Test cases for addition, subtraction, multiplication, and modulo in the secp256k1 finite field

test/bigint.test.ts

@@ -8,21 +8,7 @@ const F1Field = require("ffjavascript").F1Field;
 const Scalar = require("ffjavascript").Scalar;
 exports.p = Scalar.fromString("21888242871839275222246405745257275088548364400416034343698204186575808495617");
 const Fr = new F1Field(exports.p);
-
-function bigint_to_array(n: number, k: number, x: bigint) {
-    let mod: bigint = 1n;
-    for (var idx = 0; idx < n; idx++) {
-        mod = mod * 2n;
-    }
-
-    let ret: bigint[] = [];
-    var x_temp: bigint = x;
-    for (var idx = 0; idx < k; idx++) {
-        ret.push(x_temp % mod);
-        x_temp = x_temp / mod;
-    }
-    return ret;
-}
+import { bigint_to_array } from './utils'
 
 describe("BigMod n = 2, k = 2 exhaustive", function() {
     this.timeout(1000 * 1000);

test/circuits/test_secp256k1_fp_add.circom

@@ -0,0 +1,37 @@
+pragma circom 2.0.2;
+
+include "../../circuits/bigint.circom";
+include "../../circuits/secp256k1_func.circom";
+
+template Secp256k1_Fp_Add(n, k) {
+    signal input a[k];
+    signal input b[k];
+    signal output out[k];
+
+    component adder = BigAdd(n, k);
+    for (var i = 0; i < k; i ++) {
+        adder.a[i] <== a[i];
+        adder.b[i] <== b[i];
+    }
+
+    component mod = BigMod(n, k);
+
+    for (var i = 0; i < k + 1; i ++) {
+        mod.a[i] <== adder.out[i];
+    }
+
+    for (var i = k + 1; i < k * 2; i ++) {
+        mod.a[i] <== 0;
+    }
+
+    mod.b[0] <== 18446744069414583343;
+    mod.b[1] <== 18446744073709551615;
+    mod.b[2] <== 18446744073709551615;
+    mod.b[3] <== 18446744073709551615;
+
+    for (var i = 0; i < k; i ++) {
+        out[i] <== mod.mod[i];
+    }
+}
+
+component main {public [a, b]} = Secp256k1_Fp_Add(64, 4);

test/circuits/test_secp256k1_fp_mod.circom

@@ -0,0 +1,29 @@
+pragma circom 2.0.2;
+
+include "../../circuits/bigint.circom";
+
+template Secp256k1_Fp_Mod() {
+    var n = 64;
+    var k = 4;
+
+    signal input a[k];
+    signal output out[k];
+
+    component m = BigMod(n, k);
+
+    for (var i = 0; i < k; i ++) {
+        m.a[i] <== a[i];
+        m.a[k + i] <== 0;
+    }
+
+    m.b[0] <== 18446744069414583343;
+    m.b[1] <== 18446744073709551615;
+    m.b[2] <== 18446744073709551615;
+    m.b[3] <== 18446744073709551615;
+
+    for (var i = 0; i < k; i ++) {
+        out[i] <== m.mod[i];
+    }
+}
+
+component main {public [a]} = Secp256k1_Fp_Mod();

test/circuits/test_secp256k1_fp_mul.circom

@@ -0,0 +1,25 @@
+pragma circom 2.0.2;
+
+include "../../circuits/bigint.circom";
+
+template Secp256k1_Fp_Mul(n, k) {
+    signal input a[k];
+    signal input b[k];
+    signal output out[k];
+
+    component mul_mod_p = BigMultModP(n, k);
+    for (var i = 0; i < k; i ++) {
+        mul_mod_p.a[i] <== a[i];
+        mul_mod_p.b[i] <== b[i];
+    }
+    mul_mod_p.p[0] <== 18446744069414583343;
+    mul_mod_p.p[1] <== 18446744073709551615;
+    mul_mod_p.p[2] <== 18446744073709551615;
+    mul_mod_p.p[3] <== 18446744073709551615;
+
+    for (var i = 0; i < k; i ++) {
+        out[i] <== mul_mod_p.out[i];
+    }
+}
+
+component main {public [a, b]} = Secp256k1_Fp_Mul(64, 4);

test/circuits/test_secp256k1_fp_sub.circom

@@ -0,0 +1,27 @@
+pragma circom 2.0.2;
+
+include "../../circuits/bigint.circom";
+include "../../circuits/secp256k1_func.circom";
+
+template Secp256k1_Fp_Sub(n, k) {
+    signal input a[k];
+    signal input b[k];
+    signal output out[k];
+
+    component sub = BigSubModP(n, k);
+    for (var i = 0; i < k; i ++) {
+        sub.a[i] <== a[i];
+        sub.b[i] <== b[i];
+    }
+
+    sub.p[0] <== 18446744069414583343;
+    sub.p[1] <== 18446744073709551615;
+    sub.p[2] <== 18446744073709551615;
+    sub.p[3] <== 18446744073709551615;
+
+    for (var i = 0; i < k; i ++) {
+        out[i] <== sub.out[i];
+    }
+}
+
+component main {public [a, b]} = Secp256k1_Fp_Sub(64, 4);

test/ecdsa.test.ts

@@ -9,47 +9,7 @@ const F1Field = require("ffjavascript").F1Field;
 const Scalar = require("ffjavascript").Scalar;
 exports.p = Scalar.fromString("21888242871839275222246405745257275088548364400416034343698204186575808495617");
 const Fr = new F1Field(exports.p);
-
-function bigint_to_tuple(x: bigint) {
-    let mod: bigint = 2n ** 64n;
-    let ret: [bigint, bigint, bigint, bigint] = [0n, 0n, 0n, 0n];
-
-    var x_temp: bigint = x;
-    for (var idx = 0; idx < ret.length; idx++) {
-        ret[idx] = x_temp % mod;
-        x_temp = x_temp / mod;
-    }
-    return ret;
-}
-
-function bigint_to_array(n: number, k: number, x: bigint) {
-    let mod: bigint = 1n;
-    for (var idx = 0; idx < n; idx++) {
-        mod = mod * 2n;
-    }
-
-    let ret: bigint[] = [];
-    var x_temp: bigint = x;
-    for (var idx = 0; idx < k; idx++) {
-        ret.push(x_temp % mod);
-        x_temp = x_temp / mod;
-    }
-    return ret;
-}
-
-// converts x = sum of a[i] * 2 ** (small_stride * i) for 0 <= 2 ** small_stride - 1
-//      to:     sum of a[i] * 2 ** (stride * i)
-function get_strided_bigint(stride: bigint, small_stride: bigint, x: bigint) {
-    var ret: bigint = 0n;
-    var exp: bigint = 0n;
-    while (x > 0) {
-        var mod: bigint = x % (2n ** small_stride);
-        ret = ret + mod * (2n ** (stride * exp));
-        x = x / (2n ** small_stride);
-        exp = exp + 1n;
-    }
-    return ret;
-}
+import { bigint_to_array, bigint_to_tuple, get_strided_bigint } from './utils'
 
 describe("ECDSAPrivToPub", function () {
     this.timeout(1000 * 1000);

test/secp256k1.test.ts

@@ -9,21 +9,7 @@ const F1Field = require("ffjavascript").F1Field;
 const Scalar = require("ffjavascript").Scalar;
 exports.p = Scalar.fromString("21888242871839275222246405745257275088548364400416034343698204186575808495617");
 const Fr = new F1Field(exports.p);
-
-function bigint_to_array(n: number, k: number, x: bigint) {
-    let mod: bigint = 1n;
-    for (var idx = 0; idx < n; idx++) {
-        mod = mod * 2n;
-    }
-
-    let ret: bigint[] = [];
-    var x_temp: bigint = x;
-    for (var idx = 0; idx < k; idx++) {
-        ret.push(x_temp % mod);
-        x_temp = x_temp / mod;
-    }
-    return ret;
-}
+import { bigint_to_array } from './utils'
 
 describe("Secp256k1AddUnequal", function () {
     this.timeout(1000 * 1000);