update circuits

.prettierignore

@@ -0,0 +1,5 @@
+biomebase/
+init/
+move/
+perlin/
+range_proof/

README.md

@@ -1 +1,56 @@
-A beginning is the time for taking the most delicate care that the balances are correct.
+# Dark Forest ZK Circuits
+
+## Development Guide
+
+### Folder setup
+
+Each of the primary Dark Forest circuits is stored in its own subdirectory:
+
+- `/circuits/init`: Proof for initializing a player into the universe
+- `/circuits/move`: Proof for initiating a move between two planets
+- `/circuits/reveal`: Proof for broadcasting/revealing the coordinates of a
+  planet. Note that nothing in the broadcast action needs to happen in
+  "zero-knowledge"; we just found it easier to implement verification of MiMC
+  hash preimage via a ZK verifier than via a Solidity verifier.
+- `/circuits/biomebase`: Proof that a planet has a given `biomebase`, which in
+  combination with the planet's `spacetype` will specify the planet's biome.
+
+There are two additional subdirectories for auxiliary utility circuits:
+
+- `/circuits/perlin`: Perlin Noise ZK Circuit.
+- `/circuits/range_proof`: Proof that an input, or list of inputs, has an
+  absolute value that is at most a user-provided upper bound.
+
+### Installing Core Dependencies
+
+- Node (v14.x OR v16.x)
+- Yarn (Javascript Package Manager)
+
+#### Installing The Correct Node Version Using NVM
+
+Dark Forest is built and tested using Node.js v14/v16 and might not run properly on other Node.js versions. We recommend using NVM to switch between multiple Node.js version on your machine.
+
+Refer to [nvm's official documentation](https://github.com/nvm-sh/nvm#installing-and-updating) for the installation guide.
+
+After the installation is finished, you can run `node --version` to verify that you are running v14 or v16
+
+#### Installing Yarn & Other Dev Dependencies
+
+Refer to [Yarn's official documentation](https://classic.yarnpkg.com/en/docs/install) for the installation guide.
+
+After you have Yarn installed, run `yarn` to install dependencies.
+
+### Local Usage
+
+This set of circuits is meant to be used in conjunction with the public smart
+contract subdirectory [eth](https://github.com/darkforest-eth/eth) and [Project
+Sophon's](https://github.com/projectsophon)
+[hardhat-circom](https://github.com/projectsophon/hardhat-circom) plugin. If these two
+directories are unified as sibling directories under a common root, you can run
+`yarn circom:dev` in `eth` to compile and run the circuits on provided input files.
+
+For your convenience, a sample `input.json` and `public.json` pair is included
+for sanity test checks. `input.json` is a sample input, `public.json` is public
+parameters. `yarn dev` or `yarn prod` will create `witness.json` and
+`verification_key.json`, and print to the console verifying that the proof is
+generated and verifies properly.

Verifier.sol.template

@@ -0,0 +1,282 @@
+//
+// Copyright 2017 Christian Reitwiessner
+// Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+// The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+//
+// 2019 OKIMS
+//      ported to solidity 0.5
+//      fixed linter warnings
+//      added requiere error messages
+//
+pragma solidity ^0.7.6;
+
+library Pairing {
+    struct G1Point {
+        uint256 X;
+        uint256 Y;
+    }
+    // Encoding of field elements is: X[0] * z + X[1]
+    struct G2Point {
+        uint256[2] X;
+        uint256[2] Y;
+    }
+
+    /// @return the generator of G1
+    function P1() internal pure returns (G1Point memory) {
+        return G1Point(1, 2);
+    }
+
+    /// @return the generator of G2
+    function P2() internal pure returns (G2Point memory) {
+        // Original code point
+        return
+            G2Point(
+                [
+                    11559732032986387107991004021392285783925812861821192530917403151452391805634,
+                    10857046999023057135944570762232829481370756359578518086990519993285655852781
+                ],
+                [
+                    4082367875863433681332203403145435568316851327593401208105741076214120093531,
+                    8495653923123431417604973247489272438418190587263600148770280649306958101930
+                ]
+            );
+
+        /*
+        // Changed by Jordi point
+        return G2Point(
+            [10857046999023057135944570762232829481370756359578518086990519993285655852781,
+             11559732032986387107991004021392285783925812861821192530917403151452391805634],
+            [8495653923123431417604973247489272438418190587263600148770280649306958101930,
+             4082367875863433681332203403145435568316851327593401208105741076214120093531]
+        );
+*/
+    }
+
+    /// @return r the negation of p, i.e. p.addition(p.negate()) should be zero.
+    function negate(G1Point memory p) internal pure returns (G1Point memory r) {
+        // The prime q in the base field F_q for G1
+
+
+            uint256 q
+         = 21888242871839275222246405745257275088696311157297823662689037894645226208583;
+        if (p.X == 0 && p.Y == 0) return G1Point(0, 0);
+        return G1Point(p.X, q - (p.Y % q));
+    }
+
+    /// @return r the sum of two points of G1
+    function addition(G1Point memory p1, G1Point memory p2)
+        internal
+        view
+        returns (G1Point memory r)
+    {
+        uint256[4] memory input;
+        input[0] = p1.X;
+        input[1] = p1.Y;
+        input[2] = p2.X;
+        input[3] = p2.Y;
+        bool success;
+        // solium-disable-next-line security/no-inline-assembly
+        assembly {
+            success := staticcall(sub(gas(), 2000), 6, input, 0xc0, r, 0x60)
+            // Use "invalid" to make gas estimation work
+            switch success
+                case 0 {
+                    invalid()
+                }
+        }
+        require(success, "pairing-add-failed");
+    }
+
+    /// @return r the product of a point on G1 and a scalar, i.e.
+    /// p == p.scalar_mul(1) and p.addition(p) == p.scalar_mul(2) for all points p.
+    function scalar_mul(G1Point memory p, uint256 s)
+        internal
+        view
+        returns (G1Point memory r)
+    {
+        uint256[3] memory input;
+        input[0] = p.X;
+        input[1] = p.Y;
+        input[2] = s;
+        bool success;
+        // solium-disable-next-line security/no-inline-assembly
+        assembly {
+            success := staticcall(sub(gas(), 2000), 7, input, 0x80, r, 0x60)
+            // Use "invalid" to make gas estimation work
+            switch success
+                case 0 {
+                    invalid()
+                }
+        }
+        require(success, "pairing-mul-failed");
+    }
+
+    /// @return the result of computing the pairing check
+    /// e(p1[0], p2[0]) *  .... * e(p1[n], p2[n]) == 1
+    /// For example pairing([P1(), P1().negate()], [P2(), P2()]) should
+    /// return true.
+    function pairing(G1Point[] memory p1, G2Point[] memory p2)
+        internal
+        view
+        returns (bool)
+    {
+        require(p1.length == p2.length, "pairing-lengths-failed");
+        uint256 elements = p1.length;
+        uint256 inputSize = elements * 6;
+        uint256[] memory input = new uint256[](inputSize);
+        for (uint256 i = 0; i < elements; i++) {
+            input[i * 6 + 0] = p1[i].X;
+            input[i * 6 + 1] = p1[i].Y;
+            input[i * 6 + 2] = p2[i].X[0];
+            input[i * 6 + 3] = p2[i].X[1];
+            input[i * 6 + 4] = p2[i].Y[0];
+            input[i * 6 + 5] = p2[i].Y[1];
+        }
+        uint256[1] memory out;
+        bool success;
+        // solium-disable-next-line security/no-inline-assembly
+        assembly {
+            success := staticcall(
+                sub(gas(), 2000),
+                8,
+                add(input, 0x20),
+                mul(inputSize, 0x20),
+                out,
+                0x20
+            )
+            // Use "invalid" to make gas estimation work
+            switch success
+                case 0 {
+                    invalid()
+                }
+        }
+        require(success, "pairing-opcode-failed");
+        return out[0] != 0;
+    }
+
+    /// Convenience method for a pairing check for two pairs.
+    function pairingProd2(
+        G1Point memory a1,
+        G2Point memory a2,
+        G1Point memory b1,
+        G2Point memory b2
+    ) internal view returns (bool) {
+        G1Point[] memory p1 = new G1Point[](2);
+        G2Point[] memory p2 = new G2Point[](2);
+        p1[0] = a1;
+        p1[1] = b1;
+        p2[0] = a2;
+        p2[1] = b2;
+        return pairing(p1, p2);
+    }
+
+    /// Convenience method for a pairing check for three pairs.
+    function pairingProd3(
+        G1Point memory a1,
+        G2Point memory a2,
+        G1Point memory b1,
+        G2Point memory b2,
+        G1Point memory c1,
+        G2Point memory c2
+    ) internal view returns (bool) {
+        G1Point[] memory p1 = new G1Point[](3);
+        G2Point[] memory p2 = new G2Point[](3);
+        p1[0] = a1;
+        p1[1] = b1;
+        p1[2] = c1;
+        p2[0] = a2;
+        p2[1] = b2;
+        p2[2] = c2;
+        return pairing(p1, p2);
+    }
+
+    /// Convenience method for a pairing check for four pairs.
+    function pairingProd4(
+        G1Point memory a1,
+        G2Point memory a2,
+        G1Point memory b1,
+        G2Point memory b2,
+        G1Point memory c1,
+        G2Point memory c2,
+        G1Point memory d1,
+        G2Point memory d2
+    ) internal view returns (bool) {
+        G1Point[] memory p1 = new G1Point[](4);
+        G2Point[] memory p2 = new G2Point[](4);
+        p1[0] = a1;
+        p1[1] = b1;
+        p1[2] = c1;
+        p1[3] = d1;
+        p2[0] = a2;
+        p2[1] = b2;
+        p2[2] = c2;
+        p2[3] = d2;
+        return pairing(p1, p2);
+    }
+}
+
+library Verifier {
+    using Pairing for *;
+    struct VerifyingKey {
+        Pairing.G1Point alfa1;
+        Pairing.G2Point beta2;
+        Pairing.G2Point gamma2;
+        Pairing.G2Point delta2;
+        Pairing.G1Point[] IC;
+    }
+    struct Proof {
+        Pairing.G1Point A;
+        Pairing.G2Point B;
+        Pairing.G1Point C;
+    }
+
+    function verify(
+        uint256[] memory input,
+        Proof memory proof,
+        VerifyingKey memory vk
+    ) internal view returns (uint256) {
+        uint256 snark_scalar_field = 21888242871839275222246405745257275088548364400416034343698204186575808495617;
+        require(input.length + 1 == vk.IC.length, "verifier-bad-input");
+        // Compute the linear combination vk_x
+        Pairing.G1Point memory vk_x = Pairing.G1Point(0, 0);
+        for (uint256 i = 0; i < input.length; i++) {
+            require(input[i] < snark_scalar_field, "verifier-gte-snark-scalar-field");
+            vk_x = Pairing.addition(vk_x, Pairing.scalar_mul(vk.IC[i + 1], input[i]));
+        }
+        vk_x = Pairing.addition(vk_x, vk.IC[0]);
+        if (
+            !Pairing.pairingProd4(
+                Pairing.negate(proof.A),
+                proof.B,
+                vk.alfa1,
+                vk.beta2,
+                vk_x,
+                vk.gamma2,
+                proof.C,
+                vk.delta2
+            )
+        ) return 1;
+        return 0;
+    }
+
+    function verifyProof(
+        uint256[2] memory a,
+        uint256[2][2] memory b,
+        uint256[2] memory c,
+        uint256[] memory input,
+        VerifyingKey memory vk
+    ) internal view returns (bool) {
+        Proof memory proof;
+        proof.A = Pairing.G1Point(a[0], a[1]);
+        proof.B = Pairing.G2Point([b[0][0], b[0][1]], [b[1][0], b[1][1]]);
+        proof.C = Pairing.G1Point(c[0], c[1]);
+        if (verify(input, proof, vk) == 0) {
+            return true;
+        } else {
+            return false;
+        }
+    }
+
+   <%full_circuit%>
+}

biomebase/circuit.circom

@@ -0,0 +1,49 @@
+/*
+    Prove: I know (x,y) such that:
+    - biomeperlin(x, y) = biomeBase
+    - MiMCSponge(x,y) = hash
+*/
+
+include "../perlin/perlin.circom"
+
+template Main() {
+    signal private input x;
+    signal private input y;
+    // todo: label this as planetHashKey
+    signal input PLANETHASH_KEY;
+    signal input BIOMEBASE_KEY;
+    // SCALE is the length scale of the perlin function.
+    // You can imagine that the perlin function can be scaled up or down to have features at smaller or larger scales, i.e. is it wiggly at the scale of 1000 units or is it wiggly at the scale of 10000 units.
+    // must be power of 2 at most 16384 so that DENOMINATOR works
+    signal input SCALE;
+    signal input xMirror; // 1 is true, 0 is false
+    signal input yMirror; // 1 is true, 0 is false
+
+    signal output hash;
+    signal output biomeBase;
+
+    /* check MiMCSponge(x,y) = pub */
+    /*
+        220 = 2 * ceil(log_5 p), as specified by mimc paper, where
+        p = 21888242871839275222246405745257275088548364400416034343698204186575808495617
+    */
+    component mimc = MiMCSponge(2, 220, 1);
+
+    mimc.ins[0] <== x;
+    mimc.ins[1] <== y;
+    mimc.k <== PLANETHASH_KEY;
+
+    hash <== mimc.outs[0];
+
+    /* check perlin(x, y) = p */
+    component perlin = MultiScalePerlin();
+    perlin.p[0] <== x;
+    perlin.p[1] <== y;
+    perlin.SCALE <== SCALE;
+    perlin.xMirror <== xMirror;
+    perlin.yMirror <== yMirror;
+    perlin.KEY <== BIOMEBASE_KEY;
+    biomeBase <== perlin.out;
+}
+
+component main = Main();