From 80cca0ecac45f9ff5fbdb754747e520b8cfa8290 Mon Sep 17 00:00:00 2001
From: diegomrsantos <diego@status.im>
Date: Thu, 6 Apr 2023 16:19:01 +0200
Subject: [PATCH] Does not allow an empty MA (#877)

---
 libp2p/multiaddress.nim    | 10 ++++++++--
 tests/testmultiaddress.nim |  4 ++++
 tests/testnameresolve.nim  |  1 -
 3 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/libp2p/multiaddress.nim b/libp2p/multiaddress.nim
index c046dba..23cd3d5 100644
--- a/libp2p/multiaddress.nim
+++ b/libp2p/multiaddress.nim
@@ -34,7 +34,7 @@ type
     coder*: Transcoder
 
   MultiAddress* = object
-    data*: VBuffer
+    data: VBuffer
 
   MaPatternOp* = enum
     Eq, Or, And
@@ -63,6 +63,10 @@ const
   IPPROTO_TCP = Protocol.IPPROTO_TCP
   IPPROTO_UDP = Protocol.IPPROTO_UDP
 
+proc data*(ma: MultiAddress): VBuffer =
+  ## Returns the data buffer of the MultiAddress.
+  return ma.data
+
 proc hash*(a: MultiAddress): Hash =
   var h: Hash = 0
   h = h !& hash(a.data.buffer)
@@ -873,6 +877,8 @@ proc getProtocol(name: string): MAProtocol {.inline.} =
 proc init*(mtype: typedesc[MultiAddress],
            value: string): MaResult[MultiAddress] =
   ## Initialize MultiAddress object from string representation ``value``.
+  if len(value) == 0 or value == "/":
+    return err("multiaddress: Address must not be empty!")
   var parts = value.trimRight('/').split('/')
   if len(parts[0]) != 0:
     err("multiaddress: Invalid MultiAddress, must start with `/`")
@@ -920,7 +926,7 @@ proc init*(mtype: typedesc[MultiAddress],
            data: openArray[byte]): MaResult[MultiAddress] =
   ## Initialize MultiAddress with array of bytes ``data``.
   if len(data) == 0:
-    err("multiaddress: Address could not be empty!")
+    err("multiaddress: Address must not be empty!")
   else:
     var res: MultiAddress
     res.data = initVBuffer()
diff --git a/tests/testmultiaddress.nim b/tests/testmultiaddress.nim
index 3a0b9af..845424c 100644
--- a/tests/testmultiaddress.nim
+++ b/tests/testmultiaddress.nim
@@ -1,4 +1,5 @@
 import unittest2
+import stew/byteutils
 import ../libp2p/[multicodec, multiaddress]
 
 when defined(nimHasUsed): {.used.}
@@ -62,6 +63,8 @@ const
   ]
 
   FailureVectors = [
+    "",
+    "/",
     "/ip4",
     "/ip4/::1",
     "/ip4/fdpsofodsajfdoisa",
@@ -299,6 +302,7 @@ suite "MultiAddress test suite":
   test "go-multiaddr failure test vectors":
     for item in FailureVectors:
       check MultiAddress.init(item).isErr()
+      check MultiAddress.init(item.toBytes()).isErr()
 
   test "rust-multiaddr success test vectors":
     ## Rust test vectors are with changed UDP encoding and without WSS
diff --git a/tests/testnameresolve.nim b/tests/testnameresolve.nim
index 4a4dd40..4c5da1f 100644
--- a/tests/testnameresolve.nim
+++ b/tests/testnameresolve.nim
@@ -144,7 +144,6 @@ suite "Name resolving":
     test "getHostname":
       check:
         MultiAddress.init("/dnsaddr/bootstrap.libp2p.io/").tryGet().getHostname == "bootstrap.libp2p.io"
-        MultiAddress.init("").tryGet().getHostname == ""
         MultiAddress.init("/ip4/147.75.69.143/tcp/4001/p2p/QmNnooDu7bfjPFoTZYxMNLWUQJyrVwtbZg5gBMjTezGAJN").tryGet().getHostname == "147.75.69.143"
         MultiAddress.init("/ip6/2604:1380:1000:6000::1/tcp/4001/p2p/QmNnooDu7bfjPFoTZYxMNLWUQJyrVwtbZg5gBMjTezGAJN").tryGet().getHostname == "2604:1380:1000:6000::1"
         MultiAddress.init("/dns/localhost/udp/0").tryGet().getHostname == "localhost"