Crystal: Move Crypto::MD5 to Digest and consolidate its API

[Papierkorb]

Hello,

Right now MD5 lives in the Crypto module, while SHA1 lives in the Digest module.
I think the latter would be a better fit for MD5. Further, I'd love to see the MD5 API to mirror the one of SHA1:

| Digest::SHA1 | Crypto::MD5 |
|---------|--------|
| Is a module | Is a class |
| Context is private | Context is public |
| .digest(String | Bytes) | Doesn't exist |
| .hexdigest(String | Bytes) No underscore | .hex_digest(String | Bytes) Has underscore |
| Doesn't exist | .hex_digest() with yield |
| .base64digest(String | Bytes) | Doesn't exist |

I'd thus like to do:

1. Move MD5 to Digest
2. Make both a module OR a class
3. Rename hex_digest to hexdigest
4. Add missing methods (from above) to both of them

I could work on this, though I'd like to get community feedback first before wasting everyones time :)

Cheers!

[rg-3]

great analysis and breakdown of the differences between the two!
fwiw in Ruby it's Digest::MD5 and Digest::SHA1. :+1: for mirroring the APIs.

edit: forgot to +1

[RX14]

I'm always hesitant to use crystal implementations of crypto functions, mainly because of the possibility of timing attacks. AFAIK openssl uses mostly hand-written assembly to help ensure this constant-time.

[ysbaddaden]

MD5 has nothing to do in Crypto land. Digest is a better place.

[Papierkorb]

Thanks y'all for the positive feedback. I'll work on it tomorrow (Tuesday) then.

[Papierkorb]

As #4037 was merged (Thanks!), I'll close this.