RobotApp/RobotApp/Services/MQTTClientCertificatesProvider.cs

using MQTTnet;
using MQTTnet.Certificates;
using System.Security.Cryptography.X509Certificates;

namespace RobotApp.Services;

public class MQTTClientCertificatesProvider(string? CerFile, string? KeyFile) : IMqttClientCertificatesProvider
{
    private readonly string certificatesPath = "MqttCertificates";
    private readonly string cerFilePath = "cer";
    private readonly string keyFilePath = "key";

    public X509CertificateCollection? GetCertificates()
    {
        if (!string.IsNullOrEmpty(CerFile) && !string.IsNullOrEmpty(KeyFile))
        {
            if (Directory.Exists(certificatesPath))
            {
                var certFolder = Path.Combine(certificatesPath, cerFilePath);
                var keyFolder = Path.Combine(certificatesPath, keyFilePath);
                if (Directory.Exists(certFolder) && Directory.Exists(keyFolder))
                {
                    var certLocal = Path.Combine(certFolder, CerFile);
                    var keyLocal = Path.Combine(keyFolder, KeyFile);
                    if (File.Exists(certLocal) && File.Exists(keyLocal))
                    {
                        var cert = X509Certificate2.CreateFromPem(File.ReadAllText(certLocal), File.ReadAllText(keyLocal));
                        var pfxBytes = cert.Export(X509ContentType.Pfx);
                        var pfxCert = X509CertificateLoader.LoadPkcs12(pfxBytes, "", X509KeyStorageFlags.Exportable | X509KeyStorageFlags.PersistKeySet);
                        return [pfxCert];
                    }
                }
            }
        }
        return null;
    }
}