Added file to encrypt and decrypt messages using the SHA256

Author: KonstantinosAng

Gripper/encryption.py

@@ -0,0 +1,74 @@
+# Encrypt and Decrypt a string of data
+import os
+from cryptography.fernet import Fernet
+
+
+# Generate a key to encrypt and decrypt messages
+def generate_key():
+    """
+    Generates a key.key file with the encryption password inside the password_provided variable
+    :return: None
+    """
+    # import here for optimization
+    import base64
+    from cryptography.hazmat.backends import default_backend
+    from cryptography.hazmat.primitives import hashes
+    from cryptography.hazmat.primitives.kdf.pbkdf2 import PBKDF2HMAC
+
+    password_provided = "root"  # This is input in the form of a string
+    password = password_provided.encode()
+    salt = b'salt_'  # CHANGE THIS - recommend using a key from os.urandom(16), must be of type bytes
+    kdf = PBKDF2HMAC(
+        algorithm=hashes.SHA256(),
+        length=32,
+        salt=salt,
+        iterations=100000,
+        backend=default_backend()
+    )
+    key = base64.urlsafe_b64encode(kdf.derive(password))  # Can only use kdf once
+    file = open(os.path.join(os.path.dirname(os.path.realpath(__file__)), 'key.key'), 'wb')
+    file.write(key)  # The key is type bytes still
+    file.close()
+
+
+def encrypt(msg):
+    """
+    Encrypts a string of characters using the key.key encryption password
+    :param msg: A string of characters
+    :return Encrypted string of characters
+    """
+    if not os.path.exists((os.path.join(os.path.dirname(os.path.realpath(__file__)), 'key.key'))):
+        print('Call generate_key() to generate an encryption key first')
+    else:
+        file = open(os.path.join(os.path.dirname(os.path.realpath(__file__)), 'key.key'), 'rb')
+        key = file.read()  # The key will be type bytes
+        file.close()
+        f = Fernet(key)
+        return f.encrypt(msg)
+
+
+def decrypt(msg):
+    """
+    Decrypts a string of characters using the key.key encryption password
+    :param msg: An encrypted string of characters
+    :return Decrypted string of characters
+    """
+    if not os.path.exists((os.path.join(os.path.dirname(os.path.realpath(__file__)), 'key.key'))):
+        print('Call generate_key() to generate an encryption key first')
+    else:
+        file = open(os.path.join(os.path.dirname(os.path.realpath(__file__)), 'key.key'), 'rb')
+        key = file.read()  # The key will be type bytes
+        file.close()
+        f = Fernet(key)
+        return f.decrypt(msg)
+
+
+if __name__ == '__main__':
+    # Test functionality
+    generate_key()
+    message = 'hello'
+    one = encrypt(message.encode())
+    two = decrypt(one)
+    print(message)
+    print(one)
+    print(two)