我尝试在Unity（C#）中设置一个MQTT客户端，它将与AWS IoT Core通信。以下是我采取的步骤：
1)使用来自AWS的证书文件生成.pfx文件：
第一个月
2)将.pem和.pfx文件放在项目的Resources文件夹中。代码中设备认证的路径为：deviceCertPath="Assets/Resources/certificate.cert.pfx"
3)添加M2Mqtt.net dll到插件文件夹（从NuGet下载）
4）我的代码如下：

using System.Collections;
using System.Collections.Generic;
using System.Security.Cryptography.X509Certificates;
using System.Text;
using System.Threading;
using UnityEngine;

using uPLibrary.Networking.M2Mqtt;
using uPLibrary.Networking.M2Mqtt.Messages;

// Variables

private void Start()   
{
    caCert = X509Certificate2.CreateFromCertFile(caCertPath);
    deviceCert = new X509Certificate2(deviceCertPath);

    client = new MqttClient(broker, port, true, caCert, deviceCert, MqttSslProtocols.TLSv1_2);

    client.MqttMsgPublishReceived += Client_MqttMsgPublishReceived;
    client.MqttMsgSubscribed += Client_MqttMsgSubscribed;

    //Connect
    client.Connect(clientId);
    Debug.Log($"Connected to AWS IoT with client id: {clientId}.");
}

// Message Methods

当我尝试运行代码时，我得到了一个错误，这是在尝试创建deviceCert时发生的（代码片段中的第16行对应于错误日志中提到的第32行）：

ArgumentException: unsupported HMAC
Mono.Security.X509.PKCS12.Decode (System.Byte[] data) (at <b2e147cb24644c1580a142ea3d6c249e>:0)
Mono.Security.X509.PKCS12..ctor (System.Byte[] data, System.String password) (at <b2e147cb24644c1580a142ea3d6c249e>:0)
System.Security.Cryptography.X509Certificates.X509Certificate2ImplMono.ImportPkcs12 (System.Byte[] rawData, System.String password) (at <6d7c4c8dd3624dc596686fb7270ae1e6>:0)
System.Security.Cryptography.X509Certificates.X509Certificate2ImplMono.ImportPkcs12 (System.Byte[] rawData, Microsoft.Win32.SafeHandles.SafePasswordHandle password) (at <6d7c4c8dd3624dc596686fb7270ae1e6>:0)
System.Security.Cryptography.X509Certificates.X509Certificate2ImplMono..ctor (System.Byte[] rawData, Microsoft.Win32.SafeHandles.SafePasswordHandle password, System.Security.Cryptography.X509Certificates.X509KeyStorageFlags keyStorageFlags) (at <6d7c4c8dd3624dc596686fb7270ae1e6>:0)
Mono.X509PalImpl.ImportFallback (System.Byte[] data, Microsoft.Win32.SafeHandles.SafePasswordHandle password, System.Security.Cryptography.X509Certificates.X509KeyStorageFlags keyStorageFlags) (at <6d7c4c8dd3624dc596686fb7270ae1e6>:0)
Mono.X509PalImplMono.Import (System.Byte[] data, Microsoft.Win32.SafeHandles.SafePasswordHandle password, System.Security.Cryptography.X509Certificates.X509KeyStorageFlags keyStorageFlags) (at <6d7c4c8dd3624dc596686fb7270ae1e6>:0)
Mono.SystemCertificateProvider.Import (System.Byte[] data, Microsoft.Win32.SafeHandles.SafePasswordHandle password, System.Security.Cryptography.X509Certificates.X509KeyStorageFlags keyStorageFlags, Mono.CertificateImportFlags importFlags) (at <6d7c4c8dd3624dc596686fb7270ae1e6>:0)
Mono.SystemCertificateProvider.Mono.ISystemCertificateProvider.Import (System.Byte[] data, Microsoft.Win32.SafeHandles.SafePasswordHandle password, System.Security.Cryptography.X509Certificates.X509KeyStorageFlags keyStorageFlags, Mono.CertificateImportFlags importFlags) (at <6d7c4c8dd3624dc596686fb7270ae1e6>:0)
System.Security.Cryptography.X509Certificates.X509Helper.Import (System.Byte[] rawData, Microsoft.Win32.SafeHandles.SafePasswordHandle password, System.Security.Cryptography.X509Certificates.X509KeyStorageFlags keyStorageFlags) (at <6073cf49ed704e958b8a66d540dea948>:0)
System.Security.Cryptography.X509Certificates.X509Certificate..ctor (System.String fileName, System.String password, System.Security.Cryptography.X509Certificates.X509KeyStorageFlags keyStorageFlags) (at <6073cf49ed704e958b8a66d540dea948>:0)
System.Security.Cryptography.X509Certificates.X509Certificate..ctor (System.String fileName) (at <6073cf49ed704e958b8a66d540dea948>:0)
System.Security.Cryptography.X509Certificates.X509Certificate.CreateFromSignedFile (System.String filename) (at <6073cf49ed704e958b8a66d540dea948>:0)
MQTT.Start () (at Assets/Circulate/Scripts/Networking/MQTT/MQTT.cs:32)

当前的.pfx文件没有密码，尽管我尝试使用一个带密码的文件，但得到了相同的错误。当我检查证书的详细信息时，发现两个证书的签名哈希算法都是sha 256。我不确定为什么会收到此错误，并且我无法找到有关不受支持的HMAC的更多信息。感谢任何帮助，谢谢！