FreeCryptProvFromCertEx function

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The FreeCryptProvFromCertEx function releases the handle either to a cryptographic service provider (CSP) or to a Cryptography API: Next Generation (CNG) key.

Note

This function has no associated header file or import library. To call this function, you must create a user-defined header file and use the LoadLibrary and GetProcAddress functions to dynamically link to Mssign32.dll.

Syntax

void WINAPI FreeCryptProvFromCertEx(
  _In_     BOOL                            fAcquired,
  _In_     HCRYPTPROV_OR_NCRYPT_KEY_HANDLE hProv,
           DWORD                           dwKeySpec,
  _In_opt_ LPWSTR                          pwszCapiProvider,
  _In_     DWORD                           dwProviderType,
  _In_opt_ LPWSTR                          pwszTmpContainer
);

Parameters

fAcquired [in]

A value that specifies whether the provider handle was acquired from the certificate.

hProv [in]

A handle to a CAPICOM CSP or a handle to a CNG key.

dwKeySpec

The address of a DWORD variable that receives additional information about the key. This can be one of the following values.

Value Meaning
AT_KEYEXCHANGE
 The key pair is a key exchange pair.
AT_SIGNATURE
 The key pair is a signature pair.
CERT_NCRYPT_KEY_SPEC
 The key is a CNG key.
Windows Server 2003 and Windows XP: This value is not supported.

pwszCapiProvider [in, optional]

A pointer to a null-terminated string for the provider name.

dwProviderType [in]

Specifies the CSP type. This can be zero or one of the Cryptographic Provider Types. If this member is zero, the key container is one of the CNG key storage providers.

pwszTmpContainer [in, optional]

A pointer to a null-terminated string for the name of the temporary key container.

Return value

This function does not return a value.

Requirements

Requirement Value
Minimum supported client Windows 7 [desktop apps only]
Minimum supported server Windows Server 2008 R2 [desktop apps only]
DLL Mssign32.dll