ICEnroll3::EnumAlgs method (xenroll.h)

Article
10/13/2021

[This method is no longer available for use as of Windows Server 2008 and Windows Vista.]

The EnumAlgs method retrieves the IDs of cryptographic algorithms in a given algorithm class that are supported by the current cryptographic service provider (CSP). This method was first defined in the ICEnroll3 interface.

Syntax

HRESULT EnumAlgs(
  [in]  LONG dwIndex,
  [in]  LONG algClass,
  [out] LONG *pdwAlgID
);

Parameters

[in] dwIndex

Specifies the ordinal position of the algorithm whose ID will be retrieved. Specify zero for the first algorithm.

[in] algClass

A cryptographic algorithm class. The IDs returned by this method will be in the specified class. Specify one of the following:

ALG_CLASS_HASH
ALG_CLASS_KEY_EXCHANGE
ALG_CLASS_MSG_ENCRYPT
ALG_CLASS_DATA_ENCRYPT
ALG_CLASS_SIGNATURE

[out] pdwAlgID

A pointer to a variable to receive a cryptographic algorithm ID that is supported by the current CSP.

Return value

C++

The return value is an HRESULT. A value of S_OK indicates success. When there are no more algorithms to enumerate, the value ERROR_NO_MORE_ITEMS is returned.

VB

A cryptographic algorithm ID which is supported by the current CSP. When there are no more algorithms to enumerate, the value ERROR_NO_MORE_ITEMS is returned.

Remarks

For algorithm ID and class constants used by this method, see Wincrypt.h.

Examples

#include <windows.h>
#include <stdio.h>
#include <Xenroll.h>

DWORD     dwAlgID;
DWORD     dwIndex;

BSTR      bstrAlgName = NULL;

HRESULT   hr, hr2;

// Loop through the AlgIDs.
dwIndex = 0;
while ( TRUE )
{
    // Enumerate the alg IDs for a specific class.
    hr = pEnroll->EnumAlgs(dwIndex, ALG_CLASS_SIGNATURE, &dwAlgID);
    if ( S_OK != hr )
    {
       break;
    }

    // Do something with the AlgID.
    // For example, retrieve the corresponding name.
    hr2 = pEnroll->GetAlgName( dwAlgID, &bstrAlgName);
    if ( FAILED( hr2 ) )    
        printf("Failed GetAlgName [%x]\n", hr);
    else
        printf("AlgID: %d Name: %S\n", dwAlgID, bstrAlgName );

    // Reuse the BSTR variable in next iteration.
    if ( NULL != bstrAlgName )
    {
        SysFreeString( bstrAlgName );
        bstrAlgName = NULL;
    }

    // Increment the index.
    dwIndex++;
}

Requirements

Requirement	Value
Minimum supported client	Windows XP [desktop apps only]
Minimum supported server	Windows Server 2003 [desktop apps only]
Target Platform	Windows
Header	xenroll.h
Library	Uuid.lib
DLL	Xenroll.dll