1 files changed, 54 insertions, 0 deletions
diff --git a/crypto/src/crypto/digests/XofUtils.cs b/crypto/src/crypto/digests/XofUtils.cs
new file mode 100644
index 000000000..e4c893e01
--- /dev/null
+++ b/crypto/src/crypto/digests/XofUtils.cs
@@ -0,0 +1,54 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace Org.BouncyCastle.Crypto.Digests
+{
+    public class XofUtils
+    {
+        public static byte[] leftEncode(long strLen)
+        {
+            byte n = 1;
+
+            long v = strLen;
+            while ((v >>= 8) != 0)
+            {
+                n++;
+            }
+
+            byte[] b = new byte[n + 1];
+
+            b[0] = n;
+
+            for (int i = 1; i <= n; i++)
+            {
+                b[i] = (byte)(strLen >> (8 * (n - i)));
+            }
+
+            return b;
+        }
+
+        public static byte[] rightEncode(long strLen)
+        {
+            byte n = 1;
+
+            long v = strLen;
+            while ((v >>= 8) != 0)
+            {
+                n++;
+            }
+
+            byte[] b = new byte[n + 1];
+
+            b[n] = n;
+
+            for (int i = 0; i < n; i++)
+            {
+                b[i] = (byte)(strLen >> (8 * (n - i - 1)));
+            }
+
+            return b;
+        }
+    }
+}