fix: set min and max protocol length (#21)

* fix: set min and max protocol length

* fix: import statement

Co-authored-by: Alex Potsides <[email protected]>

* chore: add tests

* fix: 0-lnegth test error code

Co-authored-by: Alex Potsides <[email protected]>
Co-authored-by: Marin Petrunic <[email protected]>

Author: 3 people

src/constants.ts

@@ -1,2 +1,6 @@
 
 export const PROTOCOL_ID = '/multistream/1.0.0'
+
+// Conforming to go-libp2p
+// See https://github.com/multiformats/go-multistream/blob/master/multistream.go#L297
+export const MAX_PROTOCOL_LENGTH = 1024

src/multistream.ts

@@ -12,6 +12,7 @@ import type { AbortOptions } from '@libp2p/interfaces'
 import type { Source } from 'it-stream-types'
 import type { Reader } from 'it-reader'
 import type { MultistreamSelectInit } from '.'
+import { MAX_PROTOCOL_LENGTH } from './constants.js'
 
 const NewLine = uint8ArrayFromString('\n')
 
@@ -73,11 +74,11 @@ export async function read (reader: Reader, options?: AbortOptions): Promise<Uin
 
   const buf = await pipe(
     input,
-    lp.decode({ onLength }),
+    lp.decode({ onLength, maxDataLength: MAX_PROTOCOL_LENGTH }),
     async (source) => await first(source)
   )
 
-  if (buf == null) {
+  if (buf == null || buf.length === 0) {
     throw errCode(new Error('no buffer returned'), 'ERR_INVALID_MULTISTREAM_SELECT_MESSAGE')
   }
 

test/multistream.spec.ts

@@ -87,6 +87,31 @@ describe('Multistream', () => {
         .with.property('code', 'ERR_INVALID_MULTISTREAM_SELECT_MESSAGE')
     })
 
+    it('should throw for a large message', async () => {
+      const input = new Uint8Array(10000)
+      input[input.length - 1] = '\n'.charCodeAt(0)
+
+      const source = reader([uint8ArrayConcat([
+        Uint8Array.from(Varint.encode(input.length)),
+        input
+      ])])
+
+      await expect(Multistream.read(source)).to.eventually.be.rejected()
+        .with.property('code', 'ERR_MSG_DATA_TOO_LONG')
+    })
+
+    it('should throw for a 0-length message', async () => {
+      const input = new Uint8Array(0)
+
+      const source = reader([uint8ArrayConcat([
+        Uint8Array.from(Varint.encode(input.length)),
+        input
+      ])])
+
+      await expect(Multistream.read(source)).to.eventually.be.rejected()
+        .with.property('code', 'ERR_INVALID_MULTISTREAM_SELECT_MESSAGE')
+    })
+
     it('should be abortable', async () => {
       const input = uint8ArrayFromString(`TEST${Date.now()}`)