Closed
Description
Go version
1.23 (all)
Output of go env in your module/workspace:
set GO111MODULE=
set GOARCH=amd64
set GOBIN=
set GOCACHE=C:\Users\...\AppData\Local\go-build
set GOENV=C:\Users\...\AppData\Roaming\go\env
set GOEXE=.exe
set GOEXPERIMENT=
set GOFLAGS=
set GOHOSTARCH=amd64
set GOHOSTOS=windows
set GOINSECURE=
set GOMODCACHE=C:\Users\calvip\go\pkg\mod
set GONOPROXY=
set GONOSUMDB=
set GOOS=windows
set GOPATH=C:\Users\...\go
set GOPRIVATE=
set GOPROXY=https://proxy.golang.org,direct
set GOROOT=c:\go
set GOSUMDB=sum.golang.org
set GOTMPDIR=
set GOTOOLDIR=c:\go\pkg\tool\windows_amd64
set GOVCS=
set GOVERSION=go1.22.3
set GCCGO=gccgo
set GOAMD64=v1
set AR=ar
set CC=gcc
set CXX=g++
set CGO_ENABLED=1
set GOMOD=NUL
set GOWORK=
set CGO_CFLAGS=-O2 -g
set CGO_CPPFLAGS=
set CGO_CXXFLAGS=-O2 -g
set CGO_FFLAGS=-O2 -g
set CGO_LDFLAGS=-O2 -g
set PKG_CONFIG=pkg-config
set GOGCCFLAGS=-m64 -mthreads -Wl,--no-gc-sections -fmessage-length=0 -fdebug-prefix-map=C:\Users\.....\AppData\Local\Temp\go-build939558769=/tmp/go-build -gno-record-gcc-switchesWhat did you do?
Static analysis of the x/crypto/sha3/shake.go function
What did you see happen?
The code
func bytepad(input []byte, w int) []byte {
// leftEncode always returns max 9 bytes
buf := make([]byte, 0, 9+len(input)+w)
buf = append(buf, leftEncode(uint64(w))...)
buf = append(buf, input...)
padlen := w - (len(buf) % w)
return append(buf, make([]byte, padlen)...)
}and in particular
padlen := w - (len(buf) % w)is not working properly when len(buf) % w == 0, causing an undesired padding.
The function appear to work only if the length of the input + length of the letfencoding is not a multiple of w already.
What did you expect to see?
leftEncode([]uint8("12345678"),10) // leftencode should be 2 bytelong that summed with 8 is 10
shoud return a 10 bytes result, not a 20 bytes result.