fix

lib/KeyStore.ts

@@ -7,26 +7,50 @@
 
 import { create_salt } from '@sapphirecode/crypto-helper';
 
+interface Key {
+  key: string;
+  valid_until: number;
+  timeout: NodeJS.Timeout;
+}
+
 class KeyStore {
-  private _keys: Record<string, string> = {};
+  private _keys: Record<string, Key> = {};
+
+  private set_timeout (index: string, valid_for: number): NodeJS.Timeout {
+    return setTimeout (() => {
+      delete this._keys[index];
+    }, (valid_for + 5) * 1000);
+  }
 
   public get_key (iat: number, valid_for = 0): string {
-    const key = Math.floor (iat / 60)
+    const index = Math.floor (iat / 60)
       .toFixed (0);
 
-    if (typeof this._keys[key] === 'string')
-      return this._keys[key];
+    const valid_until = (new Date)
+      .getTime () + (valid_for * 1000);
+
+    if (typeof this._keys[index] !== 'undefined') {
+      const key = this._keys[index];
+      if (valid_for !== 0 && key.valid_until < valid_until) {
+        clearTimeout (key.timeout);
+        key.timeout = this.set_timeout (index, valid_for);
+        key.valid_until = valid_until;
+      }
+      return key.key;
+    }
 
     if (valid_for !== 0) {
-      if ((iat + valid_for) * 1000 < (new Date)
+      if ((iat + 1) * 1000 < (new Date)
         .getTime ())
         throw new Error ('cannot create already expired keys');
 
-      this._keys[key] = create_salt ();
-      setTimeout (() => {
-        delete this._keys[key];
-      }, (valid_for + 5) * 1000);
-      return this._keys[key];
+      this._keys[index] = {
+        key:     create_salt (),
+        timeout: this.set_timeout (index, valid_for),
+        valid_until
+      };
+
+      return this._keys[index].key;
     }
 
     throw new Error ('key could not be found');