SCRAM-SHA-1(-PLUS) + SCRAM-SHA-256(-PLUS) + SCRAM-SHA-512(-PLUS) + SCRAM-SHA3-512(-PLUS) supports

[Neustradamus]

Dear @ruby team,

In first, I wish you a Happy New Year!

Can you add supports of :

• SCRAM-SHA-1
• SCRAM-SHA-1-PLUS
• SCRAM-SHA-256
• SCRAM-SHA-256-PLUS
• SCRAM-SHA-512
• SCRAM-SHA-512-PLUS
• SCRAM-SHA3-512
• SCRAM-SHA3-512-PLUS

You can add too:

• SCRAM-SHA-224
• SCRAM-SHA-224-PLUS
• SCRAM-SHA-384
• SCRAM-SHA-384-PLUS

"When using the SASL SCRAM mechanism, the SCRAM-SHA-256-PLUS variant SHOULD be preferred over the SCRAM-SHA-256 variant, and SHA-256 variants [RFC7677] SHOULD be preferred over SHA-1 variants [RFC5802]".

• SCRAM-SHA-1(-PLUS):
  -- https://tools.ietf.org/html/rfc5802
  -- https://tools.ietf.org/html/rfc6120

• SCRAM-SHA-256(-PLUS):
  -- https://tools.ietf.org/html/rfc7677 since 2015-11-02
  -- https://tools.ietf.org/html/rfc8600 since 2019-06-21: https://mailarchive.ietf.org/arch/msg/ietf-announce/suJMmeMhuAOmGn_PJYgX5Vm8lNA

• SCRAM-SHA-512(-PLUS):
  -- https://tools.ietf.org/html/draft-melnikov-scram-sha-512

• SCRAM-SHA3-512(-PLUS):
  -- https://tools.ietf.org/html/draft-melnikov-scram-sha3-512

https://xmpp.org/extensions/inbox/hash-recommendations.html

-PLUS variants:

• RFC5056: On the Use of Channel Bindings to Secure Channels: https://tools.ietf.org/html/rfc5056
• RFC5929: Channel Bindings for TLS: https://tools.ietf.org/html/rfc5929
• Channel-Binding Types: https://www.iana.org/assignments/channel-binding-types/channel-binding-types.xhtml
• RFC 9266: Channel Bindings for TLS 1.3: https://tools.ietf.org/html/rfc9266

IMAP:

• RFC9051: Internet Message Access Protocol (IMAP) - Version 4rev2: https://tools.ietf.org/html/rfc9051

LDAP:

• RFC5803: Lightweight Directory Access Protocol (LDAP) Schema for Storing Salted: Challenge Response Authentication Mechanism (SCRAM) Secrets: https://tools.ietf.org/html/rfc5803

HTTP:

• RFC7804: Salted Challenge Response HTTP Authentication Mechanism: https://tools.ietf.org/html/rfc7804

2FA:

• Extensions to Salted Challenge Response (SCRAM) for 2 factor authentication: https://tools.ietf.org/html/draft-melnikov-scram-2fa

IANA:

• Simple Authentication and Security Layer (SASL) Mechanisms: https://www.iana.org/assignments/sasl-mechanisms/sasl-mechanisms.xhtml

Linked to:

• State of Play scram-sasl/info#1

[nevans]

Thank you so much for simply documenting this so thoroughly and cleanly, @Neustradamus. I attached this ticket and #55 to the epic checklist on #12.

Unfortunately, the SASL-SHA-* mechanisms are still either unsupported or not enabled on every server that I work with. I understand that client support waiting for server support and vice versa creates a chicken-and-egg dilemma. (On the other hand, I'll be submitting my implementation for OAUTHBEARER soon. It is now supported by more servers than XOAUTH.)

So... I'd welcome a PR for this! :) If not a PR, perhaps a reference implementation with a suitable open source licence, preferably in ruby or another similar language?

See also:

• Support for IMAP4rev2 and modern extensions #12
• Should we create a shared net-sasl gem? #23
• SCRAM-SHA-1(-PLUS) + SCRAM-SHA-256(-PLUS) + SCRAM-SHA-512(-PLUS) + SCRAM-SHA3-512(-PLUS) supports nevans/net-sasl#1

[Neustradamus]

@nevans: Thanks to all comments about my tickets :)

I hope that one guy can add the support which is officially needed in the last IMAP RFC.

About memcached, there is a fork (inactive) which supports it:

• https://github.com/couchbase/memcached/tree/master/cbsasl
• https://github.com/couchbase/memcached/search?o=asc&q=scram&s=committer-date&type=commits

Note: I have done a ticket in https://github.com/memcached/memcached too...

[Neustradamus]

@singpolyma has done a PR in net-sasl:

• Add support for SCRAM-SHA-* nevans/net-sasl#5

[nevans]

It's still just a draft, I will definitely be updating and rebasing it, and I might split into multiple smaller PRs. But #78 contains SCRAM-SHA-1 and SCRAM-SHA-256 implementations, and I'd welcome code-review, comments, testing (etc).

[Neustradamus]

@nevans: Good job!

Have you looked for draft-melnikov-scram-sha-512 and draft-melnikov-scram-sha3-512?

[nevans]

@nevans: Good job!

Have you looked for draft-melnikov-scram-sha-512 and draft-melnikov-scram-sha3-512?

yes. They both expired back in April. :(

I'd guess they'll probably be resurrected at some point. And probably there won't be any surprising changes to the algorithm nor to the recommended settings.

Just the same, unless there is a very significant deployment of these not-yet-standard mechanisms, I'd rather not add "official" support until they are standardized. It will only be a few lines of code to add support for any digest that's supported by OpenSSL::Digest, so I don't think that's an undue burden for any project that wants to add those mechanisms for themselves.