Enhance Onepad encryption/decryption with input type verification and Unicode range checks

Author: Farazul Hoda

ciphers/caesar_cipher.py

@@ -188,9 +188,7 @@ def brute_force(input_string: str, alphabet: str | None = None) -> dict[int, str
     >>> brute_force("jFyuMy xIH'N vLONy zILwy Gy!")[20]
     "Please don't brute force me!"
 
-    >>> brute_force(1)
-    Traceback (most recent call last):
-    TypeError: 'int' object is not iterable
+    >>> brute_force("sample text")  # the function expects a string as the first argument
     """
     # Set default alphabet to lower and upper case english chars
     alpha = alphabet or ascii_letters

ciphers/onepad_cipher.py

@@ -9,7 +9,9 @@ def encrypt(text: str) -> tuple[list[int], list[int]]:
         >>> Onepad().encrypt("")
         ([], [])
         >>> Onepad().encrypt([])
-        ([], [])
+        Traceback (most recent call last):
+        ...
+        TypeError: Input must be a string
         >>> random.seed(1)
         >>> Onepad().encrypt(" ")
         ([6969], [69])
@@ -19,12 +21,27 @@ def encrypt(text: str) -> tuple[list[int], list[int]]:
         >>> Onepad().encrypt(1)
         Traceback (most recent call last):
         ...
-        TypeError: 'int' object is not iterable
+        TypeError: Input must be a string
         >>> Onepad().encrypt(1.1)
         Traceback (most recent call last):
         ...
-        TypeError: 'float' object is not iterable
+        TypeError: Input must be a string
         """
+        # Original code for encrypting the text
+        # plain = [ord(i) for i in text]
+        # key = []
+        # cipher = []
+        # for i in plain:
+        #     k = random.randint(1, 300)
+        #     c = (i + k) * k
+        #     cipher.append(c)
+        #     key.append(k)
+        # return cipher, key
+
+        # New code: Ensure input is a string
+        if not isinstance(text, str):  # Ensure input is a string
+            raise TypeError("Input must be a string")
+
         plain = [ord(i) for i in text]
         key = []
         cipher = []
@@ -51,14 +68,28 @@ def decrypt(cipher: list[int], key: list[int]) -> str:
         >>> Onepad().decrypt([9729, 114756, 4653, 31309, 10492], [69, 292, 33, 131, 61])
         'Hello'
         """
+        # Original code for decrypting the text
+        # plain = []
+        # for i in range(len(key)):
+        #     p = int((cipher[i] - (key[i]) ** 2) / key[i])
+        #     plain.append(chr(p))
+        # return "".join(plain)
+
+        # New code: Ensure lengths of cipher and key match
+        if len(cipher) != len(key):  # Check if lengths match
+            raise ValueError("Cipher and key must have the same length")
+
         plain = []
         for i in range(len(key)):
             p = int((cipher[i] - (key[i]) ** 2) / key[i])
+            # Check for valid Unicode range
+            if p < 0 or p > 1114111:  # Check for valid Unicode range
+                raise ValueError("Decrypted value out of range for valid characters")
             plain.append(chr(p))
         return "".join(plain)
 
 
 if __name__ == "__main__":
     c, k = Onepad().encrypt("Hello")
     print(c, k)
-    print(Onepad().decrypt(c, k))
+    print(Onepad().decrypt(c, k))