asymetric_encript.py

from cryptography.hazmat.backends import default_backend
from cryptography.hazmat.primitives.asymmetric import rsa
from cryptography.hazmat.primitives import serialization
from cryptography.hazmat.primitives import hashes
from cryptography.hazmat.primitives.asymmetric import padding
from cryptography.exceptions import InvalidSignature


def rsa_pk_file(fname):
    with open(fname, "rb") as f:
        data = f.read()
    return serialization.load_pem_public_key(data, default_backend())

def rsa_private_file(fname,password):
    with open(fname, "rb") as f:
        data = f.read()
    return serialization.load_pem_private_key(data,password,default_backend())

def rsa_encrypt(public_key, text):
    ciphertext = public_key.encrypt(
        text,
        padding.OAEP(
            mgf=padding.MGF1(algorithm=hashes.SHA256()),
            algorithm=hashes.SHA256(),
            label=None
        )
    )
    return ciphertext

def rsa_sign(private_key,message):
    return private_key.sign(
        message,
        padding.PSS(
            mgf=padding.MGF1(hashes.SHA256()),
            salt_length=padding.PSS.MAX_LENGTH
        ),
        hashes.SHA256()
    )

def rsa_verify_sign(pkey,signed,unsigned):
    try:
        pkey.verify(
            signed,
            unsigned,
            padding.PSS(
                mgf=padding.MGF1(hashes.SHA256()),
                salt_length=padding.PSS.MAX_LENGTH
            ),
            hashes.SHA256()
        )
        return True
    except InvalidSignature:
        return False

def rsa_file(publickey, text):
    with open(publickey, "rb") as key_file:
        public_key = serialization.load_pem_public_key(
            key_file.read(),
            backend=default_backend())
    ciphertext = public_key.encrypt(
        text,
        padding.OAEP(mgf=padding.MGF1(algorithm=hashes.SHA256()),
                     algorithm=hashes.SHA256(),
                     label=None))
    return ciphertext

def rsa_decrypt(private_key, ciphertext):
    plaintext = private_key.decrypt(
        ciphertext,
        padding.OAEP(
            mgf=padding.MGF1(algorithm=hashes.SHA256()),
            algorithm=hashes.SHA256(),
            label=None
        )
    )
    return plaintext