Allow non-cgo builds to use filetoken and scdtoken

cmdline/token/token.go

@@ -18,13 +18,15 @@ package token
 
 import (
 	"errors"
+	"fmt"
 	"os"
+	"sort"
+	"strings"
 
 	"github.com/sassoftware/relic/cmdline/shared"
 	"github.com/sassoftware/relic/config"
 	"github.com/sassoftware/relic/token"
-	"github.com/sassoftware/relic/token/p11token"
-	"github.com/sassoftware/relic/token/scdtoken"
+	"github.com/sassoftware/relic/token/open"
 	"github.com/spf13/cobra"
 )
 
@@ -55,7 +57,6 @@ var (
 func init() {
 	shared.RootCmd.AddCommand(TokenCmd)
 	TokenCmd.PersistentFlags().StringVarP(&argToken, "token", "t", "", "Name of token")
-	TokenCmd.PersistentFlags().StringVar(&argType, "type", "", "Provider type (pkcs11, scdaemon)")
 	TokenCmd.PersistentFlags().StringVar(&argProvider, "provider", "", "Provider module path")
 
 	TokenCmd.AddCommand(TokensCmd)
@@ -64,6 +65,17 @@ func init() {
 	ContentsCmd.Flags().StringVarP(&argLabel, "label", "l", "", "Display objects with this label only")
 	ContentsCmd.Flags().StringVarP(&argId, "id", "i", "", "Display objects with this ID only")
 	ContentsCmd.Flags().BoolVarP(&argValues, "values", "v", false, "Show contents of objects")
+
+	shared.AddLateHook(addProviderTypeHelp) // deferred so token providers can init()
+}
+
+func addProviderTypeHelp() {
+	var listable []string
+	for ptype := range token.Listers {
+		listable = append(listable, ptype)
+	}
+	sort.Strings(listable)
+	TokenCmd.PersistentFlags().StringVar(&argType, "type", "", fmt.Sprintf("Provider type (%s)", strings.Join(listable, ", ")))
 }
 
 func tokensCmd(cmd *cobra.Command, args []string) error {
@@ -85,16 +97,7 @@ func tokensCmd(cmd *cobra.Command, args []string) error {
 			argProvider = tokenConf.Provider
 		}
 	}
-	var err error
-	switch argType {
-	case "pkcs11":
-		err = p11token.List(argProvider, os.Stdout)
-	case "scdaemon":
-		err = scdtoken.List(argProvider, os.Stdout)
-	default:
-		return errors.New("unsupported provider type")
-	}
-	return shared.Fail(err)
+	return shared.Fail(open.List(argType, argProvider, os.Stdout))
 }
 
 func contentsCmd(cmd *cobra.Command, args []string) error {

impure.go

@@ -17,8 +17,4 @@
 
 package main
 
-// Local signing commands using tokens
-
-import (
-	_ "github.com/sassoftware/relic/cmdline/token"
-)
+import _ "github.com/sassoftware/relic/token/p11token"

nonclient.go

@@ -17,9 +17,13 @@
 
 package main
 
-// Commands that are disabled for client-only builds
-
 import (
+	// Commands that are disabled for client-only builds
 	_ "github.com/sassoftware/relic/cmdline/auditor"
 	_ "github.com/sassoftware/relic/cmdline/servecmd"
+	_ "github.com/sassoftware/relic/cmdline/token"
+
+	// Token types that don't require cgo
+	_ "github.com/sassoftware/relic/token/filetoken"
+	_ "github.com/sassoftware/relic/token/scdtoken"
 )

token/filetoken/filetoken.go

@@ -31,6 +31,10 @@ import (
 	"github.com/sassoftware/relic/token"
 )
 
+func init() {
+	token.Openers["file"] = Open
+}
+
 type fileToken struct {
 	config    *config.Config
 	tokenConf *config.TokenConfig

token/open/open.go

@@ -18,30 +18,26 @@ package open
 
 import (
 	"fmt"
+	"io"
 
 	"github.com/sassoftware/relic/config"
 	"github.com/sassoftware/relic/lib/passprompt"
 	"github.com/sassoftware/relic/token"
-	"github.com/sassoftware/relic/token/filetoken"
-	"github.com/sassoftware/relic/token/p11token"
-	"github.com/sassoftware/relic/token/scdtoken"
 )
 
 func Token(cfg *config.Config, tokenName string, prompt passprompt.PasswordGetter) (token.Token, error) {
 	tcfg, err := cfg.GetToken(tokenName)
 	if err != nil {
 		return nil, err
 	}
-	switch tcfg.Type {
-	case "pkcs11":
-		return p11token.Open(cfg, tokenName, prompt)
-	case "file":
-		return filetoken.Open(cfg, tokenName, prompt)
-	case "scdaemon":
-		return scdtoken.Open(cfg, tokenName, prompt)
-	default:
-		return nil, fmt.Errorf("unknown token type %s", tcfg.Type)
+	if ofunc := token.Openers[tcfg.Type]; ofunc != nil {
+		return ofunc(cfg, tokenName, prompt)
 	}
+	var msg string
+	if tcfg.Type == "pkcs11" {
+		msg = " -- built without pkcs11 support"
+	}
+	return nil, fmt.Errorf("unknown token type %s%s", tcfg.Type, msg)
 }
 
 func Key(cfg *config.Config, keyName string, prompt passprompt.PasswordGetter) (token.Key, error) {
@@ -60,3 +56,17 @@ func Key(cfg *config.Config, keyName string, prompt passprompt.PasswordGetter) (
 	}
 	return key, nil
 }
+
+func List(tokenType, provider string, w io.Writer) error {
+	if listFunc := token.Listers[tokenType]; listFunc != nil {
+		return listFunc(provider, w)
+	}
+	if token.Openers[tokenType] != nil {
+		return fmt.Errorf("list operation not supported for token type %s", tokenType)
+	}
+	var msg string
+	if tokenType == "pkcs11" {
+		msg = " -- built without pkcs11 support"
+	}
+	return fmt.Errorf("unknown token type %s%s", tokenType, msg)
+}

token/p11token/token.go

@@ -45,6 +45,11 @@ const (
 	CKK_ECDSA = pkcs11.CKK_ECDSA
 )
 
+func init() {
+	token.Openers["pkcs11"] = open
+	token.Listers["pkcs11"] = List
+}
+
 var providerMap map[string]*pkcs11.Ctx
 var providerMutex sync.Mutex
 
@@ -115,6 +120,11 @@ func Open(config *config.Config, tokenName string, pinProvider passprompt.Passwo
 	return tok, nil
 }
 
+// compat shim for token.Openers
+func open(cfg *config.Config, tokenName string, prompt passprompt.PasswordGetter) (token.Token, error) {
+	return Open(cfg, tokenName, prompt)
+}
+
 func openLib(tokenConf *config.TokenConfig, write bool) (*pkcs11.Ctx, error) {
 	if tokenConf.Provider == "" {
 		return nil, errors.New("Missing attribute \"provider\" in token configuration")

token/register.go

@@ -0,0 +1,34 @@
+//
+// Copyright (c) SAS Institute Inc.
+//
+// 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 token
+
+import (
+	"io"
+
+	"github.com/sassoftware/relic/config"
+	"github.com/sassoftware/relic/lib/passprompt"
+)
+
+type (
+	OpenFunc func(cfg *config.Config, tokenName string, prompt passprompt.PasswordGetter) (Token, error)
+	ListFunc func(provider string, dest io.Writer) error
+)
+
+var (
+	Openers = make(map[string]OpenFunc)
+	Listers = make(map[string]ListFunc)
+)

token/scdtoken/scdtoken.go

@@ -36,6 +36,11 @@ import (
 	"github.com/sassoftware/relic/token"
 )
 
+func init() {
+	token.Openers["scdtoken"] = Open
+	token.Listers["scdtoken"] = List
+}
+
 var defaultScdSockets = []string{
 	"/run/user/$UID/gnupg/S.scdaemon",
 	"/var/run/user/$UID/gnupg/S.scdaemon",
@@ -95,7 +100,7 @@ func List(sockPath string, output io.Writer) error {
 	return nil
 }
 
-func Open(conf *config.Config, tokenName string, prompt passprompt.PasswordGetter) (tok *scdToken, err error) {
+func Open(conf *config.Config, tokenName string, prompt passprompt.PasswordGetter) (token.Token, error) {
 	tconf, err := conf.GetToken(tokenName)
 	if err != nil {
 		return nil, err
@@ -111,7 +116,7 @@ func Open(conf *config.Config, tokenName string, prompt passprompt.PasswordGette
 	if err != nil {
 		return nil, err
 	}
-	tok = &scdToken{
+	tok := &scdToken{
 		config:    conf,
 		tokenConf: tconf,
 		sock:      sock,