NET 4.8, which according to Microsoft ensures that TLS 1.2 is supported without any code or registry changes:īut it isn't. NET framework does not support the TLS 1.2 protocol and cannot fallback to lower (unsecure) protocols. On the webserver we reconfigured to only allow TLS 1.2 and suddenly the HTTP Requests do not work anymore with this WebException: The underlying connection was closed: An unexpected error occurred on a send. Buyer beware and all that.Īdditionally, if you're using external libraries (Dlls) in any type of project, you must make sure that they too have their settings changed.I have an Excel Add-in, which does HTTP REST calls and transforms the output to ranges in the current workbook. NET Core, you may wish to enter that into the Configure() method in Startup.cs, however you will need to reference the System.NET namespace - which may or may not be feasible depending on which platform you're targeting. NET Framework (or above) which, at the time of writing, is 4.7.2, the easiest method I found was to add the following code to my global.ascx file: = SecurityProtocolType.Tls12 If you're using the latest version of the. Here's a link to their documentation which helped me a lot: TL DR - The Easiest Way NET Framework version you go (which, to be honest, you'd expect). NET Application To TLS 1.2įortunately, Microsoft have documented the process of migrating applications to newer versions of TLS and the process is fairly straight forward - although it gets progressively more involved the further back in. Unfortunately, there are no fixes or patches that can properly repair SSL or early TLS, so it is critically important that you upgrade to a secure alternative, and disable any fallback to those earlier versions. Exploits such as POODLE and BEAST are just a couple of examples of how attackers have compromised systems relying on earlier versions of SSL and TSL.

There are many security vulnerabilities in SSL and early TLS which put companies at risk of being breached. Why do I need to update to a newer version? It is used to authenticate one or both systems with one another, and protects the confidentiality and integrity of any data that passes between them. Transport Layer Security (TLS) is a cryptographic protocol used to establish a secure communications channel between two computer systems. As you might be aware, 30th June 2018 is the deadline for disabling SSL and early versions of TLS in order to meet the PCI Data Security Standard (PCI DSS) for safeguarding payment data, which means you must implement a more secure encryption protocol - TLS 1.1 or higher (TLS v1.2 is recommended).

How to test tls 1.2 .net