Is it possible to add ECDHE ciphers to Xp or is it a stupid thought?

[maile3241]

Hi there,
Is it possible to add ECDHE ciphers? To access the Windows Update website without ProxhttpsProxy. I read that you can update the ciphers in the registry editor, or am I wrong?

I found these entries:

The Windows Update website requires these ciphers:

[RainyShadow]

I believe this registry edit would only disable the already available ciphers. 

To add new ones they have to be programmed in the .DLL that does the actual work.

[maile3241]

20 minutes ago, RainyShadow said:

I believe this registry edit would only disable the already available ciphers. 

To add new ones they have to be programmed in the .DLL that does the actual work.

OK. Unfortunately, I'm not a programmer who can do that. Would it work if we take the file from Vista?

[RainyShadow]

8 minutes ago, maile3241 said:

Would it work if we take the file from Vista?

I think this was attempted before without success. 

Check the begining of the few big related threads (about TLS 1.2, or the WU/MU one maybe), it was mentioned somewhere there.

[AstroSkipper]

2 hours ago, RainyShadow said:

I think this was attempted before without success. 

Have a look into this thread: 

It's all about TLS, SSL, ProxHTTPSProxy and a lot of observations relating to schannel.dll where Ciphers are provided.

Edited March 22, 2022 by AstroSkipper
correction

[AstroSkipper]

4 hours ago, maile3241 said:

Hi there,
Is it possible to add ECDHE ciphers? To access the Windows Update website without ProxhttpsProxy. I read that you can update the ciphers in the registry editor, or am I wrong?

As @RainyShadow said above these registry entries can only enable or disable ciphers which already exist in file schannel.dll. Here is a link:
https://www.ssl.com/de/wie-man/Wählen-Sie-die-richtigen-Cipher-Suites-in-der-Schannel-DLL/
And replacing files is simple but in most cases it won't work at all. A lot of dll files have dependencies and need special registry entries too. Some people have already tried that. For example here: 

Edited March 22, 2022 by AstroSkipper
correction

[maile3241]

I have read through the post. It would certainly be possible somehow, but it will probably require a lot of work.