There is a windows 10 server in which tls1.0,ssl3 are disabled by IISCrypto for refusing weak ssl protocol from client requests. tls1.1 and tls1.2 are disabled on the client system and just ssl3 is enabled on it and will be expected any requests from client to server be refused.I'm using IIS10 and an asp mvc project website that is loaded on .I've searched and figure out there is no way to reject these request in asp mvc.The only way was using something like this System.Net.ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;
but doesn't work at all.By using wireshark and just look at Client Hello I realized the connection between server and client is stablished by tls1.2. I think my question is clear and no need to give code anymore.
Is there any help ?
Related
Recently, we have encountered a problem while installing one of our applications for a customer. During installation the application needs to perform some requests to our cloud service and we realised it could not establish HTTPS connection: the very TLS handshake failed. After researching a bit we found the server was a Windows Server 2008 which does not support TLS v1.2, which is the minimum required to connect to our servers. There are some workarounds (this one, for instance) but none of them worked. In addition, we cannot install any update to that windows due to customer policies.
While looking for a solution, using wireshark, we noticed that our program tried to connect using TLS v1.2 and failed, but Chrome browser was able to connect to the same cloud server using TLS v1.3, which is not even supported in Windows Server 2008. From that we deduced that Chrome is likely using its own TLS stack to establish the connection.
I am wondering that if Chrome is doing that, we should also be able to do the same. The application is developed in .Net Core and I have googled a lot looking for information on how to do this, and I've found lots of information on how to configure TLS certificates in .Net Core, but none on replacing the TLS stack with, say, OpenSSL or others. I do know this is possible in Java, so is it possible to replace the TLS stack in .Net core?
.NET Core itself doesn't let you plug in your own crypto stack.
You pointed to Bouncy Castle as an example of Java letting you use an alternate crypto stack; there's a port of Bouncy Castle to C#/.NET as well.
Their source code has a test case that demonstrates how to write a TLS client using Bouncy Castle:
https://github.com/bcgit/bc-csharp/blob/master/crypto/test/src/crypto/tls/test/TlsClientTest.cs
I have java app deployed to tomcat server 8.5.32.
I configured the server to use only TLS 1.2 so if the user send a request to the app(tomcat server) using browser and the browser is old(supports only TLS 1.0 and TLS 1.1) then i want to know that someone tries to reach my app but no handshake is made and I want to make a record in DB.
Is there any way I can know that client is using TLS version that my server is not supporting it and somehow get that info what is the TLS version of the client? OR at least to know that client is using older TLS version?
For my current project i need to implement http over tls at client ,for this i need a local server able to simulate this . is there any online or offline tool. which i can use and and see the handshake in wireshark .
For watching the TLS handshake you might not get far enough with wireshark. For such kind of monitoring you would ensure the security is low enough for wireshark to be able getting the session key from watching the handshake for decoding the later parts. Thus, you need to avoid any forward secrecy.
Otherwise any (https) server that is accessible (and willing to talk) to your client will do.
In case you are in an environment that is supported (e.g. any unix/linux), you might try using openssl. It allows setting up a server that will do handshake. And it will log the handshake such that you will be able looking at what is going on. This will eliminate the need for using wireshark for debugging.
For achieving this you need a Web Server accepting connection over TLS.I have achieved this on Apache Tomcat web Server.
TLS configuration needs to be done in the server.xml file present in config directory of Tomcat webserver. Connector tag needs to be added in the server.xml file that contains information like
TLS version to be used, port, List of supported Cipher Suites, Keystore path and password, Truststore path and password.
Any regular Rest client can be used to make a call like Postman client. But to use that over TLS/SSL certificate is needed to be installed in Chrome browser.
Hope this answers your doubt.
Our company currently have an application created in VB6 running on a Windows 7 desktop computer. This application needs to connect to a web service using HTTPS.
For some reason this application can not connect to the target server. The target server is behind an Apache web server that also acts as a load balancer.
I traced the connection via wire shark and it seems that after the Client Hello the server responded with [FIN, ACK] than a Server Hello. Can anyone tell me what the problem is.
Client Hello & Server [FIN, ACK]
[![Client HEllo][1]][1]
[1]: https://i.stack.imgur.com/btXyX.jpg
[![enter image description here][2]][2]
[2]: https://i.stack.imgur.com/O5WDq.jpg
However, we can connect successfully in the following scenarios
If we use the same application under Windows 10. Please note when using Windows 10 our SSL version is TLS1.2.
If the application connect directly to the Application Server instead of the Apache Web Server. In this case our SSL protocol is still TLS1.0
I am guessing that we need to configure the Web Server to allow our application to connect. Our Administrator told us they already activated the TLS1.0 protocols so I am not entirely sure what is wrong now.
Why the server closed the connection, or any ideas what part of the logs or Web server configuration should I check to find out?
Please note that we are aware that we are using TLS1 protocol for this connection but this application is only for internal use and its replacement is already in development. However, there is a business need to make this work for the current environment.
In the case the Server doesn't support any of the Cipher-Suites suggested in the "Client Hello" packet, it may just close the connection.
You can check what is the returned Cipher-Suite in the case it works (when you use Windows10) and then investigate how to enable this Cipher-Suite in Windows7
I am trying to connect a client to a secure (SSL/TLS) IMAP server. The client code cannot handle SSL/TLS correctly, so I am trying to see if a proxy server can be used in the middle. I was thinking something like the following:
IMAP Client <------- Plain Text Requests -------> Proxy <------- SSL/TLS Requests -------> SSL/TLS protected IMAP server.
I think this is possible but I am curious on what products can be used for the proxy? And, is this a normal deployment option?
Thanks much,
Ash
Use stunnel. With it you can do direct TLS (i.e. imaps, port 993) and also TLS upgrade of a plain IMAP connection (port 143) using the STARTTLS command. See the documentation for more details.
This is insane. An obvious fix is to find out why your client software cannot handle TLS. Deploying proxies or standalone tunnels makes little sense.
Seriously, if your "client" cannot even establish a TLS connection, it's either severely misconfigured, has damaged installation, or so bad that it won't reliably work even after you deploy this bandaid.