added blacklist storage interface

blacklist.go

@@ -0,0 +1,40 @@
+// Copyright (C) 2018 Marius Schellenberger
+
+package jwt
+
+// Blacklist is the blacklisting storage interface
+type Blacklist interface {
+	Add(string, int64)
+	Remove(string)
+	Check(string) bool
+	Map() MapBlacklist
+}
+
+// MapBlacklist implements the Blacklist interface
+type MapBlacklist map[string]int64
+
+// NewMapBlacklist
+func NewMapBlacklist() MapBlacklist {
+	return make(MapBlacklist)
+}
+
+// Add adds a new token signature with expiration time to the blacklist
+func (mb MapBlacklist) Add(sig string, exp int64) {
+	mb[sig] = exp
+}
+
+// Remove deletes a token signature from the blacklist
+func (mb MapBlacklist) Remove(sig string) {
+	delete(mb, sig)
+}
+
+// Check returns true if a token signature is blacklisted and false otherwise
+func (mb MapBlacklist) Check(sig string) (ok bool) {
+	_, ok = mb[sig]
+	return
+}
+
+// Map returns the blacklist in the form of a iterable map structure for cleanup
+func (mb MapBlacklist) Map() MapBlacklist {
+	return mb
+}