init

internal/security/nonce.go

@@ -0,0 +1,31 @@
+package security
+
+import (
+	"sync"
+	"time"
+)
+
+type NonceStore struct {
+	mu  sync.Mutex
+	m   map[string]int64
+	ttl time.Duration
+}
+
+func NewNonceStore(ttl time.Duration) *NonceStore {
+	return &NonceStore{m: map[string]int64{}, ttl: ttl}
+}
+
+func (s *NonceStore) Use(nonce string, now time.Time) bool {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if exp, ok := s.m[nonce]; ok && exp >= now.Unix() {
+		return false
+	}
+	s.m[nonce] = now.Add(s.ttl).Unix()
+	for k, v := range s.m {
+		if v < now.Unix() {
+			delete(s.m, k)
+		}
+	}
+	return true
+}