无法验证在 https://api.paypal.com 上找到的证书答案

【问题标题】：Unable to verify certificate(s) found at https://api.paypal.com无法验证在 https://api.paypal.com 上找到的证书
【发布时间】：2019-08-25 04:33:45
【问题描述】：

开始在我们的 Paypal webhook 的生产环境中收到这些异常：

PayPal.PayPalException: Unable to verify the certificate(s) found at https://api.paypal.com/v1/notifications/certs/CERT-360caa42-fca2a594-8079afec
   at PayPal.CertificateManager.GetCertificatesFromUrl(String certUrl)
   at PayPal.Api.WebhookEvent.ValidateReceivedEvent(APIContext apiContext, NameValueCollection requestHeaders, String requestBody, String webhookId)

PayPal/AUHR-214.0-51787073

我们所有的 Nuget 包都是最新的：

贝宝 (1.9.1)
布伦特里 (4.11.0)

我们的环境是：

Windows Server 2012 R2 Datacenter（已安装所有更新）
Azure 上的负载均衡器背后

我似乎看不到我们最近所做的任何可能导致此问题的更改。有谁知道我们如何解决这个问题？

编辑
下载证书，运行以下代码：

        var str = @"-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----";

        string[] strArray = str.Split(new string[2]
{
    "-----BEGIN CERTIFICATE-----",
    "-----END CERTIFICATE-----"
}, StringSplitOptions.RemoveEmptyEntries);
        foreach (string str2 in strArray)
        {
            Response.Write(str2 + "<hr>");

            string s = str2.Trim();
            if (!string.IsNullOrEmpty(s))
            {
                X509Certificate2 certificate = new X509Certificate2(Encoding.UTF8.GetBytes(s));
                if (!certificate.Verify())
                {
                    Response.Write("Unable to verify the certificate(s) found<hr>");


                    X509Chain chain = new X509Chain();

                    try
                    {
                        var chainBuilt = chain.Build(certificate);
                        Response.Write(string.Format("Chain building status: {0}", chainBuilt));

                        if (chainBuilt == false)
                            foreach (X509ChainStatus chainStatus in chain.ChainStatus)
                                Response.Write(string.Format("Chain error: {0} {1}", chainStatus.Status, chainStatus.StatusInformation));
                    }
                    catch (Exception ex)
                    {
                        Response.Write(ex.ToString());
                    }
                }
            }
        }

返回错误：

Chain building status: FalseChain error: Revoked The certificate is revoked.

这就是抛出异常的原因。不知道怎么解决。

【问题讨论】：

标签： ssl paypal paypal-ipn webhooks

【解决方案1】：

可在此处找到解决方法：
https://serverfault.com/questions/961681/revoked-ssl-certificate

Paypal 的官方 .NET SDK 最新版本似乎在某处引用了已撤销的证书。不好。

【讨论】：