Platform: Code4rena
Start Date: 01/08/2022
Pot Size: $50,000 USDC
Total HM: 26
Participants: 133
Period: 5 days
Judge: Jack the Pug
Total Solo HM: 6
Id: 151
League: ETH
Rank: 78/133
Findings: 2
Award: $62.35
🌟 Selected for report: 0
🚀 Solo Findings: 0
🌟 Selected for report: Lambda
Also found by: 0x1f8b, 0x52, 0xA5DF, 0xNazgul, 0xNineDec, 0xSmartContract, 0xSolus, 0xf15ers, 0xkatana, 0xsolstars, 8olidity, Aymen0909, Bahurum, Bnke0x0, CertoraInc, Chom, CodingNameKiki, Deivitto, Dravee, ElKu, Extropy, Funen, GalloDaSballo, Guardian, IllIllI, JC, Jujic, MEP, Noah3o6, ReyAdmirado, Rohan16, Rolezn, Ruhum, Sm4rty, SooYa, Soosh, Throne6g, TomJ, Tomio, TrungOre, Waze, Yiko, _Adam, __141345__, a12jmx, ajtra, ak1, arcoun, asutorufos, ayeslick, benbaessler, berndartmueller, bin2chen, bobirichman, brgltd, bulej93, byndooa, c3phas, codexploder, cryptonue, cryptphi, defsec, delfin454000, dipp, djxploit, erictee, exd0tpy, fatherOfBlocks, gogo, hake, hansfriese, horsefacts, hyh, ignacio, indijanc, joestakey, kaden, mics, minhquanym, neumo, obront, oyc_109, p_crypt0, pfapostol, poirots, rbserver, robee, rokinot, rotcivegaf, sach1r0, saian, samruna, saneryee, scaraven, sikorico, simon135, sseefried, supernova
40.6283 USDC - $40.63
https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Community.sol#L206 the doc says that you canot submit a project with no total budget. therefore it require at least one task with a budget > 0. this will allows builder to publish their project which doesnt has a task in it or tasks with 0 budget.
Currently now use the solidity 0.8.6 version, and its better to upgrade the solidity to the latest version
https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Disputes.sol#L179
// Revert is signer is not builder, contractor or subcontractor.
should change is with if after revert.
https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L379
// If balance is present then it to the builder.
Should be add transfer after then word.
🌟 Selected for report: c3phas
Also found by: 0x040, 0x1f8b, 0xA5DF, 0xNazgul, 0xSmartContract, 0xSolus, 0xc0ffEE, 0xkatana, 0xsam, 8olidity, Aymen0909, Bnke0x0, CertoraInc, Chinmay, Chom, CodingNameKiki, Deivitto, Dravee, ElKu, Extropy, Fitraldys, Funen, GalloDaSballo, Guardian, IllIllI, JC, Lambda, MEP, Metatron, MiloTruck, Noah3o6, NoamYakov, PaludoX0, ReyAdmirado, Rohan16, Rolezn, Ruhum, Sm4rty, SooYa, TomJ, Tomio, Waze, _Adam, __141345__, a12jmx, ajtra, ak1, apostle0x01, asutorufos, ballx, benbaessler, bharg4v, bobirichman, brgltd, cryptonue, defsec, delfin454000, dharma09, djxploit, durianSausage, eierina, erictee, fatherOfBlocks, gerdusx, gogo, hake, hyh, ignacio, jag, kaden, kyteg, lucacez, mics, minhquanym, oyc_109, pfapostol, rbserver, ret2basic, robee, rokinot, sach1r0, saian, samruna, scaraven, sikorico, simon135, supernova, teddav, tofunmi, zeesaw
21.7223 USDC - $21.72
!= 0 costs less gas compared to > 0 for unsigned integers in require statements with the optimizer enabled (6 gas)
Proof: While it may seem that > 0 is cheaper than !=, this is only true without the optimizer enabled and outside a require statement. If you enable the optimizer at 10k AND you’re in a require statement, this will save gas. You can see this tweet for more proofs: https://twitter.com/gzeon/status/1485428085885640706 I suggest changing > 0 with != 0 here:
https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L195 https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Community.sol#L764
To optimize the for loop and make it consume less gas, i suggest to:
If a variable is not set/initialized, it is assumed to have the default value (0 for uint, false for bool, address(0) for address…). Explicitly initializing it with its default value is an anti-pattern and wastes gas.
Use ++i instead of i++, which is a cheaper operation (in this case there is no difference between i++ and ++i because we dont use the return value of this expression, which is the only difference between these two expression).
Reading array length at each iteration of the loop takes 6 gas (3 for mload and 3 to place memory_offset) in the stack.
Caching the array length in the stack saves around 3 gas per iteration. I suggest storing the array’s length in a variable before the for-loop.
As an example:
for (uint256 i = 0; i < numIterations.length; ++i) {
should be replaced with
for (uint256 i; i < newVariable; ++i) {
I suggest to change the code here:
https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L248 https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L311 https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L322 https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L710 https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Community.sol#L624 https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L368
SPLITTING REQUIRE() STATEMENTS THAT USE && SAVES GAS Instead of using the && operator in a single require statement to check multiple conditions, I suggest using multiple require statements with 1 condition per require statement (saving 3 gas per &):
https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Disputes.sol#L61 https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Disputes.sol#L106 https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Community.sol#L353