Fixed ZoKrates vulnerability

CCTF_Solutions_main/ctf.sol

@@ -8,7 +8,6 @@ pragma solidity ^0.8.16;
 
 import "./verifier.sol";
 
-
 contract CCTF9 is Verifier {
     address public admin;
     uint256 public volMaxPoints;
@@ -25,12 +24,12 @@ contract CCTF9 is Verifier{
         uint256 points;
     }
 
-    modifier onlyAdmin {
+    modifier onlyAdmin() {
         require(msg.sender == admin, "Not admin");
         _;
     }
 
-    modifier onlyActive {
+    modifier onlyActive() {
         require(started == true, "CCTF not started.");
         _;
     }
@@ -72,44 +71,66 @@ contract CCTF9 is Verifier{
     }
 
     /// creates a new capturable flag according to the arguments
-    function setFlag(uint256 _flagId,Hash memory _flagHash, bool _onlyFirstSolver, uint256 _points, string memory _skill) external onlyAdmin{
+    function setFlag(
+        uint256 _flagId,
+        Hash memory _flagHash,
+        bool _onlyFirstSolver,
+        uint256 _points,
+        string memory _skill
+    ) external onlyAdmin {
         flags[_flagId] = Flag(_flagHash, _onlyFirstSolver, _points, _skill);
         emit FlagAdded(_flagId, _flagHash);
     }
 
     /// registers the caller as a player
     function register() external {
-        require(players[msg.sender].status == PlayerStatus.Unverified, 'Already registered or banned');
+        require(
+            players[msg.sender].status == PlayerStatus.Unverified,
+            "Already registered or banned"
+        );
         players[msg.sender].status = PlayerStatus.Verified;
     }
+
     /// sets the player's status either to Unverified, Verified or Banned
-    function setPlayerStatus(address player, PlayerStatus status) external onlyAdmin {
+    function setPlayerStatus(address player, PlayerStatus status)
+    external
+    onlyAdmin
+    {
         players[player].status = status;
     }
 
-
     ////////// Submit flags
     mapping(address => mapping(uint256 => bool)) Solves; // address -> challenge ID -> solved/not
     uint256 public submission_success_count = 0; // For statistics
 
-    function SubmitFlag(Proof memory p, uint256 _submitFor) external onlyActive {
-        require(players[msg.sender].status == PlayerStatus.Verified, "You are not even playing");
+    function SubmitFlag(Proof memory p, uint256 _submitFor)
+    external
+    onlyActive
+    {
+        require(
+            players[msg.sender].status == PlayerStatus.Verified,
+            "You are not even playing"
+        );
 
-        uint[13] memory inputs;
-        for(uint i =0 ; i < 8;++i){
+        uint256[13] memory inputs;
+        for (uint256 i = 0; i < 8; ++i) {
             inputs[i] = flags[_submitFor].flagHash.value[i];
         }
         uint32[5] memory addr = addressToUint32(msg.sender);
-        for(uint i =0; i < 5;++i){
+        for (uint256 i = 0; i < 5; ++i) {
             inputs[8 + i] = addr[i];
         }
-        bool valid = verifyTx(p,inputs);
-        assert(valid);
 
-        require(!Solves[msg.sender][_submitFor]); // can't submit the same flag multiple times
+
+        bool valid = verifyTx(p, inputs);
+        require(valid,"The proof is invalid");
+
+        require(!Solves[msg.sender][_submitFor],"You cannot submit your solution more than once"); // can't submit the same flag multiple times
         Solves[msg.sender][_submitFor] = true;
         players[msg.sender].points += flags[_submitFor].points;
-        players[msg.sender].points = players[msg.sender].points < volMaxPoints ? players[msg.sender].points : volMaxPoints;
+        players[msg.sender].points = players[msg.sender].points < volMaxPoints
+        ? players[msg.sender].points
+        : volMaxPoints;
 
         if (flags[_submitFor].onlyFirstSolver) {
             flags[_submitFor].points = 0;
@@ -120,24 +141,36 @@ contract CCTF9 is Verifier{
     }
 
     /// maps an address to unsigned int
-    function addressToUint32 (address _addr) public pure returns (uint32[5] memory)
+    function addressToUint32(address _addr)
+    public
+    pure
+    returns (uint32[5] memory)
     {
         uint256 targetUint = uint256(uint160(_addr));
-        uint32[5] memory addr = [uint32(targetUint/4294967296**4),
+        uint32[5] memory addr = [
+        uint32(targetUint / 4294967296**4),
         uint32(targetUint / 4294967296**3),
         uint32(targetUint / 4294967296**2),
         uint32(targetUint / 4294967296),
-                                uint32(targetUint)];
+        uint32(targetUint)
+        ];
         return addr;
     }
 
     ////////// Check status, scores, etc
-    function getPlayerStatus(address _player) external view returns (PlayerStatus) {
+    function getPlayerStatus(address _player)
+    external
+    view
+    returns (PlayerStatus)
+    {
         return players[_player].status;
     }
 
     function getPlayerPoints(address _player) external view returns (uint256) {
-        return players[_player].points < volMaxPoints ? players[_player].points : volMaxPoints;
+        return
+        players[_player].points < volMaxPoints
+        ? players[_player].points
+        : volMaxPoints;
     }
 
     function getSuccessfulSubmissionCount() external view returns (uint256) {

CCTF_Solutions_main/root.zok

@@ -1,11 +1,10 @@
 import "hashes/sha256/sha256Padded.zok" as sha256;
 from "utils/casts.zok" import cast;
 
-def main(public u32[8] hash,public u32[5] address,private u8[64] flag) -> u32[8]{
+def main(public u32[8] hash,public u32[5] address,private u8[64] flag){
      u8[20] addr8 = cast(address);
      u32[8] genHash = sha256(flag);
      log("Hash: {} {} {} {} {} {} {} {}",genHash[0],genHash[1],genHash[2],genHash[3],genHash[4],genHash[5],genHash[6],genHash[7]);
      assert(genHash == hash);
-     u8[32] hash8 = cast(hash);
-     return sha256([...addr8,...hash8]);
+     return;
 }