configfile: use map[flagIota] for feature flags

This should make things saner and more extensible. It prepares
the infrastructure for "required feature flags" that will be used
to deprecate old gocryptfs version.

1 files changed, 41 insertions, 0 deletions

diff --git a/internal/configfile/feature_flags.go b/internal/configfile/feature_flags.go
new file mode 100644
index 0000000..d439363
--- /dev/null
+++ b/internal/configfile/feature_flags.go
@@ -0,0 +1,41 @@
+package configfile
+
+type flagIota int
+
+const (
+	FlagPlaintextNames flagIota = iota
+	FlagDirIV
+	FlagEMENames
+	FlagGCMIV128
+	FlagLongNames
+)
+
+// knownFlags stores the known feature flags and their string representation
+var knownFlags map[flagIota]string = map[flagIota]string{
+	FlagPlaintextNames: "PlaintextNames",
+	FlagDirIV:          "DirIV",
+	FlagEMENames:       "EMENames",
+	FlagGCMIV128:       "GCMIV128",
+	FlagLongNames:      "LongNames",
+}
+
+// isFeatureFlagKnown verifies that we understand a feature flag
+func (cf *ConfFile) isFeatureFlagKnown(flag string) bool {
+	for _, knownFlag := range knownFlags {
+		if knownFlag == flag {
+			return true
+		}
+	}
+	return false
+}
+
+// isFeatureFlagSet - is the feature flag "flagWant" enabled?
+func (cf *ConfFile) IsFeatureFlagSet(flagWant flagIota) bool {
+	flagString := knownFlags[flagWant]
+	for _, flag := range cf.FeatureFlags {
+		if flag == flagString {
+			return true
+		}
+	}
+	return false
+}