python生成数字签名及验证签名

公私钥生成方法，请见前文

实例：python生成数字签名及验证

import base64

from Crypto.Hash import SHA256
from Crypto.PublicKey import RSA
from Crypto.Signature import pkcs1_15

# 签名消息
message = "action=xx&contract_no=xx&offer_id=xx&product_id=xx&OjJNgXdJxAVDeSNEUhi4ANNCQmtYHFN1"


def ras_en(privateKey_file):
    """使用私钥生成数字签名"""
    with open(privateKey_file, 'r') as f:
        h = SHA256.new(message.encode("utf-8"))
        print(h.hexdigest())

        key = RSA.importKey(f.read())
        signer = pkcs1_15.new(key).sign(h)
        signature = base64.b64encode(signer)

        print(signature.decode('utf-8'))
        return signature


def verify_key(publicKey_file, signature):
    """使用公钥验证数字签名"""
    with open(publicKey_file, 'r') as f:
        h = SHA256.new(message.encode("utf-8"))
        key = RSA.importKey(f.read())
        try:
            pkcs1_15.new(key).verify(h, base64.b64decode(signature))
            print("The signature is valid.")
        except (ValueError, TypeError):
            print("The signature is not valid.")


def main():
    private_file = 'private.rsa'
    public_file = 'public.rsa'

    signature = ras_en(private_file)
    verify_key(public_file, signature)


if __name__ == '__main__':
    main()