Ithaca account

[Dargon789]

Summary by Sourcery

Add Merkle tree–based signature support to IthacaAccount and extend the wrapped signature format, along with corresponding tests and benchmarks.

New Features:

• Support Merkle proof–based signature verification in IthacaAccount via a wrapped Merkle root signature.
• Introduce a benchmark covering ERC20 transfers via the orchestrator using passkey-based authorization.

Enhancements:

• Extend the wrapped signature encoding to include a flag for Merkle-based verification alongside the prehash flag.
• Simplify EIP-712 domain handling by only reading the verifyingContract from the domain tuple.

Tests:

• Add fuzz tests for Merkle proof–backed signatures, including invalid proof, tampered proof, and wrong-root scenarios.
• Update existing tests and helpers to use the extended signature encoding with the Merkle flag placeholder.

[snyk-io]

✅ Snyk checks have passed. No issues have been found so far.

Status	Scan Engine	Critical	High	Medium	Low	Total (0)
✅	Open Source Security	0	0	0	0	0 issues

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[sourcery-ai]

Reviewer's Guide

Adds Merkle tree–based signature support to IthacaAccount, updates the wrapped signature encoding to include a merkle flag, introduces tests for Merkle signatures and a new benchmark for passkey-based ERC20 transfers via the orchestrator, and adjusts existing tests and domain handling accordingly.

Sequence diagram for merkle-based signature validation in IthacaAccount

sequenceDiagram
    participant Caller
    participant IthacaAccount
    participant MerkleProofLib
    participant ECDSA

    Caller->>IthacaAccount: unwrapAndValidateSignature(digest, wrappedSignature)
    activate IthacaAccount
    IthacaAccount->>IthacaAccount: parse keyHash, prehashFlag, merkleFlag
    alt prehashFlag is true
        IthacaAccount->>IthacaAccount: digest = EfficientHashLib.sha2(digest)
    end
    alt merkleFlag is true
        IthacaAccount->>IthacaAccount: _verifyMerkleSig(digest, innerSignature)
        activate IthacaAccount
        IthacaAccount->>IthacaAccount: decode proof, root, rootSig from innerSignature
        IthacaAccount->>MerkleProofLib: verifyCalldata(proof, root, digest)
        activate MerkleProofLib
        MerkleProofLib-->>IthacaAccount: isMerkleValid
        deactivate MerkleProofLib
        alt isMerkleValid
            IthacaAccount->>IthacaAccount: unwrapAndValidateSignature(root, rootSig)
            note right of IthacaAccount: Recursive validation of root signature
            IthacaAccount-->>Caller: (isValid, keyHash)
        else isMerkleValid is false
            IthacaAccount-->>Caller: (false, 0)
        end
        deactivate IthacaAccount
    else merkleFlag is false
        IthacaAccount->>IthacaAccount: getKey(keyHash)
        IthacaAccount->>ECDSA: recoverCalldata(digest, innerSignature)
        activate ECDSA
        ECDSA-->>IthacaAccount: signer
        deactivate ECDSA
        IthacaAccount-->>Caller: (isValid, keyHash)
    end
    deactivate IthacaAccount

Loading

Updated class diagram for IthacaAccount merkle signature support

classDiagram
    class IthacaAccount {
        +unwrapAndValidateSignature(digest bytes32, signature bytes) bool isValid
        -_verifyMerkleSig(digest bytes32, signature bytes) bool isValid
        +eip712Domain() string name
        <<implements>> IIthacaAccount
        <<inherits>> EIP712
        <<inherits>> GuardedExecutor
    }

    class IIthacaAccount
    class EIP712
    class GuardedExecutor

    class MerkleProofLib {
        +verifyCalldata(proof bytes32[], root bytes32, leaf bytes32) bool
    }

    class LibBytes {
        +loadCalldata(data bytes, index uint256) bytes32
        +truncatedCalldata(data bytes, index uint256) bytes
    }

    class EfficientHashLib {
        +sha2(input bytes32) bytes32
    }

    class ECDSA {
        +recoverCalldata(digest bytes32, signature bytes) address
    }

    IthacaAccount ..> MerkleProofLib : uses
    IthacaAccount ..> LibBytes : uses
    IthacaAccount ..> EfficientHashLib : uses
    IthacaAccount ..> ECDSA : uses
    IthacaAccount ..|> IIthacaAccount
    IthacaAccount --|> EIP712
    IthacaAccount --|> GuardedExecutor

Loading

File-Level Changes

Change	Details	Files
Add Merkle tree–based signature verification path to IthacaAccount and extend wrapped signature format with a merkle flag.	Import MerkleProofLib for Merkle proof verification using calldata Implement internal _verifyMerkleSig that decodes proof/root/rootSig from the inner signature using memory-safe assembly and verifies the leaf digest against the Merkle root Update unwrapAndValidateSignature to treat wrapped signatures as abi.encode(innerSignature, keyHash, prehashFlag, merkleFlag), parse the new merkle flag, and dispatch to _verifyMerkleSig when set Bump the EIP712 version string of the account contract from 0.5.10 to 0.5.11	src/IthacaAccount.sol
Align all test-side signature helpers and call sites with the new wrapped signature encoding and add Merkle-signature coverage.	Update P256, secp256k1, multi-sig, and test-intent helper encoders to append an extra zero-valued merkle flag byte after the prehash flag when constructing signatures Adjust various tests that fabricate junk or simulation signatures to include the additional merkle flag byte Simplify eip712Domain tuple unpacking in Account tests to only use verifyingContract	test/Base.t.sol test/Account.t.sol test/Orchestrator.t.sol test/SimulateExecute.t.sol
Introduce fuzz test for Merkle-based signatures and a new benchmark for ERC20 transfers via the orchestrator using a passkey.	Add Account test that builds a random Merkle tree of digests, wraps a valid leaf digest under a Merkle-based wrapped signature, and asserts correct verification, rejection of non-members, and resistance to tampered proofs and roots Add orchestrator benchmark that configures a passkey-authorized delegated EOA with ERC20 permissions and measures gas for an ERC20 transfer intent signed with the passkey	test/Account.t.sol test/Benchmark.t.sol
Add IDE project metadata files (IntelliJ IDEA) to the repository.	Introduce .idea configuration and module files for the project, including code style, markdown, and VCS mappings	.idea/.gitignore .idea/account.iml .idea/caches/deviceStreaming.xml .idea/codeStyles/Project.xml .idea/codeStyles/codeStyleConfig.xml .idea/copilot.data.migration.ask2agent.xml .idea/markdown.xml .idea/modules.xml .idea/vcs.xml

Possibly linked issues

• Chore bump contract versions due to bytecode changes  #60: PR exactly implements the issue’s Merkle signature support, wrapped-signature merkle flag, tests updates, and version bump.
• Fix tests account #30: PR adds Merkle-proof signature verification, extends wrapped signature format, adjusts EIP712 domain use, and updates tests/benchmarks.
• Legion rouge #41: The PR implements the Merkle verification flow, new signature encoding, tests, and version bump exactly as described.

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[gemini-code-assist]

Code Review

This pull request adds Merkle signature verification to the IthacaAccount contract, allowing for batch signature validation, and increments the version to 0.5.11. The changes include the addition of a _verifyMerkleSig function, updates to the signature unwrapping logic to handle a new Merkle flag, and new fuzz tests. The review feedback recommends replacing manual assembly with abi.decode for safer calldata handling, adding a length check to prevent potential underflows during signature parsing, and correcting documentation regarding the signature format. Additionally, the reviewer advised removing IDE-specific configuration files from the repository.

[sourcery-ai]

Hey - I've found 1 issue, and left some high level feedback:

• The ABI decoding in _verifyMerkleSig looks incorrect for root: calldataload(add(signature.offset, 0x20)) reads the offset to the root, not the root value; you should first load the root’s offset (like you do for rootSigOffset) and then read the value from that offset.
• Because _verifyMerkleSig calls unwrapAndValidateSignature(root, rootSig), a merkle-wrapped rootSig can cause unbounded recursion; consider explicitly rejecting or stripping the merkle flag for rootSig to prevent recursive merkle verification.
• The .idea project files added in this PR are editor-specific and probably shouldn’t be committed; it would be better to remove them and add the .idea directory to .gitignore if needed.

Prompt for AI Agents

Please address the comments from this code review:

## Overall Comments
- The ABI decoding in `_verifyMerkleSig` looks incorrect for `root`: `calldataload(add(signature.offset, 0x20))` reads the offset to the root, not the root value; you should first load the root’s offset (like you do for `rootSigOffset`) and then read the value from that offset.
- Because `_verifyMerkleSig` calls `unwrapAndValidateSignature(root, rootSig)`, a merkle-wrapped `rootSig` can cause unbounded recursion; consider explicitly rejecting or stripping the merkle flag for `rootSig` to prevent recursive merkle verification.
- The `.idea` project files added in this PR are editor-specific and probably shouldn’t be committed; it would be better to remove them and add the `.idea` directory to `.gitignore` if needed.

## Individual Comments

### Comment 1
<location path="src/IthacaAccount.sol" line_range="523-525" />
<code_context>
+        return (false, bytes32(0));
+    }
+
     /// @dev Returns if the signature is valid, along with its `keyHash`.
     /// The `signature` is a wrapped signature, given by
-    /// `abi.encodePacked(bytes(innerSignature), bytes32(keyHash), bool(prehash))`.
+    /// `abi.encode(bytes(innerSignature), bytes32(keyHash), bool(prehash), bool(merkle))`.
     function unwrapAndValidateSignature(bytes32 digest, bytes calldata signature)
         public
</code_context>
<issue_to_address>
**issue (bug_risk):** The documented wrapped signature encoding does not match the actual packed layout used in the code.

The implementation uses a packed layout `bytes(innerSignature) || bytes32(keyHash) || bytes1(prehash) || bytes1(merkle)`, computing `n = signature.length - 0x22` and reading the last two bytes as flags. This does not match `abi.encode(bytes, bytes32, bool, bool)`, which uses a head with dynamic offsets and places the `bytes` payload later. Leaving the docstring as `abi.encode(...)` will likely cause integrators to construct incompatible signatures. Please either document the packed layout explicitly or change the implementation to use real ABI encoding and decode accordingly.
</issue_to_address>

Fix all in Cursor

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Project	Deployment	Actions	Updated (UTC)
legion	Ready	Preview, Comment	Apr 30, 2026 11:20am