fix(dash): normalize PlatformNodeId to canonical byte order at consensus boundary

[QuantumExplorer]

Fixes #887

Problem

PlatformNodeId (#885) held bytes in two different orders depending on construction path, so values from the two paths never compared equal:

• consensus_decode (ProRegTx / ProUpServTx / SML entry platformNodeID) kept the wire bytes as-is — Dash Core serializes the field as a uint160, whose internal blob order is reversed relative to the canonical id.
• from_ed25519_public_key (fix(key-wallet): platform node id is the Tenderdash node ID (SHA256[0..20]), not hash160 #884) produces the canonical forward Tenderdash node id (SHA256(pubkey)[0..20]).

Consequences: key-wallet's provider matching (account_checker.rs) could never recognize a wallet-owned platform node id from a decoded ProRegTx, and Display of a decoded id showed the reversed form matching neither dashmate, Tenderdash, nor explorers.

Fix

Normalize at the consensus boundary so the newtype always holds canonical forward bytes:

• consensus_decode reverses the wire bytes into canonical order.
• consensus_encode reverses back to wire order, so re-encoding is byte-identical to the original wire bytes (payload hashes, SML entry hashes, and merkle roots are unaffected).
• from_ed25519_public_key, Display, FromHex, serde, and the bincode layout are unchanged.

Tests

• consensus_round_trip now uses asymmetric bytes and asserts wire order is the byte-reversal of canonical order.
• New consensus_decode_yields_canonical_order uses the mainnet evonode vector from the issue: wire 8cb97997…7968 decodes to canonical 68794393…b98c and re-encodes byte-identically.
• New decoded_wire_id_matches_derived_id asserts a wire-decoded id equals the id derived from the matching Ed25519 public key — the exact mismatch from the issue.
• Updated the real ProRegTx v2 fixture test (test_payload_version_2_encoding_and_decoding): the decoded id is now the canonical (reversed) form; the existing re-encode assertion confirms wire bytes are unchanged.

Ran: cargo test -p dashcore --all-features, cargo test -p key-wallet --all-features, cargo test -p dash-spv and cargo test -p dash-spv-ffi --test dashd_sync with dashd regtest integration tests — all green. cargo fmt --check and cargo clippy -p dashcore --all-features --all-targets clean.

Note for downstream

• dashpay/platform picks this up via pin bump (per the issue, no downstream workaround was added, so no double-reversal).
• Masternode-list snapshots persisted before this fix stored the wire-reversed bytes in the bincode blob; lists re-synced after this fix hold canonical bytes. Anyone comparing persisted pre-fix ids against freshly derived/decoded ones should re-sync the list.

🤖 Generated with Claude Code

Summary by CodeRabbit

• Bug Fixes

  • Corrected platform node ID encoding and decoding to consistently handle canonical and wire byte order.
  • Improved compatibility when reading and writing versioned provider registration data.
  • Ensured decoded node IDs match their expected canonical representation and preserve accurate round-trip serialization.

• Tests

  • Expanded coverage for node ID conversion, provider registration payloads, and Ed25519-derived identifiers.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: 9a3f990d-30c1-4a1b-b146-d5d487a517ef

📥 Commits

Reviewing files that changed from the base of the PR and between ac8828c and 47bb91e.

📒 Files selected for processing (2)

• dash/src/blockdata/transaction/special_transaction/provider_registration.rs
• dash/src/platform_node_id.rs

---

📝 Walkthrough

Walkthrough

PlatformNodeId now stores canonical forward-order bytes and reverses them only for Dash consensus wire encoding. Documentation and tests were updated, including provider-registration payload expectations and equality with Ed25519-derived identifiers.

Changes

PlatformNodeId normalization

Layer / File(s)	Summary
Canonical storage and consensus encoding dash/src/platform_node_id.rs	Documentation distinguishes canonical bytes from Dash Core wire order, while consensus encoding and decoding reverse the 20-byte identifier at the boundary.
Byte-order regression coverage dash/src/platform_node_id.rs, dash/src/blockdata/transaction/special_transaction/provider_registration.rs	Tests verify canonical decoding, byte-identical round trips, Ed25519-derived identifier equality, and the updated version-2 provider payload value.

Estimated code review effort: 2 (Simple) | ~10 minutes

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly describes the main change: normalizing PlatformNodeId byte order at the consensus boundary.
Linked Issues check	✅ Passed	The changes match #887 by normalizing decode/encode byte order and updating tests to preserve wire round-trips and match derived IDs.
Out of Scope Changes check	✅ Passed	The PR is tightly scoped to PlatformNodeId byte-order normalization and related tests, with no clear unrelated changes.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch claude/issue-887-fix-57947a

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 74.37%. Comparing base (2045cd2) to head (47bb91e).
⚠️ Report is 1 commits behind head on dev.

Additional details and impacted files

@@           Coverage Diff           @@
##              dev     #889   +/-   ##
=======================================
  Coverage   74.37%   74.37%           
=======================================
  Files         327      327           
  Lines       74747    74771   +24     
=======================================
+ Hits        55590    55610   +20     
- Misses      19157    19161    +4     

Flag	Coverage Δ
core	77.29% <100.00%> (+0.03%)	⬆️
ffi	50.30% <ø> (-0.01%)	⬇️
rpc	20.00% <ø> (ø)
spv	91.08% <ø> (-0.04%)	⬇️
wallet	74.40% <ø> (ø)

Files with missing lines	Coverage Δ
...ction/special_transaction/provider_registration.rs	65.65% <100.00%> (ø)
dash/src/platform_node_id.rs	98.82% <100.00%> (+5.38%)	⬆️

... and 5 files with indirect coverage changes