What version of Go are you using (go version)?

$ go version
go version go1.10.3 windows/amd64

Does this issue reproduce with the latest release?

yes

What operating system and processor architecture are you using (go env)?

$ go env
set GOARCH=amd64
set GOBIN=
set GOCACHE=C:\Users\----\AppData\Local\go-build
set GOEXE=.exe
set GOHOSTARCH=amd64
set GOHOSTOS=windows
set GOOS=windows
set GOPATH=C:\Users\----\go
set GORACE=
set GOROOT=C:\Go
set GOTMPDIR=
set GOTOOLDIR=C:\Go\pkg\tool\windows_amd64
set GCCGO=gccgo
set CC=gcc
set CXX=g++
set CGO_ENABLED=1
set CGO_CFLAGS=-g -O2
set CGO_CPPFLAGS=
set CGO_CXXFLAGS=-g -O2
set CGO_FFLAGS=-g -O2
set CGO_LDFLAGS=-g -O2
set PKG_CONFIG=pkg-config
set GOGCCFLAGS=-m64 -mthreads -fmessage-length=0 -fdebug-prefix-map=C:\Users\----\AppData\Local\Temp\go-build094907166=/tmp/go-build -gno-record-gcc-switches

What did you do?

I am trying to import privatekey generated with sunec 'sect571r1'

func decodePrivateKeyFromString(pemEncoded string) (*ecdsa.PrivateKey, error) {
val, _ := base64.StdEncoding.DecodeString(pemEncoded)
fmt.Println(string(val))
privateKey, err := x509.ParsePKCS8PrivateKey(val)
if err != nil {
fmt.Println(err)
return nil, errors.New("Failed to parse ECDSA private key")
}
switch privateKey := privateKey.(type) {
case *ecdsa.PrivateKey:
return privateKey, nil
}
return nil, errors.New("Unsupported public key type")
}

What did you expect to see?

To get the private key

What did you see instead?

x509: unknown elliptic curve