Add project files

LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2024 Julian Müller
+Copyright (c) 2024 Julian Müller (ChaoticByte)
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

obf/__init__.py

@@ -0,0 +1,45 @@
+# Copyright (c) 2024 Julian Müller (ChaoticByte)
+# License: MIT
+
+def obf(data: bytes, key: bytes, decrypt: bool = False, iterations: int = 64) -> bytes:
+    assert type(data) == bytes
+    assert type(key) == bytes
+    assert type(iterations) == int
+    assert type(decrypt) == bool
+    data = bytearray(data)
+    key = bytearray(key)
+    len_data = len(data)
+    len_key = len(key)
+    def a(d):
+        # shift (encrypt)
+        if not decrypt:
+            for i in range(len_data):
+                n = key[i % len_key]
+                d[i] = (d[i] + n) % 256
+        # transpose
+        swap_indices = [] # list of tuples that stores transposition data (from, to)
+        k = 0
+        for i in range(len_data):
+            k += i + key[i % len_key] # we add to k
+            j = k % len_data          # and use it to make cryptanalysis harder (I think?)
+            swap_indices.append((i, j)) # store transposition data
+        if decrypt:
+            swap_indices.reverse()
+        for a, b in swap_indices:
+            # swap values
+            a_ = d[a]
+            b_ = d[b]
+            d[a] = b_
+            d[b] = a_
+        # unshift (decrypt)
+        if decrypt:
+            for i in range(len_data):
+                n = key[i % len_key]
+                b = d[i] - n
+                while b < 0:
+                    b = 256 + b
+                d[i] = b
+        return d
+    for i in range(iterations):
+        data = a(data)
+    return bytes(data)