ModernKeePassLib implements HMAC correctly

Blake2b also implemented, but not tested
ModernKeePass app better implements focus on database password box (but still not working correctly)

ModernKeePassLib/Cryptography/Hash/HMACSHA1.cs

@@ -0,0 +1,15 @@
+using Org.BouncyCastle.Crypto.Digests;
+using Org.BouncyCastle.Crypto.Macs;
+using Org.BouncyCastle.Crypto.Parameters;
+
+namespace ModernKeePassLib.Cryptography.Hash
+{
+    public class HMACSHA1: HMAC
+    {
+        public HMACSHA1(byte[] key)
+        {
+            _hmac = new HMac(new Sha1Digest());
+            _hmac.Init(new KeyParameter(key));
+        }
+    }
+}