从 Postman 与 Visual Studio Webtest 调用 REST API

Question

我遇到了一个奇怪的问题，我能够从 POSTMAN 调用 (https://my.factcorp.com/ABCorp/Reporting/api/Events/) Rest API，但不能从 Visual Studio Web Test 调用。

PostMan 呼叫跟踪

GET https://my.factcorp.com/ABCorp/Reporting/api/Events/HTTP/1.1

主机：my.factcorp.com

连接：保持活动

授权：基本

缓存控制：无缓存

用户代理：Mozilla/5.0（Windows NT 10.0；Win64；x64）AppleWebKit/537.36（KHTML，如 Gecko）Chrome/54.0.2840.71 Safari/537.36

邮递员令牌：4dfaa309-c7d8-6785-d59c-9679ad4f3aaa

接受：/

接受编码：gzip、deflate、sdch、br

接受语言：en-US,en;q=0.8

然而，当我从 Webtest 调用相同的 REST API 时，出现以下错误

请求失败：现有连接被远程主机强行关闭

我可以看到 Postman 在请求中添加了一些额外的标头，我也尝试通过手动添加所有这些标头。

任何想法表示赞赏。

谢谢

Answer 1

实际上找到了根本原因，为什么调用从 Postman 而不是从 VS WebTest 成功。

原因是 Postman 足够聪明，可以将请求安全性更正为 (TLS/1.2)

而 WebTest 无法做到这一点，因为它使用较低级别的 System.Net 协议。

现在要解决这个问题，我们实际上可以编写自定义 WebTest 插件，它可以覆盖默认的安全行为。

using System;
using System.ComponentModel;
using System.Net;
using System.Net.Security;
using System.Security.Cryptography.X509Certificates;
using Microsoft.VisualStudio.TestTools.WebTesting;

namespace MyWebTest
{
    [Description("This plugin will force the underlying System.Net ServicePointManager to negotiate downlevel SSLv3 instead of TLS. WARNING: The servers X509 Certificate will be ignored as part of this process, so verify that you are testing the correct system.")]
    public class TLS12ForcedPlugin : WebTestPlugin
    {

        [Description("Enable or Disable the plugin functionality")]
        [DefaultValue(true)]
        public bool Enabled { get; set; }

        public override void PreWebTest(object sender, PreWebTestEventArgs e)
        {
            base.PreWebTest(sender, e);

            //For TLS
            ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;

            //For SSL
            //ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3;

            //we wire up the callback so we can override  behavior and force it to accept the cert
            ServicePointManager.ServerCertificateValidationCallback = RemoteCertificateValidationCB;

            //let them know we made changes to the service point manager
            e.WebTest.AddCommentToResult(this.ToString() + " has made the following modification-> ServicePointManager.SecurityProtocol set to use SSLv3 in WebTest Plugin.");
        }
        public static bool RemoteCertificateValidationCB(Object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors)
        {
            //If it is really important, validate the certificate issuer here.
            //this will accept any certificate
            return true;
        }
    }
}