GetSignedElement Method

Summary

Returns the signed Data Element at the specified index.

Syntax

C++

public DicomElement GetSignedElement( 
   DicomElement signatureItem, 
   int index 
)

Public Function GetSignedElement( _ 
   ByVal signatureItem As DicomElement, _ 
   ByVal index As Integer _ 
) As DicomElement

public: 
DicomElement^ GetSignedElement(  
   DicomElement^ signatureItem, 
   int index 
)

Parameters

signatureItem
The Digital Signatures Sequence Item that corresponds to the Digital Signature. This cannot be null.

index
The zero-based index of the required signed Data Element. This should be a number from 0 to GetSignedElementsCount(signatureItem) - 1.

Return Value

The required signed Data Element. The return value can be a null reference (Nothing in VB); e.g., if the specified index is invalid.

Remarks

The Digital Signatures Sequence Item of a Digital Signature should reference an item under the Message Authentication Code (MAC) Parameters Sequence associated with the Digital Signatures Sequence. The Data Elements Signed (0400,0020) under the referenced MAC Parameters Sequence Item specifies the tags of the Data Elements covered by the Digital Signature. These Data Elements should be located at the same level as the MAC Parameters Sequence and the Digital Signatures Sequence. The GetSignedElementsCount method returns the number of signed Data Elements as specified by the Data Elements Signed (0400,0020). The GetSignedElement method searches the level at which the MAC Parameters Sequence appears for the Data Element with the tag determined by the passed index and returns the Data Element if it does exist; if it does not exist, the method returns a null reference (Nothing in VB).

Note: In addition to the Data Elements specified by the Data Elements Signed (0400,0020), certain Data Elements under the Digital Signatures Sequence Item are always covered by the Digital Signature.

The following methods can also be used to get information about the Digital Signature:

Example

For an example, refer to VerifySignature.

Requirements

Target Platforms