RSA_sign(), object(3) and NID_sha1

The manpage for RSA_sign() says about the type parameter:

type denotes the message digest alg开发者_如何学JAVAorithm that was used to generate m. It usually is one of NID_sha1, NID_ripemd160 and NID_md5; see objects(3) for details.

I included the headers as suggested, but my IDE claims there are no variables starting with NID_ and I couldn't find the objects manpage anywhere on the internet.

What am I missing?

Apparently the objects manpage has never been written. Here's the bug report from whoopin' 2007.

As Dan Grossman helpfully pointed out, the objects manpage would document objects.h; including either that, or engine.h as the RSA manpage suggests, fixed the problem.