Merge pull request #107 from ChainSafe/cayman/discv5.1

Initial discv5.1 update
ChainSafe · Nov 19, 2020 · 05ba828 · 05ba828
2 parents a4c9cb4 + 77c54ff
commit 05ba828
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Showing 28 changed files with 1,397 additions and 1,312 deletions.
diff --git a/package.json b/package.json
@@ -54,11 +54,13 @@
     "typescript": "^3.8.3"
   },
   "dependencies": {
+    "@types/err-code": "^2.0.0",
     "base64url": "^3.0.1",
     "bcrypto": "^4.2.8",
     "bigint-buffer": "^1.1.5",
     "debug": "^4.1.1",
     "dgram": "^1.0.1",
+    "err-code": "^2.0.3",
     "ip6addr": "^0.2.3",
     "is-ip": "^3.1.0",
     "libp2p-crypto": "^0.18.0",

diff --git a/src/message/create.ts b/src/message/create.ts
@@ -31,11 +31,11 @@ export function createPongMessage(
   };
 }
 
-export function createFindNodeMessage(distance: number): IFindNodeMessage {
+export function createFindNodeMessage(distances: number[]): IFindNodeMessage {
   return {
     type: MessageType.FINDNODE,
     id: createRequestId(),
-    distance,
+    distances,
   };
 }
 

diff --git a/src/message/decode.ts b/src/message/decode.ts
@@ -13,6 +13,8 @@ import {
   ITopicQueryMessage,
   Message,
   MessageType,
+  ITalkReqMessage,
+  ITalkRespMessage,
 } from "./types";
 import { ENR } from "../enr";
 
@@ -29,6 +31,10 @@ export function decode(data: Buffer): Message {
       return decodeFindNode(data);
     case MessageType.NODES:
       return decodeNodes(data);
+    case MessageType.TALKREQ:
+      return decodeTalkReq(data);
+    case MessageType.TALKRESP:
+      return decodeTalkResp(data);
     case MessageType.REGTOPIC:
       return decodeRegTopic(data);
     case MessageType.TICKET:
@@ -78,10 +84,14 @@ function decodeFindNode(data: Buffer): IFindNodeMessage {
   if (!Array.isArray(rlpRaw) || rlpRaw.length !== 2) {
     throw new Error(ERR_INVALID_MESSAGE);
   }
+  if (!Array.isArray(rlpRaw[1])) {
+    throw new Error(ERR_INVALID_MESSAGE);
+  }
+  const distances = ((rlpRaw[1] as unknown) as Buffer[]).map((x) => (x.length ? x.readUInt8(0) : 0));
   return {
     type: MessageType.FINDNODE,
     id: toBigIntBE(rlpRaw[0]),
-    distance: rlpRaw[1].length ? rlpRaw[1].readUInt8(0) : 0,
+    distances,
   };
 }
 
@@ -98,6 +108,31 @@ function decodeNodes(data: Buffer): INodesMessage {
   };
 }
 
+function decodeTalkReq(data: Buffer): ITalkReqMessage {
+  const rlpRaw = (RLP.decode(data.slice(1)) as unknown) as RLP.Decoded;
+  if (!Array.isArray(rlpRaw) || rlpRaw.length !== 3) {
+    throw new Error(ERR_INVALID_MESSAGE);
+  }
+  return {
+    type: MessageType.TALKREQ,
+    id: toBigIntBE(rlpRaw[0]),
+    protocol: rlpRaw[1],
+    request: rlpRaw[2],
+  };
+}
+
+function decodeTalkResp(data: Buffer): ITalkRespMessage {
+  const rlpRaw = (RLP.decode(data.slice(1)) as unknown) as RLP.Decoded;
+  if (!Array.isArray(rlpRaw) || rlpRaw.length !== 2) {
+    throw new Error(ERR_INVALID_MESSAGE);
+  }
+  return {
+    type: MessageType.TALKRESP,
+    id: toBigIntBE(rlpRaw[0]),
+    response: rlpRaw[1],
+  };
+}
+
 function decodeRegTopic(data: Buffer): IRegTopicMessage {
   const rlpRaw = (RLP.decode(data.slice(1)) as unknown) as Buffer[];
   if (!Array.isArray(rlpRaw) || rlpRaw.length !== 4 || !Array.isArray(rlpRaw[2])) {

diff --git a/src/message/encode.ts b/src/message/encode.ts
@@ -13,6 +13,8 @@ import {
   ITopicQueryMessage,
   Message,
   MessageType,
+  ITalkReqMessage,
+  ITalkRespMessage,
 } from "./types";
 
 export function encode(message: Message): Buffer {
@@ -25,6 +27,10 @@ export function encode(message: Message): Buffer {
       return encodeFindNodeMessage(message as IFindNodeMessage);
     case MessageType.NODES:
       return encodeNodesMessage(message as INodesMessage);
+    case MessageType.TALKREQ:
+      return encodeTalkReqMessage(message as ITalkReqMessage);
+    case MessageType.TALKRESP:
+      return encodeTalkRespMessage(message as ITalkRespMessage);
     case MessageType.REGTOPIC:
       return encodeRegTopicMessage(message as IRegTopicMessage);
     case MessageType.TICKET:
@@ -58,7 +64,7 @@ export function encodePongMessage(m: IPongMessage): Buffer {
 }
 
 export function encodeFindNodeMessage(m: IFindNodeMessage): Buffer {
-  return Buffer.concat([Buffer.from([MessageType.FINDNODE]), RLP.encode([toBuffer(m.id), m.distance])]);
+  return Buffer.concat([Buffer.from([MessageType.FINDNODE]), RLP.encode([toBuffer(m.id), m.distances])]);
 }
 
 export function encodeNodesMessage(m: INodesMessage): Buffer {
@@ -68,6 +74,14 @@ export function encodeNodesMessage(m: INodesMessage): Buffer {
   ]);
 }
 
+export function encodeTalkReqMessage(m: ITalkReqMessage): Buffer {
+  return Buffer.concat([Buffer.from([MessageType.TALKREQ]), RLP.encode([toBuffer(m.id), m.protocol, m.request])]);
+}
+
+export function encodeTalkRespMessage(m: ITalkRespMessage): Buffer {
+  return Buffer.concat([Buffer.from([MessageType.TALKRESP]), RLP.encode([toBuffer(m.id), m.response])]);
+}
+
 export function encodeRegTopicMessage(m: IRegTopicMessage): Buffer {
   return Buffer.concat([
     Buffer.from([MessageType.REGTOPIC]),

diff --git a/src/message/types.ts b/src/message/types.ts
@@ -7,17 +7,24 @@ export enum MessageType {
   PONG = 2,
   FINDNODE = 3,
   NODES = 4,
-  REGTOPIC = 5,
-  TICKET = 6,
-  REGCONFIRMATION = 7,
-  TOPICQUERY = 8,
+  TALKREQ = 5,
+  TALKRESP = 6,
+  REGTOPIC = 7,
+  TICKET = 8,
+  REGCONFIRMATION = 9,
+  TOPICQUERY = 10,
 }
 
 export type Message = RequestMessage | ResponseMessage;
 
-export type RequestMessage = IPingMessage | IFindNodeMessage | IRegTopicMessage | ITopicQueryMessage;
+export type RequestMessage = IPingMessage | IFindNodeMessage | ITalkReqMessage | IRegTopicMessage | ITopicQueryMessage;
 
-export type ResponseMessage = IPongMessage | INodesMessage | ITicketMessage | IRegConfirmationMessage;
+export type ResponseMessage =
+  | IPongMessage
+  | INodesMessage
+  | ITalkRespMessage
+  | ITicketMessage
+  | IRegConfirmationMessage;
 
 export interface IPingMessage {
   type: MessageType.PING;
@@ -36,7 +43,7 @@ export interface IPongMessage {
 export interface IFindNodeMessage {
   type: MessageType.FINDNODE;
   id: RequestId;
-  distance: number;
+  distances: number[];
 }
 
 export interface INodesMessage {
@@ -46,6 +53,19 @@ export interface INodesMessage {
   enrs: ENR[];
 }
 
+export interface ITalkReqMessage {
+  type: MessageType.TALKREQ;
+  id: RequestId;
+  protocol: Buffer;
+  request: Buffer;
+}
+
+export interface ITalkRespMessage {
+  type: MessageType.TALKRESP;
+  id: RequestId;
+  response: Buffer;
+}
+
 export interface IRegTopicMessage {
   type: MessageType.REGTOPIC;
   id: RequestId;

diff --git a/src/packet/constants.ts b/src/packet/constants.ts
@@ -1,22 +1,31 @@
-// length of a tag in a packet
-export const TAG_LENGTH = 32;
+export const MAX_PACKET_SIZE = 1280;
+export const MIN_PACKET_SIZE = 63;
 
-// length of an authentication tag
-export const AUTH_TAG_LENGTH = 12;
+export const MASKING_KEY_SIZE = 16;
 
-// length of magic token
-export const MAGIC_LENGTH = 32;
+export const PROTOCOL_SIZE = 6;
+export const VERSION_SIZE = 2;
+export const FLAG_SIZE = 1;
+export const NONCE_SIZE = 12;
+export const AUTHDATA_SIZE_SIZE = 2;
+export const STATIC_HEADER_SIZE = 23;
 
-// length of nonce
-export const ID_NONCE_LENGTH = 32;
+export const MESSAGE_AUTHDATA_SIZE = 32;
+export const WHOAREYOU_AUTHDATA_SIZE = 24;
+export const MIN_HANDSHAKE_AUTHDATA_SIZE = 34 + 64 + 33;
 
-export const RANDOM_DATA_LENGTH = 44;
+export const SIG_SIZE_SIZE = 1;
+export const EPH_KEY_SIZE_SIZE = 1;
 
-export const MAX_PACKET_SIZE = 1280;
+export const MASKING_IV_SIZE = 16;
+
+export const ID_NONCE_SIZE = 16;
+
+export const ERR_TOO_SMALL = "ERR_PACKET_TOO_SMALL";
+export const ERR_TOO_LARGE = "ERR_PACKET_TOO_LARGE";
 
-export const WHOAREYOU_STRING = "WHOAREYOU";
+export const ERR_INVALID_PROTOCOL_ID = "ERR_INVALID_PROTOCOL_ID";
+export const ERR_INVALID_VERSION = "ERR_INVALID_VERSION";
+export const ERR_INVALID_FLAG = "ERR_INVALID_FLAG";
 
-export const ERR_TOO_SMALL = "packet too small";
-export const ERR_TOO_LARGE = "packet too large";
-export const ERR_UNKNOWN_FORMAT = "unknown format";
-export const ERR_INVALID_BYTE_SIZE = "invalid byte size";
+export const ERR_INVALID_AUTHDATA_SIZE = "ERR_INVALID_AUTHDATA_SIZE";
diff --git a/src/packet/create.ts b/src/packet/create.ts
@@ -1,78 +1,41 @@
 import { randomBytes } from "bcrypto/lib/random";
-import sha256 = require("bcrypto/lib/sha256");
+import { NodeId, SequenceNumber } from "../enr";
+import { ID_NONCE_SIZE, MASKING_IV_SIZE, NONCE_SIZE } from "./constants";
+import { encodeMessageAuthdata, encodeWhoAreYouAuthdata } from "./encode";
+import { IHeader, IPacket, PacketType } from "./types";
 
-import { AUTH_TAG_LENGTH, ID_NONCE_LENGTH, RANDOM_DATA_LENGTH, WHOAREYOU_STRING } from "./constants";
-import { Tag, AuthTag, IWhoAreYouPacket, IAuthResponse, Nonce, IAuthHeader, PacketType, IRandomPacket } from "./types";
-import { NodeId, SequenceNumber, ENR } from "../enr";
-import { fromHex, toHex } from "../util";
-
-export function createRandomPacket(tag: Tag): IRandomPacket {
-  return {
-    type: PacketType.Random,
-    tag,
-    authTag: randomBytes(AUTH_TAG_LENGTH),
-    message: randomBytes(RANDOM_DATA_LENGTH),
-  };
-}
-
-export function createMagic(nodeId: NodeId): Buffer {
-  return sha256.digest(Buffer.concat([fromHex(nodeId), Buffer.from(WHOAREYOU_STRING, "utf-8")]));
-}
-
-export function createWhoAreYouPacket(nodeId: NodeId, authTag: AuthTag, enrSeq: SequenceNumber): IWhoAreYouPacket {
+export function createHeader(flag: PacketType, authdata: Buffer, nonce = randomBytes(NONCE_SIZE)): IHeader {
   return {
-    type: PacketType.WhoAreYou,
-    magic: createMagic(nodeId),
-    token: authTag,
-    idNonce: randomBytes(ID_NONCE_LENGTH),
-    enrSeq: Number(enrSeq),
+    protocolId: "discv5",
+    version: 1,
+    flag,
+    nonce,
+    authdataSize: authdata.length,
+    authdata,
   };
 }
 
-export function createAuthTag(): AuthTag {
-  return randomBytes(AUTH_TAG_LENGTH);
-}
-
-export function createAuthHeader(
-  idNonce: Nonce,
-  ephemeralPubkey: Buffer,
-  authResponse: Buffer,
-  authTag?: AuthTag
-): IAuthHeader {
+export function createRandomPacket(srcId: NodeId): IPacket {
+  const authdata = encodeMessageAuthdata({ srcId });
+  const header = createHeader(PacketType.Message, authdata);
+  const maskingIv = randomBytes(MASKING_IV_SIZE);
+  const message = randomBytes(44);
   return {
-    authTag: authTag || createAuthTag(),
-    idNonce,
-    authSchemeName: "gcm",
-    ephemeralPubkey,
-    authResponse,
+    maskingIv,
+    header,
+    message,
   };
 }
 
-export function createAuthResponse(signature: Buffer, enr?: ENR): IAuthResponse {
+export function createWhoAreYouPacket(nonce: Buffer, enrSeq: SequenceNumber): IPacket {
+  const idNonce = randomBytes(ID_NONCE_SIZE);
+  const authdata = encodeWhoAreYouAuthdata({ idNonce, enrSeq });
+  const header = createHeader(PacketType.WhoAreYou, authdata, nonce);
+  const maskingIv = randomBytes(MASKING_IV_SIZE);
+  const message = Buffer.alloc(0);
   return {
-    version: 5,
-    signature,
-    nodeRecord: enr,
+    maskingIv,
+    header,
+    message,
   };
 }
-
-// calculate node id / tag
-
-export function createSrcId(dstId: NodeId, tag: Tag): NodeId {
-  const hash = sha256.digest(fromHex(dstId));
-  // reuse `hash` buffer for output
-  for (let i = 0; i < 32; i++) {
-    hash[i] = hash[i] ^ tag[i];
-  }
-  return toHex(hash);
-}
-
-export function createTag(srcId: NodeId, dstId: NodeId): Tag {
-  const nodeId = fromHex(srcId);
-  const hash = sha256.digest(fromHex(dstId));
-  // reuse `hash` buffer for output
-  for (let i = 0; i < 32; i++) {
-    hash[i] = hash[i] ^ nodeId[i];
-  }
-  return hash;
-}