NCryptEnumKeys function (ncrypt.h)

Article
10/13/2021

The NCryptEnumKeys function obtains the names of the keys that are stored by the provider.

Syntax

SECURITY_STATUS NCryptEnumKeys(
  [in]           NCRYPT_PROV_HANDLE hProvider,
  [in, optional] LPCWSTR            pszScope,
  [out]          NCryptKeyName      **ppKeyName,
  [in, out]      PVOID              *ppEnumState,
  [in]           DWORD              dwFlags
);

Parameters

[in] hProvider

The handle of the key storage provider to enumerate the keys for. This handle is obtained with the NCryptOpenStorageProvider function.

[in, optional] pszScope

This parameter is not currently used and must be NULL.

[out] ppKeyName

The address of a pointer to an NCryptKeyName structure that receives the name of the retrieved key. When the application has finished using this memory, free it by calling the NCryptFreeBuffer function.

[in, out] ppEnumState

The address of a VOID pointer that receives enumeration state information that is used in subsequent calls to this function. This information only has meaning to the key storage provider and is opaque to the caller. The key storage provider uses this information to determine which item is next in the enumeration. If the variable pointed to by this parameter contains NULL, the enumeration is started from the beginning.

When this memory is no longer needed, it must be freed by passing this pointer to the NCryptFreeBuffer function.

[in] dwFlags

Flags that modify function behavior. This can be zero or a combination of one or more of the following values.

Value	Meaning
NCRYPT_MACHINE_KEY_FLAG	Enumerate the keys for the local computer. If this flag is not present, the current user keys are enumerated.
NCRYPT_SILENT_FLAG	Requests that the key service provider (KSP) not display any user interface. If the provider must display the UI to operate, the call fails and the KSP should set the NTE_SILENT_CONTEXT error code as the last error.

Return value

Returns a status code that indicates the success or failure of the function.

Possible return codes include, but are not limited to, the following.

Return code	Description
ERROR_SUCCESS	The function was successful.
NTE_BAD_FLAGS	The dwFlags parameter contains a value that is not valid.
NTE_INVALID_HANDLE	The hProvider parameter is not valid.
NTE_INVALID_PARAMETER	One or more parameters are not valid.
NTE_NO_MEMORY	A memory allocation failure occurred.
NTE_NO_MORE_ITEMS	The end of the enumeration has been reached.
NTE_SILENT_CONTEXT	The dwFlags parameter contains the NCRYPT_SILENT_FLAG flag, but the key being enumerated requires user interaction.

Remarks

This function retrieves only one item each time it is called. The state of the enumeration is stored in the variable pointed to by the ppEnumState parameter, so this must be preserved between calls to this function. When the last key stored by the provider has been retrieved, this function will return NTE_NO_MORE_ITEMS the next time it is called. To start the enumeration over, set the variable pointed to by the ppEnumState parameter to NULL, free the memory pointed to by the ppKeyName parameter, if it is not NULL, and call this function again.

A service must not call this function from its StartService Function. If a service calls this function from its StartService function, a deadlock can occur, and the service may stop responding.

Requirements

Requirement	Value
Minimum supported client	Windows Vista [desktop apps \| UWP apps]
Minimum supported server	Windows Server 2008 [desktop apps \| UWP apps]
Target Platform	Windows
Header	ncrypt.h
Library	Ncrypt.lib
DLL	Ncrypt.dll

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