From 835ddb8810eb8253b3a8aecd20764c06bcf8da33 Mon Sep 17 00:00:00 2001
From: arnaucube <root@arnaucube.com>
Date: Mon, 11 May 2020 12:02:02 +0200
Subject: [PATCH] Add initial version of deposit circuit

---
 circuits/deposit.circom       | 84 +++++++++++++++++++++++++++++++++++
 circuits/withdraw.circom      | 11 ++---
 test/circuits/deposit.test.ts | 72 ++++++++++++++++++++++++++++++
 3 files changed, 162 insertions(+), 5 deletions(-)
 create mode 100644 circuits/deposit.circom
 create mode 100644 test/circuits/deposit.test.ts

diff --git a/circuits/deposit.circom b/circuits/deposit.circom
new file mode 100644
index 0000000..bb0fea2
--- /dev/null
+++ b/circuits/deposit.circom
@@ -0,0 +1,84 @@
+/*
+
+# deposit.circom
+
+                     +----------+              +----------+
+PUB_nullifier+------>+          |              |          |
+                     |          |              | SMT      |
+PUB_coinCode+------->+          |              | Poseidon +<------+PUB_rootOld
+                     | Poseidon +-+----------->+ Verifier |
+PUB_amount+--------->+          | |            | Non      |
+                     |          | |            | Existance+<------+PRI_siblings
+PRI_secret+--------->+          | |            |          |          +
+                     +----------+ |            +----------+          |
+                                  |                                  |
+                                  |                                  |
+                                  |            +----------+          |
+                                  |            |          |          |
+                                  |            |          |          |
+                   +----+         |            | SMT      +<---------+
+PUB_commitment+----> == +<--------+----------->+ Poseidon |
+                   +----+                      | Verifier |
+                                               |          +<------+PUB_rootNew
+                                               |          |
+                                               +----------+
+
+
+*/
+
+include "../node_modules/circomlib/circuits/comparators.circom";
+include "../node_modules/circomlib/circuits/poseidon.circom";
+include "../node_modules/circomlib/circuits/smt/smtverifier.circom";
+
+template Deposit(nLevels) {
+	signal input coinCode;
+	signal input amount;
+	signal private input secret;
+	signal input nullifier;
+	signal private input siblingsOld[nLevels];
+	signal private input siblingsNew[nLevels];
+	signal input rootOld;
+	signal input rootNew;
+	signal input commitment;
+
+	component hash = Poseidon(4, 6, 8, 57);
+	hash.inputs[0] <== coinCode;
+	hash.inputs[1] <== amount;
+	hash.inputs[2] <== secret;
+	hash.inputs[3] <== nullifier;
+
+	component comCheck = IsEqual();
+	comCheck.in[0] <== hash.out;
+	comCheck.in[1] <== commitment;
+	comCheck.out === 1;
+
+	// TODO instead of 2 siblings input, get siblingsOld from siblingsNew[len-1]
+
+	component smtOld = SMTVerifier(nLevels);
+	smtOld.enabled <== 1;
+	smtOld.fnc <== 1;
+	smtOld.root <== rootOld;
+	for (var i=0; i<nLevels; i++) {
+		smtOld.siblings[i] <== siblingsOld[i];
+	}
+	smtOld.oldKey <== 1;
+	smtOld.oldValue <== 0;
+	smtOld.isOld0 <== 0;
+	smtOld.key <== hash.out;
+	smtOld.value <== 0;
+
+	component smtNew = SMTVerifier(nLevels);
+	smtNew.enabled <== 1;
+	smtNew.fnc <== 0;
+	smtNew.root <== rootNew;
+	for (var i=0; i<nLevels; i++) {
+		smtNew.siblings[i] <== siblingsNew[i];
+	}
+	smtNew.oldKey <== 0;
+	smtNew.oldValue <== 0;
+	smtNew.isOld0 <== 0;
+	smtNew.key <== hash.out;
+	smtNew.value <== 0;
+}
+
+component main = Deposit(5);
diff --git a/circuits/withdraw.circom b/circuits/withdraw.circom
index 16c23df..8d460bf 100644
--- a/circuits/withdraw.circom
+++ b/circuits/withdraw.circom
@@ -5,16 +5,17 @@ WARNING: WIP, very initial version of the miksi circuit
 
 
 
-                                               +----------+
-                                               |          |
-PUB_nullifier+------>+----------+              |          |
+                     -----------+              +----------+
+PUB_nullifier+------>+          |              |          |
+                     |          |              |          |
 PUB_coinCode+------->+          |              | SMT      +<------+PRI_siblings
-                     |          |              | Poseidon |
-PUB_amount+--------->+ Poseidon +------------->+ Verifier |
+                     | Poseidon +------------->+ Poseidon |
+PUB_amount+--------->+          |              | Verifier |
                      |          |              |          +<------+PUB_root
 PRI_secret+--------->+          |              |          |        +
                      +----------+              +----------+        |
                                                                    |
+                                                                   |
                              +----+                  +----+        |
              PUB_address+--->+ != +<-------+0+------>+ != +<-------+
                              +----+                  +----+
diff --git a/test/circuits/deposit.test.ts b/test/circuits/deposit.test.ts
new file mode 100644
index 0000000..fdc54e3
--- /dev/null
+++ b/test/circuits/deposit.test.ts
@@ -0,0 +1,72 @@
+const path = require("path");
+const tester = require("circom").tester;
+const chai = require("chai");
+const assert = chai.assert;
+const circomlib = require("circomlib");
+const smt = require("circomlib").smt;
+
+export {};
+
+describe("deposit test", function () {
+    this.timeout(200000);
+
+
+    it("Test Deposit", async () => {
+        const circuit = await tester(
+            path.join(__dirname, "../../circuits", "deposit.circom"),
+            {reduceConstraints: false}
+        );
+
+        const nLevels = 5;
+        const secret = "1234567890";
+
+        const coinCode = "0";
+        const amount = '1000000000000000000';
+        const nullifier = "567891234";
+
+        const poseidon = circomlib.poseidon.createHash(6, 8, 57);
+        const commitment = poseidon([coinCode, amount, secret, nullifier]).toString();
+
+        // add commitment into SMT
+        let tree = await smt.newMemEmptyTrie();
+        await tree.insert(1, 0);
+        await tree.insert(2, 0);
+
+        let rootOld = tree.root;
+        let res = await tree.find(commitment);
+        // console.log(res);
+        assert(!res.found);
+        let siblingsOld = res.siblings;
+        while (siblingsOld.length < nLevels) {
+            siblingsOld.push("0");
+        };
+        console.log("siblingsOld", siblingsOld);
+
+        await tree.insert(commitment, 0);
+        let rootNew = tree.root;
+
+        res = await tree.find(commitment);
+        // console.log(res);
+        assert(res.found);
+        let siblingsNew = res.siblings;
+        while (siblingsNew.length < nLevels) {
+            siblingsNew.push("0");
+        };
+        console.log("siblingsNew", siblingsNew);
+        console.log("rootOld", rootOld);
+        console.log("rootNew", rootNew);
+        
+        const witness = await circuit.calculateWitness({
+            "coinCode": coinCode,
+            "amount": amount,
+            "secret": secret,
+            "nullifier": nullifier,
+            "siblingsOld": siblingsOld,
+            "siblingsNew": siblingsNew,
+            "rootOld": rootOld,
+            "rootNew": rootNew,
+            "commitment": commitment
+        });
+        await circuit.checkConstraints(witness);
+    });
+});