agent: Add utility functions for flipping bits

monkey/infection_monkey/utils/bit_manipulators.py

@@ -0,0 +1,11 @@
+def flip_bits(data: bytes) -> bytes:
+    flipped_bits = bytearray(len(data))
+
+    for i, byte in enumerate(data):
+        flipped_bits[i] = flip_bits_in_single_byte(byte)
+
+    return bytes(flipped_bits)
+
+
+def flip_bits_in_single_byte(byte) -> int:
+    return 255 ^ byte

monkey/tests/unit_tests/infection_monkey/utils/test_bit_manipulators.py

@@ -0,0 +1,29 @@
+from infection_monkey.utils import bit_manipulators
+
+
+def test_flip_bits_in_single_byte():
+    for i in range(0, 256):
+        assert bit_manipulators.flip_bits_in_single_byte(i) == (255 - i)
+
+
+def test_flip_bits():
+    test_input = bytes(b"ABCDEFGHIJNLMNOPQRSTUVWXYZabcdefghijnlmnopqrstuvwxyz1234567890!@#$%^&*()")
+    expected_output = (
+        b"\xbe\xbd\xbc\xbb\xba\xb9\xb8\xb7\xb6\xb5\xb1\xb3\xb2\xb1\xb0\xaf\xae\xad"
+        b"\xac\xab\xaa\xa9\xa8\xa7\xa6\xa5\x9e\x9d\x9c\x9b\x9a\x99\x98\x97\x96\x95"
+        b"\x91\x93\x92\x91\x90\x8f\x8e\x8d\x8c\x8b\x8a\x89\x88\x87\x86\x85\xce\xcd"
+        b"\xcc\xcb\xca\xc9\xc8\xc7\xc6\xcf\xde\xbf\xdc\xdb\xda\xa1\xd9\xd5\xd7\xd6"
+    )
+
+    assert bit_manipulators.flip_bits(test_input) == expected_output
+
+
+def test_flip_bits__reversible():
+    test_input = bytes(
+        b"ABCDEFGHIJNLM\xffNOPQRSTUVWXYZabcde\xf5fghijnlmnopqr\xC3stuvwxyz1\x87234567890!@#$%^&*()"
+    )
+
+    test_output = bit_manipulators.flip_bits(test_input)
+    test_output = bit_manipulators.flip_bits(test_output)
+
+    assert test_input == test_output