绕过 .net 核心中的无效 SSL 证书

Question

我正在做一个需要连接到 https 站点的项目。每次连接时，我的代码都会抛出异常，因为该站点的证书来自不受信任的站点。有没有办法绕过 .net core http 中的证书检查？

我在以前版本的 .NET 中看到了这段代码。我想我只需要这样的东西。

 ServicePointManager.ServerCertificateValidationCallback += (sender, cert, chain, sslPolicyErrors) => true;

Answer 1

.Net Core 不支持 ServicePointManager.ServerCertificateValidationCallback。

目前的情况是，这将是一个 即将推出的 4.1.* System.Net.Http 合约 (HttpClient) 的新 ServerCertificateCustomValidationCallback 方法。 .NET Core 团队现在正在敲定 4.1 合同。您可以在here on github 阅读有关此内容的信息

您可以直接在 CoreFx 或 MYGET 提要中使用源代码来试用 System.Net.Http 4.1 的预发布版本： https://dotnet.myget.org/gallery/dotnet-core

Github 上当前的 WinHttpHandler.ServerCertificateCustomValidationCallback 定义

Answer 2

来到这里寻找相同问题的答案，但我正在使用 WCF for NET Core。如果您在同一条船上，请使用：

client.ClientCredentials.ServiceCertificate.SslCertificateAuthentication = 
    new X509ServiceCertificateAuthentication()
    {
        CertificateValidationMode = X509CertificateValidationMode.None,
        RevocationMode = X509RevocationMode.NoCheck
    };

Answer 3

更新：

如下所述，并非所有实现都支持此回调（即 iOS 等平台）。在这种情况下，正如docs 所说，您可以显式设置验证器：

handler.ServerCertificateCustomValidationCallback = HttpClientHandler.DangerousAcceptAnyServerCertificateValidator;

这也适用于 .NET Core 2.2、3.0 和 3.1

旧答案，有更多控制权但可能会抛出PlatformNotSupportedException：

您可以使用这样的匿名回调函数覆盖 HTTP 调用上的 SSL 证书检查

using (var httpClientHandler = new HttpClientHandler())
{
   httpClientHandler.ServerCertificateCustomValidationCallback = (message, cert, chain, errors) => { return true; };
   using (var client = new HttpClient(httpClientHandler))
   {
       // Make your request...
   }
}

另外，我建议对HttpClient 使用工厂模式，因为它是一个共享对象，可能不会立即释放，因此connections will stay open。

Answer 4

在 .NET Core 2.2 和 Docker Linux 容器上使用自签名证书和客户端证书身份验证时，我遇到了同样的问题。在我的开发 Windows 机器上一切正常，但在 Docker 中出现这样的错误：

System.Security.Authentication.AuthenticationException：根据验证程序，远程证书无效

幸运的是，证书是使用链生成的。 当然，你可以随时忽略这个解决方案，使用上面的解决方案。

所以这是我的解决方案：

1. 我使用 Chrome 以 P7B 格式将证书保存在我的计算机上。

2. 使用以下命令将证书转换为 PEM 格式：
   openssl pkcs7 -inform DER -outform PEM -in <cert>.p7b -print_certs > ca_bundle.crt

3. 打开 ca_bundle.crt 文件并删除所有主题记录，留下一个干净的文件。下面的例子：

    -----BEGIN CERTIFICATE-----
    _BASE64 DATA_
    -----END CERTIFICATE-----
    -----BEGIN CERTIFICATE-----
    _BASE64 DATA_
    -----END CERTIFICATE-----
    -----BEGIN CERTIFICATE-----
    _BASE64 DATA_
    -----END CERTIFICATE-----

4. 将这些行放入 Dockerfile（在最后的步骤中）：

    # Update system and install curl and ca-certificates
    RUN apt-get update && apt-get install -y curl && apt-get install -y ca-certificates
    # Copy your bundle file to the system trusted storage
    COPY ./ca_bundle.crt /usr/local/share/ca-certificates/ca_bundle.crt
    # During docker build, after this line you will get such output: 1 added, 0 removed; done.
    RUN update-ca-certificates

5. 在应用中：

    var address = new EndpointAddress("https://serviceUrl");                
    var binding = new BasicHttpsBinding
    {
        CloseTimeout = new TimeSpan(0, 1, 0),
        OpenTimeout = new TimeSpan(0, 1, 0),
        ReceiveTimeout = new TimeSpan(0, 1, 0),
        SendTimeout = new TimeSpan(0, 1, 0),
        MaxBufferPoolSize = 524288,
        MaxBufferSize = 65536,
        MaxReceivedMessageSize = 65536,
        TextEncoding = Encoding.UTF8,
        TransferMode = TransferMode.Buffered,
        UseDefaultWebProxy = true,
        AllowCookies = false,
        BypassProxyOnLocal = false,
        ReaderQuotas = XmlDictionaryReaderQuotas.Max,
        Security =
        {
            Mode = BasicHttpsSecurityMode.Transport,
            Transport = new HttpTransportSecurity
            {
                ClientCredentialType = HttpClientCredentialType.Certificate,
                ProxyCredentialType = HttpProxyCredentialType.None
            }
        }
    };
    var client = new MyWSClient(binding, address);
    client.ClientCredentials.ClientCertificate.Certificate = GetClientCertificate("clientCert.pfx", "passwordForClientCert");
    // Client certs must be installed
    client.ClientCredentials.ServiceCertificate.SslCertificateAuthentication = new X509ServiceCertificateAuthentication
    {
        CertificateValidationMode = X509CertificateValidationMode.ChainTrust,
        TrustedStoreLocation = StoreLocation.LocalMachine,
        RevocationMode = X509RevocationMode.NoCheck
    };

GetClientCertificate 方法：

private static X509Certificate2 GetClientCertificate(string clientCertName, string password)
{
    //Create X509Certificate2 object from .pfx file
    byte[] rawData = null;
    using (var f = new FileStream(Path.Combine(AppContext.BaseDirectory, clientCertName), FileMode.Open, FileAccess.Read))
    {
        var size = (int)f.Length;
        var rawData = new byte[size];
        f.Read(rawData, 0, size);
        f.Close();
    }
    return new X509Certificate2(rawData, password);
}

Answer 5

在.NetCore中，你可以在服务配置方法中添加以下代码sn-p，我添加了一个检查以确保我们只在开发环境中绕过SSL证书

services.AddHttpClient("HttpClientName", client => {
// code to configure headers etc..
}).ConfigurePrimaryHttpMessageHandler(() => {
                  var handler = new HttpClientHandler();
                  if (hostingEnvironment.IsDevelopment())
                  {
                      handler.ServerCertificateCustomValidationCallback = (message, cert, chain, errors) => { return true; };
                  }
                  return handler;
              });

Answer 6

我解决了这个问题：

Startup.cs

public void ConfigureServices(IServiceCollection services)
    {
        services.AddHttpClient("HttpClientWithSSLUntrusted").ConfigurePrimaryHttpMessageHandler(() => new HttpClientHandler
        {
            ClientCertificateOptions = ClientCertificateOption.Manual,
            ServerCertificateCustomValidationCallback =
            (httpRequestMessage, cert, cetChain, policyErrors) =>
            {
                return true;
            }
        });

YourService.cs

public UserService(IHttpClientFactory clientFactory, IOptions<AppSettings> appSettings)
    {
        _appSettings = appSettings.Value;
        _clientFactory = clientFactory;
    }

var request = new HttpRequestMessage(...

var client = _clientFactory.CreateClient("HttpClientWithSSLUntrusted");

HttpResponseMessage response = await client.SendAsync(request);

Answer 7

首先，不要在生产中使用它

如果您正在使用 AddHttpClient 中间件，这将很有用。 我认为它是开发目的而不是生产所需要的。在您创建有效证书之前，您可以使用此功能。

Func<HttpMessageHandler> configureHandler = () =>
        {
            var bypassCertValidation = Configuration.GetValue<bool>("BypassRemoteCertificateValidation");
            var handler = new HttpClientHandler();
            //!DO NOT DO IT IN PRODUCTION!! GO AND CREATE VALID CERTIFICATE!
            if (bypassCertValidation)
            {
                handler.ServerCertificateCustomValidationCallback = (httpRequestMessage, x509Certificate2, x509Chain, sslPolicyErrors) =>
                {
                    return true;
                };
            }
            return handler;
        };

并像这样应用它

services.AddHttpClient<IMyClient, MyClient>(x => { x.BaseAddress = new Uri("https://localhost:5005"); })
        .ConfigurePrimaryHttpMessageHandler(configureHandler);

Answer 8

允许所有证书非常强大，但也可能很危险。如果您只想允许有效证书和某些特定证书，可以这样做。

using (var httpClientHandler = new HttpClientHandler())
{
    httpClientHandler.ServerCertificateCustomValidationCallback = (message, cert, chain, sslPolicyErrors) => {
        if (sslPolicyErrors == SslPolicyErrors.None)
        {
            return true;   //Is valid
        }

        if (cert.GetCertHashString() == "99E92D8447AEF30483B1D7527812C9B7B3A915A7")
        {
            return true;
        }
        return false;
    };
    using (var httpClient = new HttpClient(httpClientHandler))
    {
        var httpResponse = httpClient.GetAsync("https://example.com").Result;
    }
}

原文出处：

https://stackoverflow.com/a/44140506/3850405