ICEnroll4::GetKeyLenEx method (xenroll.h)

Article
02/22/2024

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

The GetKeyLenEx method retrieves size information for the signature and exchange keys. This method was first defined in the ICEnroll4 interface.

The values retrieved by this method are dependent upon the current cryptographic service provider (CSP).

Syntax

HRESULT GetKeyLenEx(
  [in]  LONG lSizeSpec,
  [in]  LONG lKeySpec,
  [out] LONG *pdwKeySize
);

Parameters

[in] lSizeSpec

A value that indicates the type of size information to be retrieved. This parameter can be one of the following values.

Value	Meaning
XEKL_KEYSIZE_MIN	The minimum key size.
XEKL_KEYSIZE_MAX	The maximum key size.
XEKL_KEYSIZE_INC	The size of the key increment. For more information, see Remarks.

[in] lKeySpec

Specifies the key for which size information is returned. This parameter can be one of the following values.

Value	Meaning
XEKL_KEYSPEC_KEYX	Exchange key
XEKL_KEYSPEC_SIG	Signature key

[out] pdwKeySize

A pointer to a variable that receives the key size, in bits.

Return value

C++

If the method succeeds, the method returns S_OK.

If the method fails, it returns an HRESULT value that indicates the error. For a list of common error codes, see Common HRESULT Values.

VB

A value that represents the key size, in bits.

Remarks

If the CSP does not support this method, an error is returned.

For more information about the XEKL_KEYSIZE_INC value, see PP_SIG_KEYSIZE_INC usage in the CryptGetProvParam reference page.

Examples

DWORD dwExchMin, dwExchMax, dwSignDef, dwSignInc;

// Determine the minimum and maximum key length values.
// hr is HRESULT variable.
hr = pEnroll4->GetKeyLenEx( XEKL_KEYSIZE_MIN,
                            XEKL_KEYSPEC_KEYX,
                            &dwExchMin );
if ( FAILED( hr ) )    
    printf("Failed GetKeyLenEx for Exchange Minimum [%x]\n", hr);
else
    printf("Exchange key Min: %d\n", dwExchMin);

hr = pEnroll4->GetKeyLenEx( XEKL_KEYSIZE_MAX,
                            XEKL_KEYSPEC_KEYX,
                            &dwExchMax );
if ( FAILED( hr ) )
    printf("Failed GetKeyLenEx for Exchange Maximum [%x]\n", hr);
else
    printf("Exchange key Max: %d\n", dwExchMax );

hr = pEnroll4->GetKeyLenEx( XEKL_KEYSIZE_DEFAULT,
                            XEKL_KEYSPEC_SIG,
                            &dwSignDef );
if ( FAILED( hr ) )
    printf("Failed GetKeyLenEx for Signature Default "
   "Key size [%x]\n", hr);
else
    printf("Signature key default size: %d\n", dwSignDef );

hr = pEnroll4->GetKeyLenEx( XEKL_KEYSIZE_INC,
                            XEKL_KEYSPEC_SIG,
                            &dwSignInc );
if ( FAILED( hr ) )    
    printf("Failed GetKeyLenEx for Signature "
   "Key Size Increment [%x]\n", hr);
else
    printf("Signature key increment size: %d\n", dwSignInc );

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

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