fix(contracts): OZ-L1-M01 Enforced Transactions Signed Off-Chain Are Likely to Fail

[zimpha]

Purpose or design rationale of this PR

This PR fix the bug (M-01 Enforced Transactions Signed Off-Chain Are Likely to Fail) reported by OpenZeppelin. The following are the details:

The EnforcedTxGateway contract allows users to sign a transaction hash that authorizes an L1 to L2 transaction. During the verification of the signature, the signed hash is computed given the sendTransaction function parameters, except for the _queueIndex value, which is fetched as the supposedly following index from the message queue.

Timing this queue index during signing becomes challenging considering the following scenario:

1. User A signs the transaction off-chain for index i .
2. User B queues a transaction unrelated to A, thereby incrementing the queue index to
   i+1.
3. User C tries to submit user A's transaction, which reverts due to the mismatching queue
   indices.

Depending on the activity of the messenger contract and the delay between users A and C, it is likely that this call reverts.

Consider repurposing the queue index to a nonce that is signed as part of the transaction hash by taking it as an additional function parameter. The replayability must therefore be prevented by keeping track of used transaction hashes in a mapping. Also, consider adding an expiration timestamp and chain id to the message such that signed messages are not indefinitely valid and are chain dependent. Otherwise, a signature can be reused for a rollup that follows the same message format and is signed by the same user. It's important to note that the transaction hash should not be constructed over the signature when an OpenZeppelin library version lower than 4.7.3 is used, due to a signature malleability issue.

PR title

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• feat: A new feature
• fix: A bug fix
• perf: A code change that improves performance
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• test: Adding missing tests or correcting existing tests

Deployment tag versioning

Has tag in common/version.go been updated?

• No, this PR doesn't involve a new deployment, git tag, docker image tag
• Yes

Breaking change label

Does this PR have the breaking-change label?

• No, this PR is not a breaking change
• Yes

[github-actions]

LCOV of commit eeb20be during Contracts #1134

Summary coverage rate:
  lines......: 51.3% (894 of 1744 lines)
  functions..: 67.9% (203 of 299 functions)
  branches...: no data found

Files changed coverage rate: n/a