fix: respect the IPNS TTL field (#482)

Uses the `@libp2p/record` `timeReceived` property and the `.ttl` field
of the IPNS Record to calculate the TTL of the record separately from
the record EOL.

This was going to be a push to #473 but it was merged prematurely.

---------

Co-authored-by: Russell Dempsey <1173416+SgtPooki@users.noreply.github.com>

packages/ipns/package.json

@@ -171,7 +171,7 @@
     "@libp2p/peer-id": "^4.0.7",
     "@multiformats/dns": "^1.0.1",
     "interface-datastore": "^8.2.11",
-    "ipns": "^9.0.0",
+    "ipns": "^9.1.0",
     "multiformats": "^13.1.0",
     "progress-events": "^1.0.0",
     "uint8arrays": "^5.0.2"

packages/ipns/src/index.ts

@@ -254,6 +254,8 @@ const HOUR = 60 * MINUTE
 const DEFAULT_LIFETIME_MS = 24 * HOUR
 const DEFAULT_REPUBLISH_INTERVAL_MS = 23 * HOUR
 
+const DEFAULT_TTL_NS = BigInt(HOUR) * 1_000_000n
+
 export type PublishProgressEvents =
   ProgressEvent<'ipns:publish:start'> |
   ProgressEvent<'ipns:publish:success', IPNSRecord> |
@@ -425,8 +427,8 @@ class DefaultIPNS implements IPNS {
 
       if (await this.localStore.has(routingKey, options)) {
         // if we have published under this key before, increment the sequence number
-        const buf = await this.localStore.get(routingKey, options)
-        const existingRecord = unmarshal(buf)
+        const { record } = await this.localStore.get(routingKey, options)
+        const existingRecord = unmarshal(record)
         sequenceNumber = existingRecord.sequence + 1n
       }
 
@@ -539,17 +541,46 @@ class DefaultIPNS implements IPNS {
       log('record is present in the cache')
 
       if (options.nocache !== true) {
-        // check the local cache first
-        const record = await this.localStore.get(routingKey, options)
-
         try {
+          // check the local cache first
+          const { record, created } = await this.localStore.get(routingKey, options)
+
+          this.log('record retrieved from cache')
+
+          // validate the record
           await ipnsValidator(routingKey, record)
 
-          this.log('record successfully retrieved from cache')
+          this.log('record was valid')
+
+          // check the TTL
+          const ipnsRecord = unmarshal(record)
 
-          return unmarshal(record)
+          // IPNS TTL is in nanoseconds, convert to milliseconds, default to one
+          // hour
+          const ttlMs = Number((ipnsRecord.ttl ?? DEFAULT_TTL_NS) / 1_000_000n)
+          const ttlExpires = created.getTime() + ttlMs
+
+          if (ttlExpires > Date.now()) {
+            // the TTL has not yet expired, return the cached record
+            this.log('record TTL was valid')
+            return ipnsRecord
+          }
+
+          if (options.offline === true) {
+            // the TTL has expired but we are skipping the routing search
+            this.log('record TTL has been reached but we are resolving offline-only, returning record')
+            return ipnsRecord
+          }
+
+          this.log('record TTL has been reached, searching routing for updates')
+
+          // add the local record to our list of resolved record, and also
+          // search the routing for updates - the most up to date record will be
+          // returned
+          records.push(record)
         } catch (err) {
           this.log('cached record was invalid', err)
+          await this.localStore.delete(routingKey, options)
         }
       } else {
         log('ignoring local cache due to nocache=true option')

packages/ipns/src/routing/local-store.ts

@@ -1,8 +1,9 @@
 import { Record } from '@libp2p/kad-dht'
 import { type Datastore, Key } from 'interface-datastore'
 import { CustomProgressEvent, type ProgressEvent } from 'progress-events'
+import { equals as uint8ArrayEquals } from 'uint8arrays/equals'
 import { toString as uint8ArrayToString } from 'uint8arrays/to-string'
-import type { GetOptions, IPNSRouting, PutOptions } from '../routing'
+import type { GetOptions, PutOptions } from '../routing'
 import type { AbortOptions } from '@libp2p/interface'
 
 function dhtRoutingKey (key: Uint8Array): Key {
@@ -14,8 +15,16 @@ export type DatastoreProgressEvents =
   ProgressEvent<'ipns:routing:datastore:get'> |
   ProgressEvent<'ipns:routing:datastore:error', Error>
 
-export interface LocalStore extends IPNSRouting {
+export interface GetResult {
+  record: Uint8Array
+  created: Date
+}
+
+export interface LocalStore {
+  put(routingKey: Uint8Array, marshaledRecord: Uint8Array, options?: PutOptions): Promise<void>
+  get(routingKey: Uint8Array, options?: GetOptions): Promise<GetResult>
   has(routingKey: Uint8Array, options?: AbortOptions): Promise<boolean>
+  delete(routingKey: Uint8Array, options?: AbortOptions): Promise<void>
 }
 
 /**
@@ -29,6 +38,21 @@ export function localStore (datastore: Datastore): LocalStore {
       try {
         const key = dhtRoutingKey(routingKey)
 
+        // don't overwrite existing, identical records as this will affect the
+        // TTL
+        try {
+          const existingBuf = await datastore.get(key)
+          const existingRecord = Record.deserialize(existingBuf)
+
+          if (uint8ArrayEquals(existingRecord.value, marshalledRecord)) {
+            return
+          }
+        } catch (err: any) {
+          if (err.code !== 'ERR_NOT_FOUND') {
+            throw err
+          }
+        }
+
         // Marshal to libp2p record as the DHT does
         const record = new Record(routingKey, marshalledRecord, new Date())
 
@@ -39,7 +63,7 @@ export function localStore (datastore: Datastore): LocalStore {
         throw err
       }
     },
-    async get (routingKey: Uint8Array, options: GetOptions = {}): Promise<Uint8Array> {
+    async get (routingKey: Uint8Array, options: GetOptions = {}): Promise<GetResult> {
       try {
         const key = dhtRoutingKey(routingKey)
 
@@ -49,7 +73,10 @@ export function localStore (datastore: Datastore): LocalStore {
         // Unmarshal libp2p record as the DHT does
         const record = Record.deserialize(buf)
 
-        return record.value
+        return {
+          record: record.value,
+          created: record.timeReceived
+        }
       } catch (err: any) {
         options.onProgress?.(new CustomProgressEvent<Error>('ipns:routing:datastore:error', err))
         throw err
@@ -58,6 +85,10 @@ export function localStore (datastore: Datastore): LocalStore {
     async has (routingKey: Uint8Array, options: AbortOptions = {}): Promise<boolean> {
       const key = dhtRoutingKey(routingKey)
       return datastore.has(key, options)
+    },
+    async delete (routingKey, options): Promise<void> {
+      const key = dhtRoutingKey(routingKey)
+      return datastore.delete(key, options)
     }
   }
 }

packages/ipns/src/routing/pubsub.ts

@@ -72,7 +72,7 @@ class PubSubRouting implements IPNSRouting {
     await ipnsValidator(routingKey, message.data)
 
     if (await this.localStore.has(routingKey)) {
-      const currentRecord = await this.localStore.get(routingKey)
+      const { record: currentRecord } = await this.localStore.get(routingKey)
 
       if (uint8ArrayEquals(currentRecord, message.data)) {
         log('not storing record as we already have it')
@@ -128,7 +128,9 @@ class PubSubRouting implements IPNSRouting {
       }
 
       // chain through to local store
-      return await this.localStore.get(routingKey, options)
+      const { record } = await this.localStore.get(routingKey, options)
+
+      return record
     } catch (err: any) {
       options.onProgress?.(new CustomProgressEvent<Error>('ipns:pubsub:error', err))
       throw err

packages/ipns/test/publish.spec.ts

@@ -44,7 +44,7 @@ describe('publish', () => {
     const ipnsEntry = await name.publish(key, cid)
 
     expect(ipnsEntry).to.have.property('sequence', 1n)
-    expect(ipnsEntry).to.have.property('ttl', 8640000000000n) // 24 hours
+    expect(ipnsEntry).to.have.property('ttl', 3_600_000_000_000n) // 1 hour
   })
 
   it('should publish an IPNS record with a custom ttl params', async function () {
@@ -55,7 +55,7 @@ describe('publish', () => {
     })
 
     expect(ipnsEntry).to.have.property('sequence', 1n)
-    expect(ipnsEntry).to.have.property('ttl', BigInt(lifetime) * 100000n)
+    expect(ipnsEntry).to.have.property('ttl', 3_600_000_000_000n)
 
     expect(heliaRouting.put.called).to.be.true()
     expect(customRouting.put.called).to.be.true()

packages/ipns/test/resolve.spec.ts

@@ -6,7 +6,7 @@ import { createEd25519PeerId } from '@libp2p/peer-id-factory'
 import { expect } from 'aegir/chai'
 import { MemoryDatastore } from 'datastore-core'
 import { type Datastore, Key } from 'interface-datastore'
-import { create, marshal, peerIdToRoutingKey, unmarshal } from 'ipns'
+import { create, createWithExpiration, marshal, peerIdToRoutingKey, unmarshal } from 'ipns'
 import drain from 'it-drain'
 import { CID } from 'multiformats/cid'
 import Sinon from 'sinon'
@@ -78,6 +78,7 @@ describe('resolve', () => {
   })
 
   it('should skip the local cache when resolving a record', async () => {
+    const cachePutSpy = Sinon.spy(datastore, 'put')
     const cacheGetSpy = Sinon.spy(datastore, 'get')
 
     const key = await createEd25519PeerId()
@@ -92,7 +93,9 @@ describe('resolve', () => {
 
     expect(heliaRouting.get.called).to.be.true()
     expect(customRouting.get.called).to.be.true()
-    expect(cacheGetSpy.called).to.be.false()
+
+    // we call `.get` during `.put`
+    cachePutSpy.calledBefore(cacheGetSpy)
   })
 
   it('should retrieve from local cache when resolving a record', async () => {
@@ -198,4 +201,99 @@ describe('resolve', () => {
 
     expect(result).to.have.deep.property('record', record)
   })
+
+  it('should not search the routing for updated IPNS records when a locally cached copy is within the TTL', async () => {
+    const key = await createEd25519PeerId()
+    const customRoutingKey = peerIdToRoutingKey(key)
+    const dhtKey = new Key('/dht/record/' + uint8ArrayToString(customRoutingKey, 'base32'), false)
+
+    // create a record with a valid lifetime and a non-expired TTL
+    const ipnsRecord = await create(key, cid, 1, Math.pow(2, 10), {
+      ttlNs: 10_000_000
+    })
+    const dhtRecord = new Record(customRoutingKey, marshal(ipnsRecord), new Date(Date.now()))
+
+    await datastore.put(dhtKey, dhtRecord.serialize())
+
+    const result = await name.resolve(key)
+    expect(result).to.have.deep.property('record', unmarshal(marshal(ipnsRecord)))
+
+    // should not have searched the routing
+    expect(customRouting.get.called).to.be.false()
+  })
+
+  it('should search the routing for updated IPNS records when a locally cached copy has passed the TTL', async () => {
+    const key = await createEd25519PeerId()
+
+    const customRoutingKey = peerIdToRoutingKey(key)
+    const dhtKey = new Key('/dht/record/' + uint8ArrayToString(customRoutingKey, 'base32'), false)
+
+    // create a record with a valid lifetime but an expired ttl
+    const ipnsRecord = await create(key, cid, 1, Math.pow(2, 10), {
+      ttlNs: 10
+    })
+    const dhtRecord = new Record(customRoutingKey, marshal(ipnsRecord), new Date(Date.now() - 1000))
+
+    await datastore.put(dhtKey, dhtRecord.serialize())
+
+    const result = await name.resolve(key)
+    expect(result).to.have.deep.property('record', unmarshal(marshal(ipnsRecord)))
+
+    // should have searched the routing
+    expect(customRouting.get.called).to.be.true()
+  })
+
+  it('should search the routing for updated IPNS records when a locally cached copy has passed the TTL and choose the record with a higher sequence number', async () => {
+    const key = await createEd25519PeerId()
+
+    const customRoutingKey = peerIdToRoutingKey(key)
+    const dhtKey = new Key('/dht/record/' + uint8ArrayToString(customRoutingKey, 'base32'), false)
+
+    // create a record with a valid lifetime but an expired ttl
+    const ipnsRecord = await create(key, cid, 10, Math.pow(2, 10), {
+      ttlNs: 10
+    })
+    const dhtRecord = new Record(customRoutingKey, marshal(ipnsRecord), new Date(Date.now() - 1000))
+
+    await datastore.put(dhtKey, dhtRecord.serialize())
+
+    // the routing returns a valid record with an higher sequence number
+    const ipnsRecordFromRouting = await create(key, cid, 11, Math.pow(2, 10), {
+      ttlNs: 10_000_000
+    })
+    customRouting.get.withArgs(customRoutingKey).resolves(marshal(ipnsRecordFromRouting))
+
+    const result = await name.resolve(key)
+    expect(result).to.have.deep.property('record', unmarshal(marshal(ipnsRecordFromRouting)))
+
+    // should have searched the routing
+    expect(customRouting.get.called).to.be.true()
+  })
+
+  it('should search the routing when a locally cached copy has an expired lifetime', async () => {
+    const key = await createEd25519PeerId()
+
+    const customRoutingKey = peerIdToRoutingKey(key)
+    const dhtKey = new Key('/dht/record/' + uint8ArrayToString(customRoutingKey, 'base32'), false)
+
+    // create a record with an expired lifetime but valid TTL
+    const ipnsRecord = await createWithExpiration(key, cid, 10, new Date(Date.now() - Math.pow(2, 10)).toString(), {
+      ttlNs: 10_000_000
+    })
+    const dhtRecord = new Record(customRoutingKey, marshal(ipnsRecord), new Date(Date.now()))
+
+    await datastore.put(dhtKey, dhtRecord.serialize())
+
+    // the routing returns a valid record with an higher sequence number
+    const ipnsRecordFromRouting = await create(key, cid, 11, Math.pow(2, 10), {
+      ttlNs: 10_000_000
+    })
+    customRouting.get.withArgs(customRoutingKey).resolves(marshal(ipnsRecordFromRouting))
+
+    const result = await name.resolve(key)
+    expect(result).to.have.deep.property('record', unmarshal(marshal(ipnsRecordFromRouting)))
+
+    // should have searched the routing
+    expect(customRouting.get.called).to.be.true()
+  })
 })