feat(abci): impl Hashable for ValidatorSet

[lklimek]

Issue being fixed or feature implemented

Hash of validators stored in Header.ValidatorsHash and Header.NextValidatorsHash is calculated from quorum
hash and threshold-recovered public key. We need a way to calculate this hash in ABCI app, in order to double-check
consistency of the validator set used in a block.

What was done?

• Ported implementation of merkle tree root calculations from Tenderdash; see Tenderdash sources
• Implemented Hashable interface for ValidatorSet

How Has This Been Tested?

Added unit tests

Breaking Changes

None

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added or updated relevant unit/integration/functional/e2e tests
• I have made corresponding changes to the documentation

For repository code-owners and collaborators only

• I have assigned this pull request to a milestone

Summary by CodeRabbit

• New Features

  • Added Merkle tree implementation for cryptographic operations
  • Introduced new cryptographic signature and hashing capabilities for validator sets
  • Enhanced library with optional crypto-related functionality

• Documentation

  • Added implementation details for Merkle root hash calculation
  • Included test cases for verifying cryptographic operations

[coderabbitai]

Walkthrough

The pull request introduces cryptographic functionality to the ABCI library by adding a new module for Merkle tree implementation and enhancing signature-related operations. These changes are conditionally compiled under the "crypto" feature flag, allowing for optional inclusion of these components. The new module provides methods for calculating Merkle root hashes, implements the Hashable trait for ValidatorSet, and supports various cryptographic operations.

Changes

File	Changes
abci/src/lib.rs	- Added mod merkle under #[cfg(feature = "crypto")] - Added pub mod signatures under #[cfg(feature = "crypto")]
abci/src/merkle.rs	- Implemented merkle_hash function - Added leaf, inner, and empty_hash helper functions - Included get_split_point utility function - Added test module for Merkle root hash verification
abci/src/signatures.rs	- Implemented Hashable trait for ValidatorSet - Added calculate_msg_hash method - Updated import statements - Added test_validator_set_hash test case

Sequence Diagram

sequenceDiagram
    participant Client
    participant MerkleModule
    participant SignaturesModule

    Client->>MerkleModule: Calculate Merkle Root Hash
    MerkleModule-->>Client: Return Hash

    Client->>SignaturesModule: Calculate Validator Set Hash
    SignaturesModule-->>Client: Return Hash

Loading

Poem

🐰 Merkle trees and signatures dance,
Crypto features now enhance our chance!
Hashing roots with cryptic might,
Validator sets now shine so bright.
CodeRabbit's magic, code so neat! 🔒✨

---

📜 Recent review details

Configuration used: CodeRabbit UI
Review profile: CHILL
Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between f80fb53 and d197f0f.

📒 Files selected for processing (1)

• abci/src/signatures.rs (4 hunks)

🚧 Files skipped from review as they are similar to previous changes (1)

• abci/src/signatures.rs

⏰ Context from checks skipped due to timeout of 90000ms (2)

• GitHub Check: test-all
• GitHub Check: build (debian)

---

Thank you for using CodeRabbit. We offer it for free to the OSS community and would appreciate your support in helping us grow. If you find it useful, would you consider giving us a shout-out on your favorite social media?

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

🪧 Tips

Chat

There are 3 ways to chat with CodeRabbit:

• Review comments: Directly reply to a review comment made by CodeRabbit. Example:
  • I pushed a fix in commit <commit_id>, please review it.
  • Generate unit testing code for this file.
  • Open a follow-up GitHub issue for this discussion.
• Files and specific lines of code (under the "Files changed" tab): Tag @coderabbitai in a new review comment at the desired location with your query. Examples:
  • @coderabbitai generate unit testing code for this file.
  • @coderabbitai modularize this function.
• PR comments: Tag @coderabbitai in a new PR comment to ask questions about the PR branch. For the best results, please provide a very specific query, as very limited context is provided in this mode. Examples:
  • @coderabbitai gather interesting stats about this repository and render them as a table. Additionally, render a pie chart showing the language distribution in the codebase.
  • @coderabbitai read src/utils.ts and generate unit testing code.
  • @coderabbitai read the files in the src/scheduler package and generate a class diagram using mermaid and a README in the markdown format.
  • @coderabbitai help me debug CodeRabbit configuration file.

Note: Be mindful of the bot's finite context window. It's strongly recommended to break down tasks such as reading entire modules into smaller chunks. For a focused discussion, use review comments to chat about specific files and their changes, instead of using the PR comments.

CodeRabbit Commands (Invoked using PR comments)

• @coderabbitai pause to pause the reviews on a PR.
• @coderabbitai resume to resume the paused reviews.
• @coderabbitai review to trigger an incremental review. This is useful when automatic reviews are disabled for the repository.
• @coderabbitai full review to do a full review from scratch and review all the files again.
• @coderabbitai summary to regenerate the summary of the PR.
• @coderabbitai generate docstrings to generate docstrings for this PR. (Beta)
• @coderabbitai resolve resolve all the CodeRabbit review comments.
• @coderabbitai configuration to show the current CodeRabbit configuration for the repository.
• @coderabbitai help to get help.

Other keywords and placeholders

• Add @coderabbitai ignore anywhere in the PR description to prevent this PR from being reviewed.
• Add @coderabbitai summary to generate the high-level summary at a specific location in the PR description.
• Add @coderabbitai anywhere in the PR title to generate the title automatically.

CodeRabbit Configuration File (.coderabbit.yaml)

• You can programmatically configure CodeRabbit by adding a .coderabbit.yaml file to the root of your repository.
• Please see the configuration documentation for more information.
• If your editor has YAML language server enabled, you can add the path at the top of this file to enable auto-completion and validation: # yaml-language-server: $schema=https://coderabbit.ai/integrations/schema.v2.json

Documentation and Community

• Visit our Documentation for detailed information on how to use CodeRabbit.
• Join our Discord Community to get help, request features, and share feedback.
• Follow us on X/Twitter for updates and announcements.

[coderabbitai]

Actionable comments posted: 0

🧹 Nitpick comments (2)

abci/src/merkle.rs (1)

39-50: Add detailed documentation for the get_split_point function.

The bit manipulation logic in this function would benefit from more detailed documentation explaining:

• Why the specific bit operations are used
• How it ensures a balanced tree structure
• The mathematical reasoning behind the implementation

abci/src/signatures.rs (1)

426-473: LGTM! Well-implemented ValidatorSet hashing with comprehensive error handling.

The implementation correctly:

• Extracts and validates the threshold public key
• Handles all public key types (Bls12381, Ed25519, Secp256k1)
• Uses merkle_hash to combine the key with quorum hash

However, consider consolidating the error handling:

     let threshold_public_key_enum = self
         .threshold_public_key
         .as_ref()
-        .ok_or(Error::Canonical("missing threshold public key".to_string()))?;
+        .and_then(|key| key.sum.as_ref())
+        .ok_or_else(|| Error::Canonical("missing threshold public key".to_string()))?;

-    let threshold_public_key = match &threshold_public_key_enum.sum {
-        Some(Bls12381(pk)) => pk,
-        Some(Ed25519(pk)) => pk,
-        Some(Secp256k1(pk)) => pk,
-        None => return Err(Error::Canonical("missing threshold public key".to_string())),
+    let threshold_public_key = match threshold_public_key_enum {
+        Bls12381(pk) => pk,
+        Ed25519(pk) => pk,
+        Secp256k1(pk) => pk,
     };

📜 Review details

Configuration used: CodeRabbit UI
Review profile: CHILL
Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 36999a4 and f80fb53.

📒 Files selected for processing (3)

• abci/src/lib.rs (1 hunks)
• abci/src/merkle.rs (1 hunks)
• abci/src/signatures.rs (4 hunks)

⏰ Context from checks skipped due to timeout of 90000ms (5)

• GitHub Check: test-all
• GitHub Check: docs
• GitHub Check: build (debian)
• GitHub Check: build (alpine)
• GitHub Check: tenderdash

🔇 Additional comments (3)

abci/src/lib.rs (1)

28-32: LGTM!

The new modules are properly feature-gated under the "crypto" flag and follow the codebase's module organization pattern.

abci/src/merkle.rs (1)

1-71: LGTM! Well-implemented Merkle tree functionality.

The implementation correctly ports the Tenderdash Merkle tree logic with:

• Proper prefix handling for leaf and inner nodes
• Correct recursive structure for building the tree
• Comprehensive test coverage with vectors from Tenderdash

The code is well-structured and maintains consistency with the original implementation.

abci/src/signatures.rs (1)

655-684: LGTM! Comprehensive test coverage with real test vectors.

The test case properly verifies the ValidatorSet hash implementation against known good values, ensuring compatibility with the Tenderdash implementation.

[lklimek]

@coderabbitai review

[coderabbitai]

✅ Actions performed

Review triggered.

Note: CodeRabbit is an incremental review system and does not re-review already reviewed commits. This command is applicable only when automatic reviews are paused.

[lklimek]

@coderabbitai review

[coderabbitai]

✅ Actions performed

Review triggered.

Note: CodeRabbit is an incremental review system and does not re-review already reviewed commits. This command is applicable only when automatic reviews are paused.

[shumkov]

👍