messing around

README.md

@@ -1,3 +1,10 @@
 # multilingual_aes
 
-Implementing AES in every language I can!
+Implementing AES in every language I can!
+
+## Project Goals
+
+- Provide a clear, idiomatic AES implementation in multiple languages.
+- Keep APIs and test vectors consistent across implementations so outputs are comparable.
+
+

python/src/from src.py

@@ -0,0 +1,3 @@
+from src.utility import mix_columns
+state = b'\xDB\x13\x53\x45\xDB\x13\x53\x45\xDB\x13\x53\x45\xDB\x13\x53\x45'
+mix_columns(state)

python/src/utility.py

@@ -17,6 +17,7 @@ _SBOX = [
     0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16,
 ]
 
+
 def s_box(byte: int) -> int:
     """
     Substitutes a single byte using the AES S-Box.
@@ -46,28 +47,6 @@ def shift_rows(state: bytes) -> bytes:
         rot_bytes(state[i:i+4], i//4) for i in range(0, 16, 4)
     ])
 
-_polynomial = [0x02, 0x03, 0x01, 0x01]
-_mix_cols_mat = [
-    _polynomial,
-    rot_bytes(_polynomial, 1),
-    rot_bytes(_polynomial, 2),
-    rot_bytes(_polynomial, 3),
-]
-
-def mix_columns(state: bytes) -> bytes:
-    """
-    Performs the MixColumns transformation on the state.
-    Args:
-        state (bytes): The state to be transformed, expected to be 16 bytes long.
-    Returns:
-        bytes: The transformed state after applying MixColumns.
-    Raises:
-        ValueError: If the input state is not 16 bytes long.
-    """
-    for i in range(4):
-        b = state[i]
-        newb = state[i]          
-
 
 def rot_bytes(word: bytes, n_rots: int = 1) -> bytes:
     """
@@ -95,7 +74,51 @@ def xor_bytes(a: bytes, b: bytes) -> bytes:
     if len(a) != len(b):
         raise ValueError("Byte arrays must be of the same length")
     
-    return bytes(x ^ y for x, y in zip(a, b))
+    return 
+
+_polynomial = [0x02, 0x03, 0x01, 0x01]
+_mix_cols_mat = [
+    _polynomial,
+    rot_bytes(_polynomial, 1),
+    rot_bytes(_polynomial, 2),
+    rot_bytes(_polynomial, 3),
+]
+
+def _get_col(a: bytes, i: int) -> bytes:   
+    return bytes(a[i + j * 4] for j in range(4))
+
+def _xor_dot_product(a: bytes, b: bytes) -> int:
+    print(f"Multiplying {a.hex()} and {b.hex()}")
+    prod = [a[i]*b[i] for i in range(len(a))]
+    result = prod[0]
+    for i in range(len(prod)-1):
+        if prod[i+1] > 0xff:
+            prod[i+1] ^= 0x11b
+        result ^= prod[i+1]
+    return result%256
+
+def mix_columns(state: bytes) -> bytes:
+    """
+    Performs the MixColumns transformation on the state.
+    Args:
+        state (bytes): The state to be transformed, expected to be 16 bytes long.
+    Returns:
+        bytes: The transformed state after applying MixColumns.
+    Raises:
+        ValueError: If the input state is not 16 bytes long.
+    """
+    new_state = bytearray(16)
+    for i in range(0, 4):
+        for j in range(0,4):
+            new_state[j*4+i] = _xor_dot_product(
+                bytes(_mix_cols_mat[j]),
+                bytes(_get_col(state, i))
+            )
+
+    return bytes(new_state)
+              
+
+
 
 def get_rcon(n_rounds: int) -> list:
     """