在.NET Core中检查证书的到期日期

DateTime notAfter = DateTime.UtcNow;

var httpClientHandler = new HttpClientHandler
{
    ServerCertificateCustomValidationCallback = (request, cert, chain, policyErrors) =>
    {
        notAfter = cert.NotAfter;
        return true;
    }
};

using HttpClient httpClient = new HttpClient(httpClientHandler);
await httpClient.SendAsync(new HttpRequestMessage(HttpMethod.Head, url));
            
Assert.IsTrue(notAfter > DateTime.UtcNow.AddDays(60));

using NUnit.Framework;
using System;
using System.Net.Http;
using System.Threading.Tasks;