vendor: import KillerPDF 1.7.5 source (GPL-3.0) as the base for MMD PDF

third_party/PdfSharpCore/Pdf.Security/IEncryptor.cs

@@ -0,0 +1,21 @@
+namespace PdfSharpCore.Pdf.Security
+{
+    internal interface IEncryptor
+    {
+        bool PasswordValid { get; }
+
+        bool HaveOwnerPermission { get; }
+
+        void Initialize(PdfDocument document, PdfDictionary encryptionDict);
+
+        void InitEncryptionKey(string password);
+
+        bool ValidatePassword(string password);
+
+        void SetEncryptionKey(byte[] key);
+
+        void CreateHashKey(PdfObjectID objectId);
+
+        byte[] Encrypt(byte[] bytes);
+    }
+}