ICspInformation::GetDefaultSecurityDescriptor method

The GetDefaultSecurityDescriptor method retrieves the default private key security descriptor.


HRESULT GetDefaultSecurityDescriptor(
  [in]  VARIANT_BOOL MachineContext,
  [out] BSTR         *pValue


MachineContext [in]

A VARIANT_BOOL variable that indicates whether to retrieve the security descriptor for the computer or the user. Specify VARIANT_TRUE for the computer and VARIANT_FALSE for the user.

pValue [out]

Pointer to a BSTR variable that contains the security descriptor.

Return value

If the function succeeds, the function returns S_OK.

If the function fails, it returns an HRESULT value that indicates the error. Possible values include, but are not limited to, those in the following table. For a list of common error codes, see Common HRESULT Values.

Return code/valueDescription

The property value could not be found.


The cryptographic provider does not support security descriptors.


The cryptographic provider does not support security descriptors.


The cryptographic provider does not support security descriptors.



To use the security descriptor, you must call the ConvertStringSecurityDescriptorToSecurityDescriptor function included with the Microsoft Authorization API and specify the string returned by the GetDefaultSecurityDescriptor method. The function returns a pointer to a SECURITY_DESCRIPTOR structure.

The default security descriptor is used to define access to private keys for the computer and user in the following manner:

  • By default, only local administrators and services running under the LocalSystem account can access private keys associated with the computer account.
  • When a provider stores the private key of a user in an encrypted file in the user profile, it uses a security descriptor to set access permissions to the file.

This method retrieves the default security descriptor that will be associated with the specified MachineContext parameter and the current provider if a new private key is created. You can use the default descriptor to create a custom descriptor. Custom descriptors are typically created when a private key associated with a computer context certificate must be used by a service running under an account other than the LocalSystem account.

Some cryptographic providers do not support security descriptors. Examples include smart card and hardware security module (HSM) providers.


Minimum supported client

Windows Vista [desktop apps only]

Minimum supported server

Windows Server 2008 [desktop apps only]





See also




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