exitcodes: define code 12 for "password incorrect"

internal/configfile/config_file.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/rfjakob/gocryptfs/internal/contentenc"
 	"github.com/rfjakob/gocryptfs/internal/cryptocore"
+	"github.com/rfjakob/gocryptfs/internal/exitcodes"
 	"github.com/rfjakob/gocryptfs/internal/tlog"
 )
 import "os"
@@ -163,7 +164,7 @@ func LoadConfFile(filename string, password string) ([]byte, *ConfFile, error) {
 	tlog.Warn.Enabled = true
 	if err != nil {
 		tlog.Warn.Printf("failed to unlock master key: %s", err.Error())
-		return nil, nil, fmt.Errorf("Password incorrect.")
+		return nil, nil, exitcodes.NewErr("Password incorrect.", exitcodes.PasswordIncorrect)
 	}
 
 	return key, &cf, err

internal/exitcodes/exitcodes.go

@@ -0,0 +1,38 @@
+// Package exitcodes contains all well-defined exit codes that gocryptfs
+// can return.
+package exitcodes
+
+import (
+	"fmt"
+	"os"
+)
+
+const (
+	// Other error - please inspect the message
+	Other = 11
+	// The password was incorrect
+	PasswordIncorrect = 12
+	// TODO several other exit codes are defined in main.go. These will be
+	// ported over here.
+)
+
+type Err struct {
+	error
+	code int
+}
+
+// NewErr returns an error containing "msg" and the exit code "code".
+func NewErr(msg string, code int) Err {
+	return Err{
+		error: fmt.Errorf(msg),
+		code:  code,
+	}
+}
+
+func Exit(err error) {
+	err2, ok := err.(Err)
+	if !ok {
+		os.Exit(Other)
+	}
+	os.Exit(err2.code)
+}

mount.go

@@ -21,6 +21,7 @@ import (
 	"github.com/rfjakob/gocryptfs/internal/configfile"
 	"github.com/rfjakob/gocryptfs/internal/cryptocore"
 	"github.com/rfjakob/gocryptfs/internal/ctlsock"
+	"github.com/rfjakob/gocryptfs/internal/exitcodes"
 	"github.com/rfjakob/gocryptfs/internal/fusefrontend"
 	"github.com/rfjakob/gocryptfs/internal/fusefrontend_reverse"
 	"github.com/rfjakob/gocryptfs/internal/readpassword"
@@ -96,7 +97,7 @@ func doMount(args *argContainer) int {
 				// Close the socket file (which also deletes it)
 				args._ctlsockFd.Close()
 			}
-			os.Exit(ErrExitLoadConf)
+			exitcodes.Exit(err)
 		}
 		readpassword.CheckTrailingGarbage()
 		printMasterKey(masterkey)