Add back support for building with CGO_ENABLED=0 (#293)

Signed-off-by: Ville Aikas <vaikas@chainguard.dev>

cmd/app/createcanocgo.go

@@ -0,0 +1,41 @@
+//go:build !cgo
+// +build !cgo
+
+// Copyright 2021 The Sigstore Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+package app
+
+import (
+	"github.com/sigstore/fulcio/pkg/log"
+	"github.com/spf13/cobra"
+)
+
+// Just a placeholder for erroring with a meaningful message if the
+// binary has been built with GCO_ENABLED=0 tags.
+func newCreateCACmd() *cobra.Command {
+	return &cobra.Command{
+		Use:   "createca",
+		Short: "Create a root CA in a pkcs11 device (**not supported in this binary**)",
+		Long: `Create an x509 root CA within a pkcs11 device using values
+such as organization, country etc. This can then be used as the root
+certificate authority for an instance of sigstore fulcio`,
+		Run: runCreateCACmdPlaceholder,
+	}
+}
+
+func runCreateCACmdPlaceholder(cmd *cobra.Command, args []string) {
+	log.Logger.Fatal("Binary has been built with CGO_ENABLED=0, createca is not supported")
+}

pkg/ca/x509ca/x509canocgo.go

@@ -22,8 +22,14 @@ import (
 	"errors"
 )
 
+type Params struct {
+	ConfigPath string
+	RootID     string
+	CAPath     *string
+}
+
 // NewX509CA is a placeholder for erroring with a meaningful message if the
-// binary has been built with purego tags.
-func NewX509CA() (*X509CA, error) {
+// binary has been built with CGO_ENABLED=0 tags.
+func NewX509CA(params Params) (*X509CA, error) {
 	return nil, errors.New("binary has been built with no cgo support, PKCS11 not supported")
 }