Python Encryption, Decryption, Key Serialization, and File I/O

In this project, I created a Python program that uses symmetric encryption to encrypt a message using an AES mode selected by the user. The symmetric key is then encrypted using RSA asymmetric encryption with the receiver's public key. The receiver's private key is also encrypted, serialized, and password protected. The program also stores the ciphertext and the encrypted symmetric key in a file type specified by the user. Finally, by entering the password for the serialized private key, the private key can be decrypted, deserialized, and used to decrypt the symmetric key. The decrypted symmetric key is then used to decrypt the ciphertext and reveal the original message.