System.IO.IOException：身份验证或解密失败

Question

我尝试在Xamarin中实现RestSharp（ http://restsharp.org/ ）客户端。 但是当我尝试连接到服务器时，我得到异常： System.IO.IOException: The authentication or decryption has failed

当我用命令certmgr -ssl https://myservice.com/api --machine检查时，我得到了同样的错误。

所以我的结论是：Mono没有存储受信任的根证书。

但是当我尝试导入它们时： mozroots --import --machine --sync它不起作用，因为Mac OS X Sierra不允许访问目录"/usr/share/.mono" 。 该脚本抛出错误： Error: System.UnauthorizedAccessException: Access to the path "/usr/share/.mono" is denied. 因为我无法存储单声道的根。

然后我尝试添加证书验证回调，如：

public static class Security {

    public static System.Security.Cryptography.AesCryptoServiceProvider aesCryptoServiceProvider = new System.Security.Cryptography.AesCryptoServiceProvider();

    public static void RegisterValidationCallBack() { 
        ServicePointManager.ServerCertificateValidationCallback += CertificateValidationCallBack;
        Console.WriteLine("### registered validation callback");
    }

    private static bool CertificateValidationCallBack(object sender, System.Security.Cryptography.X509Certificates.X509Certificate certificate, System.Security.Cryptography.X509Certificates.X509Chain chain, System.Net.Security.SslPolicyErrors sslPolicyErrors) {
        Console.WriteLine("### validating: " + certificate);

        // If the certificate is a valid, signed certificate, return true.
        if (sslPolicyErrors == System.Net.Security.SslPolicyErrors.None) {
            Console.WriteLine("### no ssl policy errors");
            return true;
        }

        // If there are errors in the certificate chain, look at each error to determine the cause.
        if ((sslPolicyErrors & System.Net.Security.SslPolicyErrors.RemoteCertificateChainErrors) != 0) {
            if (chain != null && chain.ChainStatus != null) {
                foreach (System.Security.Cryptography.X509Certificates.X509ChainStatus status in chain.ChainStatus) {
                    if ((certificate.Subject == certificate.Issuer) &&
                       (status.Status == System.Security.Cryptography.X509Certificates.X509ChainStatusFlags.UntrustedRoot)) {
                        // Self-signed certificates with an untrusted root are valid. 
                        Console.WriteLine("### self signed cert");
                        continue;
                    } else {
                        if (status.Status != System.Security.Cryptography.X509Certificates.X509ChainStatusFlags.NoError) {
                            // If there are any other errors in the certificate chain, the certificate is invalid,
                            // so the method returns false.
                            Console.WriteLine("### error in certificate chain");
                            return false;
                        }
                    }
                }
            }

            // When processing reaches this line, the only errors in the certificate chain are 
            // untrusted root errors for self-signed certificates. These certificates are valid
            // for default Exchange server installations, so return true.
            return true;
        } else {
            // In all other cases, return false.
            return false;
        }
    }
}

并在此处安装了回调：

public partial class App : Application {
    public App() {
        Security.RegisterValidationCallBack();

        InitializeComponent();
        MainPage = new TabbedMainPage();
    }

    protected override void OnStart() {
        // Handle when your app starts
    }

    protected override void OnSleep() {
        // Handle when your app sleeps
    }

    protected override void OnResume() {
        // Handle when your app resumes
    }
}

但似乎回调甚至没有出于某种原因使用...输出没有出现在输出窗口中。

我错过了什么？