C# 在 .net 中获取 ssl 证书
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get ssl certificate in .net
提问by user166013
i am looking to get the data from any given domain names SSL certificate. For example I want to put in any website address e.g. "http://stackoverflow.com" and my code would firstly check if an SSL certificate exists. If it does then I want it to pull out the expiry date of the certificate. [ i am reading Domainnames from DB ] Example :http://www.digicert.com/help/
我希望从任何给定的域名 SSL 证书中获取数据。例如，我想输入任何网站地址，例如“ http://stackoverflow.com”，我的代码将首先检查 SSL 证书是否存在。如果是这样，那么我希望它提取证书的到期日期。[我正在从数据库读取域名] 示例：http: //www.digicert.com/help/
i need to create a web service to check expiry date. how can i implement it?? - I have looked up loads of different things such as RequestCertificateValidationCallback and ClientCertificates etc.
我需要创建一个网络服务来检查到期日期。我该如何实施？- 我查了很多不同的东西，比如 RequestCertificateValidationCallback 和 ClientCertificates 等。
I could be completely wrong (hence why I need help) but would I create a HTTPWebRequest and then somehow request the client certificate and specific elements that way?
我可能完全错了（因此我需要帮助）但是我会创建一个 HTTPWebRequest 然后以某种方式请求客户端证书和特定元素吗？
i tried the example provided @SSL certificate pre-fetch .NET, but i am getting forbitten 403 error.
我尝试了@ SSL 证书预取 .NET提供的示例，但我收到了禁止 403 错误。
采纳答案by cdev
For this to work your project will need a reference to System.Security:
为此，您的项目需要参考System.Security：
using System.Security;
using System.Security.Cryptography;
using System.Security.Cryptography.X509Certificates;
//Do webrequest to get info on secure site
HttpWebRequest request = (HttpWebRequest)WebRequest.Create("https://mail.google.com");
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
response.Close();
//retrieve the ssl cert and assign it to an X509Certificate object
X509Certificate cert = request.ServicePoint.Certificate;
//convert the X509Certificate to an X509Certificate2 object by passing it into the constructor
X509Certificate2 cert2 = new X509Certificate2(cert);
string cn = cert2.GetIssuerName();
string cedate = cert2.GetExpirationDateString();
string cpub = cert2.GetPublicKeyString();
//display the cert dialog box
X509Certificate2UI.DisplayCertificate(cert2);
.Net Core 2.1
.Net 核心 2.1
You can use HttpClientHandlerand ServerCertificateCustomValidationCallbackProperty. (This class is available in .net 4.7.1 and above also).
您可以使用HttpClientHandler和ServerCertificateCustomValidationCallback属性。（此类在 .net 4.7.1 及更高版本中也可用）。
var handler = new HttpClientHandler
{
UseDefaultCredentials = true,
ServerCertificateCustomValidationCallback = (sender, cert, chain, error) =>
{
/// Access cert object.
return true;
}
};
using (HttpClient client = new HttpClient(handler))
{
using (HttpResponseMessage response = await client.GetAsync("https://mail.google.com"))
{
using (HttpContent content = response.Content)
{
}
}
}
回答by user60177
One thing to note is that you might need to set request.AllowAutoRedirect = False. Otherwise, if the server redirects HTTPS to HTTP, you won't be able to get the certificate from the HttpWebRequestobject.
需要注意的一件事是您可能需要设置request.AllowAutoRedirect = False. 否则，如果服务器将 HTTPS 重定向到 HTTP，您将无法从HttpWebRequest对象获取证书。
回答by Poulad
@cdev's solutiondidn't work for me on .NET Core 2.1. It seems HttpWebRequestis not completely supportedon .NET Core.
@cdev 的解决方案在 .NET Core 2.1 上对我不起作用。这似乎HttpWebRequest是不完全支持.NET的核心。
Here is the function I'm using on .NET Coreto get any server's X509 certificate:
这是我在 .NET Core 上用来获取任何服务器的 X509 证书的函数：
// using System;
// using System.Net.Http;
// using System.Security.Cryptography.X509Certificates;
// using System.Threading.Tasks;
static async Task<X509Certificate2> GetServerCertificateAsync(string url)
{
X509Certificate2 certificate = null;
var httpClientHandler = new HttpClientHandler
{
ServerCertificateCustomValidationCallback = (_, cert, __, ___) =>
{
certificate = new X509Certificate2(cert.GetRawCertData());
return true;
}
};
var httpClient = new HttpClient(httpClientHandler);
await httpClient.SendAsync(new HttpRequestMessage(HttpMethod.Head, url));
return certificate ?? throw new NullReferenceException();
}
