from Crypto.PublicKey import RSA
from Crypto.Signature import pss
from Crypto.Hash import SHA256

key = RSA.generate(2048)

# Generate / write alice pub key
with open("alice_public.pem", "wb") as file:
    file.write(key.publickey().export_key())

m = input("Message: ").encode()

h = SHA256.new(m)

signer = pss.new(key)

signature: bytes = signer.sign(h)

print(f'Signature: {signature}')

with open("sigtext", 'wb') as file:
    file.write(m + signature)