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4/8/2010

This function adds one to the reference count of an HCRYPTPROVhandle.

Syntax 

BOOL WINAPI CryptContextAddRef( 
  HCRYPTPROV 
hProv,
  DWORD* 
pdwReserved, 
  DWORD 
dwFlags
);

Parameters

hProv

[in] HCRYPTPROVhandle to a cryptographic service provider (CSP) created by a call to the CryptAcquireContextfunction for which the reference count is being incremented.

pdwReserved

[in] Reserved for future use and must be set to NULL.

dwFlags

[in] Reserved for future use and must be set to zero.

Return Value

TRUE indicates success. FALSE indicates failure. To get extended error information, call the GetLastErrorfunction.

A common value for GetLastErroris ERROR_INVALID_PARAMETER. It means that one of the parameters contain an invalid value, which is often an illegal pointer.

Remarks

This function should be used if the CSP handle is included as a member of any structure passed to another function. The CryptReleaseContextfunction should be called when the CSP handle is no longer needed.

This function increases the reference count of a HCRYPTPROVhandle; therefore, multiple calls to the CryptReleaseContextfunction are required to actually free the handle.

Example Code

Copy Code 
HCRYPTPROV hProv = 0;
// Acquire a context handle using CryptAcquireContext
// For sample code, see <A
HREF="wce50lrfcryptacquirecontext.htm">CryptAcquireContext</A>.
...
if (!CryptContextAddRef(&hProv, NULL, 0)) {
 printf("Error %x during CryptContextAddRef!\n", GetLastError);
 return;
}
...
// The first call to CryptReleaseContext will not free the provider

// handle because the reference count has been bumped up.
if (!CryptReleaseContext(hProv, 0)) {
 printf("Error %x during CryptReleaseContext!\n", GetLastError);
 return;
}
// Free the provider handle.
if (!CryptReleaseContext(hProv, 0)) {
 printf("Error %x during CryptReleaseContext!\n", GetLastError);
 return;
}

Requirements

Header wincrypt.h
Library coredll.lib
Windows Embedded CE Windows CE 2.10 and later
Windows Mobile Windows Mobile Version 5.0 and later

See Also