websocket: add extented payload length check for the case of 7+64 bits

cixtor · cixtor · commit 84649876d010 · 2015-08-04T03:31:07.000Z
Fixes golang/go#11999. Change-Id: I7ee0966d2e8f79973814f48afc7e8f2cd4af1e50 Reviewed-on: https://go-review.googlesource.com/13059 Reviewed-by: Andrew Gerrand <adg@golang.org>
diff --git a/websocket/hybi.go b/websocket/hybi.go
@@ -157,6 +157,9 @@ func (buf hybiFrameReaderFactory) NewFrameReader() (frame frameReader, err error
 		if err != nil {
 			return
 		}
+		if lengthFields == 8 && i == 0 { // MSB must be zero when 7+64 bits
+			b &= 0x7f
+		}
 		header = append(header, b)
 		hybiFrame.header.Length = hybiFrame.header.Length*256 + int64(b)
 	}

Original file line number	Diff line number	Diff line change
`@@ -157,6 +157,9 @@ func (buf hybiFrameReaderFactory) NewFrameReader() (frame frameReader, err error`
`157`	`157`	`if err != nil {`
`158`	`158`	`return`
`159`	`159`	`}`
	`160`	`+ if lengthFields == 8 && i == 0 { // MSB must be zero when 7+64 bits`
	`161`	`+ b &= 0x7f`
	`162`	`+ }`
`160`	`163`	`header = append(header, b)`
`161`	`164`	`hybiFrame.header.Length = hybiFrame.header.Length*256 + int64(b)`
`162`	`165`	`}`