1 files changed, 41 insertions, 0 deletions
diff --git a/wrappers/dotnet/VNLib.Utils.Cryptography.Noscrypt/src/Nip04Util.cs b/wrappers/dotnet/VNLib.Utils.Cryptography.Noscrypt/src/Nip04Util.cs
new file mode 100644
index 0000000..82704db
--- /dev/null
+++ b/wrappers/dotnet/VNLib.Utils.Cryptography.Noscrypt/src/Nip04Util.cs
@@ -0,0 +1,41 @@
+// Copyright (C) 2024 Vaughn Nugent
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as
+// published by the Free Software Foundation, either version 3 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+using System;
+
+using VNLib.Utils.Extensions;
+
+namespace VNLib.Utils.Cryptography.Noscrypt
+{
+    public static class Nip04Util
+    {
+        public static bool IsValidPayload(ReadOnlySpan<char> payload)
+        {
+            /* Iv is base64 encoded so it should be 33% larger than 16 byte iv */
+            ReadOnlySpan<char> iv = payload.SliceAfterParam("?iv=");
+            return iv.Length > 20 && iv.Length <= 26;
+        }
+
+        public static ReadOnlySpan<char> GetIV(ReadOnlySpan<char> payload) => payload.SliceAfterParam("?iv=");
+
+        public static ReadOnlySpan<char> GetCipherText(ReadOnlySpan<char> payload) => payload.SliceBeforeParam("?iv=");
+
+        public static int CalcBufferSize(int dataSize)
+        {
+            throw new NotImplementedException();
+        }
+    }
+
+}