HttpClient fails to establish SSL connection with server configured with RSA 4096 key.

Anonymous

I am using .net framework 4.7 in WinForms application and using HttpClient for SSO login, When I call server url with using HttpClient then initial handshaking fails with following error.

The request was aborted: Could not create SSL/TLS secure channel.

It seems .net supports RSA 2048 key but not the RSA 4096 key.

I have already tried by setting TLS1.2 as ServiceProtocol, but same error.

Jack J Jun 24,296 Reputation points Microsoft Vendor

2023-01-31T09:40:51.09+00:00

@Rajeev Pradhan, Welcome to Microsoft Q&A, does it still throw the exception when you use the RSA 2048 key? If not, why not consider using RSA 2048 key?
Anonymous

2023-01-31T11:32:02.97+00:00

It works with RSA 2048 key. We want to improve on security and It is decided to go with highly secure key i.e. RSA 4096 key,

We tried to connect using Java Program that uses RestTemplate and we get the response on same windows machine. However our .net program still fails with HttpClient or HttpWebRequest.