CryptSetProviderExA function (wincrypt.h)

Article
02/22/2024

Important This API is deprecated. New and existing software should start using Cryptography Next Generation APIs. Microsoft may remove this API in future releases.

The CryptSetProviderEx function specifies the default cryptographic service provider (CSP) of a specified provider type for the local computer or current user.

Note Typical applications do not use this function. It is intended for use solely by administrative applications.

Syntax

BOOL CryptSetProviderExA(
  [in] LPCSTR pszProvName,
  [in] DWORD  dwProvType,
  [in] DWORD  *pdwReserved,
  [in] DWORD  dwFlags
);

Parameters

[in] pszProvName

The name of the new default CSP. This must be a CSP installed on the computer. For a list of available cryptographic providers, see Cryptographic Provider Names.

[in] dwProvType

The provider type of the CSP specified by pszProvName.

[in] pdwReserved

This parameter is reserved for future use and must be NULL.

[in] dwFlags

The following flag values are defined.

Value	Meaning
CRYPT_DELETE_DEFAULT 0x00000004	Can be used in conjunction with CRYPT_MACHINE_DEFAULT or CRYPT_USER_DEFAULT to delete the default.
CRYPT_USER_DEFAULT 0x00000002	Causes the user-context default CSP of the specified type to be set.
CRYPT_MACHINE_DEFAULT 0x00000001	Causes the computer default CSP of the specified type to be set.

Return value

If the function succeeds, the return value is nonzero (TRUE).

If the function fails, the return value is zero (FALSE). For extended error information, call GetLastError. Possible error codes include those shown in the following table.

Return code	Description
ERROR_INVALID_PARAMETER	One of the parameters contains a value that is not valid. This is most often a pointer that is not valid.
ERROR_NOT_ENOUGH_MEMORY	The operating system ran out of memory.

Remarks

Most applications do not specify a CSP name when calling the CryptAcquireContext function; however, an application can specify a CSP name and thereby select a CSP with an appropriate level of security. Because calls to CryptSetProviderEx determine the CSP of a specified type used by all applications from that point on, CryptSetProviderEx must never be called without a user's consent.

Note

The wincrypt.h header defines CryptSetProviderEx as an alias which automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.

Requirements

Requirement	Value
Minimum supported client	Windows XP [desktop apps only]
Minimum supported server	Windows Server 2003 [desktop apps only]
Target Platform	Windows
Header	wincrypt.h
Library	Advapi32.lib
DLL	Advapi32.dll