password-hash: support password hashes with libcrypt (a.k.a. bcrypt) Base64?

[tarcieri]

bcrypt and SHA-crypt (and more generally it seems libcrypt) use a slightly different Base64 alphabet:

https://text.nxg.me.uk/2019/1

The alphabet is:

./0-9A-Za-b

Perhaps we could support it as well, and with it "MCF hashes" compatible with libcrypt.

[tarcieri]

Support for the crypt(3) Base64 alphabet was added in #515 and #518, along with support for the bcrypt Base64 alphabet.

However, it seems things aren't quite this simple and though the alphabet was the same, SHA-crypt uses a non-sequential byte encoding:

RustCrypto/password-hashes#122 (comment)

So it seems this feature is effectively is "done", but unfortunately not immediately useful without additional work in the respective crate implementations, and whether some sort of abstraction is possible remains to be seen.

All that said, closing this issue.