Nori 2

Market.sol currently allows for RestrictedNORI to fail to be minted for a supplier if their address is not ERC1155 compatible during the Removal purchasing workflow (see the try catch block in the fulfillOrderXXX() functions). Nori’s plan is to allow for suppliers to have the failed-to-be-minted RestrictedNORI minted to a different address for the suppliers.

This plan isn’t currently achievable with the code as written. RestrictedNORI.sol doesn’t allow for RestrictedNORI to be minted to an arbitrary address as the mint() function on line 451 pulls the receiver for the mint from the removalID's encoding:

address supplierAddress = RemovalIdLib.supplierAddress({
    removalId: removalId
  });
super._mint({to: supplierAddress, id: projectId, amount: amount, data: ""});

Remediations to Consider:

• Adding a function to RestrictedNORI.sol with a parameter for the mint receiver.

  Note: we’d also like to recommend that this function only be able to mint the amount of RestrictedNORI which corresponds to the amount of RestrictedNORI which failed to be minted in the Market.sol workflow. This could be achieved by recording in RestrictedNORI.sol the amount of RestrictedNORI that should’ve been minted during the catch of the try-catch blocks. This would promote safer accounting and prevent Nori from accidentally minting too-much RestrictedNORI for a supplier.

• Ensuring that suppliers are aware that they should use addresses which are able to handle ERC1155 tokens.

Nori’s Certificate contract is intended to show that the Certificate-NFTs are backed by Removals. Currently, there isn’t a way to easily validate on-chain that the Certificate contract is properly backed.

For example, after release events occur which release Removals that were backing the Certificates, it’s hard to show that the Certificate contract is no longer properly backed. This will make it harder to show in the future, once replacement logic is written, that the Certificate contract and its Certificate-NFTs are once again properly backed.

Remediations to consider:

• Adding accounting variables to show how many Removals are missing from the Certificate’s backing.

There is no guarantee that the IERC20WithPermit _purchasingToken will inherit OZ’s ERC20 which reverts on failure to transfer. The transfer could be unsuccessful and return false, and the recipient will still be minted a Certificate token even though the removal was not successfully purchased.

Checking return values is a good practice to prevent unforeseeable situations, like USDC upgrading their contracts to an implementation which returns false instead of reverting.

Remediations to Consider:

• Consider checking the return value of _purchasingToken.transferFrom() so that suppliers are guaranteed to receive their earned tokens and the recipient is not minted a Certificate token that is unearned.

The only difference between the two functions is the following in the without-fee variant on lines 1326-1330:

_purchasingToken.transferFrom({ 
  from: from, 
  to: _noriFeeWallet, 
  amount: this.calculateNoriFee(removalAmounts[i])  
});

Remediations to consider:

• Lifting this logic outside of the function to be done once on the total certificateAmount instead of on the individual supplier removal amounts. This would allow the _fulfillOrder() logic to be re-used.

Remediations to consider:

• Using OpenZeppelin’s MathUpgradeable library instead.

In Certificate.sol, there are 2 functions that are missing comments regarding purchasingTokenAddress and priceMultiple:

1. _receieveRemovalBatch()
   • This function accepts recipient, certificateAmount, removalsIds, removalAmounts, purchasingTokenAddress, and priceMultiple as parameters. However, there are missing Natspec @param tags for purchasingTokenAddress and priceMultiple.
2. onERC1155BatchReceived()
   • This function accepts data as a parameter which encodes recipient, certificateAmount, purchasingTokenAddress, and priceMultiple. However, the Natspec comment does not mention the purchasingTokenAddress or priceMultiple, and instead states: @param data The bytes that encode the certificate's recipient address and total amount.

Remediations to consider:

• Consider expanding the comments to include information on purchasingTokenAddress and priceMultiple.

RestrictedNORI.sol’s documentation states:

It is possible to create more than one schedule per owner address and also to transfer full or partial restricted balances between addresses.

However, restricted Nori token transfers are disabled as of this update.

Remediation to Consider:

• Update the spec to mention that restricted Nori balances cannot be transferred, yet it might be possible in a future release.

Currently, Market.sol’s _permit() function requires that the transaction initiator also be the signer of the signed message:

_purchasingToken.permit({
    owner: _msgSender(),
    spender: address(this),
    value: amount,
    deadline: deadline,
    v: v,
    r: r,
    s: s
});

This design is slightly different from the typical use cases of signed messages. Many projects allow signed messages to be submitted by accounts other than the message signer to enable other parties to (1) pay for gas costs and (2) allow for other custom business logic.

Nori could use this pattern to enable things like allowing other parties to fund buyers’ gas costs or enabling other accounts besides the MARKET_ADMIN_ROLE to fund the no-fee swap endpoints.

Note, that if this approach is introduced, it should be communicated to users that if they sign messages with the Market contract as the spender of the purchasing tokens, that the user is giving permission for a purchase to be made with the amount of permitted token in Market.sol.