/// <summary>
/// Creates a new <see cref="PatchEncryptionKey"/> based on the provided
/// <see cref="vector"/>.
/// </summary>
/// <param name="vector">The vector to base the key from.</param>
/// <returns>A new initalized patch encryption key.</returns>
public static PatchEncryptionKey Create(uint vector)
{
PatchEncryptionKey key = new PatchEncryptionKey();
InitializeKey(key, vector);
return(key);
}
public PatchServerCryptoProvider(PatchEncryptionKey key)
{
if (key == null)
{
throw new ArgumentNullException(nameof(key));
}
Key = key;
}
//TODO: Gett fixed pointer to span may be unsafe, we need pinnable reference probably.
public unsafe void CRYPT_PC_CryptData(PatchEncryptionKey key, Span <byte> data, int offset, int count)
{
for (uint x = (uint)offset; x < count; x += 4)
{
fixed(void *p = &data[(int)x])
{
*(uint *)p = (*(uint *)p) ^ key.CRYPT_PC_GetNextKey();
}
}
}
private static void InitializeKey(PatchEncryptionKey key, uint val)
{
uint index, tmp;
tmp = 1;
key.Keys[55] = val;
for (int i1 = 0x15; i1 <= 0x46E; i1 += 0x15)
{
index = (uint)(i1 % 55);
val -= tmp;
key.Keys[index] = tmp;
tmp = val;
val = (uint)key.Keys[index];
}
for (int i = 0; i < 4; i++)
{
key.CRYPT_PC_MixKeys();
}
key.Position = 56;
}