Merge pull request #29 from dgcoffman/dgc/expose-verify-proof

Expose verifyKzgProof

bindings/node.js/kzg.cxx

@@ -59,6 +59,15 @@ Napi::TypedArrayOf<uint8_t> napi_typed_array_from_bytes(uint8_t* array, size_t l
   return Napi::Uint8Array::New(env, length, buffer, 0);
 }
 
+const uint8_t * extract_byte_array_from_param(const Napi::CallbackInfo& info, const int index, const std::string name) {
+  auto param = info[index].As<Napi::TypedArray>();
+  if (!param.IsTypedArray() || param.TypedArrayType() != napi_uint8_array) {
+    throw_invalid_argument_type(info.Env(), name, "UInt8Array");
+  }
+  return param.As<Napi::Uint8Array>().Data();
+}
+
+
 // loadTrustedSetup: (filePath: string) => SetupHandle;
 Napi::Value LoadTrustedSetup(const Napi::CallbackInfo& info) {
   auto env = info.Env();
@@ -125,11 +134,10 @@ Napi::Value BlobToKzgCommitment(const Napi::CallbackInfo& info) {
     return throw_invalid_arguments_count(expected_argument_count, argument_count, env);
   }
 
-  auto blob_param = info[0].As<Napi::TypedArray>();
+  auto blob = extract_byte_array_from_param(info, 0, "blob");
-  if (!blob_param.IsTypedArray() || blob_param.TypedArrayType() != napi_uint8_array) {
+  if (env.IsExceptionPending()) {
-     return throw_invalid_argument_type(env, "blob", "UInt8Array");
+    return env.Null();
   }
-  auto blob = blob_param.As<Napi::Uint8Array>().Data();
 
   auto kzg_settings = info[1].As<Napi::External<KZGSettings>>().Data();
 
@@ -280,32 +288,16 @@ Napi::Value VerifyKzgProof(const Napi::CallbackInfo& info) {
     return throw_invalid_arguments_count(expected_argument_count, argument_count, env);
   }
 
-  auto c_param = info[0].As<Napi::TypedArray>();
+  auto polynomial_kzg = extract_byte_array_from_param(info, 0, "polynomialKzg");
-  if (c_param.TypedArrayType() != napi_uint8_array) {
+  auto z = extract_byte_array_from_param(info, 1, "z");
-    return throw_invalid_argument_type(env, "polynomialKzg", "UInt8Array");
+  auto y = extract_byte_array_from_param(info, 2, "y");
-  }
+  auto kzg_proof = extract_byte_array_from_param(info, 3, "kzgProof");
-  auto polynomial_kzg = c_param.As<Napi::Uint8Array>().Data();
-
-  auto z_param = info[1].As<Napi::TypedArray>();
-  if (z_param.TypedArrayType() != napi_uint8_array) {
-     return throw_invalid_argument_type(env, "z", "UInt8Array");
-  }
-  auto z = z_param.As<Napi::Uint8Array>().Data();
-
-  auto y_param = info[2].As<Napi::TypedArray>();
-  if (y_param.TypedArrayType() != napi_uint8_array) {
-    return throw_invalid_argument_type(env, "y", "UInt8Array");
-  }
-  auto y = y_param.As<Napi::Uint8Array>().Data();
-
-  auto proof_param = info[3].As<Napi::TypedArray>();
-  if (proof_param.TypedArrayType() != napi_uint8_array) {
-     return throw_invalid_argument_type(env, "kzgProof", "UInt8Array");
-  }
-  auto kzg_proof = proof_param.As<Napi::Uint8Array>().Data();
-
   auto kzg_settings = info[4].As<Napi::External<KZGSettings>>().Data();
 
+  if (env.IsExceptionPending()) {
+    return env.Null();
+  }
+
   KZGCommitment commitment;
   auto ret = bytes_to_g1(&commitment, polynomial_kzg);
   if (ret != C_KZG_OK) {

bindings/node.js/kzg.ts

@@ -35,7 +35,6 @@ type KZG = {
     setupHandle: SetupHandle,
   ) => boolean;
 
-  // Currently unused -- not exported
   verifyKzgProof: (
     polynomialKzg: KZGCommitment,
     z: BLSFieldElement,
@@ -113,6 +112,21 @@ export function computeAggregateKzgProof(blobs: Blob[]): KZGProof {
   return kzg.computeAggregateKzgProof(blobs, requireSetupHandle());
 }
 
+export function verifyKzgProof(
+  polynomialKzg: KZGCommitment,
+  z: BLSFieldElement,
+  y: BLSFieldElement,
+  kzgProof: KZGProof,
+): boolean {
+  return kzg.verifyKzgProof(
+    polynomialKzg,
+    z,
+    y,
+    kzgProof,
+    requireSetupHandle(),
+  );
+}
+
 export function verifyAggregateKzgProof(
   blobs: Blob[],
   expectedKzgCommitments: KZGCommitment[],

bindings/node.js/package.json

@@ -1,6 +1,6 @@
 {
   "name": "c-kzg",
-  "version": "1.0.7",
+  "version": "1.0.8",
   "description": "NodeJS bindings for C-KZG",
   "author": "Dan Coffman",
   "license": "MIT",

bindings/node.js/test.ts

@@ -5,6 +5,7 @@ import {
   loadTrustedSetup,
   freeTrustedSetup,
   blobToKzgCommitment,
+  verifyKzgProof,
   computeAggregateKzgProof,
   verifyAggregateKzgProof,
   BYTES_PER_FIELD_ELEMENT,
@@ -68,6 +69,28 @@ describe("C-KZG", () => {
     );
   });
 
+  it("verifies a valid KZG proof", () => {
+    const commitment = new Uint8Array(48).fill(0);
+    commitment[0] = 0xc0;
+    const z = new Uint8Array(32).fill(0);
+    const y = new Uint8Array(32).fill(0);
+    const proof = new Uint8Array(48).fill(0);
+    proof[0] = 0xc0;
+
+    expect(verifyKzgProof(commitment, z, y, proof)).toBe(true);
+  });
+
+  it("verifies an invalid valid KZG proof", () => {
+    const commitment = new Uint8Array(48).fill(0);
+    commitment[0] = 0xc0;
+    const z = new Uint8Array(32).fill(1);
+    const y = new Uint8Array(32).fill(1);
+    const proof = new Uint8Array(48).fill(0);
+    proof[0] = 0xc0;
+
+    expect(verifyKzgProof(commitment, z, y, proof)).toBe(false);
+  });
+
   it("computes the aggregate proof when for a single blob", () => {
     let blobs = new Array(1).fill(0).map(generateRandomBlob);
     let commitments = blobs.map(blobToKzgCommitment);