main: Add '-devrandom' commandline option

Allows to use /dev/random for generating the master key instead of the
default Go implementation. When the kernel random generator has been
properly initialized both are considered equally secure, however:

* Versions of Go prior to 1.9 just fall back to /dev/urandom if the
  getrandom() syscall would be blocking (Go Bug #19274)

* Kernel versions prior to 3.17 do not support getrandom(), and there
  is no check if the random generator has been properly initialized
  before reading from /dev/urandom

This is especially useful for embedded hardware with low-entroy. Please
note that generation of the master key might block indefinitely if the
kernel cannot harvest enough entropy.

1 files changed, 10 insertions, 3 deletions

diff --git a/internal/configfile/config_test.go b/internal/configfile/config_test.go
index dc796ea..b984a37 100644
--- a/internal/configfile/config_test.go
+++ b/internal/configfile/config_test.go
@@ -60,7 +60,7 @@ func TestLoadV2StrangeFeature(t *testing.T) {
 }
 
 func TestCreateConfDefault(t *testing.T) {
-	err := CreateConfFile("config_test/tmp.conf", "test", false, 10, "test", false)
+	err := CreateConfFile("config_test/tmp.conf", "test", false, 10, "test", false, false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -80,8 +80,15 @@ func TestCreateConfDefault(t *testing.T) {
 	}
 }
 
+func TestCreateConfDevRandom(t *testing.T) {
+	err := CreateConfFile("config_test/tmp.conf", "test", false, 10, "test", false, true)
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
 func TestCreateConfPlaintextnames(t *testing.T) {
-	err := CreateConfFile("config_test/tmp.conf", "test", true, 10, "test", false)
+	err := CreateConfFile("config_test/tmp.conf", "test", true, 10, "test", false, false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -102,7 +109,7 @@ func TestCreateConfPlaintextnames(t *testing.T) {
 
 // Reverse mode uses AESSIV
 func TestCreateConfFileAESSIV(t *testing.T) {
-	err := CreateConfFile("config_test/tmp.conf", "test", false, 10, "test", true)
+	err := CreateConfFile("config_test/tmp.conf", "test", false, 10, "test", true, false)
 	if err != nil {
 		t.Fatal(err)
 	}