(WebCrypto / HTTPServer) : Use stream size for secure checksum + Endianess fix.

(WebCrypto / HTTPServer) : Use stream size for secure checksum + Endianess fix.

Author: GitHubProUser67

BackendServices/CyberBackendLibrary/Crypto/WebCrypto.cs

@@ -405,7 +405,7 @@ public static class WebCrypto
                     .InitiateCTRBuffer(Convert.FromBase64String(Encoding.UTF8.GetString(ByteArrayToDecrypt).Replace("<Secure>", string.Empty).Replace("</Secure>", string.Empty)), Convert.FromBase64String(AccessKey), IV);
         }
 
-        public static string? ProcessSecureCheckum(byte[] inputData, uint initialValue)
+        public static string? ProcessSecureCheckum(byte[] inputData, long initialValue)
         {
             byte currentByte = 0;
             int DataIndex = 0;
@@ -416,7 +416,7 @@ public static class WebCrypto
 
             do
             {
-                currentByte = (byte)(inputData[DataIndex] ^ BitConverter.SingleToInt32Bits(tempFloat));
+                currentByte = (byte)(inputData[DataIndex] ^ BitConverter.SingleToInt32Bits(!BitConverter.IsLittleEndian ? EndianTools.EndianUtils.EndianSwap(tempFloat) : tempFloat));
                 CheckSumBytes[DataIndex] = currentByte;
                 tempFloat = (ChecksumFloatBox[currentByte]) / 
                             (float)(((uint)(ChecksumByteBox[(uint)tempFloat & 0xFF]) << 0x10) |

WebServers/HTTPServer/HttpProcessor.cs

@@ -1106,6 +1106,8 @@ private static void WriteResponse(Stream stream, HttpRequest? request, HttpRespo
                     {
                         string EtagMD5 = ComputeStreamChecksum(response.ContentStream);
 
+                        response.ContentStream.Position = 0;
+
                         if (!string.IsNullOrEmpty(request.Method) && request.Method == "OPTIONS")
                         {
                             response.Headers.Add("Access-Control-Allow-Headers", "Content-Type, Accept, X-Requested-With");
@@ -1704,6 +1706,8 @@ private static void Handle_LocalFile_Stream(Stream stream, HttpRequest request,
                     {
                         string EtagMD5 = ComputeStreamChecksum(response.ContentStream);
 
+                        response.ContentStream.Position = 0;
+
                         if (request.Headers.TryGetValue("If-None-Match", out string? value1) && value1.Equals(EtagMD5))
                         {
                             response.Headers.Clear();
@@ -1977,13 +1981,11 @@ private static string ComputeStreamChecksum(Stream input)
 
             byte[] bytes = MD5.Create().ComputeHash(input);
 
-            input.Position = 0;
-
             StringBuilder builder = new();
             for (int i = 0; i < bytes.Length; i++)
                 builder.Append(bytes[i].ToString("x2"));
 
-            return builder.ToString() + $":{WebCrypto.ProcessSecureCheckum(bytes, 0x5BCD9F0F)}";
+            return builder.ToString() + $":{WebCrypto.ProcessSecureCheckum(bytes, input.Length)}";
         }
 
 #if NET7_0_OR_GREATER