Convert OpenSSL Public Key to NSS

How to convert a public key generated by OpenSSL to one NSS will understand? I generated a key from OpenSSL, exported it to pkcs12 format, imported it into the NSS database, and then extracted the public key using the McCoy utility. And that was different from my big surprise. This is most likely a coding question, but which one should I use?

Update: It looks like OpenSSL contains the NSS key inside, so the question is, how do I know which part of the OpenSSL key is also the NSS key?