Add LeiosCert to DijkstraBlockBody

[ch1bo]

Description

This adds the LeiosCert as an SMaybe to the DijkstraBlockBody. The type and its encoding is defined in cardano-crypto-leios, a new package on the cardano-base repository. See IntersectMBO/cardano-base#670

This also includes a fix of the DijkstrBlockBodyRaw instance for EncCBORGroup instance: it was missing the invalid transactions field.

New block_body CDDL after this change (also regenerated in the diff):

block_body =
  [ invalid_transactions : invalid_transactions/ nil
  , transactions      : [* transaction]
  , leios_certificate : leios_certificate/ nil
  , peras_certificate : peras_certificate/ nil
  ]

with

leios_certificate =
  [ signers              : bytes           ;bitfield
  , aggregated_signature : leios_signature
  ]

leios_signature = bytes .size 48

Checklist

• Commits in meaningful sequence and with useful messages.
• Tests added or updated when needed.
• CHANGELOG.md files updated for packages with externally visible changes.
  NOTE: New section is never added with the code changes. (See RELEASING.md).
• Versions updated in .cabal and CHANGELOG.md files when necessary, according to the
  versioning process.
• Version bounds in .cabal files updated when necessary.
  NOTE: If bounds change in a cabal file, that package itself must have a version increase. (See RELEASING.md).
• Code formatted (use scripts/fourmolize.sh).
• Cabal files formatted (use scripts/cabal-format.sh).
• CDDL files are up to date (use scripts/gen-cddl.sh)
• hie.yaml updated (use scripts/gen-hie.sh).
• Self-reviewed the diff.

[Copilot]

Pull request overview

This PR extends the Dijkstra era block body format to optionally include a Leios certificate (LeiosCert) and updates the corresponding CBOR and CDDL representations, along with test generators/specs to exercise both the “TxsRB” and “CertRB” shapes.

Changes:

• Add StrictMaybe LeiosCert to DijkstraBlockBodyRaw / DijkstraBlockBody and update CBOR encoding/decoding accordingly.
• Regenerate/update Dijkstra CDDL + Huddle rules to include leios_certificate (and make cert fields / nil in block_body).
• Update testlib instances/generators and CDDL specs to cover both block body shapes; add new cardano-crypto-leios dependency wiring.

Reviewed changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
libs/cardano-ledger-binary/src/Cardano/Ledger/Binary/Decoding/Decoder.hs	Adds an in-code review note inside decodeRecordNamedT (should be removed).
eras/dijkstra/impl/testlib/Test/Cardano/Ledger/Dijkstra/TreeDiff.hs	Adds ToExpr LeiosCert for better diffs without orphan signature instances.
eras/dijkstra/impl/testlib/Test/Cardano/Ledger/Dijkstra/Binary/Annotator.hs	Updates block body decoding to expect 4 fields and decode optional Leios cert.
eras/dijkstra/impl/testlib/Test/Cardano/Ledger/Dijkstra/Arbitrary.hs	Adds Arbitrary LeiosCert and new small block body generators for “TxsRB” vs “CertRB”.
eras/dijkstra/impl/test/Test/Cardano/Ledger/Dijkstra/Binary/CddlSpec.hs	Splits block_body CDDL round-trip specs into “TxsRB” and “CertRB”.
eras/dijkstra/impl/src/Cardano/Ledger/Dijkstra/BlockBody/Internal.hs	Adds Leios cert field + updates CBOR encode/decode; updates EncCBORGroup (currently mismatched for StrictMaybe encoding).
eras/dijkstra/impl/cddl/lib/Cardano/Ledger/Dijkstra/HuddleSpec.hs	Adds Leios certificate/signature rules; updates block_body rule layout and generator to 4 fields.
eras/dijkstra/impl/cddl/data/dijkstra.cddl	Updates block_body CDDL and defines leios_certificate / leios_signature.
eras/dijkstra/impl/cardano-ledger-dijkstra.cabal	Adds cardano-crypto-leios (+ hedgehog-quickcheck for generators) to relevant components.
cabal.project	Adds a source-repository-package pin to pull in cardano-crypto-leios from cardano-base.

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[ch1bo]

Well, it was exactly my intention to reach a reviewer in this PR :)

[lehins]

This is looking great. Thank you.

[lehins]

Naturally, we can't merge this PR, until caradno-crypto-leios is on CHaP

[ch1bo]

Sure, we need the upstream PR merged first and then I'll release it.

[lehins]

I'd like to understand all possible modes here for block body contents, so could you please provide a response to this message, so we make sure we get validation logic right.
This is my understanding today of valid block contents in Dijkstra:

• Praos block:
  • Transactions, No Leios Certificate, maybe Peras Certificate
  • No Transactions, No Leios Certificate, maybe Peras Certificate
• Ranking Block can contain:
  • No Transactions, Leios Certificate, maybe Peras Certificate
• Endorsed Block:
  • Transactions (many of them). No Leios Certificate, No Peras Certificate.

Is my understanding on block contents correct?

Also, I believe EB, must always follow RB, otherwise chain is invalid, right?

[ch1bo]

From a Leios perspective we call all Praos blocks "Ranking blocks" (RB) and distinguish two cases for the block body:

• TxsRB = txs, no leios cert (and optional peras or other things)
• CertRB = no txs, leios cert (and optional peras or other things)

An "Endorser block" (EB) also has an invalid txs index, but otherwise just contains transaction hashes. One could inline those transactions and call the inlined structure the EB.

Yes, EBs would extend an RB (that announced the EB) and be followed by a CertRB (that certifies the EB).

It's currently not settled how we'd be validating EBs (by the ledger). A first sketch just folds calls to ApplyTx (mempool API) to update the ledger state when we see a CertRB. See this, very recent prototype code:

• Call to validate the EB txs (after loading them from disk and doing UTxO-HD) https://github.com/IntersectMBO/ouroboros-consensus/pull/2068/changes#diff-728ab9cd7036ec19e2f2c7d1836121ab14bdf1d3a4983238caab27042e8d3916R548
• This results in this call to the ledger here https://github.com/IntersectMBO/ouroboros-consensus/pull/2068/changes#diff-3a235edac184289e0b719564cdb5256ce2af015c8b34a4ce27c192b81220c888R177

[lehins]

Is there any upper or lower limit on the size of certificate, aside from block body size limit?

[ch1bo]

For leios (you commented on peras here), certs will be 48 bytes for the signature + committee size / 8 bytes + cbor overhead. The maximum committee size would be all registered pools ~ 3000 - typically it would rather be < 1000. So the maximum you can expect is 429B and typical 178B.