From 7180699d401e64b52447ccb2cfb33004b7deb672 Mon Sep 17 00:00:00 2001
From: Felix Lange <fjl@twurst.com>
Date: Fri, 17 Apr 2015 03:11:24 +0200
Subject: [PATCH] rlp: require declared number of input elements for array
types
---
rlp/decode.go | 40 +++++++++++++++-------------------------
rlp/decode_test.go | 26 +++++++++++---------------
2 files changed, 26 insertions(+), 40 deletions(-)
diff --git a/rlp/decode.go b/rlp/decode.go
index 97eacf64b..6952ecaea 100644
--- a/rlp/decode.go
+++ b/rlp/decode.go
@@ -59,7 +59,9 @@ type Decoder interface {
//
// To decode into a slice, the input must be a list and the resulting
// slice will contain the input elements in order. For byte slices,
-// the input must be an RLP string.
+// the input must be an RLP string. Array types decode similarly, with
+// the additional restriction that the number of input elements (or
+// bytes) must match the array's length.
//
// To decode into a Go string, the input must be an RLP string. The
// input bytes are taken as-is and will not necessarily be valid UTF-8.
@@ -279,19 +281,10 @@ func decodeListSlice(s *Stream, val reflect.Value, elemdec decoder) error {
}
func decodeListArray(s *Stream, val reflect.Value, elemdec decoder) error {
- size, err := s.List()
+ _, err := s.List()
if err != nil {
return wrapStreamError(err, val.Type())
}
- if size == 0 {
- zero(val, 0)
- return s.ListEnd()
- }
-
- // The approach here is stolen from package json, although we differ
- // in the semantics for arrays. package json discards remaining
- // elements that would not fit into the array. We generate an error in
- // this case because we'd be losing information.
vlen := val.Len()
i := 0
for ; i < vlen; i++ {
@@ -302,7 +295,7 @@ func decodeListArray(s *Stream, val reflect.Value, elemdec decoder) error {
}
}
if i < vlen {
- zero(val, i)
+ return &decodeError{msg: "input list has too few elements", typ: val.Type()}
}
return wrapStreamError(s.ListEnd(), val.Type())
}
@@ -321,23 +314,28 @@ func decodeByteArray(s *Stream, val reflect.Value) error {
if err != nil {
return err
}
+ vlen := val.Len()
switch kind {
case Byte:
- if val.Len() == 0 {
+ if vlen == 0 {
return &decodeError{msg: "input string too long", typ: val.Type()}
}
+ if vlen > 1 {
+ return &decodeError{msg: "input string too short", typ: val.Type()}
+ }
bv, _ := s.Uint()
val.Index(0).SetUint(bv)
- zero(val, 1)
case String:
- if uint64(val.Len()) < size {
+ if uint64(vlen) < size {
return &decodeError{msg: "input string too long", typ: val.Type()}
}
- slice := val.Slice(0, int(size)).Interface().([]byte)
+ if uint64(vlen) > size {
+ return &decodeError{msg: "input string too short", typ: val.Type()}
+ }
+ slice := val.Slice(0, vlen).Interface().([]byte)
if err := s.readFull(slice); err != nil {
return err
}
- zero(val, int(size))
// Reject cases where single byte encoding should have been used.
if size == 1 && slice[0] < 56 {
return wrapStreamError(ErrCanonSize, val.Type())
@@ -348,14 +346,6 @@ func decodeByteArray(s *Stream, val reflect.Value) error {
return nil
}
-func zero(val reflect.Value, start int) {
- z := reflect.Zero(val.Type().Elem())
- end := val.Len()
- for i := start; i < end; i++ {
- val.Index(i).Set(z)
- }
-}
-
func makeStructDecoder(typ reflect.Type) (decoder, error) {
fields, err := structFields(typ)
if err != nil {
diff --git a/rlp/decode_test.go b/rlp/decode_test.go
index 0b69ff1f4..d07520bd0 100644
--- a/rlp/decode_test.go
+++ b/rlp/decode_test.go
@@ -290,11 +290,6 @@ var (
)
)
-var (
- sharedByteArray [5]byte
- sharedPtr = new(*uint)
-)
-
var decodeTests = []decodeTest{
// integers
{input: "05", ptr: new(uint32), value: uint32(5)},
@@ -315,11 +310,16 @@ var decodeTests = []decodeTest{
{input: "F8020004", ptr: new([]uint), error: "rlp: non-canonical size information for []uint"},
// arrays
- {input: "C0", ptr: new([5]uint), value: [5]uint{}},
{input: "C50102030405", ptr: new([5]uint), value: [5]uint{1, 2, 3, 4, 5}},
+ {input: "C0", ptr: new([5]uint), error: "rlp: input list has too few elements for [5]uint"},
+ {input: "C102", ptr: new([5]uint), error: "rlp: input list has too few elements for [5]uint"},
{input: "C6010203040506", ptr: new([5]uint), error: "rlp: input list has too many elements for [5]uint"},
{input: "F8020004", ptr: new([5]uint), error: "rlp: non-canonical size information for [5]uint"},
+ // zero sized arrays
+ {input: "C0", ptr: new([0]uint), value: [0]uint{}},
+ {input: "C101", ptr: new([0]uint), error: "rlp: input list has too many elements for [0]uint"},
+
// byte slices
{input: "01", ptr: new([]byte), value: []byte{1}},
{input: "80", ptr: new([]byte), value: []byte{}},
@@ -328,21 +328,17 @@ var decodeTests = []decodeTest{
{input: "8105", ptr: new([]byte), error: "rlp: non-canonical size information for []uint8"},
// byte arrays
- {input: "01", ptr: new([5]byte), value: [5]byte{1}},
- {input: "80", ptr: new([5]byte), value: [5]byte{}},
+ {input: "02", ptr: new([1]byte), value: [1]byte{2}},
{input: "850102030405", ptr: new([5]byte), value: [5]byte{1, 2, 3, 4, 5}},
// byte array errors
+ {input: "02", ptr: new([5]byte), error: "rlp: input string too short for [5]uint8"},
+ {input: "80", ptr: new([5]byte), error: "rlp: input string too short for [5]uint8"},
+ {input: "820000", ptr: new([5]byte), error: "rlp: input string too short for [5]uint8"},
{input: "C0", ptr: new([5]byte), error: "rlp: expected input string or byte for [5]uint8"},
{input: "C3010203", ptr: new([5]byte), error: "rlp: expected input string or byte for [5]uint8"},
{input: "86010203040506", ptr: new([5]byte), error: "rlp: input string too long for [5]uint8"},
- {input: "8105", ptr: new([5]byte), error: "rlp: non-canonical size information for [5]uint8"},
-
- // byte array reuse (should be zeroed)
- {input: "850102030405", ptr: &sharedByteArray, value: [5]byte{1, 2, 3, 4, 5}},
- {input: "01", ptr: &sharedByteArray, value: [5]byte{1}}, // kind: String
- {input: "850102030405", ptr: &sharedByteArray, value: [5]byte{1, 2, 3, 4, 5}},
- {input: "01", ptr: &sharedByteArray, value: [5]byte{1}}, // kind: Byte
+ {input: "8105", ptr: new([1]byte), error: "rlp: non-canonical size information for [1]uint8"},
// zero sized byte arrays
{input: "80", ptr: new([0]byte), value: [0]byte{}},
--
GitLab