Add "-extpass" cli option and associated tests

MANPAGE.md

@@ -39,6 +39,11 @@ Options:
 **-debug**
 :	Enable debug output
 
+**-extpass string**
+:	Use an external program (like ssh-askpass) for the password prompt.
+The program should return the password on stdout, a trailing newline is
+stripped by gocryptfs.
+
 **-f**
 :	Stay in the foreground
 

cryptfs/filter.go

@@ -6,8 +6,9 @@ package cryptfs
 // when file names are not encrypted
 func (be *CryptFS) IsFiltered(path string) bool {
 	// gocryptfs.conf in the root directory is forbidden
-	if be.plaintextNames == true && path == "gocryptfs.conf" {
-		Warn.Printf("The name \"/gocryptfs.conf\" is reserved when \"--plaintextnames\" is used\n")
+	if be.plaintextNames == true && path == ConfDefaultName {
+		Warn.Printf("The name /%s is reserved when -plaintextnames is used\n",
+			ConfDefaultName)
 		return true
 	}
 	return false

integration_tests/cli_test.go

@@ -0,0 +1,46 @@
+package integration_tests
+
+// Test CLI operations like "-init", "-password" etc
+
+import (
+	"os"
+	"os/exec"
+	"testing"
+
+	"github.com/rfjakob/gocryptfs/cryptfs"
+)
+
+func TestInit(t *testing.T) {
+	dir := tmpDir + "TestInit/"
+	err := os.Mkdir(dir, 0777)
+	if err != nil {
+		t.Fatal(err)
+	}
+	cmd := exec.Command(gocryptfsBinary, "-init", "-extpass", "echo test", dir)
+	if testing.Verbose() {
+		cmd.Stdout = os.Stdout
+		cmd.Stderr = os.Stderr
+	}
+	err = cmd.Run()
+	if err != nil {
+		t.Error(err)
+	}
+	_, err = os.Stat(dir + cryptfs.ConfDefaultName)
+	if err != nil {
+		t.Error(err)
+	}
+}
+
+// "dir" has been initialized by TestInit
+func TestPasswd(t *testing.T) {
+	dir := tmpDir + "TestInit/"
+	cmd := exec.Command(gocryptfsBinary, "-passwd", "-extpass", "echo test", dir)
+	if testing.Verbose() {
+		cmd.Stdout = os.Stdout
+		cmd.Stderr = os.Stderr
+	}
+	err := cmd.Run()
+	if err != nil {
+		t.Error(err)
+	}
+}

integration_tests/helpers.go

@@ -10,13 +10,13 @@ import (
 	"testing"
 )
 
+// Note: the code assumes that all have a trailing slash
 const tmpDir = "/tmp/gocryptfs_main_test/"
-
-// Mountpoint
-// Note: the code assumes that both have a trailing slash!
 const plainDir = tmpDir + "plain/"
 const cipherDir = tmpDir + "cipher/"
 
+const gocryptfsBinary = "../gocryptfs"
+
 func resetTmpDir() {
 	fu := exec.Command("fusermount", "-z", "-u", plainDir)
 	fu.Run()
@@ -40,11 +40,11 @@ func mount(extraArgs ...string) {
 	//args = append(args, "--fusedebug")
 	args = append(args, cipherDir)
 	args = append(args, plainDir)
-	c := exec.Command("../gocryptfs", args...)
-	// Warning messages clutter the test output. Uncomment if you want to debug
-	// failures.
-	//c.Stdout = os.Stdout
-	//c.Stderr = os.Stderr
+	c := exec.Command(gocryptfsBinary, args...)
+	if testing.Verbose() {
+		c.Stdout = os.Stdout
+		c.Stderr = os.Stderr
+	}
 	err := c.Run()
 	if err != nil {
 		fmt.Println(err)

main.go

@@ -44,7 +44,7 @@ func initDir(args *argContainer) {
 	}
 
 	cryptfs.Info.Printf("Choose a password for protecting your files.\n")
-	password := readPasswordTwice()
+	password := readPasswordTwice(args.extpass)
 	err = cryptfs.CreateConfFile(args.config, password, args.plaintextnames)
 	if err != nil {
 		fmt.Println(err)
@@ -66,25 +66,25 @@ func usageText() {
 type argContainer struct {
 	debug, init, zerokey, fusedebug, openssl, passwd, foreground, version,
 	plaintextnames, quiet bool
-	masterkey, mountpoint, cipherdir, cpuprofile, config string
+	masterkey, mountpoint, cipherdir, cpuprofile, config, extpass string
 	notifypid                                                     int
 }
 
 var flagSet *flag.FlagSet
 
 // loadConfig - load the config file "filename", prompting the user for the password
-func loadConfig(filename string) (masterkey []byte, confFile *cryptfs.ConfFile) {
+func loadConfig(args *argContainer) (masterkey []byte, confFile *cryptfs.ConfFile) {
 	// Check if the file exists at all before prompting for a password
-	_, err := os.Stat(filename)
+	_, err := os.Stat(args.config)
 	if err != nil {
 		fmt.Print(err)
 		os.Exit(ERREXIT_LOADCONF)
 	}
 	fmt.Printf("Password: ")
-	pw := readPassword()
+	pw := readPassword(args.extpass)
 	cryptfs.Info.Printf("Decrypting master key... ")
 	cryptfs.Warn.Disable() // Silence DecryptBlock() error messages on incorrect password
-	masterkey, confFile, err = cryptfs.LoadConfFile(filename, pw)
+	masterkey, confFile, err = cryptfs.LoadConfFile(args.config, pw)
 	cryptfs.Warn.Enable()
 	if err != nil {
 		fmt.Println(err)
@@ -97,10 +97,10 @@ func loadConfig(filename string) (masterkey []byte, confFile *cryptfs.ConfFile)
 }
 
 // changePassword - change the password of config file "filename"
-func changePassword(filename string) {
-	masterkey, confFile := loadConfig(filename)
+func changePassword(args *argContainer) {
+	masterkey, confFile := loadConfig(args)
 	fmt.Printf("Please enter your new password.\n")
-	newPw := readPasswordTwice()
+	newPw := readPasswordTwice(args.extpass)
 	confFile.EncryptKey(masterkey, newPw)
 	err := confFile.WriteFile()
 	if err != nil {
@@ -139,6 +139,7 @@ func main() {
 	flagSet.StringVar(&args.masterkey, "masterkey", "", "Mount with explicit master key")
 	flagSet.StringVar(&args.cpuprofile, "cpuprofile", "", "Write cpu profile to specified file")
 	flagSet.StringVar(&args.config, "config", "", "Use specified config file instead of CIPHERDIR/gocryptfs.conf")
+	flagSet.StringVar(&args.extpass, "extpass", "", "Use external program for the password prompt")
 	flagSet.IntVar(&args.notifypid, "notifypid", 0, "Send USR1 to the specified process after "+
 		"successful mount - used internally for daemonization")
 	flagSet.Parse(os.Args[1:])
@@ -215,7 +216,7 @@ func main() {
 			fmt.Printf("Usage: %s -passwd [OPTIONS] CIPHERDIR\n", PROGRAM_NAME)
 			os.Exit(ERREXIT_USAGE)
 		}
-		changePassword(args.config) // does not return
+		changePassword(&args) // does not return
 	}
 	// Mount
 	// Check mountpoint
@@ -248,7 +249,7 @@ func main() {
 	} else {
 		// Load master key from config file
 		var confFile *cryptfs.ConfFile
-		masterkey, confFile = loadConfig(args.config)
+		masterkey, confFile = loadConfig(&args)
 		printMasterKey(masterkey)
 		args.plaintextnames = confFile.PlaintextNames()
 	}

password.go

@@ -2,15 +2,18 @@ package main
 
 import (
 	"fmt"
-	"golang.org/x/crypto/ssh/terminal"
 	"os"
+	"os/exec"
+	"strings"
+
+	"golang.org/x/crypto/ssh/terminal"
 )
 
-func readPasswordTwice() string {
+func readPasswordTwice(extpass string) string {
 	fmt.Printf("Password: ")
-	p1 := readPassword()
+	p1 := readPassword(extpass)
 	fmt.Printf("Repeat:   ")
-	p2 := readPassword()
+	p2 := readPassword(extpass)
 	if p1 != p2 {
 		fmt.Printf("Passwords do not match\n")
 		os.Exit(ERREXIT_PASSWORD)
@@ -18,14 +21,39 @@ func readPasswordTwice() string {
 	return p1
 }
 
-// Get password from terminal
-func readPassword() string {
-	fd := int(os.Stdin.Fd())
-	p, err := terminal.ReadPassword(fd)
-	fmt.Printf("\n")
+// readPassword - get password from terminal
+// or from the "extpass" program
+func readPassword(extpass string) string {
+	var password string
+	var err error
+	var output []byte
+	if extpass != "" {
+		parts := strings.Split(extpass, " ")
+		cmd := exec.Command(parts[0], parts[1:]...)
+		cmd.Stderr = os.Stderr
+		output, err = cmd.Output()
 		if err != nil {
-		fmt.Printf("Error: Could not read password: %v\n", err)
+			fmt.Printf("extpass program returned error: %v\n", err)
 			os.Exit(ERREXIT_PASSWORD)
 		}
-	return string(p)
+		fmt.Printf("(extpass)\n")
+		// Trim trailing newline like terminal.ReadPassword() does
+		if output[len(output)-1] == '\n' {
+			output = output[:len(output)-1]
+		}
+	} else {
+		fd := int(os.Stdin.Fd())
+		output, err = terminal.ReadPassword(fd)
+		if err != nil {
+			fmt.Printf("Error: Could not read password from terminal: %v\n", err)
+			os.Exit(ERREXIT_PASSWORD)
+		}
+		fmt.Printf("\n")
+	}
+	password = string(output)
+	if password == "" {
+		fmt.Printf("Error: password is empty\n")
+		os.Exit(ERREXIT_PASSWORD)
+	}
+	return password
 }