Added secure cleanup for most functions

- Moved 'secure_cleanup' in 'wallet_client.py' to the DataManipulation class in 'cryptographic_util.py'
- Removed redundant 'secure_delete' function from 'wallet_client.py' because it was already in the DataManipulation of 'cryptographic_util.py'
- Most functions will now call the secure_cleanup method in the DataManipulation class whenever there is an error, return statment, or basically any exit point. This ensures that any (potential) sensitive variables are deleted but also purged from memory. This minimizes the potential risks associated with sensitive data lingering in memory. However proformance is slower as a result.
- Fixed the path to the denaro qr logo in the 'handle_new_encrypted_wallet'. It was causeing the script to error out when generating a new encrypted wallet with 2-Factor Authentication.

.gitignore

@@ -2,4 +2,5 @@ __pycache__/
 *.py[cod]
 env
 denaro/wallet/wallets
-wallets
+wallets
+testing.sh

denaro/key_generation.py

@@ -7,6 +7,7 @@
 from math import ceil
 from datetime import datetime, timezone
 from typing import Union
+import os
 
 # Importing third-party libraries
 import base58
@@ -18,6 +19,12 @@
 from icecream import ic
 import binascii
 
+# Get the absolute path of the directory containing the current script.
+dir_path = os.path.dirname(os.path.realpath(__file__))
+# Insert folder paths for modules
+sys.path.insert(0, dir_path + "/wallet")
+from denaro.wallet.cryptographic_util import DataManipulation
+
 # Custom print function definition
 _print = print  # Saving the original print function for later use
 
@@ -36,7 +43,9 @@ def log(s):
     Parameters:
         s (str): Message to log
     """
-    logging.getLogger('denaro').info(s)  # Logging the message under the 'denaro' namespace
+    # Logging the message under the 'denaro' namespace
+    logging.getLogger('denaro').info(s)
+    DataManipulation.secure_cleanup([var for var in locals().values() if var is not None])
 
 # Configure Icecream for custom logging
 ic.configureOutput(outputFunction=log)  # Redirecting icecream output to custom log function
@@ -52,7 +61,9 @@ def get_json(obj):
         dict: Object as a dictionary.
     """
     # Convert object to JSON and then deserialize it to dictionary
-    return json.loads(json.dumps(obj, default=lambda o: getattr(o, 'as_dict', getattr(o, '__dict__', str(o)))))
+    result = json.loads(json.dumps(obj, default=lambda o: getattr(o, 'as_dict', getattr(o, '__dict__', str(o)))))
+    DataManipulation.secure_cleanup([var for var in locals().values() if var is not None and var is not result])
+    return result
 
 def timestamp():
     """
@@ -62,7 +73,9 @@ def timestamp():
         int: Current timestamp in UTC timezone.
     """
     # Getting current time, setting it to UTC and returning its timestamp
-    return int(datetime.now(timezone.utc).replace(tzinfo=timezone.utc).timestamp())
+    result = int(datetime.now(timezone.utc).replace(tzinfo=timezone.utc).timestamp())
+    DataManipulation.secure_cleanup([var for var in locals().values() if var is not None and var is not result])
+    return result
 
 def sha256(message: Union[str, bytes]):
     """
@@ -78,7 +91,9 @@ def sha256(message: Union[str, bytes]):
     if isinstance(message, str):
         message = bytes.fromhex(message)
     # Calculate SHA-256 hash and return it as a hexadecimal string
-    return hashlib.sha256(message).hexdigest()
+    result = hashlib.sha256(message).hexdigest()
+    DataManipulation.secure_cleanup([var for var in locals().values() if var is not None and var is not result])
+    return result
 
 def byte_length(i: int):
     """
@@ -91,7 +106,9 @@ def byte_length(i: int):
         int: Byte length of the integer.
     """
     # Calculate byte length using bit length and ceiling function
-    return ceil(i.bit_length() / 8.0)
+    result = ceil(i.bit_length() / 8.0)
+    DataManipulation.secure_cleanup([var for var in locals().values() if var is not None and var is not result])
+    return result
 
 def normalize_block(block) -> dict:
     """
@@ -109,6 +126,7 @@ def normalize_block(block) -> dict:
     block['address'] = block['address'].strip(' ')
     # Convert and normalize the 'timestamp' field to UTC timestamp
     block['timestamp'] = int(block['timestamp'].replace(tzinfo=timezone.utc).timestamp())
+    DataManipulation.secure_cleanup([var for var in locals().values() if var is not None and var is not block])
     return block
 
 def x_to_y(x: int, is_odd: bool = False):
@@ -129,7 +147,9 @@ def x_to_y(x: int, is_odd: bool = False):
     # Compute the square root of y^2 modulo p
     y_res, y_mod = mod_sqrt(y2, p)
     # Return either y_res or y_mod based on whether y should be odd
-    return y_res if y_res % 2 == is_odd else y_mod
+    result = y_res if y_res % 2 == is_odd else y_mod
+    DataManipulation.secure_cleanup([var for var in locals().values() if var is not None and var is not result])
+    return result
 
 class AddressFormat(Enum):
     """
@@ -151,13 +171,18 @@ def bytes_to_point(point_bytes: bytes) -> Point:
     # If the byte length is 64, it's a full point (x and y coordinates)
     if len(point_bytes) == 64:
         x, y = int.from_bytes(point_bytes[:32], ENDIAN), int.from_bytes(point_bytes[32:], ENDIAN)  # Extract x and y from bytes
-        return Point(x, y, CURVE)  # Return as Point object
+        result = Point(x, y, CURVE)  # Return as Point object
+        DataManipulation.secure_cleanup([var for var in locals().values() if var is not None and var is not result])
+        return result
     # If the byte length is 33, it's a compressed point
     elif len(point_bytes) == 33:
         specifier = point_bytes[0]  # First byte is the specifier for odd/even y-coordinate
         x = int.from_bytes(point_bytes[1:], ENDIAN)  # Extract x from the bytes
-        return Point(x, x_to_y(x, specifier == 43))  # Compute y and return as Point object
+        result = Point(x, x_to_y(x, specifier == 43))  # Compute y and return as Point object
+        DataManipulation.secure_cleanup([var for var in locals().values() if var is not None and var is not result])
+        return result
     else:
+        DataManipulation.secure_cleanup([var for var in locals().values() if var is not None])
         # Unsupported byte length
         raise NotImplementedError()
 
@@ -178,9 +203,12 @@ def bytes_to_string(point_bytes: bytes) -> str:
     elif len(point_bytes) == 33:
         address_format = AddressFormat.COMPRESSED  # Compressed format
     else:
+        DataManipulation.secure_cleanup([var for var in locals().values() if var is not None])
         # Unsupported byte length
         raise NotImplementedError()
-    return point_to_string(point, address_format)  # Convert point to string based on the determined format
+    result = point_to_string(point, address_format)  # Convert point to string based on the determined format
+    DataManipulation.secure_cleanup([var for var in locals().values() if var is not None and var is not result])
+    return result
 
 def point_to_bytes(point: Point, address_format: AddressFormat = AddressFormat.FULL_HEX) -> bytes:
     """
@@ -195,11 +223,16 @@ def point_to_bytes(point: Point, address_format: AddressFormat = AddressFormat.F
     """
     # If full hexadecimal format is chosen
     if address_format is AddressFormat.FULL_HEX:
-        return point.x.to_bytes(32, byteorder=ENDIAN) + point.y.to_bytes(32, byteorder=ENDIAN)
+        result = point.x.to_bytes(32, byteorder=ENDIAN) + point.y.to_bytes(32, byteorder=ENDIAN)
+        DataManipulation.secure_cleanup([var for var in locals().values() if var is not None and var is not result])
+        return result
     # If compressed format is chosen
     elif address_format is AddressFormat.COMPRESSED:
-        return string_to_bytes(point_to_string(point, AddressFormat.COMPRESSED))
+        result = string_to_bytes(point_to_string(point, AddressFormat.COMPRESSED))
+        DataManipulation.secure_cleanup([var for var in locals().values() if var is not None and var is not result])
+        return result
     else:
+        DataManipulation.secure_cleanup([var for var in locals().values() if var is not None])
         # Raise an exception for unsupported formats
         raise NotImplementedError()
 
@@ -218,13 +251,18 @@ def point_to_string(point: Point, address_format: AddressFormat = AddressFormat.
     # For full hexadecimal format
     if address_format is AddressFormat.FULL_HEX:
         point_bytes = point_to_bytes(point)  # Convert point to bytes
-        return point_bytes.hex()  # Convert bytes to hexadecimal string
+        result = point_bytes.hex()  # Convert bytes to hexadecimal string
+        DataManipulation.secure_cleanup([var for var in locals().values() if var is not None and var is not result])
+        return result
     # For compressed format
     elif address_format is AddressFormat.COMPRESSED:
         # Convert point to Base58 string
         address = base58.b58encode((42 if y % 2 == 0 else 43).to_bytes(1, ENDIAN) + x.to_bytes(32, ENDIAN))
-        return address if isinstance(address, str) else address.decode('utf-8')  # Ensure the result is a string
+        result = address if isinstance(address, str) else address.decode('utf-8')  # Ensure the result is a string
+        DataManipulation.secure_cleanup([var for var in locals().values() if var is not None and var is not result])
+        return result
     else:
+        DataManipulation.secure_cleanup([var for var in locals().values() if var is not None])
         # Unsupported format
         raise NotImplementedError()
 
@@ -241,9 +279,11 @@ def string_to_bytes(string: str) -> bytes:
     try:
         # Try to convert from hexadecimal to bytes
         point_bytes = bytes.fromhex(string)
+        DataManipulation.secure_cleanup([var for var in locals().values() if var is not None and var is not point_bytes])
     except ValueError:
         # If not hexadecimal, assume it's Base58 and decode it
         point_bytes = base58.b58decode(string)
+        DataManipulation.secure_cleanup([var for var in locals().values() if var is not None and var is not point_bytes])
     return point_bytes
 
 def string_to_point(string: str):
@@ -257,7 +297,9 @@ def string_to_point(string: str):
         Point: The converted ECDSA point.
     """
     # Convert the string to bytes and then to an ECDSA point
-    return bytes_to_point(string_to_bytes(string))
+    result = bytes_to_point(string_to_bytes(string))
+    DataManipulation.secure_cleanup([var for var in locals().values() if var is not None and var is not result])
+    return result
 
 def hex_to_point(x_hex: str, y_hex: str, curve_obj):
     """
@@ -273,7 +315,9 @@ def hex_to_point(x_hex: str, y_hex: str, curve_obj):
     """
     x_int = int(x_hex, 16)  # Convert x from hex to integer
     y_int = int(y_hex, 16)  # Convert y from hex to integer
-    return Point(x_int, y_int, curve_obj)  # Create and return the ECDSA point
+    result = Point(x_int, y_int, curve_obj)  # Create and return the ECDSA point
+    DataManipulation.secure_cleanup([var for var in locals().values() if var is not None and var is not result])
+    return result
 
 def private_to_public_key_fastecdsa(private_key_hex):
     """
@@ -298,7 +342,9 @@ def private_to_public_key_fastecdsa(private_key_hex):
     compressed_public_key = prefix + format(public_point.x, '064x')
 
     # Return the public point and its compressed representation
-    return public_point, compressed_public_key
+    result = public_point, compressed_public_key
+    DataManipulation.secure_cleanup([var for var in locals().values() if var is not None and var is not result])
+    return result
 
 def generate(mnemonic_phrase=None, passphrase=None, index=0, deterministic=False, fields=None):
     """
@@ -367,5 +413,5 @@ def generate(mnemonic_phrase=None, passphrase=None, index=0, deterministic=False
             result["public_key"] = public_key_hex
         if "address" in fields:
             result["address"] = address
-
+    DataManipulation.secure_cleanup([var for var in locals().values() if var is not None and var is not result])
     return result  # Return the generated information as a dictionary