feat: add private key to libp2p components (#2348)

- Add `privateKey` to `Components`
- Non-breaking version of #2303

---------

Co-authored-by: Alex Potsides <alex@achingbrain.net>
Co-authored-by: chad <chad.nehemiah94@gmail.com>

packages/libp2p/src/components.ts

@@ -1,11 +1,12 @@
 import { CodeError } from '@libp2p/interface'
-import { isStartable, type Startable, type Libp2pEvents, type ComponentLogger, type NodeInfo, type ConnectionProtector, type ConnectionGater, type ContentRouting, type TypedEventTarget, type Metrics, type PeerId, type PeerRouting, type PeerStore, type Upgrader } from '@libp2p/interface'
+import { isStartable, type Startable, type Libp2pEvents, type ComponentLogger, type NodeInfo, type ConnectionProtector, type ConnectionGater, type ContentRouting, type TypedEventTarget, type Metrics, type PeerId, type PeerRouting, type PeerStore, type PrivateKey, type Upgrader } from '@libp2p/interface'
 import { defaultLogger } from '@libp2p/logger'
 import type { AddressManager, ConnectionManager, Registrar, TransportManager } from '@libp2p/interface-internal'
 import type { Datastore } from 'interface-datastore'
 
 export interface Components extends Record<string, any>, Startable {
   peerId: PeerId
+  privateKey: PrivateKey
   nodeInfo: NodeInfo
   logger: ComponentLogger
   events: TypedEventTarget<Libp2pEvents>
@@ -25,6 +26,7 @@ export interface Components extends Record<string, any>, Startable {
 
 export interface ComponentsInit {
   peerId?: PeerId
+  privateKey?: PrivateKey
   nodeInfo?: NodeInfo
   logger?: ComponentLogger
   events?: TypedEventTarget<Libp2pEvents>

packages/libp2p/src/config.ts

@@ -1,4 +1,5 @@
 import { CodeError, FaultTolerance } from '@libp2p/interface'
+import { peerIdFromKeys } from '@libp2p/peer-id'
 import { defaultAddressSort } from '@libp2p/utils/address-sort'
 import { dnsaddrResolver } from '@multiformats/multiaddr/resolvers'
 import mergeOptions from 'merge-options'
@@ -25,12 +26,16 @@ const DefaultConfig: Partial<Libp2pInit> = {
   }
 }
 
-export function validateConfig <T extends ServiceMap = Record<string, unknown>> (opts: RecursivePartial<Libp2pInit<T>>): Libp2pInit<T> {
+export async function validateConfig <T extends ServiceMap = Record<string, unknown>> (opts: RecursivePartial<Libp2pInit<T>>): Promise<Libp2pInit<T>> {
   const resultingOptions: Libp2pInit<T> = mergeOptions(DefaultConfig, opts)
 
   if (resultingOptions.connectionProtector === null && globalThis.process?.env?.LIBP2P_FORCE_PNET != null) { // eslint-disable-line no-undef
     throw new CodeError(messages.ERR_PROTECTOR_REQUIRED, codes.ERR_PROTECTOR_REQUIRED)
   }
 
+  if (!(await peerIdFromKeys(resultingOptions.privateKey.public.bytes, resultingOptions.privateKey.bytes)).equals(resultingOptions.peerId)) {
+    throw new CodeError('Private key doesn\'t match peer id', codes.ERR_INVALID_KEY)
+  }
+
   return resultingOptions
 }

packages/libp2p/src/index.ts

@@ -19,7 +19,7 @@ import type { AddressManagerInit } from './address-manager/index.js'
 import type { Components } from './components.js'
 import type { ConnectionManagerInit } from './connection-manager/index.js'
 import type { TransportManagerInit } from './transport-manager.js'
-import type { Libp2p, ServiceMap, RecursivePartial, ComponentLogger, NodeInfo, ConnectionProtector, ConnectionEncrypter, ConnectionGater, ContentRouting, Metrics, PeerDiscovery, PeerId, PeerRouting, StreamMuxerFactory, Transport } from '@libp2p/interface'
+import type { Libp2p, ServiceMap, RecursivePartial, ComponentLogger, NodeInfo, ConnectionProtector, ConnectionEncrypter, ConnectionGater, ContentRouting, Metrics, PeerDiscovery, PeerId, PeerRouting, StreamMuxerFactory, Transport, PrivateKey } from '@libp2p/interface'
 import type { PersistentPeerStoreInit } from '@libp2p/peer-store'
 import type { Datastore } from 'interface-datastore'
 
@@ -36,6 +36,11 @@ export interface Libp2pInit<T extends ServiceMap = { x: Record<string, unknown>
    */
   peerId: PeerId
 
+  /**
+   * Private key associated with the peerId
+   */
+  privateKey: PrivateKey
+
   /**
    * Metadata about the node - implementation name, version number, etc
    */

packages/libp2p/src/libp2p.ts

@@ -1,4 +1,4 @@
-import { unmarshalPublicKey } from '@libp2p/crypto/keys'
+import { unmarshalPrivateKey, unmarshalPublicKey } from '@libp2p/crypto/keys'
 import { contentRoutingSymbol, CodeError, TypedEventEmitter, CustomEvent, setMaxListeners, peerDiscoverySymbol, peerRoutingSymbol } from '@libp2p/interface'
 import { defaultLogger } from '@libp2p/logger'
 import { PeerSet } from '@libp2p/peer-collections'
@@ -67,6 +67,7 @@ export class Libp2pNode<T extends ServiceMap = Record<string, unknown>> extends
     this.services = {}
     const components = this.components = defaultComponents({
       peerId: init.peerId,
+      privateKey: init.privateKey,
       nodeInfo: init.nodeInfo ?? {
         name: pkg.name,
         version: pkg.version
@@ -397,7 +398,13 @@ export class Libp2pNode<T extends ServiceMap = Record<string, unknown>> extends
  * libp2p interface and is useful for testing and debugging.
  */
 export async function createLibp2pNode <T extends ServiceMap = Record<string, unknown>> (options: Libp2pOptions<T> = {}): Promise<Libp2pNode<T>> {
-  options.peerId ??= await createEd25519PeerId()
+  const peerId = options.peerId ??= await createEd25519PeerId()
 
-  return new Libp2pNode(validateConfig(options))
+  if (peerId.privateKey == null) {
+    throw new CodeError('peer id was missing private key', 'ERR_MISSING_PRIVATE_KEY')
+  }
+
+  options.privateKey ??= await unmarshalPrivateKey(peerId.privateKey as Uint8Array)
+
+  return new Libp2pNode(await validateConfig(options))
 }