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path: root/rlp/decode.go
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Diffstat (limited to 'rlp/decode.go')
-rw-r--r--rlp/decode.go40
1 files changed, 15 insertions, 25 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 {