Implementing-cryptography-using-python

Chapter 9 ■ Mastering Cryptography Using Python 267
except:
return 0
# generate Diffie-Hellman certificates for client
def gen_client_DH():
clientDH = dh.DiffieHellman(2,17,1024)
privateKey = str(clientDH.privateKey).encode()
fd = open("client_private_dh_key.pem", "wb")
fd.write(privateKey)
fd.close()
publicKey = str(clientDH.publicKey).encode()
fd = open("client_public_dh_key.pem", "wb")
fd.write(publicKey)
fd.close()
clientDHSet = clientDH
return clientDH
# generate Diffie-Hellman certificates for server
def gen_server_DH():
svrDH = dh.DiffieHellman(2,17,1024)
privateKey = str(svrDH.privateKey).encode()
fd = open("server_private_dh_key.pem", "wb")
fd.write(privateKey)
fd.close()
publicKey = str(svrDH.publicKey).encode()
fd = open("server_public_dh_key.pem", "wb")
fd.write(publicKey)
fd.close()
key = (open('server_public_dh_key.pem').read())
serverDHSet = svrDH
return svrDH
# encrypt using Diffie-Hellman - ECC
def encrypt_dh(plaintext, dhSecret):
# encrypt using the shared secret from Client (Private) and Server
(Public)
ciphertext = encrypt_AES_GCM(plaintext,dhSecret)
ciphertext = ciphertext.encode()
#reverse = decrypt_AES_GCM(ciphertext, dhSecret)
return ciphertext