diff --git a/internal/contentenc/file_header.go b/internal/contentenc/file_header.go index 8a08ef0..5e638ff 100644 --- a/internal/contentenc/file_header.go +++ b/internal/contentenc/file_header.go @@ -5,6 +5,7 @@ package contentenc // Format: [ "Version" uint16 big endian ] [ "Id" 16 random bytes ] import ( + "bytes" "encoding/binary" "log" "syscall" @@ -41,6 +42,9 @@ func (h *FileHeader) Pack() []byte { } +// allZeroFileID is preallocated to quickly check if the data read from disk is all zero +var allZeroFileID = make([]byte, headerIDLen) + // ParseHeader - parse "buf" into fileHeader object func ParseHeader(buf []byte) (*FileHeader, error) { if len(buf) != HeaderLen { @@ -54,6 +58,10 @@ func ParseHeader(buf []byte) (*FileHeader, error) { return nil, syscall.EINVAL } h.ID = buf[headerVersionLen:] + if bytes.Equal(h.ID, allZeroFileID) { + tlog.Warn.Printf("ParseHeader: file id is all-zero. Returning EINVAL.") + return nil, syscall.EINVAL + } return &h, nil }