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Alpha Homora V2


Previous versions

Process Quality Review (0.7)

Alpha Homora V2

Final score:26%
Date:09 Dec 2021
Audit Process:version 0.7
Author:Nic of DeFiSafety
PQR Score:26%


Hack History

Date:17 Feb 2021
Details: $38m was lost to a flashloan attack.
Reference Linklink

Scoring Appendix

The final review score is indicated as a percentage. The percentage is calculated as Achieved Points due to MAX Possible Points. For each element the answer can be either Yes/No or a percentage. For a detailed breakdown of the individual weights of each question, please consult this document.

The blockchain used by this protocol

Very simply, the audit looks for the following declarations from the developer's site. With these declarations, it is reasonable to trust the smart contracts.

  • Here is my smart contract on the blockchain
  • You can see it matches a software repository used to develop the code
  • Here is the documentation that explains what my smart contract does
  • Here are the tests I ran to verify my smart contract
  • Here are the audit(s) performed to review my code by third party experts

This report is for informational purposes only and does not constitute investment advice of any kind, nor does it constitute an offer to provide investment advisory or other services. Nothing in this report shall be considered a solicitation or offer to buy or sell any security, token, future, option or other financial instrument or to offer or provide any investment advice or service to any person in any jurisdiction. Nothing contained in this report constitutes investment advice or offers any opinion with respect to the suitability of any security, and the views expressed in this report should not be taken as advice to buy, sell or hold any security. The information in this report should not be relied upon for the purpose of investing. In preparing the information contained in this report, we have not taken into account the investment needs, objectives and financial circumstances of any particular investor. This information has no regard to the specific investment objectives, financial situation and particular needs of any specific recipient of this information and investments discussed may not be suitable for all investors.

Any views expressed in this report by us were prepared based upon the information available to us at the time such views were written. The views expressed within this report are limited to DeFiSafety and the author and do not reflect those of any additional or third party and are strictly based upon DeFiSafety, its authors, interpretations and evaluation of relevant data. Changed or additional information could cause such views to change. All information is subject to possible correction. Information may quickly become unreliable for various reasons, including changes in market conditions or economic circumstances.

This completed report is copyright (c) DeFiSafety 2021. Permission is given to copy in whole, retaining this copyright label.

Code And Team


This section looks at the code deployed on the Mainnet that gets reviewed and its corresponding software repository. The document explaining these questions is here.  

1. Are the executing code addresses readily available? (%)

Answer: 0%

Contracts could not be found in either the docs or the GitHub. No audits specify the address of the contracts.

Percentage Score Guidance:
Clearly labelled and on website, docs or repo, quick to find
Clearly labelled and on website, docs or repo but takes a bit of looking
Addresses in mainnet.json, in discord or sub graph, etc
Address found but labeling not clear or easy to find
Executing addresses could not be found

2. Is the code actively being used? (%)

Answer: 0%

Activity could not be determined due to an inability to locate contract addresses.

Percentage Score Guidance:
More than 10 transactions a day
More than 10 transactions a week
More than 10 transactions a month
Less than 10 transactions a month
No activity

3. Is there a public software repository? (Y/N)

Answer: Yes

Is there a public software repository with the code at a minimum, but also normally test and scripts. Even if the repository was created just to hold the files and has just 1 transaction, it gets a "Yes". For teams with private repositories, this answer is "No"

Score Guidance:
There is a public software repository with the code at a minimum, but also normally test and scripts. Even if the repository was created just to hold the files and has just 1 transaction.
For teams with private repositories.

4. Is there a development history visible? (%)

Answer: 100%

At 400 commits, Alpha Homora demonstrates a good commitment to strong documentation practices.

This metric checks if the software repository demonstrates a strong steady history. This is normally demonstrated by commits, branches and releases in a software repository. A healthy history demonstrates a history of more than a month (at a minimum).

Percentage Score Guidance:
Any one of 100+ commits, 10+branches
Any one of 70+ commits, 7+branches
Any one of 50+ commits, 5+branches
Any one of 30+ commits, 3+branches
Less than 2 branches or less than 30 commits

5. Is the team public (not anonymous)? (Y/N)

Answer: Yes

The team is public.

For a "Yes" in this question, the real names of some team members must be public on the website or other documentation (LinkedIn, etc). If the team is anonymous, then this question is a "No".



This section looks at the software documentation. The document explaining these questions is here.

6. Is there a whitepaper? (Y/N)

Answer: Yes

7. Are the basic software functions documented? (Y/N)

Answer: No

No software functions are documented.

8. Does the software function documentation fully (100%) cover the deployed contracts? (%)

Answer: 0%

There is no software function documentation.

Percentage Score Guidance:
All contracts and functions documented
Only the major functions documented
79 - 1%
Estimate of the level of software documentation
No software documentation

9. Are there sufficiently detailed comments for all functions within the deployed contract code (%)

Answer: 0%

Code examples are in the Appendix. As per the SLOC, there is 18% commenting to code (CtC).

The Comments to Code (CtC) ratio is the primary metric for this score.

Percentage Score Guidance:
CtC > 100 Useful comments consistently on all code
90 - 70%
CtC > 70 Useful comment on most code
60 - 20%
CtC > 20 Some useful commenting
CtC < 20 No useful commenting

10. Is it possible to trace from software documentation to the implementation in code (%)

Answer: 0%

There is no traceability from software documentation to code.

Percentage Score Guidance:
Clear explicit traceability between code and documentation at a requirement level for all code
Clear association between code and documents via non explicit traceability
Documentation lists all the functions and describes their functions
No connection between documentation and code



11. Full test suite (Covers all the deployed code) (%)

Answer: 100%

Code examples are in the Appendix. As per the SLOC, there is 138% testing to code (TtC).

This score is guided by the Test to Code ratio (TtC). Generally a good test to code ratio is over 100%. However the reviewers best judgement is the final deciding factor.

Percentage Score Guidance:
TtC > 120% Both unit and system test visible
TtC > 80% Both unit and system test visible
TtC < 80% Some tests visible
No tests obvious

12. Code coverage (Covers all the deployed lines of code, or explains misses) (%)

Answer: 50%

No tests for code coverage were seen, but it's clear that this protocol has undergone testing.

Percentage Score Guidance:
Documented full coverage
99 - 51%
Value of test coverage from documented results
No indication of code coverage but clearly there is a reasonably complete set of tests
Some tests evident but not complete
No test for coverage seen

13. Scripts and instructions to run the tests? (Y/N)

Answer: Yes

Test scripts were found.

14. Report of the results (%)

Answer: 0%

No test report was found.

Percentage Score Guidance:
Detailed test report as described below
GitHub code coverage report visible
No test report evident

15. Formal Verification test done (%)

Answer: 0%

No formal verification has been undertaken.

16. Stress Testing environment (%)

Answer: 0%

No testnet deployment was documented.



This section looks at the 3rd party software audits done. It is explained in this document.

17. Did 3rd Party audits take place? (%)

Answer: 0%

Despite three audits no listed contracts mean we cannot award points for them as per guidance.

Percentage Score Guidance:
Multiple Audits performed before deployment and results public and implemented or not required
Single audit performed before deployment and results public and implemented or not required
Audit(s) performed after deployment and no changes required. Audit report is public
Audit(s) performed after deployment and changes needed but not implemented
No audit performed
Audit Performed after deployment, existence is public, report is not public and no improvements deployed OR smart contract address not found, (where question 1 is 0%)
Deduct 25% if code is in a private repo and no note from auditors that audit is applicable to deployed code.

18. Is the bug bounty acceptable high? (%)

Answer: 90%

With a $750k active bounty, this bug bounty is sufficient.

Percentage Score Guidance:
Bounty is 10% TVL or at least $1M AND active program (see below)
Bounty is 5% TVL or at least 500k AND active program
Bounty is 5% TVL or at least 500k
Bounty is 100k or over AND active program
Bounty is 100k or over
Bounty is 50k or over AND active program
Bounty is 50k or over
Bug bounty program bounty is less than 50k
No bug bounty program offered
An active program means that a third party (such as Immunefi) is actively driving hackers to the site. An inactive program would be static mentions on the docs.

Access Controls


This section covers the documentation of special access controls for a DeFi protocol. The admin access controls are the contracts that allow updating contracts or coefficients in the protocol. Since these contracts can allow the protocol admins to "change the rules", complete disclosure of capabilities is vital for user's transparency. It is explained in this document.

19. Can a user clearly and quickly find the status of the access controls (%)

Answer: 0%

Admin Control information could not be found.

Percentage Score Guidance:
Clearly labelled and on website, docs or repo, quick to find
Clearly labelled and on website, docs or repo but takes a bit of looking
Access control docs in multiple places and not well labelled
Access control docs in multiple places and not labelled
Admin Control information could not be found

20. Is the information clear and complete (%)

Answer: 0%

Admin Control information could not be found.

Percentage Score Guidance:
All the contracts are immutable -- 100% OR
a) All contracts are clearly labelled as upgradeable (or not) -- 30% AND
b) The type of ownership is clearly indicated (OnlyOwner / MultiSig / Defined Roles) -- 30% AND
c) The capabilities for change in the contracts are described -- 30%

21. Is the information in non-technical terms that pertain to the investments (%)

Answer: 0%

Admin Control information could not be found.

Percentage Score Guidance:
All the contracts are immutable
Description relates to investments safety and updates in clear, complete non-software language
Description all in software specific language
No admin control information could be found

22. Is there Pause Control documentation including records of tests (%)

Answer: 0%

Pause Control information could not be found

Percentage Score Guidance:
All the contracts are immutable or no pause control needed and this is explained OR Pause control(s) are clearly documented and there is records of at least one test within 3 months
Pause control(s) explained clearly but no evidence of regular tests
Pause controls mentioned with no detail on capability or tests
Pause control not documented or explained


 The author of this review is Rex of DeFi Safety.

Email: rex@defisafety.com
Twitter: @defisafety

I started with Ethereum just before the DAO and that was a wonderful education.  It showed the importance of code quality. The second Parity hack also showed the importance of good process.  Here my aviation background offers some value. Aerospace knows how to make reliable code using quality processes.
I was coaxed to go to EthDenver 2018 and there I started SecuEth.org with Bryant and Roman. We created guidelines on good processes for blockchain code development. We got EthFoundation funding to assist in their development Process Quality Reviews are an extension of the SecurEth guidelines that will further increase the quality processes in Solidity and Vyper development. DeFiSafety is my full time gig and we are working on funding vehicles for a permanent staff.

1pragma solidity 0.6.12;
23import 'OpenZeppelin/openzeppelin-contracts@3.4.0/contracts/token/ERC20/IERC20.sol';
4import 'OpenZeppelin/openzeppelin-contracts@3.4.0/contracts/token/ERC20/SafeERC20.sol';
5import 'OpenZeppelin/openzeppelin-contracts@3.4.0/contracts/token/ERC1155/IERC1155.sol';
6import 'OpenZeppelin/openzeppelin-contracts@3.4.0/contracts/math/SafeMath.sol';
7import 'OpenZeppelin/openzeppelin-contracts@3.4.0/contracts/math/Math.sol';
89import './Governable.sol';
10import './utils/ERC1155NaiveReceiver.sol';
11import '../interfaces/IBank.sol';
12import '../interfaces/ICErc20.sol';
13import '../interfaces/IOracle.sol';
1415library HomoraSafeMath {
16  using SafeMath for uint;
1718  /// @dev Computes round-up division.
19  function ceilDiv(uint a, uint b) internal pure returns (uint) {
20    return a.add(b).sub(1).div(b);
21  }
2324contract HomoraCaster {
25  /// @dev Call to the target using the given data.
26  /// @param target The address target to call.
27  /// @param data The data used in the call.
28  function cast(address target, bytes calldata data) external payable {
29    (bool ok, bytes memory returndata) = target.call{value: msg.value}(data);
30    if (!ok) {
31      if (returndata.length > 0) {
32        // The easiest way to bubble the revert reason is using memory via assembly
33        // solhint-disable-next-line no-inline-assembly
34        assembly {
35          let returndata_size := mload(returndata)
36          revert(add(32, returndata), returndata_size)
37        }
38      } else {
39        revert('bad cast call');
40      }
41    }
42  }
4445contract HomoraBank is Governable, ERC1155NaiveReceiver, IBank {
46  using SafeMath for uint;
47  using HomoraSafeMath for uint;
48  using SafeERC20 for IERC20;
4950  uint private constant _NOT_ENTERED = 1;
51  uint private constant _ENTERED = 2;
52  uint private constant _NO_ID = uint(-1);
53  address private constant _NO_ADDRESS = address(1);
5455  struct Bank {
56    bool isListed; // Whether this market exists.
57    uint8 index; // Reverse look up index for this bank.
58    address cToken; // The CToken to draw liquidity from.
59    uint reserve; // The reserve portion allocated to Homora protocol.
60    uint totalDebt; // The last recorded total debt since last action.
61    uint totalShare; // The total debt share count across all open positions.
62  }
6364  struct Position {
65    address owner; // The owner of this position.
66    address collToken; // The ERC1155 token used as collateral for this position.
67    uint collId; // The token id used as collateral.
68    uint collateralSize; // The size of collateral token for this position.
69    uint debtMap; // Bitmap of nonzero debt. i^th bit is set iff debt share of i^th bank is nonzero.
70    mapping(address => uint) debtShareOf; // The debt share for each token.
71  }
7273  uint public _GENERAL_LOCK; // TEMPORARY: re-entrancy lock guard.
74  uint public _IN_EXEC_LOCK; // TEMPORARY: exec lock guard.
75  uint public override POSITION_ID; // TEMPORARY: position ID currently under execution.
76  address public override SPELL; // TEMPORARY: spell currently under execution.
7778  address public caster; // The caster address for untrusted execution.
79  IOracle public oracle; // The oracle address for determining prices.
80  uint public feeBps; // The fee collected as protocol reserve in basis points from interest.
81  uint public override nextPositionId; // Next available position ID, starting from 1 (see initialize).
8283  address[] public allBanks; // The list of all listed banks.
84  mapping(address => Bank) public banks; // Mapping from token to bank data.
85  mapping(address => bool) public cTokenInBank; // Mapping from cToken to its existence in bank.
86  mapping(uint => Position) public positions; // Mapping from position ID to position data.
8788  bool public allowContractCalls; // The boolean status whether to allow call from contract (false = onlyEOA)
89  mapping(address => bool) public whitelistedTokens; // Mapping from token to whitelist status
90  mapping(address => bool) public whitelistedSpells; // Mapping from spell to whitelist status
91  mapping(address => bool) public whitelistedUsers; // Mapping from user to whitelist status
9293  uint public bankStatus; // Each bit stores certain bank status, e.g. borrow allowed, repay allowed
9495  /// @dev Ensure that the function is called from EOA when allowContractCalls is set to false and caller is not whitelisted
96  modifier onlyEOAEx() {
97    if (!allowContractCalls && !whitelistedUsers[msg.sender]) {
98      require(msg.sender == tx.origin, 'not eoa');
99    }
100    _;
101  }
102103  /// @dev Reentrancy lock guard.
104  modifier lock() {
105    require(_GENERAL_LOCK == _NOT_ENTERED, 'general lock');
107    _;
109  }
110111  /// @dev Ensure that the function is called from within the execution scope.
112  modifier inExec() {
113    require(POSITION_ID != _NO_ID, 'not within execution');
114    require(SPELL == msg.sender, 'not from spell');
115    require(_IN_EXEC_LOCK == _NOT_ENTERED, 'in exec lock');
117    _;
119  }
120121  /// @dev Ensure that the interest rate of the given token is accrued.
122  modifier poke(address token) {
123    accrue(token);
124    _;
125  }
126127  /// @dev Initialize the bank smart contract, using msg.sender as the first governor.
128  /// @param _oracle The oracle smart contract address.
129  /// @param _feeBps The fee collected to Homora bank.
130  function initialize(IOracle _oracle, uint _feeBps) external initializer {
131    __Governable__init();
134    POSITION_ID = _NO_ID;
136    caster = address(new HomoraCaster());
137    oracle = _oracle;
138    require(address(_oracle) != address(0), 'bad oracle address');
139    feeBps = _feeBps;
140    nextPositionId = 1;
141    bankStatus = 3; // allow both borrow and repay
142    emit SetOracle(address(_oracle));
143    emit SetFeeBps(_feeBps);
144  }
145146  /// @dev Return the current executor (the owner of the current position).
147  function EXECUTOR() external view override returns (address) {
148    uint positionId = POSITION_ID;
149    require(positionId != _NO_ID, 'not under execution');
150    return positions[positionId].owner;
151  }
152153  /// @dev Set allowContractCalls
154  /// @param ok The status to set allowContractCalls to (false = onlyEOA)
155  function setAllowContractCalls(bool ok) external onlyGov {
156    allowContractCalls = ok;
157  }
158159  /// @dev Set whitelist spell status
160  /// @param spells list of spells to change status
161  /// @param statuses list of statuses to change to
162  function setWhitelistSpells(address[] calldata spells, bool[] calldata statuses)
163    external
164    onlyGov
165  {
166    require(spells.length == statuses.length, 'spells & statuses length mismatched');
167    for (uint idx = 0; idx < spells.length; idx++) {
168      whitelistedSpells[spells[idx]] = statuses[idx];
169    }
170  }
171172  /// @dev Set whitelist token status
173  /// @param tokens list of tokens to change status
174  /// @param statuses list of statuses to change to
175  function setWhitelistTokens(address[] calldata tokens, bool[] calldata statuses)
176    external
177    onlyGov
178  {
179    require(tokens.length == statuses.length, 'tokens & statuses length mismatched');
180    for (uint idx = 0; idx < tokens.length; idx++) {
181      if (statuses[idx]) {
182        // check oracle suppport
183        require(support(tokens[idx]), 'oracle not support token');
184      }
185      whitelistedTokens[tokens[idx]] = statuses[idx];
186    }
187  }
188189  /// @dev Set whitelist user status
190  /// @param users list of users to change status
191  /// @param statuses list of statuses to change to
192  function setWhitelistUsers(address[] calldata users, bool[] calldata statuses) external onlyGov {
193    require(users.length == statuses.length, 'users & statuses length mismatched');
194    for (uint idx = 0; idx < users.length; idx++) {
195      whitelistedUsers[users[idx]] = statuses[idx];
196    }
197  }
198199  /// @dev Check whether the oracle supports the token
200  /// @param token ERC-20 token to check for support
201  function support(address token) public view override returns (bool) {
202    return oracle.support(token);
203  }
204205  /// @dev Set bank status
206  /// @param _bankStatus new bank status to change to
207  function setBankStatus(uint _bankStatus) external onlyGov {
208    bankStatus = _bankStatus;
209  }
210211  /// @dev Bank borrow status allowed or not
212  /// @notice check last bit of bankStatus
213  function allowBorrowStatus() public view returns (bool) {
214    return (bankStatus & 0x01) > 0;
215  }
216217  /// @dev Bank repay status allowed or not
218  /// @notice Check second-to-last bit of bankStatus
219  function allowRepayStatus() public view returns (bool) {
220    return (bankStatus & 0x02) > 0;
221  }
222223  /// @dev Trigger interest accrual for the given bank.
224  /// @param token The underlying token to trigger the interest accrual.
225  function accrue(address token) public override {
226    Bank storage bank = banks[token];
227    require(bank.isListed, 'bank not exist');
228    uint totalDebt = bank.totalDebt;
229    uint debt = ICErc20(bank.cToken).borrowBalanceCurrent(address(this));
230    if (debt > totalDebt) {
231      uint fee = debt.sub(totalDebt).mul(feeBps).div(10000);
232      bank.totalDebt = debt;
233      bank.reserve = bank.reserve.add(doBorrow(token, fee));
234    } else if (totalDebt != debt) {
235      // We should never reach here because CREAMv2 does not support *repayBorrowBehalf*
236      // functionality. We set bank.totalDebt = debt nonetheless to ensure consistency. But do
237      // note that if *repayBorrowBehalf* exists, an attacker can maliciously deflate debt
238      // share value and potentially make this contract stop working due to math overflow.
239      bank.totalDebt = debt;
240    }
241  }
242243  /// @dev Convenient function to trigger interest accrual for a list of banks.
244  /// @param tokens The list of banks to trigger interest accrual.
245  function accrueAll(address[] memory tokens) external {
246    for (uint idx = 0; idx < tokens.length; idx++) {
247      accrue(tokens[idx]);
248    }
249  }
250251  /// @dev Return the borrow balance for given position and token without triggering interest accrual.
252  /// @param positionId The position to query for borrow balance.
253  /// @param token The token to query for borrow balance.
254  function borrowBalanceStored(uint positionId, address token) public view override returns (uint) {
255    uint totalDebt = banks[token].totalDebt;
256    uint totalShare = banks[token].totalShare;
257    uint share = positions[positionId].debtShareOf[token];
258    if (share == 0 || totalDebt == 0) {
259      return 0;
260    } else {
261      return share.mul(totalDebt).ceilDiv(totalShare);
262    }
263  }
264265  /// @dev Trigger interest accrual and return the current borrow balance.
266  /// @param positionId The position to query for borrow balance.
267  /// @param token The token to query for borrow balance.
268  function borrowBalanceCurrent(uint positionId, address token) external override returns (uint) {
269    accrue(token);
270    return borrowBalanceStored(positionId, token);
271  }
272273  /// @dev Return bank information for the given token.
274  /// @param token The token address to query for bank information.
275  function getBankInfo(address token)
276    external
277    view
278    override
279    returns (
280      bool isListed,
281      address cToken,
282      uint reserve,
283      uint totalDebt,
284      uint totalShare
285    )
286  {
287    Bank storage bank = banks[token];
288    return (bank.isListed, bank.cToken, bank.reserve, bank.totalDebt, bank.totalShare);
289  }
290291  /// @dev Return position information for the given position id.
292  /// @param positionId The position id to query for position information.
293  function getPositionInfo(uint positionId)
294    public
295    view
296    override
297    returns (
298      address owner,
299      address collToken,
300      uint collId,
301      uint collateralSize
302    )
303  {
304    Position storage pos = positions[positionId];
305    return (pos.owner, pos.collToken, pos.collId, pos.collateralSize);
306  }

Solidity Contracts


Comments to Code: 123 / 671 =  18 %

JavaScript Tests


Tests to Code: 925 / 671 = 138 %