Edit

BCryptGetProperty function (bcrypt.h)

  • Article

The BCryptGetProperty function retrieves the value of a named property for a CNG object.

Syntax

NTSTATUS BCryptGetProperty(
  [in]  BCRYPT_HANDLE hObject,
  [in]  LPCWSTR       pszProperty,
  [out] PUCHAR        pbOutput,
  [in]  ULONG         cbOutput,
  [out] ULONG         *pcbResult,
  [in]  ULONG         dwFlags
);

Parameters

[in] hObject

A handle that represents the CNG object to obtain the property value for.

[in] pszProperty

A pointer to a null-terminated Unicode string that contains the name of the property to retrieve. This can be one of the predefined Cryptography Primitive Property Identifiers or a custom property identifier.

[out] pbOutput

The address of a buffer that receives the property value. The cbOutput parameter contains the size of this buffer.

[in] cbOutput

The size, in bytes, of the pbOutput buffer.

[out] pcbResult

A pointer to a ULONG variable that receives the number of bytes that were copied to the pbOutput buffer. If the pbOutput parameter is NULL, this function will place the required size, in bytes, in the location pointed to by this parameter.

[in] dwFlags

A set of flags that modify the behavior of this function. No flags are defined for this function.

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
STATUS_SUCCESS
 The function was successful.
STATUS_BUFFER_TOO_SMALL
 The buffer size specified by the cbOutput parameter is not large enough to hold the property value.
STATUS_INVALID_HANDLE
 The handle in the hObject parameter is not valid.
STATUS_INVALID_PARAMETER
 One or more parameters are not valid.
STATUS_NOT_SUPPORTED
 The named property specified by the pszProperty parameter is not supported.

Remarks

To obtain the required size for a property, pass NULL for the pbOutput parameter. This function will place the required size, in bytes, in the value pointed to by the pcbResult parameter.

Depending on what processor modes a provider supports, BCryptGetProperty can be called either from user mode or kernel mode. Kernel mode callers can execute either at PASSIVE_LEVEL IRQL or DISPATCH_LEVEL IRQL. If the current IRQL level is DISPATCH_LEVEL, any pointers passed to the BCryptGetProperty function must refer to nonpaged (or locked) memory. If the object specified in the hObject parameter is a handle, it must have been opened by using the BCRYPT_PROV_DISPATCH flag.

To call this function in kernel mode, use Cng.lib, which is part of the Driver Development Kit (DDK). Windows Server 2008 and Windows Vista:  To call this function in kernel mode, use Ksecdd.lib.

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 bcrypt.h
Library Bcrypt.lib
DLL Bcrypt.dll