add caesar and masc encryption

caesar.py

@@ -0,0 +1,2 @@
+def caesar(k : int, plain : str) -> str:
+  return str([chr(ord(c) + k) for c in plain])

masc.py

@@ -0,0 +1,23 @@
+default_alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+
+def masc(k : str, plain : str, alphabet : str = default_alphabet):
+  # make sure that k only contains characters from alphabet
+  for c in k:
+    if c not in alphabet:
+      raise ValueError("key contains character thats not in alphabet, namely: " + c)
+
+  # build key
+  ## make unique
+  k_unique = []
+  for c in k:
+    if not (c in k_unique):
+      k_unique.append(c)
+
+  ## append alphabet
+  last = k_unique[len(k_unique) - 1]
+  alphabet_pos = alphabet.index(last)
+  for i in list(range(alphabet_pos + 1, len(alphabet))) + list(range(0, alphabet_pos)):
+    if alphabet[i] not in k_unique:
+      k_unique.append(alphabet[i])
+
+  return k_unique