From 3799bcb0fb97bbe97f64c131eb5b4d579822587f Mon Sep 17 00:00:00 2001
From: Emma Nora Theuer <git@entheuer.de>
Date: Fri, 7 Feb 2025 00:12:15 +0100
Subject: [PATCH] Add random cryptography hyperfixation that won't last longer
 than 5 minutes

---
 vigenere.py | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)
 create mode 100644 vigenere.py

diff --git a/vigenere.py b/vigenere.py
new file mode 100644
index 0000000..e426af5
--- /dev/null
+++ b/vigenere.py
@@ -0,0 +1,70 @@
+#!/usr/bin/env python3
+import argparse
+import string
+
+parser: argparse.ArgumentParser = argparse.ArgumentParser(
+    prog='Basic Vigenère Cypher',
+    description='A quick and dirty implementation of the Vigenére Cypher. Accepts any key as the key.',
+    epilog='Enter the message first and the key second.'
+)
+
+group = parser.add_mutually_exclusive_group(required=True)
+group.add_argument('-e', '--encrypt', nargs=2, help="Message to be decrypted or encrypted and the key used")
+group.add_argument('-d', '--decrypt', nargs=2, help="Message to be decrypted or encrypted and the key used")
+
+class Vigenere:
+    def __init__(self) -> None:
+        self.args = parser.parse_args()
+        self.chars: str = ''.join(c for c in string.printable if c.isprintable()) + ''.join(chr(c) for c in range(128, 256) if not chr(c).isspace or c in (160,)) # All Characters from extended ASCII, excluding control codes
+        if self.args.encrypt:
+            self.msg: str = self.args.encrypt[0]
+            self.key: str = self._generate_key(self.args.encrypt[1])
+        else:
+            self.msg: str = self.args.decrypt[0]
+            self.key: str = self._generate_key(self.args.decrypt[1])
+
+    def _generate_key(self, key: str) -> str:
+        if len(key) < len(self.msg):
+            key = (key * (len(self.msg) // len(key) + 1))[:len(self.msg)]
+        else:
+            key = key[:len(self.msg)]
+        return key
+
+    def _create_alphabet(self, shift: int) -> str:
+        alphabet: str = self.chars
+        shift = (shift % len(alphabet))
+        return alphabet[shift:] + alphabet[:shift]
+
+    def _find_index(self, index: int) -> int:
+        return self.chars.index(self.key[index])
+
+    def encrypt(self) -> str:
+        encrypted_msg: str = ""
+        for index in range(len(self.msg)):
+            char: str = self.msg[index]
+            lookup_alphabet: str = self._create_alphabet(self._find_index(index))
+            original_index: int = self.chars.index(char)
+            encrypted_msg += lookup_alphabet[original_index]
+
+        return encrypted_msg
+
+    def decrypt(self) -> str:
+        decrypted_msg: str = ""
+        for index in range(len(self.msg)):
+            lookup_alphabet: str = self._create_alphabet(self._find_index(index))
+            location_index: int = lookup_alphabet.index(self.msg[index])
+            decrypted_msg += self.chars[location_index]
+
+        return decrypted_msg
+
+    def output(self) -> None:
+        if self.args.encrypt:
+            ciphertext = self.encrypt()
+            print(ciphertext)
+        else:
+            plaintext = self.decrypt()
+            print(plaintext)
+
+if __name__ == "__main__":
+    vigenere_cipher = Vigenere()
+    vigenere_cipher.output()