= context.PKeys[i];
right ^= FeistelFunc(left, context);
Swap(ref left, ref right);
}
Swap(ref left, ref right);
left ^= context.PKeys[17];
right ^= context.PKeys[16];
}
public void BlowfishDecrypt(BlowfishContext context, ref UInt32 left, ref UInt32 right)
{
for (int i = 17; i > 1; i--)
{
left ^= context.PKeys[i];
right ^= FeistelFunc(left, context);
Swap(ref left, ref right);
}
Swap(ref left, ref right);
left ^= context.PKeys[0];
right ^= context.PKeys[1];
}
private UInt32 FeistelFunc(uint halfBlock, BlowfishContext context)
{
byte x4 = (byte)(halfBlock & 0xFF);
halfBlock >>= 8;
byte x3 = (byte)(halfBlock & 0xFF);
halfBlock >>= 8;
byte x2 = (byte)(halfBlock & 0xFF);
halfBlock >>= 8;
byte x1 = (byte)(halfBlock & 0xFF);
uint result = ((context.SKeys[0][x1] + context.SKeys[1][x2]) ^ context.SKeys[2][x3]) + context.SKeys[3][x4];
return(result);
}
public void CryptPkeys(BlowfishContext context)
{
//encrypt PKeys
uint tempKey1 = 0u;
uint tempKey2 = 0u;
for (int i = 0; i < 18; i++)
{
BlowfishEncrypt(context, ref tempKey1, ref tempKey2);
context.PKeys[i] = tempKey1;
context.PKeys[++i] = tempKey2;
}
//encrypt SKeys
for (int i = 0; i < 4; i++)
{
for (int j = 0; j < 256; j++)
{
BlowfishEncrypt(context, ref tempKey1, ref tempKey2);
context.SKeys[i][j] = tempKey1;
context.SKeys[i][++j] = tempKey2;
}
}
}
public Blowfish(byte[] key)
{
context = new BlowfishContext(key);
blowFeistel = new BlowFeistel();
blowFeistel.CryptPkeys(context);
}
