diff options
| -rw-r--r-- | contracts/protocol/CHANGELOG.json | 4 | ||||
| -rw-r--r-- | contracts/protocol/contracts/protocol/AssetProxy/MultiAssetProxy.sol | 14 | ||||
| -rw-r--r-- | contracts/protocol/test/asset_proxy/proxies.ts | 32 |
3 files changed, 46 insertions, 4 deletions
diff --git a/contracts/protocol/CHANGELOG.json b/contracts/protocol/CHANGELOG.json index 2dca9794a..be374d892 100644 --- a/contracts/protocol/CHANGELOG.json +++ b/contracts/protocol/CHANGELOG.json @@ -5,6 +5,10 @@ { "note": "Added LibAddressArray", "pr": 1383 + }, + { + "note": "Add validation and comments to MultiAssetProxy", + "pr": 1455 } ] }, diff --git a/contracts/protocol/contracts/protocol/AssetProxy/MultiAssetProxy.sol b/contracts/protocol/contracts/protocol/AssetProxy/MultiAssetProxy.sol index 42231e73b..377325384 100644 --- a/contracts/protocol/contracts/protocol/AssetProxy/MultiAssetProxy.sol +++ b/contracts/protocol/contracts/protocol/AssetProxy/MultiAssetProxy.sol @@ -33,6 +33,9 @@ contract MultiAssetProxy is function () external { + // NOTE: The below assembly assumes that clients do some input validation and that the input is properly encoded according to the AbiV2 specification. + // It is technically possible for inputs with very large lengths and offsets to cause overflows. However, this would make the calldata prohibitively expensive + // and we therefore do not check for overflows in these scenarios. assembly { // The first 4 bytes of calldata holds the function selector let selector := and(calldataload(0), 0xffffffff00000000000000000000000000000000000000000000000000000000) @@ -145,7 +148,7 @@ contract MultiAssetProxy is let nestedAssetDataLen := calldataload(sub(nestedAssetDataContentsStart, 32)) // Revert if number of elements in `amounts` differs from number of elements in `nestedAssetData` - if iszero(eq(amountsLen, nestedAssetDataLen)) { + if sub(amountsLen, nestedAssetDataLen) { // Revert with `Error("LENGTH_MISMATCH")` mstore(0, 0x08c379a000000000000000000000000000000000000000000000000000000000) mstore(32, 0x0000002000000000000000000000000000000000000000000000000000000000) @@ -181,8 +184,11 @@ contract MultiAssetProxy is let amountsElement := calldataload(add(amountsContentsStart, i)) let totalAmount := mul(amountsElement, amount) - // Revert if multiplication resulted in an overflow - if iszero(eq(div(totalAmount, amount), amountsElement)) { + // Revert if `amount` != 0 and multiplication resulted in an overflow + if iszero(or( + iszero(amount), + eq(div(totalAmount, amount), amountsElement) + )) { // Revert with `Error("UINT256_OVERFLOW")` mstore(0, 0x08c379a000000000000000000000000000000000000000000000000000000000) mstore(32, 0x0000002000000000000000000000000000000000000000000000000000000000) @@ -230,7 +236,7 @@ contract MultiAssetProxy is // Only load `assetProxy` if `currentAssetProxyId` does not equal `assetProxyId` // We do not need to check if `currentAssetProxyId` is 0 since `assetProxy` is also initialized to 0 - if iszero(eq(currentAssetProxyId, assetProxyId)) { + if sub(currentAssetProxyId, assetProxyId) { // Update `assetProxyId` assetProxyId := currentAssetProxyId // To lookup a value in a mapping, we load from the storage location keccak256(k, p), diff --git a/contracts/protocol/test/asset_proxy/proxies.ts b/contracts/protocol/test/asset_proxy/proxies.ts index c4bd95905..89c8b390c 100644 --- a/contracts/protocol/test/asset_proxy/proxies.ts +++ b/contracts/protocol/test/asset_proxy/proxies.ts @@ -12,6 +12,7 @@ import { import { artifacts as tokensArtifacts, DummyERC20TokenContract, + DummyERC20TokenTransferEventArgs, DummyERC721ReceiverContract, DummyERC721TokenContract, DummyMultipleReturnERC20TokenContract, @@ -22,6 +23,7 @@ import { assetDataUtils } from '@0x/order-utils'; import { RevertReason } from '@0x/types'; import { BigNumber } from '@0x/utils'; import * as chai from 'chai'; +import { LogWithDecodedArgs } from 'ethereum-types'; import * as _ from 'lodash'; import { ERC20ProxyContract } from '../../generated-wrappers/erc20_proxy'; @@ -738,6 +740,36 @@ describe('Asset Transfer Proxies', () => { erc20Balances[toAddress][erc20TokenA.address].add(totalAmount), ); }); + it('should dispatch an ERC20 transfer when input amount is 0', async () => { + const inputAmount = constants.ZERO_AMOUNT; + const erc20Amount = new BigNumber(10); + const erc20AssetData = assetDataUtils.encodeERC20AssetData(erc20TokenA.address); + const amounts = [erc20Amount]; + const nestedAssetData = [erc20AssetData]; + const assetData = assetDataInterface.MultiAsset.getABIEncodedTransactionData(amounts, nestedAssetData); + const data = assetProxyInterface.transferFrom.getABIEncodedTransactionData( + assetData, + fromAddress, + toAddress, + inputAmount, + ); + const erc20Balances = await erc20Wrapper.getBalancesAsync(); + const logDecoder = new LogDecoder(web3Wrapper, { ...artifacts, ...tokensArtifacts }); + const tx = await logDecoder.getTxWithDecodedLogsAsync( + await web3Wrapper.sendTransactionAsync({ + to: multiAssetProxy.address, + data, + from: authorized, + }), + ); + expect(tx.logs.length).to.be.equal(1); + const log = tx.logs[0] as LogWithDecodedArgs<DummyERC20TokenTransferEventArgs>; + const transferEventName = 'Transfer'; + expect(log.event).to.equal(transferEventName); + expect(log.args._value).to.be.bignumber.equal(constants.ZERO_AMOUNT); + const newBalances = await erc20Wrapper.getBalancesAsync(); + expect(newBalances).to.deep.equal(erc20Balances); + }); it('should successfully transfer multiple of the same ERC20 token', async () => { const inputAmount = new BigNumber(1); const erc20Amount1 = new BigNumber(10); |