Add bindings for DANE

[coma64]

Overview

First of all, thanks for keeping this library maintained :D

This PR adds CGO bindings for a bunch of openssl function, most notably DANE (DNS-based Authentication of Named Entities) related functions.

New features

• Bindings for DANE
• Bindings for TLS handshake tracing
• Bindings for X509_digest()
• Bindings for X509_verify_cert_error_string()
• Bindings for SSL_get_version()

[oleg-jukovec]

Thank you for the patch! Please, fix the CI errors:

Error: ./ssl.go:219:12: cannot use _Ctype_ulong(len(data)) (value of type _Ctype_ulong) as type _Ctype_uint in variable declaration
FAIL	github.com/tarantool/go-openssl [build failed]
?   	github.com/tarantool/go-openssl/utils	[no test files]
FAIL
Error: Process completed with exit code 2.

before a review.

[coma64]

@oleg-jukovec Sorry for the inconvenience, I didn't enable actions on the fork... Everything should be fixed now

[DerekBum]

Thank you for the patch! Overall you did a great work, docs are clear and codestyle is on the level. That was a pleasure to review this patch.

But there are still some moments I would like you to fix or discuss with us:

1. You should squish your commits into one (or more, but logically separated). Right now its a mess, some commits are breaking the CI, some revert changes from other commits.
   Please, also write a commit message body (if needed) to explain the changes done for each commit. You can refer to the commit history the master branch.
2. In Tarantool every commit should end with a dot. Thank you for following this rule for code comments, but there are some missing dots in CHANGELOG and README.
3. There are some other nits and questions described below. Please forgive me in case of being too pedantic and don't be afraid to engage in dialogue with me. I hope all the comments are clear.

[DerekBum]

Another thing I forgot about is the lack of tests. Is there any difficulties writing unit tests for new methods?

[coma64]

No, for our applications this was covered by e2e tests but that's of course not the case for this library. I'll write some

[coma64]

Everything should be resolved now. Please have a look and I'll squash the commits @DerekBum

[DerekBum]

Thank you for fixing all the countless nits I had! Everything looks great, CI is all green. Just a couple of comment fixes left (just them, everything else is ok).

I will approve this PR after the squash.

[coma64]

Everything's squashed now, thanks for the quick review! :)

[DerekBum]

LGTM! Thank you for the patch!

[oleg-jukovec]

@coma64 do you need a release version with the patchset?

[coma64]

Yes please

[oleg-jukovec]

Yes please

https://github.com/tarantool/go-openssl/releases/tag/v1.1.0