tlv/stream: create MaxRecordSize, remove lnwire import, add test

This commit is contained in:
Conner Fromknecht 2019-08-21 16:30:05 -07:00
parent dfd1b38648
commit 1cc48ceaf5
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2 changed files with 20 additions and 3 deletions

@ -6,10 +6,14 @@ import (
"io"
"io/ioutil"
"math"
"github.com/lightningnetwork/lnd/lnwire"
)
// MaxRecordSize is the maximum size of a particular record that will be parsed
// by a stream decoder. This value is currently chosen to the be equal to the
// maximum message size permitted by BOLT 1, as no record should be bigger than
// an entire message.
const MaxRecordSize = 65535 // 65KB
// ErrStreamNotCanonical signals that a decoded stream does not contain records
// sorting by monotonically-increasing type.
var ErrStreamNotCanonical = errors.New("tlv stream is not canonical")
@ -189,7 +193,11 @@ func (s *Stream) Decode(r io.Reader) error {
return err
}
if length > lnwire.MaxMessagePayload {
// Place a soft limit on the size of a sane record, which
// prevents malicious encoders from causing us to allocate an
// unbounded amount of memory when decoding variable-sized
// fields.
if length > MaxRecordSize {
return ErrRecordTooLarge
}

@ -49,6 +49,8 @@ type N1 struct {
nodeAmts nodeAmts
cltvDelta uint16
alias []byte
stream *tlv.Stream
}
@ -66,6 +68,7 @@ func NewN1() *N1 {
tlv.MakePrimitiveRecord(2, &n.scid),
tlv.MakeStaticRecord(3, &n.nodeAmts, 49, ENodeAmts, DNodeAmts),
tlv.MakePrimitiveRecord(254, &n.cltvDelta),
tlv.MakePrimitiveRecord(401, &n.alias),
)
return n
@ -396,6 +399,12 @@ var tlvDecodingFailureTests = []struct {
bytes: []byte{0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x00},
expErr: tlv.ErrStreamNotCanonical,
},
{
name: "absurd record length",
bytes: []byte{0xfd, 0x01, 0x91, 0xfe, 0xff, 0xff, 0xff, 0xff},
expErr: tlv.ErrRecordTooLarge,
skipN2: true,
},
}
// TestTLVDecodingSuccess asserts that the TLV parser fails to decode invalid