The Cheat 1.0b3

[chaz/thecheat] / cheat_net.m

diff --git a/cheat_net.m b/cheat_net.m
new file mode 100644 (file)
index 0000000..be27b7c
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+++ b/cheat_net.m
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+
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// Project:   The Cheat
+//
+// File:      cheat_net.m
+// Created:   Mon Sep 08 2003
+//
+// Copyright: 2003 Chaz McGarvey.  All rights reserved.
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+#include "cheat_net.h"
+
+
+u_int32_t RandomChecksum()
+{
+       u_int8_t                byte1, byte2, byte3, byte4;
+       char                    *ptr;
+       
+       u_int32_t               checksum;
+       long                    randomValue = random();
+
+       byte1 = randomValue & 0xFF;
+       byte2 = (randomValue >> 8) & 0xFF;
+       byte3 = (randomValue >> 16) & 0xFF;
+       byte4 = CountBits( byte1 ) + CountBits( byte2 ) + CountBits( byte3 );
+       
+       ptr = (char *)(&checksum);
+
+       COPY_TO_BUFFER( ptr, &byte1, sizeof(byte1) );
+       COPY_TO_BUFFER( ptr, &byte2, sizeof(byte2) );
+       COPY_TO_BUFFER( ptr, &byte3, sizeof(byte3) );
+       COPY_TO_BUFFER( ptr, &byte4, sizeof(byte4) );
+
+       return checksum;
+}
+
+char VerifyChecksum( u_int32_t checksum )
+{
+       u_int8_t                byte1, byte2, byte3, byte4;
+       char                    *ptr = (char *)(&checksum);
+
+       COPY_FROM_BUFFER( &byte1, ptr, sizeof(byte1) );
+       COPY_FROM_BUFFER( &byte2, ptr, sizeof(byte2) );
+       COPY_FROM_BUFFER( &byte3, ptr, sizeof(byte3) );
+       COPY_FROM_BUFFER( &byte4, ptr, sizeof(byte4) );
+
+       if ( (CountBits( byte1 ) + CountBits( byte2 ) + CountBits( byte3 )) == byte4 )
+       {
+               return 1;
+       }
+
+       NSLog( @"checksum failed" );
+
+       return 0;
+}
+
+int CountBits( u_int8_t byte )
+{
+       int                             count = 0;
+       int                             i;
+
+       for ( i = 0; i < 8; i++ )
+       {
+               count += byte & 1;
+
+               byte >>= 1;
+       }
+
+       return count;
+}
+
+
+int SendBuffer( int sockfd, char const *buffer, int *length )
+{
+       int                             bytesSent = 0;
+       int                             bytesLeft = *length;
+       int                             n = 0;
+
+       while( bytesSent < *length )
+       {
+               if ( (n = send( sockfd, buffer+bytesSent, bytesLeft, 0 )) == -1 )
+               {
+                       break;
+               }
+
+               bytesSent += n;
+               bytesLeft -= n;
+       }
+
+       *length = bytesSent;
+
+       return (n == -1)? -1:0;
+}
+
+int ReadBuffer( int sockfd, char *buffer, int length )
+{
+       int                             bytesRead = 0;
+       int                             bytesLeft = length;
+       int                             n;
+
+       while( bytesRead < length )
+       {
+               if ( (n = recv( sockfd, buffer+bytesRead, bytesLeft, 0 )) == -1 || n == 0 )
+               {
+                       return (bytesRead > 0)? bytesRead:n;
+               }
+
+               bytesRead += n;
+               bytesLeft -= n;
+       }
+
+       return bytesRead;
+}
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