CryptFindCertificateKeyProvInfo function (wincrypt.h)

Article
10/13/2021

The CryptFindCertificateKeyProvInfo function enumerates the cryptographic providers and their containers to find the private key that corresponds to the certificate's public key.

Syntax

BOOL CryptFindCertificateKeyProvInfo(
  [in] PCCERT_CONTEXT pCert,
  [in] DWORD          dwFlags,
  [in] void           *pvReserved
);

Parameters

[in] pCert

A pointer to the CERT_CONTEXT structure of the certificate to use when exporting public key information.

[in] dwFlags

A set of flags that modify the behavior of this function. This can be zero or one of the following values.

Value	Meaning
CRYPT_FIND_USER_KEYSET_FLAG	Restricts the search to the user container. The default is to search both the user and machine containers.
CRYPT_FIND_MACHINE_KEYSET_FLAG	Restricts the search to the machine container. The default is to search both the user and machine containers.
CRYPT_FIND_SILENT_KEYSET_FLAG	The application requests that the CSP not display any user interface (UI) for this context. If the CSP must display the UI to operate, the call fails and the NTE_SILENT_CONTEXT error code is set as the last error.

The following flags determine which technology is used to obtain the key. If none of these flags is present, this function will only attempt to obtain the key by using CryptoAPI.

Windows Server 2003 and Windows XP: These flags are not supported.

Value	Meaning
CRYPT_ACQUIRE_ALLOW_NCRYPT_KEY_FLAG	This function will attempt to obtain the key by using CryptoAPI. If that fails, this function will attempt to obtain the key by using the Cryptography API: Next Generation (CNG). The CERT_KEY_PROV_INFO_PROP_ID property of the certificate is set to zero if CNG is used to obtain the key.
CRYPT_ACQUIRE_ONLY_NCRYPT_KEY_FLAG	This function will only attempt to obtain the key by using CNG and will not use CryptoAPI to obtain the key. The CERT_KEY_PROV_INFO_PROP_ID property of the certificate is set to zero if CNG is used to obtain the key.
CRYPT_ACQUIRE_PREFER_NCRYPT_KEY_FLAG	This function will attempt to obtain the key by using CNG. If that fails, this function will attempt to obtain the key by using CryptoAPI. The CERT_KEY_PROV_INFO_PROP_ID property of the certificate is set to zero if CNG is used to obtain the key.

[in] pvReserved

Reserved for future use and must be NULL.

Return value

TRUE if the function finds a private key that corresponds to the certificate's public key within a searched container; FALSE if the function fails to find a container or a private key within a container.

GetLastError returns the following error:

Return code	Description
NTE_NO_KEY	No container found.

Remarks

This function enumerates the cryptographic providers and their containers to find the private key that corresponds to the certificate's public key. For a match, the function updates the certificate's CERT_KEY_PROV_INFO_PROP_ID property. If the CERT_KEY_PROV_INFO_PROP_ID is already set, it is checked to determine whether it matches the provider's public key. For a match, the function skips the previously mentioned enumeration.

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	Crypt32.lib
DLL	Crypt32.dll