harden SSZ reader

2020-04-16 21:21:28 +02:00 · 2020-04-16 21:21:28 +02:00 · 71e802c740
parent 8b6c51e78d
commit 71e802c740
1 changed files with 2 additions and 0 deletions
--- a/beacon_chain/ssz/bytes_reader.nim
+++ b/beacon_chain/ssz/bytes_reader.nim
@ -169,6 +169,8 @@ func readSszValue*(input: openarray[byte], T: type): T =
          raise newException(MalformedSszError, "SSZ field offsets are not monotonically increasing")
        elif endOffset > input.len:
          raise newException(MalformedSszError, "SSZ field offset points past the end of the input")
+        elif startOffset < boundingOffsets[0]:
+          raise newException(MalformedSszError, "SSZ field offset points outside bounding offsets")

      # TODO The extra type escaping here is a work-around for a Nim issue:
      when type(FieldType) is type(SszType):