Are SSL Certificates (Private and Public key) generated by OpenSSL and makecert compatible?

Question

Are RSA SSL Certificates (Private and Public key) generated by makecert compatible with OpenSSL decryption ie. can I decrypt them with the openssl_* methods? I am working on two-way SSL authentication between a .NET client and a PHP service, so I want to know if I have to create OpenSSL certificates on the .NET side.

Answer 1

Both makecert and OpenSSL follow X.509, so they are compatible -- in theory. X.509 is extensible is various arbitrary ways, and has been extended in various arbitrary and exotic ways, so anything can happen.

Practically, OpenSSL powers a lot of existing HTTPS web sites (according to these statistics, Apache powers more than 50% of all Web sites, and when Apache does HTTPS, it does so with OpenSSL(*)) so chances are that Microsoft tried not to break compatibility in that matter. In my experience, .NET and OpenSSL talke to each other quite politely.

(*) Well, Apache can also use GnuTLS, but it seems to be rather uncommon.