Fix c tester witness file read

c tester (c/tester.js) was using a method to read the witness file
called 'readBinaryFile' that was obtaining a wrong number of witness
elements, and as consequence was returning a wrong array of witness.

Changed that method to 'readBinWitnessFile', which makes use of
wtnsUtils method from snarkjs to read the witness binary file, so now
the c tester returns the correct witness.

c/tester.js

@@ -0,0 +1,234 @@
+const chai = require("chai");
+const assert = chai.assert;
+
+const fs = require("fs");
+var tmp = require("tmp-promise");
+const path = require("path");
+
+const util = require("util");
+const exec = util.promisify(require("child_process").exec);
+
+const loadR1cs = require("r1csfile").load;
+const ZqField = require("ffjavascript").ZqField;
+
+const readWtns = require("snarkjs").wtns.exportJson;
+
+module.exports = c_tester;
+
+async function  c_tester(circomInput, _options) {
+
+    assert(await compiler_above_version("2.0.0"),"Wrong compiler version. Must be at least 2.0.0");
+    
+    tmp.setGracefulCleanup();
+
+    const dir = await tmp.dir({prefix: "circom_", unsafeCleanup: true });
+
+    // console.log(dir.path);
+
+    const baseName = path.basename(circomInput, ".circom");
+    const options = Object.assign({}, _options);
+
+    options.wasm = true;
+
+    options.sym = true;
+    options.json = options.json || false; // costraints in json format
+    //options.r1cs = options.r1cs || false; // costraints in r1cs format
+    //if (!options.json) options.r1cs = true; // r1cs if not json
+    options.r1cs = true;
+    options.output = dir.path;
+
+    await compile(baseName, circomInput, options);
+
+    return new WasmTester(dir, baseName, run);
+}
+
+async function compile (baseName, fileName, options) {    
+    var flags = "--c ";
+    if (options.sym) flags += "--sym ";
+    if (options.r1cs) flags += "--r1cs ";
+    if (options.json) flags += "--json ";
+    if (options.output) flags += "--output " + options.output + " ";
+    if (options.O === 0) flags += "--O0 "
+    if (options.O === 1) flags += "--O1 "
+
+    b = await exec("circom " + flags + fileName); 
+    assert(b.stderr == "",
+	   "circom compiler error \n" + b.stderr);
+    
+    const c_folder = path.join(options.output, baseName+"_cpp/")
+    b = await exec("make -C "+c_folder);
+    assert(b.stderr == "",
+	   "error building the executable C program\n" + b.stderr);
+}
+    
+class WasmTester {
+
+    constructor(dir, baseName, witnessCalculator) {
+        this.dir=dir;
+        this.baseName = baseName;
+        this.witnessCalculator = witnessCalculator;
+    }
+
+    async release() {
+        await this.dir.cleanup();
+    }
+
+    async calculateWitness(input) {
+	const inputjson = JSON.stringify(input);
+	const inputFile = path.join(this.dir.path, this.baseName+"_cpp/" + this.baseName + ".json");
+	const wtnsFile = path.join(this.dir.path, this.baseName+"_cpp/" + this.baseName + ".wtns");
+	const runc = path.join(this.dir.path, this.baseName+"_cpp/" + this.baseName);	
+        fs.writeFile(inputFile, inputjson, function(err) {
+	    if (err) throw err;
+	});
+	await exec("ls " + path.join(this.dir.path, this.baseName+"_cpp/"));
+	await exec(runc + " " + inputFile + " " + wtnsFile);
+	return await readBinWitnessFile(wtnsFile);
+    }
+
+    async loadSymbols() {
+        if (this.symbols) return;
+        this.symbols = {};
+        const symsStr = await fs.promises.readFile(
+            path.join(this.dir.path, this.baseName + ".sym"),
+            "utf8"
+        );
+        const lines = symsStr.split("\n");
+        for (let i=0; i<lines.length; i++) {
+            const arr = lines[i].split(",");
+            if (arr.length!=4) continue;
+            this.symbols[arr[3]] = {
+                labelIdx: Number(arr[0]),
+                varIdx: Number(arr[1]),
+                componentIdx: Number(arr[2]),
+            };
+        }
+    }
+
+    async loadConstraints() {
+        const self = this;
+        if (this.constraints) return;
+        const r1cs = await loadR1cs(path.join(this.dir.path, this.baseName + ".r1cs"),true, false);
+        self.F = new ZqField(r1cs.prime);
+        self.nVars = r1cs.nVars;
+        self.constraints = r1cs.constraints;
+    }
+
+    async assertOut(actualOut, expectedOut) {
+        const self = this;
+        if (!self.symbols) await self.loadSymbols();
+
+        checkObject("main", expectedOut);
+
+        function checkObject(prefix, eOut) {
+
+            if (Array.isArray(eOut)) {
+                for (let i=0; i<eOut.length; i++) {
+                    checkObject(prefix + "["+i+"]", eOut[i]);
+                }
+            } else if ((typeof eOut == "object")&&(eOut.constructor.name == "Object")) {
+                for (let k in eOut) {
+                    checkObject(prefix + "."+k, eOut[k]);
+                }
+            } else {
+                if (typeof self.symbols[prefix] == "undefined") {
+                    assert(false, "Output variable not defined: "+ prefix);
+                }
+                const ba = actualOut[self.symbols[prefix].varIdx].toString();
+                const be = eOut.toString();
+                assert.strictEqual(ba, be, prefix);
+            }
+        }
+    }
+
+    async getDecoratedOutput(witness) {
+        const self = this;
+        const lines = [];
+        if (!self.symbols) await self.loadSymbols();
+        for (let n in self.symbols) {
+            let v;
+            if (utils.isDefined(witness[self.symbols[n].varIdx])) {
+                v = witness[self.symbols[n].varIdx].toString();
+            } else {
+                v = "undefined";
+            }
+            lines.push(`${n} --> ${v}`);
+        }
+        return lines.join("\n");
+    }
+
+    async checkConstraints(witness) {
+        const self = this;
+        if (!self.constraints) await self.loadConstraints();
+        for (let i=0; i<self.constraints.length; i++) {
+            checkConstraint(self.constraints[i]);
+        }
+
+        function checkConstraint(constraint) {
+	    
+            const F = self.F;
+            const a = evalLC(constraint[0]);
+            const b = evalLC(constraint[1]);
+            const c = evalLC(constraint[2]);
+            assert (F.isZero(F.sub(F.mul(a,b), c)), "Constraint doesn't match");
+        }
+
+        function evalLC(lc) {
+            const F = self.F;
+            let v = F.zero;
+            for (let w in lc) {
+                v = F.add(
+                    v,
+                    F.mul( lc[w], witness[w] )
+                );
+            }
+            return v;
+        }
+    }
+
+}
+
+function version_to_list ( v ) {
+    return v.split(".").map(function(x) {
+	return parseInt(x, 10);
+    });
+}
+
+function check_versions ( v1, v2 ) {
+    //check if v1 is newer than or equal to v2
+    for (let i = 0; i < v2.length; i++) {
+	if (v1[i] > v2[i]) return true;
+	if (v1[i] < v2[i]) return false;
+    }
+    return true;
+}
+
+async function compiler_above_version(v) {
+    let output = await exec('circom --version').toString();
+    let compiler_version = version_to_list(output.slice(output.search(/\d/),-1));
+    vlist = version_to_list(v);
+    return check_versions ( compiler_version, vlist );
+}
+
+async function readBinWitnessFile(fileName) {
+    const buffWitness = await readWtns(fileName);
+    return buffWitness;
+}
+
+function fromArray8(arr) { //returns a BigInt
+    var res = BigInt(0);
+    const radix = BigInt(0x100);
+    for (let i = arr.length-1 ; i>=0; i--) {
+        res = res*radix + BigInt(arr[i]);
+    }
+    return res;
+}
+
+function fromArray8ToUint(arr) { //returns a BigInt
+    var res = 0;
+    const radix = 8;
+    for (let i = arr.length-1 ; i>=0; i--) {
+        res = res*radix + arr[i];
+    }
+    return res;
+}

index.js

@@ -1,2 +1,2 @@
 exports.wasm = require("./wasm/tester");
-//exports.c = require("./c/tester");
+exports.c = require("./c/tester");

package-lock.json

@@ -1,19 +1,19 @@
 {
   "name": "circom_tester",
-  "version": "0.0.2",
+  "version": "0.0.7",
   "lockfileVersion": 2,
   "requires": true,
   "packages": {
     "": {
       "name": "circom_tester",
-      "version": "0.0.2",
+      "version": "0.0.7",
       "license": "GPL-3.0",
       "dependencies": {
         "chai": "^4.3.4",
         "child_process": "^1.0.2",
         "ffjavascript": "^0.2.38",
         "fnv-plus": "^1.3.1",
-        "r1csfile": "^0.0.32",
+        "r1csfile": "0.0.16",
         "tmp-promise": "^3.0.2",
         "util": "^0.12.4"
       }
@@ -23,15 +23,6 @@
       "resolved": "https://registry.npmjs.org/@iden3/bigarray/-/bigarray-0.0.2.tgz",
       "integrity": "sha512-Xzdyxqm1bOFF6pdIsiHLLl3HkSLjbhqJHVyqaTxXt3RqXBEnmsUmEW47H7VOi/ak7TdkRpNkxjyK5Zbkm+y52g=="
     },
-    "node_modules/@iden3/binfileutils": {
-      "version": "0.0.8",
-      "resolved": "https://registry.npmjs.org/@iden3/binfileutils/-/binfileutils-0.0.8.tgz",
-      "integrity": "sha512-/GqTsujUssGuQY+sd/XaLrA+OiCwzm+6yH28C57QQDWCHET2Logry9fGxU10n6XKdhCQBjZ7T/YMQkLwwkpRTQ==",
-      "dependencies": {
-        "fastfile": "0.0.19",
-        "ffjavascript": "^0.2.30"
-      }
-    },
     "node_modules/assertion-error": {
       "version": "1.1.0",
       "resolved": "https://registry.npmjs.org/assertion-error/-/assertion-error-1.1.0.tgz",
@@ -196,9 +187,9 @@
       }
     },
     "node_modules/fastfile": {
-      "version": "0.0.19",
+      "version": "0.0.18",
-      "resolved": "https://registry.npmjs.org/fastfile/-/fastfile-0.0.19.tgz",
+      "resolved": "https://registry.npmjs.org/fastfile/-/fastfile-0.0.18.tgz",
-      "integrity": "sha512-tz9nWR5KYb6eR2odFQ7oxqEkx8F3YQZ6NBJoJR92YEG3DqYOqyxMck8PKvTVNKx3uwvOqGnLXNScnqpdHRdHGQ=="
+      "integrity": "sha512-q03PTKc+wptis4WmuFOwPNQx2p5myFUrl/dMgRlW9mymc1Egyc14JPHgiGnWK+sJ0+dBl2Vwtfh5GfSQltYOpw=="
     },
     "node_modules/ffjavascript": {
       "version": "0.2.38",
@@ -610,24 +601,32 @@
       }
     },
     "node_modules/r1csfile": {
-      "version": "0.0.32",
+      "version": "0.0.16",
-      "resolved": "https://registry.npmjs.org/r1csfile/-/r1csfile-0.0.32.tgz",
+      "resolved": "https://registry.npmjs.org/r1csfile/-/r1csfile-0.0.16.tgz",
-      "integrity": "sha512-DkRXeOg0iRmfhgIuWICvdkOiLHpyb7+AcUd/WHpqBJEUp27pe7wKXBR4Jr3TPYCT4sTV9a/F3bovyAC4wystnQ==",
+      "integrity": "sha512-A2jRVWzGgmXeG2lVAc0H4suJmzt50it5UvBnycJgBCpMXM3tH/M6RguP7nvs6suY/yYnkN6jX6iTScSiDUF3FA==",
       "dependencies": {
         "@iden3/bigarray": "0.0.2",
-        "@iden3/binfileutils": "0.0.8",
+        "fastfile": "0.0.18",
-        "fastfile": "0.0.19",
+        "ffjavascript": "0.2.22"
-        "ffjavascript": "0.2.35"
       }
     },
     "node_modules/r1csfile/node_modules/ffjavascript": {
-      "version": "0.2.35",
+      "version": "0.2.22",
-      "resolved": "https://registry.npmjs.org/ffjavascript/-/ffjavascript-0.2.35.tgz",
+      "resolved": "https://registry.npmjs.org/ffjavascript/-/ffjavascript-0.2.22.tgz",
-      "integrity": "sha512-xnC51tWbi0ah4SH+02jEfJyO+P+NiZWnxQrLDLtBYY1Dv3QM5ydxzd+gxnLEfWdT8i1bMM5pIh5P25l6fNCaVQ==",
+      "integrity": "sha512-EsVqap2Txm17bKW0z/jXCX3M7rQ++nQUAJY8alWDpyhjRj90xjl6GLeVSKZQ8rOFDQ/SFFXcEB8w9X8Boxid+w==",
       "dependencies": {
         "big-integer": "^1.6.48",
-        "wasmcurves": "0.0.14",
+        "wasmcurves": "0.0.12",
-        "web-worker": "^1.0.0"
+        "worker-threads": "^1.0.0"
+      }
+    },
+    "node_modules/r1csfile/node_modules/wasmcurves": {
+      "version": "0.0.12",
+      "resolved": "https://registry.npmjs.org/wasmcurves/-/wasmcurves-0.0.12.tgz",
+      "integrity": "sha512-1Jl9mkatyHSNj80ILjf85SZUNuZQBCkTjJlhzqHnZQXUmIimCIWkugaVaYNjozLs1Gun4h/keZe1MBeBN0sRpg==",
+      "dependencies": {
+        "big-integer": "^1.6.42",
+        "blakejs": "^1.1.0"
       }
     },
     "node_modules/rimraf": {
@@ -802,6 +801,11 @@
         "url": "https://github.com/sponsors/ljharb"
       }
     },
+    "node_modules/worker-threads": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/worker-threads/-/worker-threads-1.0.0.tgz",
+      "integrity": "sha512-vK6Hhvph8oLxocEJIlc3YfGAZhm210uGzjZsXSu+JYLAQ/s/w4Tqgl60JrdH58hW8NSGP4m3bp8a92qPXgX05w=="
+    },
     "node_modules/wrappy": {
       "version": "1.0.2",
       "resolved": "https://registry.npmjs.org/wrappy/-/wrappy-1.0.2.tgz",
@@ -814,15 +818,6 @@
       "resolved": "https://registry.npmjs.org/@iden3/bigarray/-/bigarray-0.0.2.tgz",
       "integrity": "sha512-Xzdyxqm1bOFF6pdIsiHLLl3HkSLjbhqJHVyqaTxXt3RqXBEnmsUmEW47H7VOi/ak7TdkRpNkxjyK5Zbkm+y52g=="
     },
-    "@iden3/binfileutils": {
-      "version": "0.0.8",
-      "resolved": "https://registry.npmjs.org/@iden3/binfileutils/-/binfileutils-0.0.8.tgz",
-      "integrity": "sha512-/GqTsujUssGuQY+sd/XaLrA+OiCwzm+6yH28C57QQDWCHET2Logry9fGxU10n6XKdhCQBjZ7T/YMQkLwwkpRTQ==",
-      "requires": {
-        "fastfile": "0.0.19",
-        "ffjavascript": "^0.2.30"
-      }
-    },
     "assertion-error": {
       "version": "1.1.0",
       "resolved": "https://registry.npmjs.org/assertion-error/-/assertion-error-1.1.0.tgz",
@@ -948,9 +943,9 @@
       }
     },
     "fastfile": {
-      "version": "0.0.19",
+      "version": "0.0.18",
-      "resolved": "https://registry.npmjs.org/fastfile/-/fastfile-0.0.19.tgz",
+      "resolved": "https://registry.npmjs.org/fastfile/-/fastfile-0.0.18.tgz",
-      "integrity": "sha512-tz9nWR5KYb6eR2odFQ7oxqEkx8F3YQZ6NBJoJR92YEG3DqYOqyxMck8PKvTVNKx3uwvOqGnLXNScnqpdHRdHGQ=="
+      "integrity": "sha512-q03PTKc+wptis4WmuFOwPNQx2p5myFUrl/dMgRlW9mymc1Egyc14JPHgiGnWK+sJ0+dBl2Vwtfh5GfSQltYOpw=="
     },
     "ffjavascript": {
       "version": "0.2.38",
@@ -1227,24 +1222,32 @@
       "integrity": "sha512-Dp6zGqpTdETdR63lehJYPeIOqpiNBNtc7BpWSLrOje7UaIsE5aY92r/AunQA7rsXvet3lrJ3JnZX29UPTKXyKQ=="
     },
     "r1csfile": {
-      "version": "0.0.32",
+      "version": "0.0.16",
-      "resolved": "https://registry.npmjs.org/r1csfile/-/r1csfile-0.0.32.tgz",
+      "resolved": "https://registry.npmjs.org/r1csfile/-/r1csfile-0.0.16.tgz",
-      "integrity": "sha512-DkRXeOg0iRmfhgIuWICvdkOiLHpyb7+AcUd/WHpqBJEUp27pe7wKXBR4Jr3TPYCT4sTV9a/F3bovyAC4wystnQ==",
+      "integrity": "sha512-A2jRVWzGgmXeG2lVAc0H4suJmzt50it5UvBnycJgBCpMXM3tH/M6RguP7nvs6suY/yYnkN6jX6iTScSiDUF3FA==",
       "requires": {
         "@iden3/bigarray": "0.0.2",
-        "@iden3/binfileutils": "0.0.8",
+        "fastfile": "0.0.18",
-        "fastfile": "0.0.19",
+        "ffjavascript": "0.2.22"
-        "ffjavascript": "0.2.35"
       },
       "dependencies": {
         "ffjavascript": {
-          "version": "0.2.35",
+          "version": "0.2.22",
-          "resolved": "https://registry.npmjs.org/ffjavascript/-/ffjavascript-0.2.35.tgz",
+          "resolved": "https://registry.npmjs.org/ffjavascript/-/ffjavascript-0.2.22.tgz",
-          "integrity": "sha512-xnC51tWbi0ah4SH+02jEfJyO+P+NiZWnxQrLDLtBYY1Dv3QM5ydxzd+gxnLEfWdT8i1bMM5pIh5P25l6fNCaVQ==",
+          "integrity": "sha512-EsVqap2Txm17bKW0z/jXCX3M7rQ++nQUAJY8alWDpyhjRj90xjl6GLeVSKZQ8rOFDQ/SFFXcEB8w9X8Boxid+w==",
           "requires": {
             "big-integer": "^1.6.48",
-            "wasmcurves": "0.0.14",
+            "wasmcurves": "0.0.12",
-            "web-worker": "^1.0.0"
+            "worker-threads": "^1.0.0"
+          }
+        },
+        "wasmcurves": {
+          "version": "0.0.12",
+          "resolved": "https://registry.npmjs.org/wasmcurves/-/wasmcurves-0.0.12.tgz",
+          "integrity": "sha512-1Jl9mkatyHSNj80ILjf85SZUNuZQBCkTjJlhzqHnZQXUmIimCIWkugaVaYNjozLs1Gun4h/keZe1MBeBN0sRpg==",
+          "requires": {
+            "big-integer": "^1.6.42",
+            "blakejs": "^1.1.0"
           }
         }
       }
@@ -1374,6 +1377,11 @@
         "is-typed-array": "^1.1.7"
       }
     },
+    "worker-threads": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/worker-threads/-/worker-threads-1.0.0.tgz",
+      "integrity": "sha512-vK6Hhvph8oLxocEJIlc3YfGAZhm210uGzjZsXSu+JYLAQ/s/w4Tqgl60JrdH58hW8NSGP4m3bp8a92qPXgX05w=="
+    },
     "wrappy": {
       "version": "1.0.2",
       "resolved": "https://registry.npmjs.org/wrappy/-/wrappy-1.0.2.tgz",

package.json

@@ -1,6 +1,6 @@
 {
   "name": "circom_tester",
-  "version": "0.0.2",
+  "version": "0.0.7",
   "description": "Tools for testing circom circuits.",
   "main": "index.js",
   "scripts": {
@@ -27,8 +27,9 @@
     "child_process": "^1.0.2",
     "ffjavascript": "^0.2.38",
     "fnv-plus": "^1.3.1",
-    "r1csfile": "^0.0.32",
+    "r1csfile": "0.0.16",
     "tmp-promise": "^3.0.2",
-    "util": "^0.12.4"
+    "util": "^0.12.4",
+    "snarkjs": "0.4.10"
   }
 }

test/multiplier2.js

@@ -1,6 +1,7 @@
 const chai = require("chai");
 const path = require("path");
 const wasm_tester = require("./../index").wasm;
+const c_tester = require("./../index").c;
 
 const F1Field = require("ffjavascript").F1Field;
 const Scalar = require("ffjavascript").Scalar;
@@ -9,14 +10,20 @@ const Fr = new F1Field(exports.p);
 
 const assert = chai.assert;
 
-describe("Exponentioation test", function () {
+describe("Simple test", function () {
     this.timeout(100000);
 
-    it("Should generate the Exponentiation table in k=0", async () => {
+    it("Checking the compilation of a simple circuit generating wasm", async () => {
 
         const circuit = await wasm_tester(path.join(__dirname, "Multiplier2.circom"));
         const w = await circuit.calculateWitness({a: 2, b: 4});
+        await circuit.checkConstraints(w);
+    });
 
+    it("Checking the compilation of a simple circuit generating C", async () => {
+
+        const circuit = await c_tester(path.join(__dirname, "Multiplier2.circom"));
+        const w = await circuit.calculateWitness({a: 2, b: 4});
         await circuit.checkConstraints(w);
 
     });

wasm/tester.js

@@ -51,8 +51,12 @@ async function compile (fileName, options) {
     if (options.r1cs) flags += "--r1cs ";
     if (options.json) flags += "--json ";
     if (options.output) flags += "--output " + options.output + " ";
+    if (options.O === 0) flags += "--O0 "
+    if (options.O === 1) flags += "--O1 "
 
-    await exec("circom " + flags + fileName);
+    b = await exec("circom " + flags + fileName);
+    assert(b.stderr == "",
+	  "circom compiler error \n" + b.stderr);
 }
     
 class WasmTester {

wasm/witness_calculator.js

@@ -80,19 +80,22 @@ class WitnessCalculator {
 	this.version = this.instance.exports.getVersion();
         this.n32 = this.instance.exports.getFieldNumLen32();
 
-//        Not needed
+        this.instance.exports.getRawPrime();
-//        this.instance.exports.getRawPrime();
+        const arr = new Array(this.n32);
-//        const arr = new Array(this.n32);
+        for (let i=0; i<this.n32; i++) {
-//        for (let i=0; i<this.n32; i++) {
+            arr[this.n32-1-i] = this.instance.exports.readSharedRWMemory(i);
-//            arr[this.n32-1-i] = this.instance.exports.readSharedRWMemory(i);
+        }
-//        }
+        this.prime = utils.fromArray32(arr);
-//        this.prime = utils.fromArray32(arr);
 
         this.witnessSize = this.instance.exports.getWitnessSize();
 
         this.sanityCheck = sanityCheck;
     }
     
+    circom_version() {
+	return this.instance.exports.getVersion();
+    }
+
     async _doCalculateWitness(input, sanityCheck) {
 	//input is assumed to be a map from signals to arrays of bigints
         this.instance.exports.init((this.sanityCheck || sanityCheck) ? 1 : 0);