Improve interfaces from chainsafe/bls usage

Author: dapplion

.gitignore

@@ -3,7 +3,7 @@ coverage
 build
 dist
 node_modules
-prebuilds
+prebuild/*.node
 
 npm-debug.log
 yarn-error.log

src/bindings.ts

@@ -242,4 +242,7 @@ export enum BLST_ERROR {
   BLST_AGGR_TYPE_MISMATCH = 4,
   BLST_VERIFY_FAIL = 5,
   BLST_PK_IS_INFINITY = 6,
+
+  // Extra errors not in native bindings
+  EMPTY_AGGREGATE_ARRAY = "EMPTY_AGGREGATE_ARRAY",
 }

src/lib.ts

@@ -5,7 +5,8 @@ const HASH_OR_ENCODE = true;
 const DST = "BLS_SIG_BLS12381G2_XMD:SHA-256_SSWU_RO_POP_";
 const RAND_BITS = 64;
 
-class ErrorBLST extends Error {
+export { BLST_ERROR };
+export class ErrorBLST extends Error {
   constructor(blstError: BLST_ERROR) {
     super(BLST_ERROR[blstError]);
   }
@@ -45,6 +46,11 @@ export class SecretKey {
     return new SecretKey(sk);
   }
 
+  toAggregatePublicKey(): AggregatePublicKey {
+    const pk = new PkConstructor(this.value);
+    return new AggregatePublicKey(pk);
+  }
+
   toPublicKey(): PublicKey {
     const pk = new PkConstructor(this.value);
     return new PublicKey(pk.to_affine());
@@ -98,14 +104,6 @@ export class Signature extends SerializeAffine<SigAffine> {
   }
 }
 
-function aggregate<P extends Pn_Affine<any, any>>(points: { value: P }[]) {
-  const agg = points[0].value.to_jacobian();
-  for (const pk of points.slice(1)) {
-    agg.aggregate(pk.value);
-  }
-  return agg;
-}
-
 export class AggregatePublicKey {
   value: Pk;
 
@@ -117,7 +115,9 @@ export class AggregatePublicKey {
     return new AggregatePublicKey(pk.value.to_jacobian());
   }
   static fromPublicKeys(pks: PublicKey[]): AggregatePublicKey {
-    return new AggregatePublicKey(aggregate(pks));
+    return aggregatePubkeys(
+      pks.map((pk) => AggregatePublicKey.fromPublicKey(pk))
+    );
   }
   static fromPublicKeysBytes(pks: Uint8Array[]): AggregatePublicKey {
     return AggregatePublicKey.fromPublicKeys(pks.map(PublicKey.fromBytes));
@@ -145,7 +145,9 @@ export class AggregateSignature {
     return new AggregateSignature(sig.value.to_jacobian());
   }
   static fromSignatures(sigs: Signature[]): AggregateSignature {
-    return new AggregateSignature(aggregate(sigs));
+    return aggregateSignatures(
+      sigs.map((sig) => AggregateSignature.fromSignature(sig))
+    );
   }
   static fromSignaturesBytes(sigs: Uint8Array[]): AggregateSignature {
     return AggregateSignature.fromSignatures(sigs.map(Signature.fromBytes));
@@ -162,6 +164,34 @@ export class AggregateSignature {
   }
 }
 
+export function aggregatePubkeys(
+  pks: AggregatePublicKey[]
+): AggregatePublicKey {
+  if (pks.length === 0) {
+    throw new ErrorBLST(BLST_ERROR.EMPTY_AGGREGATE_ARRAY);
+  }
+
+  const agg = pks
+    .map((pk) => pk.value)
+    .reduce((_agg, pk) => blst.P1.add(_agg, pk));
+
+  return new AggregatePublicKey(agg);
+}
+
+export function aggregateSignatures(
+  sigs: AggregateSignature[]
+): AggregateSignature {
+  if (sigs.length === 0) {
+    throw new ErrorBLST(BLST_ERROR.EMPTY_AGGREGATE_ARRAY);
+  }
+
+  const agg = sigs
+    .map((sig) => sig.value)
+    .reduce((_agg, sig) => blst.P2.add(_agg, sig));
+
+  return new AggregateSignature(agg);
+}
+
 export function verify(
   msg: Uint8Array,
   pk: PublicKey,
@@ -172,10 +202,10 @@ export function verify(
 
 export function fastAggregateVerify(
   msg: Uint8Array,
-  pks: PublicKey[],
+  pks: AggregatePublicKey[],
   sig: Signature
 ): boolean {
-  const aggPk = AggregatePublicKey.fromPublicKeys(pks);
+  const aggPk = aggregatePubkeys(pks);
   const pk = aggPk.toPublicKey();
   return aggregateVerify([msg], [pk], sig);
 }

src/scripts/downloadBindings.ts

@@ -4,7 +4,7 @@ import { testBindings } from "./testBindings";
 import { ensureDirFromFilepath, getBinaryName, packageJsonPath } from "./paths";
 
 const githubReleasesDownloadUrl =
-  "https://github.com/ChainSafe/blst-ts/releases/download";
+  "https://github.com/ChainSafe/blst/releases/download";
 
 export async function checkAndDownloadBinary(binaryPath: string) {
   const packageJson = require(packageJsonPath);

test/lib/index.test.ts

@@ -18,19 +18,19 @@ describe("bls lib", () => {
   describe("1 msg, N pks", () => {
     const msg = Buffer.from("sample-msg");
     const sks: bls.SecretKey[] = [];
-    const pks: bls.PublicKey[] = [];
+    const pks: bls.AggregatePublicKey[] = [];
     const sigs: bls.Signature[] = [];
 
     for (let i = 0; i < n; i++) {
       const sk = bls.SecretKey.fromKeygen(Uint8Array.from(Buffer.alloc(32, i)));
       sks.push(sk);
-      pks.push(sk.toPublicKey());
+      pks.push(sk.toAggregatePublicKey());
       sigs.push(sk.sign(msg));
     }
 
     it("verify", () => {
       for (let i = 0; i < n; i++) {
-        bls.verify(msg, pks[i], sigs[i]);
+        bls.verify(msg, pks[i].toPublicKey(), sigs[i]);
       }
     });