refactor: remove utils pkg

BREAKING CHANGE: utils package has been removed in favor of specific new
packages (http, crypto, strings)

pkg/client/rp/cli/browser.go

@@ -0,0 +1,26 @@
+package cli
+
+import (
+	"fmt"
+	"log"
+	"os/exec"
+	"runtime"
+)
+
+func OpenBrowser(url string) {
+	var err error
+
+	switch runtime.GOOS {
+	case "linux":
+		err = exec.Command("xdg-open", url).Start()
+	case "windows":
+		err = exec.Command("rundll32", "url.dll,FileProtocolHandler", url).Start()
+	case "darwin":
+		err = exec.Command("open", url).Start()
+	default:
+		err = fmt.Errorf("unsupported platform")
+	}
+	if err != nil {
+		log.Fatal(err)
+	}
+}

pkg/client/rp/cli/cli.go

@@ -5,8 +5,8 @@ import (
 	"net/http"
 
 	"github.com/caos/oidc/pkg/client/rp"
+	httphelper "github.com/caos/oidc/pkg/http"
 	"github.com/caos/oidc/pkg/oidc"
-	"github.com/caos/oidc/pkg/utils"
 )
 
 const (
@@ -28,9 +28,9 @@ func CodeFlow(ctx context.Context, relyingParty rp.RelyingParty, callbackPath, p
 	http.Handle(loginPath, rp.AuthURLHandler(stateProvider, relyingParty))
 	http.Handle(callbackPath, rp.CodeExchangeHandler(callback, relyingParty))
 
-	utils.StartServer(codeflowCtx, ":"+port)
+	httphelper.StartServer(codeflowCtx, ":"+port)
 
-	utils.OpenBrowser("http://localhost:" + port + loginPath)
+	OpenBrowser("http://localhost:" + port + loginPath)
 
 	return <-tokenChan
 }