【C#、阿里云、Tomcat、XP系统】c#下使用.NET4.0中HttpWebRequest访问Tomcat中HTTPS项目时，在XP系统中超时

情景：

1、使用Java开发的Web项目，部署在服务器Tomcat中

2、项目使用HTTPS，使用阿里云的PFX证书

阿里云推荐Tomcat配置如下

<Connector port="8443"
    protocol="HTTP/1.1"
    SSLEnabled="true"
    scheme="https"
    secure="true"
    keystoreFile="cert/214181506600131.pfx"
    keystoreType="PKCS12"
    keystorePass="证书密码"
    clientAuth="false"
    SSLProtocol="TLSv1+TLSv1.1+TLSv1.2"
    ciphers="TLS_RSA_WITH_AES_128_CBC_SHA,TLS_RSA_WITH_AES_256_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256,TLS_RSA_WITH_AES_128_CBC_SHA256,TLS_RSA_WITH_AES_256_CBC_SHA256"/>

我的Tomcat的server.xml配置如下

<Connector port="443" protocol="HTTP/1.1" SSLEnabled="true"
             maxThreads="150" scheme="https" secure="true"
             clientAuth="false" SSLProtocol="TLSv1+TLSv1.1+TLSv1.2" 
        　   keystoreFile="C:/xxx.pfx"
             keyStoreType="PKCS12"
             keystorePass="xxx"
　　　　　　　 ciphers="TLS_RSA_WITH_AES_128_CBC_SHA,TLS_RSA_WITH_AES_256_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256,TLS_RSA_WITH_AES_128_CBC_SHA256,TLS_RSA_WITH_AES_256_CBC_SHA256"/>

3、c#下的访问HTTPS代码如下

string Address = "https://www.myweb.com/customers";
string Parameters = "{"pagesize":"2","pageno":"2","conditions":{"searchtext":"","orderby":""}}";
HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(Address);
request.Method = "POST";
request.Headers.Add("X-Requested-With", "XMLHttpRequest");
request.ContentType = "application/json";
request.UserAgent = "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:40.0) Gecko/20100101 Firefox/40.0";
request.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
byte[] bytes = Encoding.UTF8.GetBytes(Parameters);
request.ContentLength = bytes.Length;
Stream poststream = request.GetRequestStream();
poststream.Write(bytes, 0, bytes.Length);
poststream.Close();
HttpWebResponse response = request.GetResponse() as HttpWebResponse;
StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.UTF8);
string content = reader.ReadToEnd();
reader.Close();
response.Close();
return content

4、以上代码，在XP系统外的系统运行正常；在XP系统中出现连接超时的情况。

解决方案：

参考文档原文：https://stackoverflow.com/questions/26506432/how-to-make-tls-requests-in-net-4-on-windows-xp-to-servers-with-ssl3-disabled

这篇文章中说明了，XP系统和Tomcat之间连接不上，是因为一个加解密的东西不对应。

解决方案是Tomcat配置文件中的ciphers配置项中加入TLS_RSA_WITH_3DES_EDE_CBC_SHA这项配置

<Connector port="443" protocol="HTTP/1.1" SSLEnabled="true"
             maxThreads="150" scheme="https" secure="true"
             clientAuth="false" SSLProtocol="TLSv1+TLSv1.1+TLSv1.2" 
        　   keystoreFile="C:/xxx.pfx"
             keyStoreType="PKCS12"
             keystorePass="xxx"
　　　　　　　 ciphers="...这里是之前设置的一堆项目...,TLS_RSA_WITH_3DES_EDE_CBC_SHA"/>

然后，XP系统就能正常和Tomcat连接了