I published a book about SSL a while back - my original plan for the book was going to be to work through the OpenSSL source code and relate each piece back to the relevant specifications, step by step. I found that the OpenSSL source code was so complex that I would have spent a lot more time discussing the intricacies of the C code itself than the cryptographic algorithms they were implementing - so much so that it made more sense to just write my own SSL implementation and walk through that.
In fairness to OpenSSL, though, I can see how and why it got so complex: they're trying to be all things to all people in a backwards compatible way. At the time, OpenSSL still had support for SSLv2, an albatross that LibreSSL doesn't have around its neck.
I published a book about SSL a while back - my original plan for the book was going to be to work through the OpenSSL source code and relate each piece back to the relevant specifications, step by step. I found that the OpenSSL source code was so complex that I would have spent a lot more time discussing the intricacies of the C code itself than the cryptographic algorithms they were implementing - so much so that it made more sense to just write my own SSL implementation and walk through that.
In fairness to OpenSSL, though, I can see how and why it got so complex: they're trying to be all things to all people in a backwards compatible way. At the time, OpenSSL still had support for SSLv2, an albatross that LibreSSL doesn't have around its neck.