From aae7660410f0ef90279e14afaaf2f429fdc2a186 Mon Sep 17 00:00:00 2001
From: Felix Lange <fjl@twurst.com>
Date: Thu, 11 Mar 2021 15:09:25 +0100
Subject: [PATCH] p2p/enr: fix decoding of incomplete lists (#22484)
Given a list of less than two elements DecodeRLP returned rlp.EOL,
leading to issues in outer decoders.
---
p2p/enr/enr.go | 7 +++++++
p2p/enr/enr_test.go | 23 +++++++++++++++++++++++
2 files changed, 30 insertions(+)
diff --git a/p2p/enr/enr.go b/p2p/enr/enr.go
index c36ae9e3e..05e43fd80 100644
--- a/p2p/enr/enr.go
+++ b/p2p/enr/enr.go
@@ -50,6 +50,7 @@ var (
errNotSorted = errors.New("record key/value pairs are not sorted by key")
errDuplicateKey = errors.New("record contains duplicate key")
errIncompletePair = errors.New("record contains incomplete k/v pair")
+ errIncompleteList = errors.New("record contains less than two list elements")
errTooBig = fmt.Errorf("record bigger than %d bytes", SizeLimit)
errEncodeUnsigned = errors.New("can't encode unsigned record")
errNotFound = errors.New("no such key in record")
@@ -209,9 +210,15 @@ func decodeRecord(s *rlp.Stream) (dec Record, raw []byte, err error) {
return dec, raw, err
}
if err = s.Decode(&dec.signature); err != nil {
+ if err == rlp.EOL {
+ err = errIncompleteList
+ }
return dec, raw, err
}
if err = s.Decode(&dec.seq); err != nil {
+ if err == rlp.EOL {
+ err = errIncompleteList
+ }
return dec, raw, err
}
// The rest of the record contains sorted k/v pairs.
diff --git a/p2p/enr/enr_test.go b/p2p/enr/enr_test.go
index 96a9ced5c..bf3f10474 100644
--- a/p2p/enr/enr_test.go
+++ b/p2p/enr/enr_test.go
@@ -231,6 +231,29 @@ func TestRecordTooBig(t *testing.T) {
require.NoError(t, signTest([]byte{5}, &r))
}
+// This checks that incomplete RLP inputs are handled correctly.
+func TestDecodeIncomplete(t *testing.T) {
+ type decTest struct {
+ input []byte
+ err error
+ }
+ tests := []decTest{
+ {[]byte{0xC0}, errIncompleteList},
+ {[]byte{0xC1, 0x1}, errIncompleteList},
+ {[]byte{0xC2, 0x1, 0x2}, nil},
+ {[]byte{0xC3, 0x1, 0x2, 0x3}, errIncompletePair},
+ {[]byte{0xC4, 0x1, 0x2, 0x3, 0x4}, nil},
+ {[]byte{0xC5, 0x1, 0x2, 0x3, 0x4, 0x5}, errIncompletePair},
+ }
+ for _, test := range tests {
+ var r Record
+ err := rlp.DecodeBytes(test.input, &r)
+ if err != test.err {
+ t.Errorf("wrong error for %X: %v", test.input, err)
+ }
+ }
+}
+
// TestSignEncodeAndDecodeRandom tests encoding/decoding of records containing random key/value pairs.
func TestSignEncodeAndDecodeRandom(t *testing.T) {
var r Record
--
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