CryptGetUserKey function

The CryptGetUserKey function retrieves a handle of one of a user's two public/private key pairs. This function is used only by the owner of the public/private key pairs and only when the handle of a cryptographic service provider (CSP) and its associated key container is available. If the CSP handle is not available and the user's certificate is, use CryptAcquireCertificatePrivateKey.

Syntax

BOOL WINAPI CryptGetUserKey(
  _In_  HCRYPTPROV hProv,
  _In_  DWORD      dwKeySpec,
  _Out_ HCRYPTKEY  *phUserKey
);

Parameters

hProv [in]

HCRYPTPROV handle of a cryptographic service provider (CSP) created by a call to CryptAcquireContext.

dwKeySpec [in]

Identifies the private key to use from the key container. It can be AT_KEYEXCHANGE or AT_SIGNATURE.

Additionally, some providers allow access to other user-specific keys through this function. For details, see the documentation on the specific provider.

phUserKey [out]

A pointer to the HCRYPTKEY handle of the retrieved keys. When you have finished using the key, delete the handle by calling the CryptDestroyKey function.

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.

The error codes prefaced by "NTE" are generated by the particular CSP being used. Some possible error codes follow.

Examples

For examples that use this function, see Example C Program: Signing a Hash and Verifying the Hash Signature and Example C Program: Exporting a Session Key.

Requirements

See also

Key Generation and Exchange Functions

CryptAcquireContext

CryptDestroyKey

CryptGenKey