Python 签名示例

import hmac
import hashlib
import base64
import time
import uuid


def sign_hmac_sha256(message: str, secret: str) -> str:
    signature = hmac.new(
        secret.encode("utf-8"),
        message.encode("utf-8"),
        hashlib.sha256
    ).digest()
    return base64.b64encode(signature).decode("utf-8")


def build_sign_string(method: str, uri: str, timestamp: str,
                      nonce: str, body: str) -> str:
    return "{}\n{}\n{}\n{}\n{}\n".format(
        method, uri, timestamp, nonce, body or ""
    )


def build_authorization(mchid: str, serial: str, nonce: str,
                        timestamp: str, signature: str) -> str:
    return 'KP-CASHIER-HMAC-SHA256 mchid="{}", serial="{}", nonce="{}", timestamp="{}", signature="{}"'.format(
        mchid, serial, nonce, timestamp, signature
    )


def build_client_header(sn: str, name: str, ip: str,
                        app: str, version: str, session: str = "") -> str:
    parts = [
        'sn="{}"'.format(sn),
        'name="{}"'.format(name),
        'ip="{}"'.format(ip),
        'app="{}"'.format(app),
        'version="{}"'.format(version),
    ]
    if session:
        parts.append('session="{}"'.format(session))
    return ", ".join(parts)


if __name__ == "__main__":
    method = "POST"
    uri = "/open/cashier/trans/micropay"
    timestamp = str(int(time.time()))
    nonce = uuid.uuid4().hex
    body = '{"amount":100,"out_trade_no":"TS20260507000001","auth_code":"134567890123456789"}'
    secret = "your_secret_key"

    sign_string = build_sign_string(method, uri, timestamp, nonce, body)
    signature = sign_hmac_sha256(sign_string, secret)
    authorization = build_authorization("100001", "KEY001", nonce, timestamp, signature)
    client_header = build_client_header("SN-DEVICE-001", "收银台A01", "192.168.1.100", "cashier-pos", "2.0.0", "abc123")

    print("Authorization: " + authorization)
    print("Ikudot-Cashier-Client: " + client_header)

AES 加解密

部分敏感字段（如支付密码）需使用 AES-256-CBC 加密后传输。

import base64
import os

from Crypto.Cipher import AES
from Crypto.Util.Padding import pad, unpad


def aes_encrypt(plaintext: str, base64_key: str) -> dict:
    key = base64.b64decode(base64_key)
    iv = os.urandom(16)
    cipher = AES.new(key, AES.MODE_CBC, iv)
    ciphertext = cipher.encrypt(pad(plaintext.encode("utf-8"), AES.block_size))
    return {
        "algorithm": "AES_256_CBC",
        "ciphertext": base64.b64encode(ciphertext).decode("utf-8"),
        "iv": base64.b64encode(iv).decode("utf-8"),
    }


def aes_decrypt(base64_ciphertext: str, base64_iv: str, base64_key: str) -> str:
    key = base64.b64decode(base64_key)
    iv = base64.b64decode(base64_iv)
    ciphertext = base64.b64decode(base64_ciphertext)
    cipher = AES.new(key, AES.MODE_CBC, iv)
    plaintext = unpad(cipher.decrypt(ciphertext), AES.block_size)
    return plaintext.decode("utf-8")


if __name__ == "__main__":
    aes_key = "Base64EncodedAesKey=="
    plaintext = "123456"

    encrypted = aes_encrypt(plaintext, aes_key)
    print("加密结果:", encrypted)

    decrypted = aes_decrypt(encrypted["ciphertext"], encrypted["iv"], aes_key)
    print("解密结果:", decrypted)