How to test RSA private key

I m on a widows machine and need to test easily if my private key is ok. I need to test it becouse im wrapping it in HSM to export it and then unwrapping it in my test application in C#. Now i just want to make sure the key was wrapped correctly and usable. Allso i dont have certification for it so the testing has to be without using cert. Allso need to mention that the key is in DER ANS.1 format. maybe there is sa simple app where i can load the key in and then do a simple encryption 开发者_运维百科decryption on a string or something like that?

I just wrote a simple application and used my keys for signing to see if they are ok.