Add UUID.v1, .v2, .v3, .v4, .v5

[threez]

add missing uuid methods v1-v5

fixes #13691

[Sija]

✨

[beta-ziliani]

Hi @threez please avoid force pushes, because that breaks the history of reviews and makes it harder for reviewers to re-review the work 🙏

[straight-shoota]

Please use the OpenSSL implementations for hash calculations unless explicitly opted out (-Dwithout_openssl). The native implementations are just a weak kludge. See #13693 (comment)

[threez]

@straight-shoota I used the {% if flag?(:without_openssl) %} which failes with wasm, but {% if flag?(:wasm32) %} would work. This is not exactly what you requested. Is there something regarding the build that needs to be fixed?

[straight-shoota]

I suppose we should probably run the WASM specs with -Dwithout_openssl. @HertzDevil WDYT?

[HertzDevil]

There are many use cases of UUIDs that don't involve the need to generate them via the two digests. IMO it is unacceptable to pull in OpenSSL stuffs from require "uuid". (Whether the runtime calls OpenSSL setup functions, and therefore mandatorily links to it when required, is an implementation detail; compare this with #13746 (comment))

[straight-shoota]

Hm, that's a good point.

However, it's worth noting that this patch does not require OpenSSL explicitly. It just uses the stdlib APIs Digest::SHA1 and Digest::MD5. They are implemented with OpenSSL, but that's an implementation detail of Digest.

This situation is quite unsatisfactory, for sure.
I'm not sure what's the best way to move forward here.

Maybe a good idea could be to refactor Digest implementations to pull in only a subset of the entire OpenSSL bindings. Just the stuff that it needs (which is actually just some parts of lib_crypto). There's no need for any global initialization nor linking any symbols unless the respective methods are actually used.
Applying this diff to all Digest implementations based on OpenSSL should do the trick:

-require "openssl"
+require "openssl/digest"

(We would want to do this as a separate change, though - not as part of this PR)

[straight-shoota]

The suggestion to minimize the digest dependency (☝️) has been implemented in #13818.
Now requiring digest/sha1 should not link libcrypto or libssl unless you explicitly call one of the methods that uses this functionality.

I think that's a reasonable solution and I'd be happy to move on with this PR. @HertzDevil WDYT?

The following patch should fix the breaking WASM job:

--- i/.github/workflows/wasm32.yml
+++ w/.github/workflows/wasm32.yml
@@ -40,7 +40,7 @@ jobs:
           rm wasm32-wasi-libs.tar.gz

       - name: Build spec/wasm32_std_spec.cr
-        run: bin/crystal build spec/wasm32_std_spec.cr -o wasm32_std_spec.wasm --target wasm32-wasi -Duse_pcre
+        run: bin/crystal build spec/wasm32_std_spec.cr -o wasm32_std_spec.wasm --target wasm32-wasi -Duse_pcre -Dwithout_opensssl
         env:
           CRYSTAL_LIBRARY_PATH: ${{ github.workspace }}/wasm32-wasi-libs

[threez]

@straight-shoota merged master and updated the wasm32 target so that openssl would not be compiled using your diff.