L_DicomGetSignature

#include "ltdic.h"

pDICOMELEMENT EXT_FUNCTION L_DicomGetSignature(hDS, pItem, uIndex)

HDICOMDS hDS;	/* a DICOM handle */
pDICOMELEMENT pItem;	/* pointer to an Item in a Sequence of Items */
L_UINT32 uIndex;	/* index of the Digital Signature */

Returns a pointer to the Digital Signatures Sequence Item that corresponds to the Digital Signature at the specified index.

Parameter

Description

hDS	A DICOM handle.
pItem	Pointer to a DICOMELEMENT structure that specifies the Item in which the required Digital Signature is located. Set this parameter to NULL if the Digital Signature is located in the main Data Set.
uIndex	The index of the required Digital Signature. This should be a number from 0 to L_DicomGetSignaturesCount(pItem) minus 1.

Returns

!NULL	Pointer to the DICOMELEMENT structure that specifies the Digital Signatures Sequence Item which corresponds to the required Digital Signature.
NULL	The specified index is invalid.

Comments

For each Digital Signature in the main Data Set or in an Item of a Sequence of Items, there should be a corresponding Item under the Digital Signatures Sequence (FFFA,FFFA) located in the main Data Set or in the Item. This function can be used to obtain a pointer to that Digital Signatures Sequence Item.

Along with this function, the function L_DicomGetSignaturesCount can be used to enumerate the Digital Signatures in the main Data Set or in an Item of a Sequence of Items. Once a pointer to the Digital Signatures Sequence Item is obtained, the following functions can be used to verify, delete, or get information about the Digital Signature:

L_DicomVerifySignature

L_DicomDeleteSignature

L_DicomGetSignatureUID

L_DicomGetSignatureDateTime

L_DicomGetSignedElementsCount

L_DicomGetSignedElement

L_DicomGetMacTransferSyntax

L_DicomGetMacAlgorithm

L_DicomSaveCertificate

You can also use the function L_DicomFindSignature to search the whole Data Set for a specific Digital Signature.

Required DLLs and Libraries

LTDIC

For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application

See Also

Functions:	L_DicomGetSignaturesCount, L_DicomFindSignature, L_DicomVerifySignature, L_DicomDeleteSignature, L_DicomGetSignatureUID, L_DicomGetSignatureDateTime, L_DicomGetSignedElementsCount, L_DicomGetSignedElement, L_DicomGetMacTransferSyntax, L_DicomGetMacAlgorithm, L_DicomSaveCertificate, L_DicomCreateSignature
Topics:	Working with Digital Signatures

Example

L_VOID EnumerateSignatures(HDICOMDS hDS)
{
   // We will enumerate the Digital Signatures in the main Data Set
   L_CHAR szMsg[128];
   L_UINT32 i;

   L_UINT32 uSignaturesCount = L_DicomGetSignaturesCount(hDS,NULL);
   if (uSignaturesCount == 0)
   {
      MessageBox(NULL,
                   "There are no Digital Signatures in the main Data Set.",
                   "Sample",
                   MB_OK);
      return;
   }

   if (uSignaturesCount == 1)
   {
      lstrcpy(szMsg,
              "There is 1 Digital Signature in the main Data Set. "
              "Do you want to examine it?");
   }
   else
   {
      wsprintf(szMsg,
               "There are %lu Digital Signatures in the main Data Set. "
               "Do you want to examine them?", uSignaturesCount);
   }
   if (MessageBox(NULL, szMsg, "Sample", MB_YESNO) != IDYES)
   {
      return;
   }

   for (i = 0; i < uSignaturesCount; i++)
   {
      // Refer to the example of L_DicomVerifySignature for the
      // function ExamineSignature
      ExamineSignature(hDS, L_DicomGetSignature(hDS,NULL, i));
   }
}