FEATURE: Allow custom hash functions to Internal libraries of: IMT

packages/imt/contracts/BinaryIMT.sol

@@ -1,25 +1,106 @@
 // SPDX-License-Identifier: MIT
 pragma solidity ^0.8.4;
-
 import {InternalBinaryIMT, BinaryIMTData} from "./InternalBinaryIMT.sol";
+import {SNARK_SCALAR_FIELD} from "./Constants.sol";
+import {IHasherT3} from "./interfaces/IHasherT3.sol";
+error WrongDefaultZeroIndex();
 
 library BinaryIMT {
     using InternalBinaryIMT for *;
 
+    // The function used for hashing. Passed as a function parameter in functions from InternalLazyIMT
+    function _hasher(uint256[2] memory input) internal view returns (uint256) {
+        return IHasherT3(HASHER_ADDRESS).hash(input);
+    }
+
+    // This is poseidonT3 from: https://github.com/chancehudson/poseidon-solidity
+    address internal constant HASHER_ADDRESS = 0x3333333C0A88F9BE4fd23ed0536F9B6c427e3B93;
+
+    uint256 internal constant Z_0 = 0;
+    uint256 internal constant Z_1 = 14744269619966411208579211824598458697587494354926760081771325075741142829156;
+    uint256 internal constant Z_2 = 7423237065226347324353380772367382631490014989348495481811164164159255474657;
+    uint256 internal constant Z_3 = 11286972368698509976183087595462810875513684078608517520839298933882497716792;
+    uint256 internal constant Z_4 = 3607627140608796879659380071776844901612302623152076817094415224584923813162;
+    uint256 internal constant Z_5 = 19712377064642672829441595136074946683621277828620209496774504837737984048981;
+    uint256 internal constant Z_6 = 20775607673010627194014556968476266066927294572720319469184847051418138353016;
+    uint256 internal constant Z_7 = 3396914609616007258851405644437304192397291162432396347162513310381425243293;
+    uint256 internal constant Z_8 = 21551820661461729022865262380882070649935529853313286572328683688269863701601;
+    uint256 internal constant Z_9 = 6573136701248752079028194407151022595060682063033565181951145966236778420039;
+    uint256 internal constant Z_10 = 12413880268183407374852357075976609371175688755676981206018884971008854919922;
+    uint256 internal constant Z_11 = 14271763308400718165336499097156975241954733520325982997864342600795471836726;
+    uint256 internal constant Z_12 = 20066985985293572387227381049700832219069292839614107140851619262827735677018;
+    uint256 internal constant Z_13 = 9394776414966240069580838672673694685292165040808226440647796406499139370960;
+    uint256 internal constant Z_14 = 11331146992410411304059858900317123658895005918277453009197229807340014528524;
+    uint256 internal constant Z_15 = 15819538789928229930262697811477882737253464456578333862691129291651619515538;
+    uint256 internal constant Z_16 = 19217088683336594659449020493828377907203207941212636669271704950158751593251;
+    uint256 internal constant Z_17 = 21035245323335827719745544373081896983162834604456827698288649288827293579666;
+    uint256 internal constant Z_18 = 6939770416153240137322503476966641397417391950902474480970945462551409848591;
+    uint256 internal constant Z_19 = 10941962436777715901943463195175331263348098796018438960955633645115732864202;
+    uint256 internal constant Z_20 = 15019797232609675441998260052101280400536945603062888308240081994073687793470;
+    uint256 internal constant Z_21 = 11702828337982203149177882813338547876343922920234831094975924378932809409969;
+    uint256 internal constant Z_22 = 11217067736778784455593535811108456786943573747466706329920902520905755780395;
+    uint256 internal constant Z_23 = 16072238744996205792852194127671441602062027943016727953216607508365787157389;
+    uint256 internal constant Z_24 = 17681057402012993898104192736393849603097507831571622013521167331642182653248;
+    uint256 internal constant Z_25 = 21694045479371014653083846597424257852691458318143380497809004364947786214945;
+    uint256 internal constant Z_26 = 8163447297445169709687354538480474434591144168767135863541048304198280615192;
+    uint256 internal constant Z_27 = 14081762237856300239452543304351251708585712948734528663957353575674639038357;
+    uint256 internal constant Z_28 = 16619959921569409661790279042024627172199214148318086837362003702249041851090;
+    uint256 internal constant Z_29 = 7022159125197495734384997711896547675021391130223237843255817587255104160365;
+    uint256 internal constant Z_30 = 4114686047564160449611603615418567457008101555090703535405891656262658644463;
+    uint256 internal constant Z_31 = 12549363297364877722388257367377629555213421373705596078299904496781819142130;
+    uint256 internal constant Z_32 = 21443572485391568159800782191812935835534334817699172242223315142338162256601;
+
+    function _defaultZero(uint256 index) internal pure returns (uint256) {
+        if (index == 0) return Z_0;
+        if (index == 1) return Z_1;
+        if (index == 2) return Z_2;
+        if (index == 3) return Z_3;
+        if (index == 4) return Z_4;
+        if (index == 5) return Z_5;
+        if (index == 6) return Z_6;
+        if (index == 7) return Z_7;
+        if (index == 8) return Z_8;
+        if (index == 9) return Z_9;
+        if (index == 10) return Z_10;
+        if (index == 11) return Z_11;
+        if (index == 12) return Z_12;
+        if (index == 13) return Z_13;
+        if (index == 14) return Z_14;
+        if (index == 15) return Z_15;
+        if (index == 16) return Z_16;
+        if (index == 17) return Z_17;
+        if (index == 18) return Z_18;
+        if (index == 19) return Z_19;
+        if (index == 20) return Z_20;
+        if (index == 21) return Z_21;
+        if (index == 22) return Z_22;
+        if (index == 23) return Z_23;
+        if (index == 24) return Z_24;
+        if (index == 25) return Z_25;
+        if (index == 26) return Z_26;
+        if (index == 27) return Z_27;
+        if (index == 28) return Z_28;
+        if (index == 29) return Z_29;
+        if (index == 30) return Z_30;
+        if (index == 31) return Z_31;
+        if (index == 32) return Z_32;
+        revert WrongDefaultZeroIndex();
+    }
+
     function defaultZero(uint256 index) public pure returns (uint256) {
-        return InternalBinaryIMT._defaultZero(index);
+        return _defaultZero(index);
     }
 
     function init(BinaryIMTData storage self, uint256 depth, uint256 zero) public {
-        InternalBinaryIMT._init(self, depth, zero);
+        InternalBinaryIMT._init(self, depth, zero, _hasher, SNARK_SCALAR_FIELD);
     }
 
     function initWithDefaultZeroes(BinaryIMTData storage self, uint256 depth) public {
-        InternalBinaryIMT._initWithDefaultZeroes(self, depth);
+        InternalBinaryIMT._initWithDefaultZeroes(self, depth, _defaultZero);
     }
 
     function insert(BinaryIMTData storage self, uint256 leaf) public returns (uint256) {
-        return InternalBinaryIMT._insert(self, leaf);
+        return InternalBinaryIMT._insert(self, leaf, _hasher, SNARK_SCALAR_FIELD, _defaultZero);
     }
 
     function update(
@@ -29,7 +110,7 @@ library BinaryIMT {
         uint256[] calldata proofSiblings,
         uint8[] calldata proofPathIndices
     ) public {
-        InternalBinaryIMT._update(self, leaf, newLeaf, proofSiblings, proofPathIndices);
+        InternalBinaryIMT._update(self, leaf, newLeaf, proofSiblings, proofPathIndices, _hasher, SNARK_SCALAR_FIELD);
     }
 
     function remove(
@@ -38,6 +119,14 @@ library BinaryIMT {
         uint256[] calldata proofSiblings,
         uint8[] calldata proofPathIndices
     ) public {
-        InternalBinaryIMT._remove(self, leaf, proofSiblings, proofPathIndices);
+        InternalBinaryIMT._remove(
+            self,
+            leaf,
+            proofSiblings,
+            proofPathIndices,
+            _hasher,
+            SNARK_SCALAR_FIELD,
+            _defaultZero(0)
+        );
     }
 }