在Xamarin.Forms（PCL）中忽略SSL证书错误

Question

有没有办法在 Xamarin.Forms PCL 应用程序中实现类似此处描述的操作：https://dev59.com/EnE85IYBdhLWcg3wpFSu#2675183？我正在使用 HttpClient 连接到服务器。

- anaid

Answer 1

ServicePointManager在PCL中未定义，但在特定于平台的类中定义。

Xamarin.iOS和Xamarin.Android均具有相同用法的ServicePointManager。您可以在平台项目中的任何类中引用它。然而，目前不存在这样的类，并且似乎没有办法为Windows Phone应用程序进行引用。

示例：

// Xamarin.Android

public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsApplicationActivity
{
    protected override void OnCreate(Bundle bundle)
    {
        // You may use ServicePointManager here
        ServicePointManager
            .ServerCertificateValidationCallback +=
            (sender, cert, chain, sslPolicyErrors) => true;

        base.OnCreate(bundle);

        global::Xamarin.Forms.Forms.Init(this, bundle);
        LoadApplication(new App());
    }
}

// Xamarin.iOS

public partial class AppDelegate : global::Xamarin.Forms.Platform.iOS.FormsApplicationDelegate
{
    public override bool FinishedLaunching(UIApplication app, NSDictionary options)
    {
        ServicePointManager
            .ServerCertificateValidationCallback +=
            (sender, cert, chain, sslPolicyErrors) => true;

        global::Xamarin.Forms.Forms.Init();
        LoadApplication(new App());

        return base.FinishedLaunching(app, options);
    }
}

- Alex Lau

---

这对我不起作用。回调从未被调用，并生成了一个说 SSL 无效的异常。 - DaveEP

AndroidClientHandler似乎不支持ServerCertificateValidationCallback。您有任何更新的信息来处理Android上的这个问题吗？ - Klatschen

这个解决方案不适用于 Android。 - Abdurakhmon

Answer 2

使用 Xamarin.Forms 的独特代码，实例化一个 HttpClientHandler。 示例：

private HttpClient _httpClient;
public HttpClient HttplicentAccount
{
    get
    {
        _httpClient = _httpClient ?? new HttpClient
        (
            new HttpClientHandler()
            {
                ServerCertificateCustomValidationCallback = (sender, cert, chain, sslPolicyErrors) =>
                {
                    //bypass
                    return true;
                },
            }
            , false
        )
        {
            BaseAddress = new Uri("YOUR_API_BASE_ADDRESS"),
        };

        // In case you need to send an auth token...
        _httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Authorization", "YOUR_TOKEN");
        return _httpClient;
    }
}

- André Tamietti Quintão

---

在这里提供的所有解决方案中，这个可以在最新的2019/20更新后，在VS2019上为Android工作。 - TheLegendaryCopyCoder

在应用了上述代码之后仍然得到相同的错误。 - parpar

这对我在最新更新的VS2022上为Android工作。我非常感激。我已经在这个问题上工作了很长时间，而我只使用了这一部分：ServerCertificateCustomValidationCallback =（sender，cert，chain，sslPolicyErrors）=> { //bypass return true; } - Karlomanio

Answer 3

如果您正在使用AndroidClientHandler，则需要提供一个SSLSocketFactory和一个自定义实现的HostnameVerifier，并关闭所有检查。为此，您需要对AndroidClientHandler进行子类化，并覆盖相应的方法。

internal class BypassHostnameVerifier : Java.Lang.Object, IHostnameVerifier
{
    public bool Verify(string hostname, ISSLSession session)
    {
        return true;
    }
}

internal class BypassSslValidationClientHandler : AndroidClientHandler
{
    protected override SSLSocketFactory ConfigureCustomSSLSocketFactory(HttpsURLConnection connection)
    {
        return SSLCertificateSocketFactory.GetInsecure(1000, null);
    }

    protected override IHostnameVerifier GetSSLHostnameVerifier(HttpsURLConnection connection)
    {
        return new BypassHostnameVerifier();
    }
}

然后

var handler = new BypassSslValidationClientHandler();
var httpClient = new System.Net.Http.HttpClient(handler);

- Bruno Caceiro

Answer 4

public static HttpClient PreparedClient() {
 HttpClientHandler handler = new HttpClientHandler();
 handler.ServerCertificateCustomValidationCallback+= (sender, cert, chain,sslPolicyErrors) => { return true; }; 
 HttpClient client = new HttpClient(handler); return client; 
}

HttpClient client = PreparedClient();

- Mark Zookeroberg

Answer 5

我遇到了类似的问题，但错误信息略有不同：

。

Ssl error:1000007d:SSL routines:OPENSSL_internal:CERTIFICATE_VERIFY_FAILED
  at /Users/builder/jenkins/workspace/archive-mono/2019-02/android/release/external/boringssl/ssl/handshake_client.c:1132

我用以下代码在 OnCreate (MainActivity.cs) 中解决了这个问题：

protected override void OnCreate(Bundle savedInstanceState)
{
    TabLayoutResource = Resource.Layout.Tabbar;
    ToolbarResource = Resource.Layout.Toolbar;

    base.OnCreate(savedInstanceState);

// HERE
#if DEBUG
System.Net.ServicePointManager.ServerCertificateValidationCallback = delegate { return true; };
#endif

    Xamarin.Essentials.Platform.Init(this, savedInstanceState);
    Forms.Init(this, savedInstanceState);

    // Initialize Material Design renderer
    FormsMaterial.Init(this, savedInstanceState);


    LoadApplication(new App());
}

这是针对Android的修复方法，将相同的代码放入iOS的FinishedLaunching (AppDelegate.cs)中也应该有效。

- Morphed

Answer 6

将以下代码放入 MainActivity.cs 的 OnCreate 方法中： System.Net.ServicePointManager.ServerCertificateValidationCallback += (sender, cert, chain, sslPolicyErrors) => true;

protected override void OnCreate(Bundle savedInstanceState)
        {

            // to bypass ssl
            System.Net.ServicePointManager.ServerCertificateValidationCallback += (sender, cert, chain, sslPolicyErrors) => true;
            ...
            ..
            LoadApplication(new App());
        }

• 现在将 var httpClient = new HttpClient();

• 改为：var httpClient = new HttpClient(new System.Net.Http.HttpClientHandler());

• 还有别忘了使用 IP 地址而不是 localhost。

- Radouane Samaali