CryptContextAddRef

A version of this page is also available for

Windows Embedded CE 6.0 R3

4/8/2010

This function adds one to the reference count of an HCRYPTPROV handle.

Syntax

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

Parameters

• hProv
  [in] HCRYPTPROV handle to a cryptographic service provider (CSP) created by a call to the CryptAcquireContext function 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 GetLastError function.

A common value for GetLastError is 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 CryptReleaseContext function should be called when the CSP handle is no longer needed.

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

Example 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

See Also

Reference

CryptAcquireContext
CryptReleaseContext
HCRYPTPROV