Add `-masterkey=stdin` functionality

https://github.com/rfjakob/gocryptfs/issues/218

3 files changed, 16 insertions, 13 deletions

diff --git a/internal/readpassword/extpass_test.go b/internal/readpassword/extpass_test.go
index cdfea4e..b35153f 100644
--- a/internal/readpassword/extpass_test.go
+++ b/internal/readpassword/extpass_test.go
@@ -26,7 +26,7 @@ func TestExtpass(t *testing.T) {
 
 func TestOnceExtpass(t *testing.T) {
 	p1 := "lkadsf0923rdfi48rqwhdsf"
-	p2 := string(Once("echo " + p1))
+	p2 := string(Once("echo "+p1, ""))
 	if p1 != p2 {
 		t.Errorf("p1=%q != p2=%q", p1, p2)
 	}
@@ -34,7 +34,7 @@ func TestOnceExtpass(t *testing.T) {
 
 func TestTwiceExtpass(t *testing.T) {
 	p1 := "w5w44t3wfe45srz434"
-	p2 := string(Once("echo " + p1))
+	p2 := string(Once("echo "+p1, ""))
 	if p1 != p2 {
 		t.Errorf("p1=%q != p2=%q", p1, p2)
 	}
diff --git a/internal/readpassword/read.go b/internal/readpassword/read.go
index e2fce8a..c99be5d 100644
--- a/internal/readpassword/read.go
+++ b/internal/readpassword/read.go
@@ -23,15 +23,18 @@ const (
 )
 
 // Once tries to get a password from the user, either from the terminal, extpass
-// or stdin.
-func Once(extpass string) []byte {
+// or stdin. Leave "prompt" empty to use the default "Password: " prompt.
+func Once(extpass string, prompt string) []byte {
 	if extpass != "" {
 		return readPasswordExtpass(extpass)
 	}
+	if prompt == "" {
+		prompt = "Password"
+	}
 	if !terminal.IsTerminal(int(os.Stdin.Fd())) {
-		return readPasswordStdin()
+		return readPasswordStdin(prompt)
 	}
-	return readPasswordTerminal("Password: ")
+	return readPasswordTerminal(prompt + ": ")
 }
 
 // Twice is the same as Once but will prompt twice if we get the password from
@@ -41,7 +44,7 @@ func Twice(extpass string) []byte {
 		return readPasswordExtpass(extpass)
 	}
 	if !terminal.IsTerminal(int(os.Stdin.Fd())) {
-		return readPasswordStdin()
+		return readPasswordStdin("Password")
 	}
 	p1 := readPasswordTerminal("Password: ")
 	p2 := readPasswordTerminal("Repeat: ")
@@ -77,11 +80,11 @@ func readPasswordTerminal(prompt string) []byte {
 
 // readPasswordStdin reads a line from stdin.
 // It exits with a fatal error on read error or empty result.
-func readPasswordStdin() []byte {
-	tlog.Info.Println("Reading password from stdin")
+func readPasswordStdin(prompt string) []byte {
+	tlog.Info.Printf("Reading %s from stdin", prompt)
 	p := readLineUnbuffered(os.Stdin)
 	if len(p) == 0 {
-		tlog.Fatal.Println("Got empty password from stdin")
+		tlog.Fatal.Printf("Got empty %s from stdin", prompt)
 		os.Exit(exitcodes.ReadPassword)
 	}
 	return p
diff --git a/internal/readpassword/stdin_test.go b/internal/readpassword/stdin_test.go
index 8cf9954..01dd701 100644
--- a/internal/readpassword/stdin_test.go
+++ b/internal/readpassword/stdin_test.go
@@ -11,7 +11,7 @@ import (
 func TestStdin(t *testing.T) {
 	p1 := "g55434t55wef"
 	if os.Getenv("TEST_SLAVE") == "1" {
-		p2 := string(readPasswordStdin())
+		p2 := string(readPasswordStdin("foo"))
 		if p1 != p2 {
 			fmt.Fprintf(os.Stderr, "%q != %q", p1, p2)
 			os.Exit(1)
@@ -44,7 +44,7 @@ func TestStdin(t *testing.T) {
 func TestStdinEof(t *testing.T) {
 	p1 := "asd45as5f4a36"
 	if os.Getenv("TEST_SLAVE") == "1" {
-		p2 := string(readPasswordStdin())
+		p2 := string(readPasswordStdin("foo"))
 		if p1 != p2 {
 			fmt.Fprintf(os.Stderr, "%q != %q", p1, p2)
 			os.Exit(1)
@@ -76,7 +76,7 @@ func TestStdinEof(t *testing.T) {
 // Provide empty password via stdin
 func TestStdinEmpty(t *testing.T) {
 	if os.Getenv("TEST_SLAVE") == "1" {
-		readPasswordStdin()
+		readPasswordStdin("foo")
 	}
 	cmd := exec.Command(os.Args[0], "-test.run=TestStdinEmpty$")
 	cmd.Env = append(os.Environ(), "TEST_SLAVE=1")