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

class RSA_Signature:
def init(self):
# Generate RSA key pair
self.private_key = rsa.generate_private_key(
public_exponent=65537,
key_size=2048
)
self.public_key = self.private_key.public_key()

def sign(self, message):
    # Ensure the message is in bytes
    if isinstance(message, str):
        message = message.encode()  # Convert string to bytes if needed

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

def verify(self, signature, message):
    # Ensure the message is in bytes
    if isinstance(message, str):
        message = message.encode()  # Convert string to bytes if needed
    
    # Verify the signature
    try:
        self.public_key.verify(
            signature,
            message,
            padding.PSS(
                mgf=padding.MGF1(hashes.SHA256()),
                salt_length=padding.PSS.MAX_LENGTH
            ),
            hashes.SHA256()
        )
        return True
    except Exception as e:
        print("Signature verification failed:", e)
        return False

Example usage:

if name == "main":
# Initialize RSA signature object
rsa_signature = RSA_Signature()

# Data to sign
message = "Hello, world!"  # You can use a string directly here

# Sign the message
signature = rsa_signature.sign(message)
print("Digital Signature:", signature)

# Verify the signature
is_verified = rsa_signature.verify(signature, message)
print("Signature verified:", is_verified)