Vigenere

vigenere/cipher.txt

@@ -0,0 +1 @@
+rgnoDVD{O0NU_WQ3_G1G3O3T3_A1AH3S_cc82272b}

vigenere/sol.py

@@ -0,0 +1,26 @@
+#!/home/maxime/.pyvenv/bin/python3
+
+key = "CYLAB"
+
+with open("cipher.txt", 'r') as f:
+    cipher = f.read()
+    
+    plaintext = ""
+    i = 0
+    for char in cipher:
+        char = ord(char)
+        a = ord('a')
+        z = ord('z')
+        A = ord('A')
+        Z = ord('Z')
+        keychar = ord(key[i%len(key)]) - A
+        if a <= char and char <= z:
+            plaintext += chr((char - a - keychar)%26 + a)
+            i += 1
+        elif A <= char and char <= Z:
+            plaintext += chr((char - A - keychar)%26 + A)
+            i += 1
+        else:
+            plaintext += chr(char)
+    print(plaintext)
+