Omniscia Boson Protocol Audit

ExchangeRedeemBase Code Style Findings

ExchangeRedeemBase Code Style Findings

ERB-01C: BPIP-13 Mismatch of Voucher Burning Approach

Description:

The BPIP-13 document specifies that the _computeBurnTokenId function is overridden by the ExchangeHandlerFacet implementation, however, no such function exists or is overridden.

Example:

contracts/protocol/bases/ExchangeRedeemBase.sol
32function burnVoucher(Exchange storage _exchange) internal {
33    // Cache protocol lookups for reference
34    ProtocolLib.ProtocolLookups storage lookups = protocolLookups();
35

36    // Decrease the voucher count
37    lookups.voucherCount[_exchange.buyerId]--;
38

39    // Burn the voucher
40    uint256 offerId = _exchange.offerId;
41    (, Offer storage offer) = fetchOffer(offerId);
42    IBosonVoucher bosonVoucher = IBosonVoucher(getCloneAddress(lookups, offer.sellerId, offer.collectionIndex));
43

44    uint256 tokenId = _exchange.id;
45    if (tokenId >= EXCHANGE_ID_2_2_0) tokenId |= (offerId << 128);
46    bosonVoucher.burnVoucher(tokenId);
47}

Recommendation:

We advise the BPIP-13 specification to be updated to match the ExchangeRedeemBase approach of using the immutable exchange ID versioning system.

Alleviation (8fccc2716047809e4bc7786c95d346e5c61b2896):

The BPIP-13 definition has been updated to match the code's implementation, addressing this exhibit.

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