Add the keys module to generate the subkeys.

cryptography_s_des_exploring/sdes/keys.py

@@ -0,0 +1,24 @@
+from cryptography_s_des_exploring.sdes.sdes import apply_table, left_shift, p8_table, p10_table
+
+
+def generate_subkeys(key: str):
+    """
+    Returns generated two subkeys: K1, K2 - from the 10-bit key
+
+    key is a binary which represented with a 10 character string.
+    """
+
+    temp = apply_table(key, p10_table)
+    left = temp[:5]
+    right = temp[5:]
+    left = left_shift(left)
+    right = left_shift(right)
+    key1 = apply_table(left + right, p8_table)
+    left = left_shift(left)
+    right = left_shift(right)
+    left = left_shift(left)
+    right = left_shift(right)
+    key2 = apply_table(left + right, p8_table)
+
+    return key1, key2
+