Ithaca

[Dargon789]

Summary by Sourcery

Add Merkle tree–based wrapped signature support to IthacaAccount and extend tests and benchmarks to cover the new signature format and behavior.

New Features:

• Support verification of Merkle tree–based wrapped signatures in IthacaAccount via a new merkle flag and helper verifier.

Enhancements:

• Extend wrapped signature encoding to include a merkle-indicator byte across helpers and tests.
• Increment the IthacaAccount EIP-712 version identifier to 0.5.11.

Tests:

• Add fuzz tests for Merkle-based signatures, including valid proofs, invalid digests, tampered proofs, and incorrect roots.
• Add a benchmark covering ERC20 transfers via the orchestrator using a passkey with updated signature formatting.
• Update existing tests and gas-estimation helpers to use the extended wrapped signature format.

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Project	Deployment	Actions	Updated (UTC)
legion	Ready	Preview, Comment	Apr 11, 2026 1:27pm

[sourcery-ai]

Reviewer's Guide

Adds Merkle-based signature support to IthacaAccount, extends the wrapped signature format with a merkle flag, and updates tests/benchmarks (including new Merkle proof tests and a passkey benchmark) to use the new encoding while bumping the account version.

Sequence diagram for merkle-based signature validation

sequenceDiagram
    actor Caller
    participant IthacaAccount
    participant MerkleProofLib
    participant ECDSA
    participant EfficientHashLib

    Caller->>IthacaAccount: unwrapAndValidateSignature(digest, signature)
    alt selfOperation
        IthacaAccount->>ECDSA: recoverCalldata(digest, signature)
        IthacaAccount-->>Caller: isValid, keyHash
    else wrappedSignature
        IthacaAccount->>IthacaAccount: parse keyHash, prehashFlag, merkleFlag
        alt prehashFlag != 0
            IthacaAccount->>EfficientHashLib: sha2(digest)
            EfficientHashLib-->>IthacaAccount: digest
        end
        alt merkleFlag != 0
            IthacaAccount->>IthacaAccount: _verifyMerkleSig(digest, innerSignature)
            IthacaAccount->>MerkleProofLib: verifyCalldata(proof, root, digest)
            alt proofValid
                IthacaAccount->>IthacaAccount: unwrapAndValidateSignature(root, rootSig)
                IthacaAccount-->>Caller: isValid, keyHash
            else invalidProof
                IthacaAccount-->>Caller: false, 0
            end
        else nonMerkle
            IthacaAccount->>ECDSA: recoverCalldata(digest, innerSignature)
            ECDSA-->>IthacaAccount: signer
            IthacaAccount-->>Caller: isValid, keyHash
        end
    end

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Updated class diagram for IthacaAccount signature verification

classDiagram
    class IthacaAccount {
        +unwrapAndValidateSignature(digest, signature)
        -_verifyMerkleSig(digest, signature)
        +getKey(keyHash)
    }

    class MerkleProofLib {
        +verifyCalldata(proof, root, leaf)
    }

    class LibBytes {
        +loadCalldata(data, offset)
        +truncatedCalldata(data, newLength)
    }

    class EfficientHashLib {
        +sha2(digest)
    }

    class ECDSA {
        +recoverCalldata(digest, signature)
    }

    IthacaAccount ..> MerkleProofLib : uses
    IthacaAccount ..> LibBytes : uses
    IthacaAccount ..> EfficientHashLib : uses
    IthacaAccount ..> ECDSA : uses

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Flow diagram for unwrapAndValidateSignature with merkle support

flowchart TD
    A[unwrapAndValidateSignature] --> B{isSelfOperation}
    B -->|yes| C[recoverCalldata and compare to self]
    C --> Z[return isValid, keyHash]
    B -->|no| D[decode keyHash, prehashFlag, merkleFlag]
    D --> E{prehashFlag != 0}
    E -->|yes| F[sha2 hash of digest]
    E -->|no| G[keep original digest]
    F --> H{merkleFlag != 0}
    G --> H
    H -->|yes| I[_verifyMerkleSig with digest and innerSignature]
    I --> J{merkle proof valid}
    J -->|yes| K[unwrapAndValidateSignature with root and rootSig]
    K --> Z
    J -->|no| L[return false and zero keyHash]
    H -->|no| M[getKey and validate nonMerkle signature]
    M --> Z

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File-Level Changes

Change	Details	Files
Introduce Merkle-tree based signature verification path in IthacaAccount and extend wrapped signature format with a merkle flag.	Import MerkleProofLib and add internal _verifyMerkleSig that ABI-decodes proof/root/rootSig from calldata and verifies Merkle membership before validating a signature on the Merkle root via unwrapAndValidateSignature. Modify unwrapAndValidateSignature to interpret signatures as abi.encode(innerSignature, keyHash, bool(prehash), bool(merkle)), adjust index math, read the new merkle flag, and delegate to _verifyMerkleSig when set; otherwise preserve existing behavior. Bump IthacaAccount EIP712 version string from 0.5.10 to 0.5.11 to reflect the new signature semantics.	src/IthacaAccount.sol
Add tests for Merkle signatures and update test helpers and callers to the new wrapped signature layout with a merkle flag.	Add Murky Merkle library import and a fuzz test that constructs a Merkle tree of digests, builds a valid proof, and checks unwrapAndValidateSignature for valid, invalid-digest, tampered-proof, and wrong-root cases using the merkle flag. Update Base.t.sol signature helper functions (_p256Sig, _secp256k1Sig, _multiSig, and gas-estimation helpers) to append an extra uint8(0) merkle flag to all constructed signatures so existing tests use the new encoding without merkle behavior. Adjust tests in Orchestrator.t.sol and SimulateExecute.t.sol that construct junk/simulation signatures to include the additional merkle flag byte.	test/Account.t.sol test/Base.t.sol test/Orchestrator.t.sol test/SimulateExecute.t.sol
Extend benchmarks to cover passkey-based ERC20 transfer via the Porto orchestrator using the updated signature format.	Add testERC20TransferViaPortoOrchestratorWithPasskey benchmark that creates a delegated EOA, authorizes a passkey, configures execution/spend limits, signs an orchestrator intent, and executes it through the orchestrator, asserting token transfer success. Ensure the new benchmark uses the same wrapped signature helpers and gas-metering pattern as existing benchmarks for apples-to-apples comparisons.	test/Benchmark.t.sol
Add IDE project configuration files (IntelliJ IDEA).	Introduce .idea project metadata and .gitignore entries for IDEA to the repository.	.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

• Legion rouge #41: PR implements the Merkle signature path, wrapped-signature flags, and version bump exactly as described in the issue diagrams.
• Legion rouge #41: The PR adds MerkleProofLib, wrapped-signature merkle flag, tests, and version bump exactly matching the issue’s design.
• Fix tests account #30: The PR introduces Merkle-backed wrapped signature verification, updated encoding, tests, and benchmarks exactly as outlined in the issue.

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[snyk-io]

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

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✅	Open Source Security	0	0	0	0	0 issues

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[mergify]

⚠️ The sha of the head commit of this PR conflicts with #48. Mergify cannot evaluate rules on this PR. Once #48 is merged or closed, Mergify will resume processing this PR. ⚠️

[sourcery-ai]

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

• The ABI decoding in _verifyMerkleSig looks incorrect for a bytes calldata containing abi.encode(bytes32[] proof, bytes32 root, bytes rootSig): signature.offset points to the bytes length, not to the start of the encoded tuple, so you likely need to add 0x20 to get to the first word of the abi.encode payload and then compute the proof/root/rootSig offsets from there rather than using calldataload(signature.offset) as an offset.
• The updated wrapped-signature layout in unwrapAndValidateSignature appears inconsistent: after setting n = signature.length - 0x22 you truncate signature to length n but then still read the prehash and merkle flags at indices n + 1 and n + 2, which now lie beyond the truncated slice and will not line up with the flag bytes appended after keyHash; consider decoding the trailing [keyHash, prehash, merkle] before truncating or computing indices relative to the original slice.
• The .idea directory and related IDE project files have been added to the repo; these are typically editor-local and should be removed from version control and covered by a top-level .gitignore instead.

Prompt for AI Agents

Please address the comments from this code review:

## Overall Comments
- The ABI decoding in `_verifyMerkleSig` looks incorrect for a `bytes calldata` containing `abi.encode(bytes32[] proof, bytes32 root, bytes rootSig)`: `signature.offset` points to the bytes length, not to the start of the encoded tuple, so you likely need to add 0x20 to get to the first word of the `abi.encode` payload and then compute the proof/root/rootSig offsets from there rather than using `calldataload(signature.offset)` as an offset.
- The updated wrapped-signature layout in `unwrapAndValidateSignature` appears inconsistent: after setting `n = signature.length - 0x22` you truncate `signature` to length `n` but then still read the prehash and merkle flags at indices `n + 1` and `n + 2`, which now lie beyond the truncated slice and will not line up with the flag bytes appended after `keyHash`; consider decoding the trailing `[keyHash, prehash, merkle]` before truncating or computing indices relative to the original slice.
- The `.idea` directory and related IDE project files have been added to the repo; these are typically editor-local and should be removed from version control and covered by a top-level `.gitignore` instead.

## Individual Comments

### Comment 1
<location path="src/IthacaAccount.sol" line_range="525-528" />
<code_context>
     /// @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):** Wrapped signature decoding does not align with `abi.encode(...)` layout and still assumes packed trailing bytes.

The new docstring describes an `abi.encode` layout, but the decoding still treats the data as a packed blob with the last 34 bytes holding `keyHash` + 2 flag bytes. In an `abi.encode` layout, `innerSignature` is dynamic and the three trailing fields each occupy full 32‑byte words; their positions depend on the ABI head/tail structure, so `n = signature.length - 0x22` and reading at `n`, `n+1`, `n+2` will not reliably map to `keyHash`, `prehash`, and `merkle`. This mismatch will cause incorrect decoding.

Please either:
- Restore and document a packed layout (e.g. `abi.encodePacked(bytes(innerSignature), bytes32(keyHash), bool(prehash), bool(merkle))`) that matches the current decoding pattern, or
- Keep `abi.encode` and implement proper ABI decoding (parse the dynamic `bytes` first, then read the subsequent 32‑byte words by offset).

Until these are aligned, signature validation is not reliable.
</issue_to_address>

Fix all in Cursor

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[gemini-code-assist]

Code Review

This pull request introduces Merkle tree signature verification to the IthacaAccount contract, enabling the validation of multiple digests against a single root signature. Key changes include the addition of the _verifyMerkleSig internal function, updates to the signature unwrapping logic to handle a new Merkle flag, and the inclusion of fuzz tests and benchmarks. The code review identified several security and robustness concerns: a potential calldata leak in the assembly block due to missing length validation, a fragile flag extraction pattern during signature truncation, and the risk of stack overflow or gas exhaustion from nested Merkle signature calls.

[mergify]

⚠️ The sha of the head commit of this PR conflicts with #48. Mergify cannot evaluate rules on this PR. Once #48 is merged or closed, Mergify will resume processing this PR. ⚠️

[Dargon789]

@Mergifyio refresh

[mergify]

refresh

✅ Pull request refreshed

[mergify]

⚠️ The sha of the head commit of this PR conflicts with #48. Mergify cannot evaluate rules on this PR. Once #48 is merged or closed, Mergify will resume processing this PR. ⚠️