Load DLL

[lfcgz]

I am hoping someone can help me .
I want to use some functions from system DLL,"rsaenh.dll",
but there are no exported functions from the DLL when main app performs a LoadLibrary on the DLL,(dynamic import),
there are some codes I want to use the CPAcquirecontext() from rsaenh.dll)

typedef BOOL (WINAPI * CPAcquireContext_DLL)(OUT HCRYPTPROV *phProv, IN LPCSTR szContainer, IN DWORD dwFlags , IN PVTableProvStruc pVTable);

_declspec(dllimport) BOOL WINAPI CPAcquireContext(OUT HCRYPTPROV *phProv, IN LPCSTR szContainer, IN DWORD dwFlags, IN PVTableProvStruc pVTable);

HINSTANCE hmod;
hmod = ::LoadLibrary ("c:\\windows\\system32\\rsaenh.dll");
if(hmod==NULL)
{
AfxMessageBox("Fail");
}
CPAcquireContext_DLL *lpproc;
lpproc = (CPAcquireContext_DLL*)GetProcAddress (hmod,"CPAcquireContext");
PVTableProvStruc pvTable=new VTableProvStruc;
pvTable->Version=3;
pvTable->FuncVerifyImage=(FARPROC ) (ProvVerifyImage);
pvTable->FuncReturnhWnd=NULL;
pvTable->dwProvType=PROV_RSA_FULL;
pvTable->pbContextInfo=NULL;
pvTable->cbContextInfo=0;

if((*lpproc)(&hCryptProv, NULL, 0, pvTable))
{
printf("A cryptographic provider has been acquired. \n");
}
else
{
if((*lpproc)(&hCryptProv, NULL, CRYPT_NEWKEYSET, pvTable))
{
printf("A new key container has been created.\n");
}
else
{
HandleError("Could not create a new key container.\n");
}

}


I find that it fails during the((*lpproc)(&hCryptProv, NULL, 0, pvTable)) call. It seems that it can not call the function.
Is there something that I don't know about loading DLL?
or can not load rsaenh.dll?
Thanks for the advice

[usman999_1]

I am hoping someone can help me .
I want to use some functions from system DLL,"rsaenh.dll",
but there are no exported functions from the DLL when main app performs a LoadLibrary on the DLL,(dynamic import),
there are some codes I want to use the CPAcquirecontext() from rsaenh.dll)

typedef BOOL (WINAPI * CPAcquireContext_DLL)(OUT HCRYPTPROV *phProv, IN LPCSTR szContainer, IN DWORD dwFlags , IN PVTableProvStruc pVTable);

_declspec(dllimport) BOOL WINAPI CPAcquireContext(OUT HCRYPTPROV *phProv, IN LPCSTR szContainer, IN DWORD dwFlags, IN PVTableProvStruc pVTable);

HINSTANCE hmod;
hmod = ::LoadLibrary ("c:\\windows\\system32\\rsaenh.dll");
if(hmod==NULL)
{
AfxMessageBox("Fail");
}
CPAcquireContext_DLL *lpproc;
lpproc = (CPAcquireContext_DLL*)GetProcAddress (hmod,"CPAcquireContext");
PVTableProvStruc pvTable=new VTableProvStruc;
pvTable->Version=3;
pvTable->FuncVerifyImage=(FARPROC ) (ProvVerifyImage);
pvTable->FuncReturnhWnd=NULL;
pvTable->dwProvType=PROV_RSA_FULL;
pvTable->pbContextInfo=NULL;
pvTable->cbContextInfo=0;

if((*lpproc)(&hCryptProv, NULL, 0, pvTable))
{
printf("A cryptographic provider has been acquired. \n");
}
else
{
if((*lpproc)(&hCryptProv, NULL, CRYPT_NEWKEYSET, pvTable))
{
printf("A new key container has been created.\n");
}
else
{
HandleError("Could not create a new key container.\n");
}

}


I find that it fails during the((*lpproc)(&hCryptProv, NULL, 0, pvTable)) call. It seems that it can not call the function.
Is there something that I don't know about loading DLL?
or can not load rsaenh.dll?
Thanks for the advice

First of all USE CODE TAGS plz.
Secondly check if the return of GetProcAddress is NULL or something valid.
Lastly call it like

if( !lpproc(&hCryptProv, NULL,  0, pvTable) )
{
    // Error...
}
else
{
    // Success...
}

Hope this helps,
Regards,
Usman.

[Alin]

try the following and post the results.

	HINSTANCE hInstance = LoadLibrary("c:\\windows\\system32\\rsaenh.dll");
	
	if (!hInstance)
		AfxMessageBox("The .dll library could not be loaded!");
	
	BOOL (*pFunction)(HCRYPTPROV *, CHAR *, DWORD, PVTableProvStruc);
	
	pFunction = (BOOL (*)(HCRYPTPROV *, CHAR *, DWORD, PVTableProvStruc)) GetProcAddress(hInstance, "CPAcquireContext");
	
	if (!pFunction)
		AfxMessageBox("The function \"CPAcquireContext\" could not be found!");
	
	// call the function
	//(*pFunction)(HCRYPTPROV *, CHAR *, DWORD, PVTableProvStruc);

[Ness]

Bah, Alin beat it to me.

[Alin]

Bah, Alin beat it to me.

i did what ?

[Ness]

i did what ?

I was about to post similar code, but you posted right before I did.

[Alin]

I was about to post similar code, but you posted right before I did.

i know what you meant, just teasing you