NodeJS bindings

.gitignore

@@ -4,7 +4,6 @@
 inc/blst.h*
 inc/blst_aux.h*
 .vscode/
-*.json
 .clang-format
 *bindings/*/*.so
 *bindings/csharp/*.exe

.gitmodules

@@ -0,0 +1,4 @@
+[submodule "blst"]
+	path = blst
+	url = https://github.com/supranational/blst
+	ignore = dirty # because we apply a patch

bindings/node.js/.gitignore

@@ -0,0 +1,3 @@
+build
+*.node
+node_modules

bindings/node.js/.prettierignore

@@ -0,0 +1,3 @@
+# Ignore artifacts:
+build
+dist

bindings/node.js/.prettierrc.json

@@ -0,0 +1,9 @@
+{
+  "trailingComma": "all",
+  "overrides": [
+    {
+      "files": "binding.gyp",
+      "options": { "parser": "json" }
+    }
+  ]
+}

bindings/node.js/Makefile

@@ -0,0 +1,22 @@
+all: clean build format test bundle
+
+clean:
+	yarn node-gyp clean
+	rm -rf build
+	rm -f *.node
+	rm -f dist/kzg.node
+	rm -f *.a
+	rm -f *.o
+
+build: kzg.cxx kzg.ts package.json binding.gyp Makefile
+	cd ../../src; make lib
+	yarn node-gyp rebuild
+
+test: build
+	yarn jest
+
+format:
+	yarn prettier --write .
+
+bundle:
+	yarn rollup --config rollup.config.js --bundleConfigAsCjs

bindings/node.js/README.md

@@ -0,0 +1,57 @@
+This directory contains the code necessary to generate NodeJS bindings for C-KZG.
+
+```js
+
+  loadTrustedSetup: (filePath: string) => SetupHandle;
+
+  freeTrustedSetup: (setupHandle: SetupHandle) => void;
+
+  blobToKzgCommitment: (blob: Blob, setupHandle: SetupHandle) => KZGCommitment;
+
+  computeAggregateKzgProof: (
+    blobs: Blob[],
+    setupHandle: SetupHandle
+  ) => KZGProof;
+
+  verifyAggregateKzgProof: (
+    blobs: Blob[],
+    expectedKzgCommitments: KZGCommitment[],
+    kzgAggregatedProof: KZGProof,
+    setupHandle: SetupHandle
+  ) => boolean;
+```
+
+Spec: https://github.com/ethereum/consensus-specs/blob/dev/specs/eip4844/polynomial-commitments.md
+
+First,
+`npm install -g yarn` if you don't have it.
+
+Install the blst submodule
+
+```sh
+git submodule update --init
+```
+
+Build blst and c_kzg_4844.c
+
+```
+cd src && make blst lib
+```
+
+Generate NodeJS bindings and run the TypeScript tests against them
+
+```sh
+cd ../bindings/node.js && yarn install && make test
+```
+
+After doing this once, you can re-build (if necessary) and re-run the tests with
+
+```sh
+make build test
+```
+
+After making changes, regenerate the distributable JS and type defs
+
+```sh
+make bundle
+```

bindings/node.js/babel.config.js

@@ -0,0 +1,6 @@
+module.exports = {
+  presets: [
+    ["@babel/preset-env", { targets: { node: "current" } }],
+    "@babel/preset-typescript",
+  ],
+};

bindings/node.js/binding.gyp

@@ -0,0 +1,41 @@
+{
+  "targets": [
+    {
+      "target_name": "kzg",
+      "cflags!": ["-fno-exceptions"],
+      "cflags_cc!": ["-fno-exceptions"],
+      "xcode_settings": {
+        "GCC_ENABLE_CPP_EXCEPTIONS": "YES",
+        "CLANG_CXX_LIBRARY": "libc++",
+        "MACOSX_DEPLOYMENT_TARGET": "13.0"
+      },
+      "sources": ["kzg.cxx"],
+      "include_dirs": [
+        "../../inc",
+        "../../src",
+        "<!@(node -p \"require('node-addon-api').include\")"
+      ],
+      "libraries": [
+        "<(module_root_dir)/c_kzg_4844.o",
+        "<(module_root_dir)/../../lib/libblst.a"
+      ],
+      "dependencies": ["<!(node -p \"require('node-addon-api').gyp\")"],
+      "defines": ["NAPI_DISABLE_CPP_EXCEPTIONS"]
+    },
+    {
+      "target_name": "action_after_build",
+      "type": "none",
+      "dependencies": ["kzg"],
+      "copies": [
+        {
+          "files": ["./build/Release/kzg.node"],
+          "destination": "."
+        },
+        {
+          "files": ["./build/Release/kzg.node"],
+          "destination": "./dist"
+        }
+      ]
+    }
+  ]
+}

bindings/node.js/dist/dts/kzg.d.ts

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+export declare type BLSFieldElement = Uint8Array;
+export declare type KZGProof = Uint8Array;
+export declare type KZGCommitment = Uint8Array;
+export declare type Blob = Uint8Array;
+export declare const FIELD_ELEMENTS_PER_BLOB: number;
+export declare const BYTES_PER_FIELD_ELEMENT: number;
+export declare function loadTrustedSetup(filePath: string): void;
+export declare function freeTrustedSetup(): void;
+export declare function blobToKzgCommitment(blob: Blob): KZGCommitment;
+export declare function computeAggregateKzgProof(blobs: Blob[]): KZGProof;
+export declare function verifyAggregateKzgProof(blobs: Blob[], expectedKzgCommitments: KZGCommitment[], kzgAggregatedProof: KZGProof): boolean;

bindings/node.js/dist/dts/test.d.ts

@@ -0,0 +1 @@
+export {};

bindings/node.js/dist/kzg.js

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+'use strict';
+
+/**
+ * The public interface of this module exposes the functions as specified by
+ * https://github.com/ethereum/consensus-specs/blob/dev/specs/eip4844/polynomial-commitments.md#kzg
+ */
+const kzg = require("./kzg.node");
+const FIELD_ELEMENTS_PER_BLOB = kzg.FIELD_ELEMENTS_PER_BLOB;
+const BYTES_PER_FIELD_ELEMENT = kzg.BYTES_PER_FIELD_ELEMENT;
+// Stored as internal state
+let setupHandle;
+function requireSetupHandle() {
+    if (!setupHandle) {
+        throw new Error("You must call loadTrustedSetup to initialize KZG.");
+    }
+    return setupHandle;
+}
+function loadTrustedSetup(filePath) {
+    if (setupHandle) {
+        throw new Error("Call freeTrustedSetup before loading a new trusted setup.");
+    }
+    setupHandle = kzg.loadTrustedSetup(filePath);
+}
+function freeTrustedSetup() {
+    kzg.freeTrustedSetup(requireSetupHandle());
+    setupHandle = undefined;
+}
+function blobToKzgCommitment(blob) {
+    return kzg.blobToKzgCommitment(blob, requireSetupHandle());
+}
+function computeAggregateKzgProof(blobs) {
+    return kzg.computeAggregateKzgProof(blobs, requireSetupHandle());
+}
+function verifyAggregateKzgProof(blobs, expectedKzgCommitments, kzgAggregatedProof) {
+    return kzg.verifyAggregateKzgProof(blobs, expectedKzgCommitments, kzgAggregatedProof, requireSetupHandle());
+}
+
+exports.BYTES_PER_FIELD_ELEMENT = BYTES_PER_FIELD_ELEMENT;
+exports.FIELD_ELEMENTS_PER_BLOB = FIELD_ELEMENTS_PER_BLOB;
+exports.blobToKzgCommitment = blobToKzgCommitment;
+exports.computeAggregateKzgProof = computeAggregateKzgProof;
+exports.freeTrustedSetup = freeTrustedSetup;
+exports.loadTrustedSetup = loadTrustedSetup;
+exports.verifyAggregateKzgProof = verifyAggregateKzgProof;

bindings/node.js/jest.config.js

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+/** @type {import('ts-jest').JestConfigWithTsJest} */
+module.exports = {
+  preset: "ts-jest",
+  testEnvironment: "node",
+};