From db0b0e28d259cc3bae4597eda543bfef4d1585c2 Mon Sep 17 00:00:00 2001
From: David Garske <david@wolfssl.com>
Date: Thu, 22 May 2025 16:34:54 -0700
Subject: [PATCH] Fix issue with CSharp and Windows CE with conversion of
 ASCII->Unicode and Unicode->ASCII with odd length and extra null terminator.

---
 wrapper/CSharp/wolfSSL_CSharp/wolfSSL.cs | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/wrapper/CSharp/wolfSSL_CSharp/wolfSSL.cs b/wrapper/CSharp/wolfSSL_CSharp/wolfSSL.cs
index 0153b8ab0..624c1910e 100644
--- a/wrapper/CSharp/wolfSSL_CSharp/wolfSSL.cs
+++ b/wrapper/CSharp/wolfSSL_CSharp/wolfSSL.cs
@@ -51,7 +51,9 @@ namespace wolfSSL.CSharp
             /* Convert Unicode to Bytes */
             byte[] bytes = Encoding.Unicode.GetBytes((string)msg.ToString());
             /* Convert to ASCII */
-            return Encoding.ASCII.GetString(bytes, 0, bytes.Length);
+            string ret = Encoding.ASCII.GetString(bytes, 0, bytes.Length);
+            /* odd length unicode might have extra null terminator, so remove */
+            return ret.Replace("\0", "");
         }
 
         /// <summary>
@@ -61,14 +63,20 @@ namespace wolfSSL.CSharp
         {
             if (msg == null)
                 return null;
-            /* Convert ASCII to Bytes */
-            byte[] bytes = Encoding.ASCII.GetBytes((string)msg.ToString());
+            /* Get length and round up to even unicode */
+            int msgLen = msg.Length;
+            msgLen = ((msgLen + 1) & ~1);
+            byte[] bytes = new byte[msgLen];
+            /* Convert Ascii to Bytes */
+            byte[] msgBytes = Encoding.ASCII.GetBytes((string)msg.ToString());
+            msgBytes.CopyTo(bytes, 0);
             /* Convert to Unicode */
             return Encoding.Unicode.GetString(bytes, 0, bytes.Length);
         }
 
         /// <summary>
-        /// WinCE version of Marshal for Unicode or Multi-byte pointer to ASCII string
+        /// WinCE version of Marshal for Unicode or Multi-byte pointer to
+        /// ASCII string
         /// </summary>
         public static string PtrToStringAnsi(IntPtr ptr)
         {