Add sig validation in binary

Signed-off-by: Lukas Bachschwell <lukas@lbsfilm.at>

.gitignore

@@ -1,2 +1,3 @@
 gitinfo.go
 dist
+privkey.pem

genKeys.sh

@@ -0,0 +1,3 @@
+#!/bin/sh
+openssl ecparam -name prime256v1 -genkey -noout -out privkey.pem
+openssl ec -in privkey.pem -pubout -out pubkey.pem

go.mod

@@ -4,4 +4,7 @@ go 1.15
 
 replace github.com/creativeprojects/go-selfupdate => /Users/LB/Desktop/z_Projects/go-selfupdate
 
-require github.com/creativeprojects/go-selfupdate v0.0.0-00010101000000-000000000000
+require (
+	github.com/creativeprojects/go-selfupdate v0.0.0-00010101000000-000000000000
+	github.com/kenshaw/pemutil v0.1.0
+)

go.sum

@@ -107,6 +107,8 @@ github.com/hashicorp/golang-lru v0.5.1/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ
 github.com/ianlancetaylor/demangle v0.0.0-20181102032728-5e5cf60278f6/go.mod h1:aSSvb/t6k1mPoxDqO4vJh6VOCGPwU4O0C2/Eqndh1Sc=
 github.com/jstemmer/go-junit-report v0.0.0-20190106144839-af01ea7f8024/go.mod h1:6v2b51hI/fHJwM22ozAgKL4VKDeJcHhJFhtBdhmNjmU=
 github.com/jstemmer/go-junit-report v0.9.1/go.mod h1:Brl9GWCQeLvo8nXZwPNNblvFj/XSXhF0NWZEnDohbsk=
+github.com/kenshaw/pemutil v0.1.0 h1:rA3FC1PkBPlt/ez3iHgMzdEEFq4Bhnpkh/g2C68oRac=
+github.com/kenshaw/pemutil v0.1.0/go.mod h1:KDF39i6NCZ2UJYtdyVVQi8l+G5S3zgE26GzAjFiLmHQ=
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=

main.go

@@ -8,6 +8,7 @@ import (
 	"runtime"
 
 	selfupdate "github.com/creativeprojects/go-selfupdate"
+	"github.com/kenshaw/pemutil"
 )
 
 //go:generate sh injectGitVars.sh
@@ -36,9 +37,24 @@ func main() {
 
 func update(version string) error {
 	source, _ := selfupdate.NewGiteaSource(selfupdate.GiteaConfig{BaseURL: "https://git.lbsfilm.at/"})
+
+	store := make(pemutil.Store)
+	err := pemutil.Decode(store, []byte(`-----BEGIN PUBLIC KEY-----
+MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAE0+99Oxlx+P6F9Cd5pUIw6oGY2oFL
+qCf//kV/S27OpD6skuEveQG+M1k6eT/o8oVDJ0sj3aIyaF+vruZaBB9HeA==
+-----END PUBLIC KEY-----`))
+	if err != nil {
+		return err
+	}
+	pubkey, ok := store.ECPublicKey()
+	if !ok {
+		return fmt.Errorf("no pubkey")
+	}
 	updater, err := selfupdate.NewUpdater(selfupdate.Config{
 		Source: source,
-		Validator: nil,
+		Validator: &selfupdate.ECDSAValidator{
+			PublicKey: pubkey,
+		},
 		OS:   runtime.GOOS,
 		Arch: runtime.GOARCH,
 		Arm:  0,

pubkey.pem

@@ -0,0 +1,4 @@
+-----BEGIN PUBLIC KEY-----
+MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAE0+99Oxlx+P6F9Cd5pUIw6oGY2oFL
+qCf//kV/S27OpD6skuEveQG+M1k6eT/o8oVDJ0sj3aIyaF+vruZaBB9HeA==
+-----END PUBLIC KEY-----