poc

contracts/WakuRln.sol

@@ -5,16 +5,25 @@ import {IPoseidonHasher} from "rln-contract/PoseidonHasher.sol";
 import {RlnBase, DuplicateIdCommitment, FullTree, InvalidIdCommitment} from "rln-contract/RlnBase.sol";
 import {Ownable} from "openzeppelin-contracts/contracts/access/Ownable.sol";
 
+import {LazyIMT, LazyIMTData} from "@zk-kit/imt.sol/LazyIMT.sol";
+
 error NotImplemented();
 
 contract WakuRln is Ownable, RlnBase {
     uint16 public immutable contractIndex;
 
+    LazyIMTData tree;
+    using LazyIMT for LazyIMTData;
+
     constructor(
         address _poseidonHasher,
         uint16 _contractIndex
     ) Ownable() RlnBase(0, 20, _poseidonHasher, address(0)) {
         contractIndex = _contractIndex;
+
+        // TODO: This errors
+        uint8 merkleTreeDepth = 32;
+        tree.init(merkleTreeDepth);
     }
 
     /// Registers a member
@@ -24,6 +33,7 @@ contract WakuRln is Ownable, RlnBase {
 
         members[idCommitment] = idCommitmentIndex;
         memberExists[idCommitment] = true;
+        tree.insert(idCommitment);
 
         emit MemberRegistered(idCommitment, idCommitmentIndex);
         idCommitmentIndex += 1;
@@ -71,4 +81,20 @@ contract WakuRln is Ownable, RlnBase {
     function withdraw() external pure override {
         revert NotImplemented();
     }
+
+    // TODO Some quick getter functions, unsure if needed
+    function merkleRoot() public view returns(uint256) {
+        return tree.root();
+    }
+
+    function numOfLeaves() public view returns(uint40) {
+        return tree.numberOfLeaves;
+    }
+
+    // Unsure how viable is to fetch elements one by one.
+    // Perhaps we just want the leafs and the client can reconstruct
+    // the hashes.
+    function getElement(uint256 elementIndex) public view returns(uint256) {
+        return tree.elements[elementIndex];
+    }
 }

docs/index.md

@@ -14,13 +14,19 @@ error NotImplemented()
 uint16 contractIndex
 ```
 
+### tree
+
+```solidity
+struct LazyIMTData tree
+```
+
 ### constructor
 
 ```solidity
 constructor(address _poseidonHasher, uint16 _contractIndex) public
 ```
 
-### _register
+### \_register
 
 ```solidity
 function _register(uint256 idCommitment) internal
@@ -30,8 +36,8 @@ Registers a member
 
 #### Parameters
 
-| Name | Type | Description |
+| Name         | Type    | Description                    |
-| ---- | ---- | ----------- |
+| ------------ | ------- | ------------------------------ |
 | idCommitment | uint256 | The idCommitment of the member |
 
 ### register
@@ -50,8 +56,8 @@ Allows a user to register as a member
 
 #### Parameters
 
-| Name | Type | Description |
+| Name         | Type    | Description                    |
-| ---- | ---- | ----------- |
+| ------------ | ------- | ------------------------------ |
 | idCommitment | uint256 | The idCommitment of the member |
 
 ### slash
@@ -64,13 +70,13 @@ _Allows a user to slash a member_
 
 #### Parameters
 
-| Name | Type | Description |
+| Name         | Type            | Description                    |
-| ---- | ---- | ----------- |
+| ------------ | --------------- | ------------------------------ |
-| idCommitment | uint256 | The idCommitment of the member |
+| idCommitment | uint256         | The idCommitment of the member |
-| receiver | address payable |  |
+| receiver     | address payable |                                |
-| proof | uint256[8] |  |
+| proof        | uint256[8]      |                                |
 
-### _validateRegistration
+### \_validateRegistration
 
 ```solidity
 function _validateRegistration(uint256 idCommitment) internal view
@@ -78,7 +84,7 @@ function _validateRegistration(uint256 idCommitment) internal view
 
 _Inheriting contracts MUST override this function_
 
-### _validateSlash
+### \_validateSlash
 
 ```solidity
 function _validateSlash(uint256 idCommitment, address payable receiver, uint256[8] proof) internal pure
@@ -92,6 +98,24 @@ function withdraw() external pure
 
 Allows a user to withdraw funds allocated to them upon slashing a member
 
+### merkleRoot
+
+```solidity
+function merkleRoot() public view returns (uint256)
+```
+
+### numOfLeaves
+
+```solidity
+function numOfLeaves() public view returns (uint40)
+```
+
+### getElement
+
+```solidity
+function getElement(uint256 elementIndex) public view returns (uint256)
+```
+
 ## StorageAlreadyExists
 
 ```solidity
@@ -160,18 +184,18 @@ modifier onlyUsableStorage()
 function initialize(address _poseidonHasher) external
 ```
 
-### _authorizeUpgrade
+### \_authorizeUpgrade
 
 ```solidity
 function _authorizeUpgrade(address newImplementation) internal
 ```
 
-_Function that should revert when `msg.sender` is not authorized to upgrade the contract. Called by
+\_Function that should revert when `msg.sender` is not authorized to upgrade the contract. Called by
 {upgradeTo} and {upgradeToAndCall}.
 
 Normally, this function will use an xref:access.adoc[access control] modifier such as {Ownable-onlyOwner}.
 
-```solidity
+````solidity
 function _authorizeUpgrade(address) internal override onlyOwner {}
 ```_
 
@@ -179,7 +203,7 @@ function _authorizeUpgrade(address) internal override onlyOwner {}
 
 ```solidity
 function _insertIntoStorageMap(address storageAddress) internal
-```
+````
 
 ### registerStorage
 
@@ -216,4 +240,3 @@ function register(uint16 storageIndex, uint256 commitment) external
 ```solidity
 function forceProgress() external
 ```
-

package.json

@@ -41,6 +41,8 @@
     "typescript": "^4.7.4"
   },
   "dependencies": {
+    "@zk-kit/imt.sol": "^2.0.0-beta",
+    "@zk-kit/incremental-merkle-tree.sol": "^1.7.0",
     "dotenv": "^16.0.1"
   },
   "lint-staged": {

yarn.lock

@@ -1043,6 +1043,20 @@
   resolved "https://registry.yarnpkg.com/@yarnpkg/lockfile/-/lockfile-1.1.0.tgz#e77a97fbd345b76d83245edcd17d393b1b41fb31"
   integrity sha512-GpSwvyXOcOOlV70vbnzjj4fW5xW/FdUF6nQEt1ENy7m4ZCczi1+/buVUPAqmGfqznsORNFzUMjctTIp8a9tuCQ==
 
+"@zk-kit/imt.sol@^2.0.0-beta":
+  version "2.0.0-beta"
+  resolved "https://registry.yarnpkg.com/@zk-kit/imt.sol/-/imt.sol-2.0.0-beta.tgz#102f88a52bd6848783fddc0db8219de2f163e684"
+  integrity sha512-bH7RvI5WHAEswUwPspUY582O2+71xbYv5aL+DM4xkaA0GdMyMLUwf5c1yJ4wrt46hp07iXCXJsLXdtLNsTnvZw==
+  dependencies:
+    poseidon-solidity "0.0.5"
+
+"@zk-kit/incremental-merkle-tree.sol@^1.7.0":
+  version "1.7.0"
+  resolved "https://registry.yarnpkg.com/@zk-kit/incremental-merkle-tree.sol/-/incremental-merkle-tree.sol-1.7.0.tgz#9d6166c2d84b8bb4fae709c7d729aae6c8c6474f"
+  integrity sha512-1HF5HEQ2GVKYBAKeNlhiQ7Fb7g2x6iBQ/bBovxBQYx8xuJlD8jPJU/fn2foMVI42+BQtz2V/V4tVtn+0uNL1Rg==
+  dependencies:
+    poseidon-solidity "0.0.4"
+
 abort-controller@^3.0.0:
   version "3.0.0"
   resolved "https://registry.yarnpkg.com/abort-controller/-/abort-controller-3.0.0.tgz#eaf54d53b62bae4138e809ca225c8439a6efb392"
@@ -6828,6 +6842,16 @@ pinkie@^2.0.0:
   resolved "https://registry.yarnpkg.com/pinkie/-/pinkie-2.0.4.tgz#72556b80cfa0d48a974e80e77248e80ed4f7f870"
   integrity sha512-MnUuEycAemtSaeFSjXKW/aroV7akBbY+Sv+RkyqFjgAe73F+MR0TBWKBRDkmfWq/HiFmdavfZ1G7h4SPZXaCSg==
 
+poseidon-solidity@0.0.4:
+  version "0.0.4"
+  resolved "https://registry.yarnpkg.com/poseidon-solidity/-/poseidon-solidity-0.0.4.tgz#fb80181fb2b17756d98449d54e4cc2ecd8daa4d0"
+  integrity sha512-+S6jlCXKARCFbw0MMOjfR8gcKUVeB8F3Vu5S+1zDvb8N8cVjiW6WsP9kPqNaZCxjRKakt6LKVRPdA39YbpWfdg==
+
+poseidon-solidity@0.0.5:
+  version "0.0.5"
+  resolved "https://registry.yarnpkg.com/poseidon-solidity/-/poseidon-solidity-0.0.5.tgz#3f93e01cfe25f6d2f2fac49734fbb00961b84655"
+  integrity sha512-NzrvSwHzvZgT4hvg2GyGqeR+UOU/eLSEt4wAoXEua+VaR7NTKKwx1X9bPlh1VMBEVEno+IWvkRBbidFGzTeAqQ==
+
 posix-character-classes@^0.1.0:
   version "0.1.1"
   resolved "https://registry.yarnpkg.com/posix-character-classes/-/posix-character-classes-0.1.1.tgz#01eac0fe3b5af71a2a6c02feabb8c1fef7e00eab"