chore!: extract decoder code

Separation of concerns by moving decoding logic in new class.

Author: fryorcraken

packages/dns-discovery/src/dns.ts

@@ -1,4 +1,4 @@
-import { ENR } from "@waku/enr";
+import { ENR, EnrDecoder } from "@waku/enr";
 import type { IEnr } from "@waku/interfaces";
 import debug from "debug";
 
@@ -131,7 +131,7 @@ export class DnsNodeDiscovery {
             next = selectRandomPath(branches, context);
             return await this._search(next, context);
           case ENRTree.RECORD_PREFIX:
-            return ENR.decodeTxt(entry);
+            return EnrDecoder.fromString(entry);
           default:
             return null;
         }

packages/enr/src/decoder.ts

@@ -0,0 +1,59 @@
+import * as RLP from "@ethersproject/rlp";
+import type { ENRKey, ENRValue } from "@waku/interfaces";
+import { bytesToHex, bytesToUtf8, hexToBytes } from "@waku/utils";
+import { log } from "debug";
+import { fromString } from "uint8arrays/from-string";
+
+import { ENR } from "./enr.js";
+
+export class EnrDecoder {
+  static fromString(encoded: string): Promise<ENR> {
+    if (!encoded.startsWith(ENR.RECORD_PREFIX)) {
+      throw new Error(
+        `"string encoded ENR must start with '${ENR.RECORD_PREFIX}'`
+      );
+    }
+    return EnrDecoder.fromRLP(fromString(encoded.slice(4), "base64url"));
+  }
+
+  static fromRLP(encoded: Uint8Array): Promise<ENR> {
+    const decoded = RLP.decode(encoded).map(hexToBytes);
+    return EnrDecoder.fromValues(decoded);
+  }
+
+  private static async fromValues(decoded: Uint8Array[]): Promise<ENR> {
+    if (!Array.isArray(decoded)) {
+      throw new Error("Decoded ENR must be an array");
+    }
+    if (decoded.length % 2 !== 0) {
+      throw new Error("Decoded ENR must have an even number of elements");
+    }
+    const [signature, seq, ...kvs] = decoded;
+    if (!signature || Array.isArray(signature)) {
+      throw new Error("Decoded ENR invalid signature: must be a byte array");
+    }
+    if (!seq || Array.isArray(seq)) {
+      throw new Error(
+        "Decoded ENR invalid sequence number: must be a byte array"
+      );
+    }
+    const obj: Record<ENRKey, ENRValue> = {};
+    for (let i = 0; i < kvs.length; i += 2) {
+      try {
+        obj[bytesToUtf8(kvs[i])] = kvs[i + 1];
+      } catch (e) {
+        log("Failed to decode ENR key to UTF-8, skipping it", kvs[i], e);
+      }
+    }
+    // If seq is an empty array, translate as value 0
+    const hexSeq = "0x" + (seq.length ? bytesToHex(seq) : "00");
+
+    const enr = await ENR.create(obj, BigInt(hexSeq), signature);
+
+    const rlpEncodedBytes = hexToBytes(RLP.encode([seq, ...kvs]));
+    if (!enr.verify(rlpEncodedBytes, signature)) {
+      throw new Error("Unable to verify ENR signature");
+    }
+    return enr;
+  }
+}

packages/enr/src/enr.spec.ts

@@ -8,6 +8,7 @@ import { equals } from "uint8arrays/equals";
 
 import { ERR_INVALID_ID } from "./constants.js";
 import { EnrCreator } from "./creator.js";
+import { EnrDecoder } from "./decoder.js";
 import { ENR } from "./enr.js";
 import { getPrivateKeyFromPeerId } from "./peer_id.js";
 
@@ -34,7 +35,7 @@ describe("ENR", function () {
       };
 
       const txt = await enr.encodeTxt(privateKey);
-      const enr2 = await ENR.decodeTxt(txt);
+      const enr2 = await EnrDecoder.fromString(txt);
 
       if (!enr.signature) throw "enr.signature is undefined";
       if (!enr2.signature) throw "enr.signature is undefined";
@@ -65,7 +66,7 @@ describe("ENR", function () {
     it("should decode valid enr successfully", async () => {
       const txt =
         "enr:-Ku4QMh15cIjmnq-co5S3tYaNXxDzKTgj0ufusA-QfZ66EWHNsULt2kb0eTHoo1Dkjvvf6CAHDS1Di-htjiPFZzaIPcLh2F0dG5ldHOIAAAAAAAAAACEZXRoMpD2d10HAAABE________x8AgmlkgnY0gmlwhHZFkMSJc2VjcDI1NmsxoQIWSDEWdHwdEA3Lw2B_byeFQOINTZ0GdtF9DBjes6JqtIN1ZHCCIyg";
-      const enr = await ENR.decodeTxt(txt);
+      const enr = await EnrDecoder.fromString(txt);
       const eth2 = enr.get("eth2");
       if (!eth2) throw "eth2 is undefined";
       expect(bytesToHex(eth2)).to.be.equal("f6775d0700000113ffffffffffff1f00");
@@ -74,7 +75,7 @@ describe("ENR", function () {
     it("should decode valid ENR with multiaddrs successfully [shared test vector]", async () => {
       const txt =
         "enr:-QEnuEBEAyErHEfhiQxAVQoWowGTCuEF9fKZtXSd7H_PymHFhGJA3rGAYDVSHKCyJDGRLBGsloNbS8AZF33IVuefjOO6BIJpZIJ2NIJpcIQS39tkim11bHRpYWRkcnO4lgAvNihub2RlLTAxLmRvLWFtczMud2FrdXYyLnRlc3Quc3RhdHVzaW0ubmV0BgG73gMAODcxbm9kZS0wMS5hYy1jbi1ob25na29uZy1jLndha3V2Mi50ZXN0LnN0YXR1c2ltLm5ldAYBu94DACm9A62t7AQL4Ef5ZYZosRpQTzFVAB8jGjf1TER2wH-0zBOe1-MDBNLeA4lzZWNwMjU2azGhAzfsxbxyCkgCqq8WwYsVWH7YkpMLnU2Bw5xJSimxKav-g3VkcIIjKA";
-      const enr = await ENR.decodeTxt(txt);
+      const enr = await EnrDecoder.fromString(txt);
 
       expect(enr.multiaddrs).to.not.be.undefined;
       expect(enr.multiaddrs!.length).to.be.equal(3);
@@ -93,7 +94,7 @@ describe("ENR", function () {
     it("should decode valid enr with tcp successfully", async () => {
       const txt =
         "enr:-IS4QAmC_o1PMi5DbR4Bh4oHVyQunZblg4bTaottPtBodAhJZvxVlWW-4rXITPNg4mwJ8cW__D9FBDc9N4mdhyMqB-EBgmlkgnY0gmlwhIbRi9KJc2VjcDI1NmsxoQOevTdO6jvv3fRruxguKR-3Ge4bcFsLeAIWEDjrfaigNoN0Y3CCdl8";
-      const enr = await ENR.decodeTxt(txt);
+      const enr = await EnrDecoder.fromString(txt);
       expect(enr.tcp).to.not.be.undefined;
       expect(enr.tcp).to.be.equal(30303);
       expect(enr.ip).to.not.be.undefined;
@@ -114,7 +115,7 @@ describe("ENR", function () {
         enr.set("id", new Uint8Array([0]));
         const txt = await enr.encodeTxt(privateKey);
 
-        await ENR.decodeTxt(txt);
+        await EnrDecoder.fromString(txt);
         assert.fail("Expect error here");
       } catch (err: unknown) {
         const e = err as Error;
@@ -126,7 +127,7 @@ describe("ENR", function () {
       try {
         const txt =
           "enr:-IS4QJ2d11eu6dC7E7LoXeLMgMP3kom1u3SE8esFSWvaHoo0dP1jg8O3-nx9ht-EO3CmG7L6OkHcMmoIh00IYWB92QABgmlkgnY0gmlwhH8AAAGJc2d11eu6dCsxoQIB_c-jQMOXsbjWkbN-kj99H57gfId5pfb4wa1qxwV4CIN1ZHCCIyk";
-        ENR.decodeTxt(txt);
+        EnrDecoder.fromString(txt);
         assert.fail("Expect error here");
       } catch (err: unknown) {
         const e = err as Error;
@@ -180,7 +181,7 @@ describe("ENR", function () {
     it("should return false", async () => {
       const txt =
         "enr:-Ku4QMh15cIjmnq-co5S3tYaNXxDzKTgj0ufusA-QfZ66EWHNsULt2kb0eTHoo1Dkjvvf6CAHDS1Di-htjiPFZzaIPcLh2F0dG5ldHOIAAAAAAAAAACEZXRoMpD2d10HAAABE________x8AgmlkgnY0gmlwhHZFkMSJc2VjcDI1NmsxoQIWSDEWdHwdEA3Lw2B_byeFQOINTZ0GdtF9DBjes6JqtIN1ZHCCIyg";
-      const enr = await ENR.decodeTxt(txt);
+      const enr = await EnrDecoder.fromString(txt);
       // should have id and public key inside ENR
       expect(enr.verify(new Uint8Array(32), new Uint8Array(64))).to.be.false;
     });
@@ -209,7 +210,7 @@ describe("ENR", function () {
 
     it("should encode/decode to RLP encoding", async function () {
       const encoded = await record.encode(privateKey);
-      const decoded = await ENR.decode(encoded);
+      const decoded = await EnrDecoder.fromRLP(encoded);
 
       record.forEach((value, key) => {
         expect(equals(decoded.get(key)!, value)).to.be.true;
@@ -220,7 +221,7 @@ describe("ENR", function () {
       // spec enr https://eips.ethereum.org/EIPS/eip-778
       const testTxt =
         "enr:-IS4QHCYrYZbAKWCBRlAy5zzaDZXJBGkcnh4MHcBFZntXNFrdvJjX04jRzjzCBOonrkTfj499SZuOh8R33Ls8RRcy5wBgmlkgnY0gmlwhH8AAAGJc2VjcDI1NmsxoQPKY0yuDUmstAHYpMa2_oxVtw0RW_QAdpzBQA8yWM0xOIN1ZHCCdl8";
-      const decoded = await ENR.decodeTxt(testTxt);
+      const decoded = await EnrDecoder.fromString(testTxt);
       // Note: Signatures are different due to the extra entropy added
       // by @noble/secp256k1:
       // https://github.com/paulmillr/noble-secp256k1#signmsghash-privatekey
@@ -403,7 +404,7 @@ describe("ENR", function () {
       enr.waku2 = waku2Protocols;
 
       const txt = await enr.encodeTxt(privateKey);
-      const decoded = (await ENR.decodeTxt(txt)).waku2!;
+      const decoded = (await EnrDecoder.fromString(txt)).waku2!;
 
       expect(decoded.relay).to.equal(false);
       expect(decoded.store).to.equal(false);
@@ -419,7 +420,7 @@ describe("ENR", function () {
 
       enr.waku2 = waku2Protocols;
       const txt = await enr.encodeTxt(privateKey);
-      const decoded = (await ENR.decodeTxt(txt)).waku2!;
+      const decoded = (await EnrDecoder.fromString(txt)).waku2!;
 
       expect(decoded.relay).to.equal(true);
       expect(decoded.store).to.equal(true);
@@ -432,7 +433,7 @@ describe("ENR", function () {
 
       enr.waku2 = waku2Protocols;
       const txt = await enr.encodeTxt(privateKey);
-      const decoded = (await ENR.decodeTxt(txt)).waku2!;
+      const decoded = (await EnrDecoder.fromString(txt)).waku2!;
 
       expect(decoded.relay).to.equal(true);
       expect(decoded.store).to.equal(false);
@@ -445,7 +446,7 @@ describe("ENR", function () {
 
       enr.waku2 = waku2Protocols;
       const txt = await enr.encodeTxt(privateKey);
-      const decoded = (await ENR.decodeTxt(txt)).waku2!;
+      const decoded = (await EnrDecoder.fromString(txt)).waku2!;
 
       expect(decoded.relay).to.equal(false);
       expect(decoded.store).to.equal(true);
@@ -458,7 +459,7 @@ describe("ENR", function () {
 
       enr.waku2 = waku2Protocols;
       const txt = await enr.encodeTxt(privateKey);
-      const decoded = (await ENR.decodeTxt(txt)).waku2!;
+      const decoded = (await EnrDecoder.fromString(txt)).waku2!;
 
       expect(decoded.relay).to.equal(false);
       expect(decoded.store).to.equal(false);
@@ -471,7 +472,7 @@ describe("ENR", function () {
 
       enr.waku2 = waku2Protocols;
       const txt = await enr.encodeTxt(privateKey);
-      const decoded = (await ENR.decodeTxt(txt)).waku2!;
+      const decoded = (await EnrDecoder.fromString(txt)).waku2!;
 
       expect(decoded.relay).to.equal(false);
       expect(decoded.store).to.equal(false);
@@ -485,7 +486,7 @@ describe("ENR", function () {
       const txt =
         "enr:-Iu4QADPfXNCM6iYyte0pIdbMirIw_AsKR7J1DeJBysXDWz4DZvyjgIwpMt-sXTVUzLJdE9FaStVy2ZKtHUVQAH61-KAgmlkgnY0gmlwhMCosvuJc2VjcDI1NmsxoQI0OCNtPJtBayNgvFvKp-0YyCozcvE1rqm_V1W51nHVv4N0Y3CC6mCFd2FrdTIH";
 
-      const decoded = (await ENR.decodeTxt(txt)).waku2!;
+      const decoded = (await EnrDecoder.fromString(txt)).waku2!;
 
       expect(decoded.relay).to.equal(true);
       expect(decoded.store).to.equal(true);

packages/enr/src/enr.ts

@@ -13,9 +13,8 @@ import type {
   SequenceNumber,
   Waku2,
 } from "@waku/interfaces";
-import { bytesToHex, bytesToUtf8, hexToBytes, utf8ToBytes } from "@waku/utils";
+import { bytesToUtf8, hexToBytes, utf8ToBytes } from "@waku/utils";
 import debug from "debug";
-import { fromString } from "uint8arrays/from-string";
 import { toString } from "uint8arrays/to-string";
 
 import {
@@ -65,57 +64,6 @@ export class ENR extends Map<ENRKey, ENRValue> implements IEnr {
 
     return enr;
   }
-
-  static async decodeFromValues(decoded: Uint8Array[]): Promise<ENR> {
-    if (!Array.isArray(decoded)) {
-      throw new Error("Decoded ENR must be an array");
-    }
-    if (decoded.length % 2 !== 0) {
-      throw new Error("Decoded ENR must have an even number of elements");
-    }
-    const [signature, seq, ...kvs] = decoded;
-    if (!signature || Array.isArray(signature)) {
-      throw new Error("Decoded ENR invalid signature: must be a byte array");
-    }
-    if (!seq || Array.isArray(seq)) {
-      throw new Error(
-        "Decoded ENR invalid sequence number: must be a byte array"
-      );
-    }
-    const obj: Record<ENRKey, ENRValue> = {};
-    for (let i = 0; i < kvs.length; i += 2) {
-      try {
-        obj[bytesToUtf8(kvs[i])] = kvs[i + 1];
-      } catch (e) {
-        log("Failed to decode ENR key to UTF-8, skipping it", kvs[i], e);
-      }
-    }
-    // If seq is an empty array, translate as value 0
-    const hexSeq = "0x" + (seq.length ? bytesToHex(seq) : "00");
-
-    const enr = await ENR.create(obj, BigInt(hexSeq), signature);
-
-    const rlpEncodedBytes = hexToBytes(RLP.encode([seq, ...kvs]));
-    if (!enr.verify(rlpEncodedBytes, signature)) {
-      throw new Error("Unable to verify ENR signature");
-    }
-    return enr;
-  }
-
-  static decode(encoded: Uint8Array): Promise<ENR> {
-    const decoded = RLP.decode(encoded).map(hexToBytes);
-    return ENR.decodeFromValues(decoded);
-  }
-
-  static decodeTxt(encoded: string): Promise<ENR> {
-    if (!encoded.startsWith(this.RECORD_PREFIX)) {
-      throw new Error(
-        `"string encoded ENR must start with '${this.RECORD_PREFIX}'`
-      );
-    }
-    return ENR.decode(fromString(encoded.slice(4), "base64url"));
-  }
-
   set(k: ENRKey, v: ENRValue): this {
     this.signature = undefined;
     this.seq++;

packages/enr/src/index.ts

@@ -1,5 +1,6 @@
 export * from "./constants.js";
 export * from "./creator.js";
+export * from "./decoder.js";
 export * from "./enr.js";
 export * from "./peer_id.js";
 export * from "./waku2_codec.js";

packages/peer-exchange/src/waku_peer_exchange.ts

@@ -5,7 +5,7 @@ import type {
   Registrar,
 } from "@libp2p/interface-registrar";
 import { BaseProtocol } from "@waku/core/lib/base_protocol";
-import { ENR } from "@waku/enr";
+import { EnrDecoder } from "@waku/enr";
 import type {
   IPeerExchange,
   PeerExchangeQueryParams,
@@ -95,7 +95,7 @@ export class WakuPeerExchange extends BaseProtocol implements IPeerExchange {
 
         const enrs = await Promise.all(
           decoded.peerInfos.map(
-            (peerInfo) => peerInfo.enr && ENR.decode(peerInfo.enr)
+            (peerInfo) => peerInfo.enr && EnrDecoder.fromRLP(peerInfo.enr)
           )
         );
 

packages/tests/tests/enr.node.spec.ts

@@ -1,6 +1,6 @@
 import { waitForRemotePeer } from "@waku/core";
 import { createRelayNode } from "@waku/create";
-import { ENR } from "@waku/enr";
+import { EnrDecoder } from "@waku/enr";
 import type { RelayNode } from "@waku/interfaces";
 import { Protocols } from "@waku/interfaces";
 import { expect } from "chai";
@@ -38,7 +38,7 @@ describe("ENR Interop: nwaku", function () {
     const nimPeerId = await nwaku.getPeerId();
 
     expect(nwakuInfo.enrUri).to.not.be.undefined;
-    const dec = await ENR.decodeTxt(nwakuInfo.enrUri ?? "");
+    const dec = await EnrDecoder.fromString(nwakuInfo.enrUri ?? "");
     expect(dec.peerId?.toString()).to.eq(nimPeerId.toString());
     expect(dec.waku2).to.deep.eq({
       relay: true,
@@ -70,7 +70,7 @@ describe("ENR Interop: nwaku", function () {
     const nimPeerId = await nwaku.getPeerId();
 
     expect(nwakuInfo.enrUri).to.not.be.undefined;
-    const dec = await ENR.decodeTxt(nwakuInfo.enrUri ?? "");
+    const dec = await EnrDecoder.fromString(nwakuInfo.enrUri ?? "");
     expect(dec.peerId?.toString()).to.eq(nimPeerId.toString());
     expect(dec.waku2).to.deep.eq({
       relay: true,
@@ -102,7 +102,7 @@ describe("ENR Interop: nwaku", function () {
     const nimPeerId = await nwaku.getPeerId();
 
     expect(nwakuInfo.enrUri).to.not.be.undefined;
-    const dec = await ENR.decodeTxt(nwakuInfo.enrUri ?? "");
+    const dec = await EnrDecoder.fromString(nwakuInfo.enrUri ?? "");
     expect(dec.peerId?.toString()).to.eq(nimPeerId.toString());
     expect(dec.waku2).to.deep.eq({
       relay: true,