جریان ایجاد امضای دیجیتال و تأیید در پایتون

pip install cryptography

from cryptography.hazmat.primitives.asymmetric import rsa
from cryptography.hazmat.primitives import serialization

# Generate private key
private_key = rsa.generate_private_key(
    public_exponent=65537,
    key_size=2048,
)

# Generate public key from the private key
public_key = private_key.public_key()

# Save the private key to a file
with open("private_key.pem", "wb") as f:
    f.write(private_key.private_bytes(
        encoding=serialization.Encoding.PEM,
        format=serialization.PrivateFormat.PKCS8,
        encryption_algorithm=serialization.NoEncryption()
    ))

# Save the public key to a file
with open("public_key.pem", "wb") as f:
    f.write(public_key.public_bytes(
        encoding=serialization.Encoding.PEM,
        format=serialization.PublicFormat.SubjectPublicKeyInfo
    ))

from cryptography.hazmat.primitives import hashes
from cryptography.hazmat.primitives.asymmetric import padding

# Message to be signed
message = b"Hello, this is a secret message!"

# Sign the message
signature = private_key.sign(
    message,
    padding.PSS(
        mgf=padding.MGF1(hashes.SHA256()),
        salt_length=padding.PSS.MAX_LENGTH
    ),
    hashes.SHA256()
)

# Save the signature to a file
with open("signature.bin", "wb") as f:
    f.write(signature)

# Load the public key
with open("public_key.pem", "rb") as f:
    public_key = serialization.load_pem_public_key(f.read())

# Load the signature
with open("signature.bin", "rb") as f:
    signature = f.read()

# Message to be verified
message = b"Hello, this is a secret message!"

# Verify the signature
try:
    public_key.verify(
        signature,
        message,
        padding.PSS(
            mgf=padding.MGF1(hashes.SHA256()),
            salt_length=padding.PSS.MAX_LENGTH
        ),
        hashes.SHA256()
    )
    print("The signature is valid.")
except:
    print("The signature is invalid.")