Log library versions at startup, and in response to a command-line option

I'd like to know which openssl/libevent/zlib that I'm using when I start Tor. This should be output with --version.

changed milestone to %Tor: unspecified

added component::core tor/tor easy milestone::Tor: unspecified priority::medium resolution::implemented status::closed tor-client type::enhancement labels

I would favor a separate --library-versions or something for this.

It should be pretty verbose: logging the compile-time and run-time versions of each library, and logging both the human-readable and the hex-encoded versions.

Trac:
Component: - Select a component to Tor Client
Milestone: N/A to Tor: unspecified

Trac:
Summary: add lib output in tor startup to Log library versions at startup, and in response to a command-line option

Trac:
Keywords: N/A deleted, easy added

Trac:
Keywords: easy deleted, easy tor-client added

Trac:
Component: Tor Client to Tor

Please check the below branch for a partial implementation. Currently treating it like '--versions' and will exit after printing. Also updated the versions string after regular startup to include runtime zlib version (was already printing openssl and libevent).

Haven't implemented hex-encoded versions yet, just need to clarify that we're just wanting the hexprint of the integer version number and not a hash of the actual lib or something? Is this also required for compile and runtime?

Are we supporting zlib <= 1.1 as I think the ZLIB_VERNUM is only usable after that, but we can just parse the ZLIB_VERSION to get a similar output if necessary. Do you have any additional requirements for the hex-encoded versions?

Thanks

https://github.com/Ryman/tor/tree/bug6384

Trac:
Username: Ry

Quick notes:

• crypto_openssl_get_header_version_str leaks its output. It should probably use the static-variable trick.
• I don't think the hex thing is actually needed. (I wonder why I mentioned it above?)
• I hope we aren't supporting zlib <= 1.1; zlib 1.1.0 was released in 1998, and several security flaws in zlib have been fixed since then.

Other than that, it seems okay to me.

It's going to conflict with #4647 (moved), but that's not a big deal. (Don't worry about this; solving merge conflicts my thing.) I'll merge it after #4647 (moved), since it'll probably be easier that way.

Oh -- parse_openssl_version_str should probably have documentation.

Commit diff: https://github.com/Ryman/tor/commit/b539b372058613b94ef31073de6595ac5d882fd1

https://github.com/Ryman/tor/tree/bug6384

Trac:
Username: Ry
Status: new to needs_review

As of 386e9fb29775f972cfaa, this looks good. I'll merge it once #4647 (moved) is in.

Merged into master; thanks!

Trac:
Resolution: N/A to implemented
Status: needs_review to closed

closed

moved to tpo/core/tor#6384 (closed)