[smtmfft]

Summary

• align gaiko2's Shasta manifest decoder with taikoxyz/taiko-mono#22173
• bump taiko-geth to the v2.7.0 commit used by that change (8e98046bfd6a)
• reject transaction encodings that the execution engine cannot decode before retaining a source
• add all 136 canonical manifest-decoding vectors plus whole-source fallback and source-isolation coverage

The validation is intentionally not fork-gated. If any transaction in a decoded source has an incompatible encoding, the entire source follows the existing default-source path; signer recovery and execution validity remain the execution engine's responsibility.

No custom zlib behavior or decompression cap is added. The shared fixtures cover complete/truncated streams, dictionaries, trailing bytes and second streams, strict RLP framing, numeric boundaries, typed parity, and blob sidecar wrappers.

Validation

• RED against the previous decoder: 37 canonical F9 cases retained incompatible transactions; the whole-source fallback assertion also failed
• go test -count=1 ./internal/prover -run '^TestManifestVectors' — passed, all 136 vectors
• go test -count=1 ./internal/prover — passed
• go test -count=1 ./... — passed, all five packages
• go vet ./... — passed
• go mod verify — passed
• repository-wide gofmt -l — clean
• go test -race -count=1 ./cmd/gaiko2 ./internal/api ./internal/tee — passed
• git diff --check — passed
• independent adversarial review — passed with no findings
• independent behavioral verification — passed, including representative zlib/framing/overflow/sidecar cases and existing blob-integrity hard errors

This PR only changes source and tests. It does not build, register, or deploy a new TEE image; the resulting enclave measurement will be handled by the release flow.

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Note

Medium Risk
Changes L2 derivation/prover manifest handling on the critical path from blob data to executed blocks; behavior shifts for previously retained hostile encodings, though extensive vectors and default-source fallback limit blast radius.

Overview
Aligns Shasta blob manifest decoding with taiko-mono by bumping the taiko-geth replace to commit 8e98046bfd6a and adding post-RLP transaction encoding checks in decodeManifestPayload.

New validateManifestTransactions rejects sources whose txs use unsupported types, out-of-range numeric fields, invalid legacy v / typed parity, or blob sidecar wrappers—one bad tx invalidates the whole source, which then follows the existing default-manifest path (same as other decode failures). Signer recovery and execution validity are still left to the engine.

Adds 136 canonical derivation vectors (manifest_cases.json plus TestManifestVectors and follow-on tests for whole-source defaulting, neighbor preservation, forced-inclusion multi-block behavior, and late invalid txs).

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Approved: Cursor Bugbot completed successfully with no findings that need human review. No additional reviewers were assigned.

  

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[davidtaikocha]

Reviewed against taiko-mono#22173 (merge commit aa3a24f5). Approving.

Verified

• internal/prover/transaction_encoding.go has the same logic as upstream packages/taiko-client/driver/chain_syncer/event/derivation/transaction_encoding.go. Only names, blank lines and doc comments differ.
• The call site is equivalent to upstream source_fetcher.go:
  • every validation failure falls back to the default source (upstream also logs a warning);
  • host-integrity blob errors stay hard errors;
  • decodeManifestPayload is still the only place source bytes are decoded.
• testdata/derivation_vectors/manifest_cases.json is byte-identical to upstream (sha256 c4c040c6…4f62d223).
• taiko-geth 4e001283f488 → 8e98046bfd6a is the v2.7.0 tag and a direct child of the old pin. The diff is only CHANGELOG.md and .release-please-manifest.json, so none of the linked go-ethereum packages change.
• go test ./internal/prover passes on go1.24.11, go1.26.0 and go1.27.1, with 142/142 vector tests each time. The compress/zlib and flate reader code is effectively identical across those versions. ego's 1.26.1 was not run directly.
• Mutation testing: removing any check, or moving its bound by one, fails the vector tests. The only exceptions are branches the geth decoder already enforces: the default: type arm, v < 35, and Sign() < 0.

Non-blocking follow-ups (test-only, so no enclave measurement impact)

1. Positional coverage. Every invalid vector puts the bad tx last in the last block. A regression that checks only the last tx or block, or the classic err = overwrite in the loop, would pass all 383 prover tests. These cases would catch it, ideally added upstream in generate.go so all three decoders get them:
   • bad tx then valid tx in the same block
   • bad block 0 then valid block 1
   • sidecar tx then valid tx
2. EIP-155 legacy overflow. All legacy overflow vectors use v=27, so EIP-155 legacy txs aren't exercised for the fee, value and r/s bounds.
3. Forced-inclusion variants. Upstream's isolation test also runs type2_parity_2, type2_control and late_bad_transaction as forced-inclusion sources. Here only two_valid_blocks runs as forced.
4. Nits:
   • The doc comment on validateManifestTransactionEncoding drops upstream's precise wording ("the Rust manifest decoder and alethia-reth's execution transaction decoder"). In gaiko2 the manifest decoder is geth, which accepts all of these encodings, so the generic wording is misleading.
   • The fixture could record its provenance (upstream commit + sha256).
   • ...DefaultWholeSourceAndPreserveNeighbor doesn't put two sources in one proposal.
   • vector := vector is redundant on Go ≥ 1.22.

Rollout notes

• No fork gate, consistent with upstream. Upstream validated local driver behaviour, not historical replay. Before registering the new MRENCLAVE, it's worth scanning mainnet/Hoodi Shasta proposals for any source that would now fall back to the default.
• raiko2 pin. raiko2 release/providers.toml (#268) pins gaiko2 a88ae8b4, this PR's head. Its release tooling runs git clone then git checkout <sha>. Since this PR is being squash-merged, please keep the fix/align-manifest-decoding branch until raiko2 is re-pinned to the squash commit on main. The tree is identical, so the MRENCLAVE is the same.