You're not going to be able to make anything near nginx's level of quality and stability in C in a sane amount of time.
Maybe if you're a mental midget. I write perfect, correct, optimal C the first time I write it and I'm done in a matter of days. And it's not because I'm good at programming but because C is the just the right level of abstraction to obtain these results the first time around. So you're using a buffer? Check the buffer length. Ok, it's good. It's as easy as that. The problems happen when people code without thinking about what they write.
But if it uses openssl it's fucked.