from Crypto.Cipher import AES, PKCS1_OAEP

from Crypto.Random import get_random_bytes

from Crypto.PublicKey import RSA

from Crypto import Random

def generateRSAKey():

private_key = RSA.generate(2048)

public_key = private_key.publickey()

return private_key, public_key

def generateSessionKey():

session_key = Random.new().read(AES.block_size) #generating an aes key or a session key

return session_key

def encryptSessionKey(session_key, c_public_key):

rsa_encrypt = PKCS1_OAEP.new(c_public_key)

enc_session_key = rsa_encrypt.encrypt(session_key)

return enc_session_key

def decryptSessionKey(enc_session_key, c_private_key):

rsa_decrypt = PKCS1_OAEP.new(c_private_key)

session_key = rsa_decrypt.decrypt(enc_session_key)

return session_key

def encryptData(data, session_key):

pad = 16 - (len(data) % 16)

data += bytes([pad]) * pad

cipher_aes = AES.new(session_key, AES.MODE_CBC, session_key)

ciphertext = cipher_aes.encrypt(data)

return ciphertext

def decryptData(ciphertext, session_key):

cipher_aes = AES.new(session_key, AES.MODE_CBC, session_key)

plaintext = cipher_aes.decrypt(ciphertext)

plaintext = plaintext[:-plaintext[-1]]

return plaintext