C# .netFramework 微信支付公钥模式验签

//微信的应答
 public static bool Sign(HttpResponseMessage response)
        {
            try
            {
                var Serial = "";//验签的微信支付平台证书序列号/微信支付公钥ID
                if (response.Headers.TryGetValues("Wechatpay-Serial", out var Values))
                {
                    // 将值集合拼接成字符串
                    Serial = string.Join(", ", Values);
                }
                string str_Timestamp = "";
                string str_Nonce = "";
                string str_Signature = "";
                if (response.Headers.TryGetValues("Wechatpay-Timestamp", out var dateValues))
                {
                    str_Timestamp = string.Join(", ", dateValues);//应答时间戳
                }
                if (response.Headers.TryGetValues("Wechatpay-Nonce", out var dateValues2))
                {
                    str_Nonce = string.Join(", ", dateValues2);//应答随机串
                }
                if (response.Headers.TryGetValues("Wechatpay-Signature", out var dateValues3))
                {
                    str_Signature = string.Join(", ", dateValues3);//应答签名
                }
                var retString = response.Content.ReadAsStringAsync().Result;//原始报文主体

                string message = string.Format("{0}\n{1}\n{2}\n", str_Timestamp, str_Nonce, retString);
                var isVerified = WxHelper.VerifySignature(message, str_Signature);

                WriteTextLogHelper.WriteTextLog("公钥验签，", Serial + " * " + str_Timestamp + " * " + str_Nonce + " * " + str_Signature + " * " + isVerified, DateTime.Now);
                return isVerified;
            }
            catch (Exception ex)
            {

                throw;
            }

        }





//验证
public static bool VerifySignature(string message, string signature)
        {
            try
            {
                string KeyPath = System.Web.Hosting.HostingEnvironment.MapPath(@"~/") + "\\Common\\WebChat\\pub_key.pem";//公钥文件保存地址
                var KeyParameter = LoadKey(KeyPath);//读取公钥
                if (KeyParameter == null)
                {
                    return false;
                }
                // 初始化 RSA 引擎用于签名
                var signer = SignerUtilities.GetSigner("SHA-256withRSA");//创建SHA256withRSA签名算法
                signer.Init(false, KeyParameter);// 初始化签名者  注意这里是false

                // 更新要签名的数据
                var dataBytes = Encoding.UTF8.GetBytes(message);
                signer.BlockUpdate(dataBytes, 0, dataBytes.Length);

                var signatureBytes = Convert.FromBase64String(signature);// 解析：要验证的签名

                return signer.VerifySignature(signatureBytes);// 验证签名
            }
            catch (Exception ex)// 处理异常
            {
                return false;
            }
        }



//读取公钥文件内容
public static AsymmetricKeyParameter LoadKey(string KeyPath)
        {
            try
            {
                // 读取公钥文件内容//含有"-----BEGIN PUBLIC KEY-----"、"-----END PUBLIC KEY-----"、"\n"等内容
                string txtKeyPem = File.ReadAllText(KeyPath);
                //SLogText.WriteLog("获取秘钥：txtKeyPem：", txtKeyPem);
                // 使用 PemReader 解析公钥
                PemReader pemReader = new PemReader(new StringReader(txtKeyPem));
                AsymmetricKeyParameter thisKey = (AsymmetricKeyParameter)pemReader.ReadObject();
                return thisKey;
            }
            catch (Exception ex)
            {
                return null;
            }
        }