Add files via upload

Assignment-1.py

@@ -0,0 +1,44 @@
+# packages required
+import os
+from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
+from cryptography.hazmat.backends import default_backend
+
+# Encryption Function
+def encrypt_func(key, iv, message):
+    message = padding(message)
+    cipher = Cipher(algorithms.AES(key), modes.CBC(iv), backend=backend)
+    encryptor = cipher.encryptor()
+    return encryptor.update(message.encode('ascii')) + encryptor.finalize()
+
+# Decryption Function
+def decrypt_func(key, iv, ct):
+    cipher = Cipher(algorithms.AES(key), modes.CBC(iv), backend=backend)
+    decryptor = cipher.decryptor()
+    message = decryptor.update(ct) + decryptor.finalize()
+    message = depadding(message.decode('ascii'))
+    return message
+
+# Function for making the msg bits multiple of 32
+def padding(message):
+    message += " "*(32-len(message)%32)
+    return message
+
+
+# Removing the added spaces
+def depadding(message):
+    while message[-1] == ' ':
+        message = message[:-1]
+        if len(message) == 0:
+            break
+    return message
+
+
+backend = default_backend()
+key = os.urandom(32)
+iv = os.urandom(16)
+message = input("Enter the msg to be encrypted: ")
+ciphertext = encrypt_func(key, iv, message)
+print(f'Ciper Text : {ciphertext}')
+decryptedmessage = decrypt_func(key, iv, ciphertext)
+print(f'Decrypted Message : {decryptedmessage}')
+