帮同学写了个hook api的例子程序,顺便post到这儿,免得将来到处找.
一个简单的console工程,vc6,vc7在win2k pro,server上调试通过.
#include <stdio.h>
#include <windows.h>
#include <Dbghelp.h>
#pragma comment(lib,"Dbghelp.lib")
#pragma comment(lib,"User32.lib")
typedef int (__stdcall *OLD_MessageBox)( HWND hWnd, LPCTSTR lpText, LPCTSTR lpCaption,UINT uType );
OLD_MessageBox g_procOldMessageBox = NULL;
int __stdcall HOOK_MessageBox( HWND hWnd, LPCTSTR lpText, LPCTSTR lpCaption,UINT uType)
{
printf("%s\t%d\r\n",__FUNCTION__,__LINE__);
if (NULL != g_procOldMessageBox)
return g_procOldMessageBox(hWnd,lpText,"不好意思,hook到了!",uType);
else
return MessageBox(hWnd,lpText,lpCaption,uType); ;
}
int replace_IAT(const char *pDllName,const char *pApiName,bool bReplace)
{
HANDLE hProcess = ::GetModuleHandle (NULL);
DWORD dwSize = 0;
PIMAGE_IMPORT_DESCRIPTOR pImageImport = (PIMAGE_IMPORT_DESCRIPTOR)ImageDirectoryEntryToData(hProcess,TRUE,
IMAGE_DIRECTORY_ENTRY_IMPORT,&dwSize);
if (NULL == pImageImport)
return 1;
PIMAGE_IMPORT_BY_NAME pImageImportByName = NULL;
PIMAGE_THUNK_DATA pImageThunkOriginal = NULL;
PIMAGE_THUNK_DATA pImageThunkReal = NULL;
while (pImageImport->Name)
{
if (0 == strcmpi((char*)((PBYTE)hProcess+pImageImport->Name),pDllName))
{
break;
}
++pImageImport;
}
if (! pImageImport->Name)
return 2;
pImageThunkOriginal = (PIMAGE_THUNK_DATA)((PBYTE)hProcess+pImageImport->OriginalFirstThunk );
pImageThunkReal = (PIMAGE_THUNK_DATA)((PBYTE)hProcess+pImageImport->FirstThunk );
while (pImageThunkOriginal->u1.Function)
{
if ((pImageThunkOriginal->u1 .Ordinal & IMAGE_ORDINAL_FLAG) != IMAGE_ORDINAL_FLAG)
{
pImageImportByName = (PIMAGE_IMPORT_BY_NAME)((PBYTE)hProcess+pImageThunkOriginal->u1 .AddressOfData );
if (0 == strcmpi(pApiName,(char*)pImageImportByName->Name))
{
MEMORY_BASIC_INFORMATION mbi_thunk;
VirtualQuery(pImageThunkReal, &mbi_thunk, sizeof(MEMORY_BASIC_INFORMATION));
VirtualProtect(mbi_thunk.BaseAddress,mbi_thunk.RegionSize, PAGE_READWRITE, &mbi_thunk.Protect);
if (true == bReplace)
{
g_procOldMessageBox =(OLD_MessageBox) pImageThunkReal->u1.Function;
pImageThunkReal->u1.Function = (DWORD)HOOK_MessageBox;
}
else
pImageThunkReal->u1.Function = (DWORD)g_procOldMessageBox;
DWORD dwOldProtect;
VirtualProtect(mbi_thunk.BaseAddress, mbi_thunk.RegionSize, mbi_thunk.Protect, &dwOldProtect);
break;
}
}
++pImageThunkOriginal;
++pImageThunkReal;
}
return 0;
}
int main()
{
replace_IAT("User32.dll","MessageBoxA",true);
MessageBox(NULL,"EnumIAT User32.dll MessageBoxA true;","",MB_OK);
replace_IAT("User32.dll","MessageBoxA",false);
MessageBox(NULL,"EnumIAT User32.dll MessageBoxA false;","",MB_OK);
return getchar();
}