L_DicomCreateSignature

#include "ltdic.h"

L_LTDIC_API L_UINT16 L_DicomCreateSignature (hDS, pItem, pszPrivateKeyFile, pszCertificateFile, pszPassword, ppSignatureItem, pszMacTransferSyntax, uMacAlgorithm, pElementsToSign, uCount, uSecurityProfile, uReserved);

Creates a Digital Signature in the Data Set.

Returns

Comments

A Digital Signature can be created in the main Data Set as well as in an Item of a Sequence of Items. Pass NULL for the parameter pItem if you want to create the Digital Signature in the main Data Set or specify an Item in the Data Set to create the Digital Signature in that Item.

The parameter pszMacTransferSyntax specifies the Transfer Syntax in which the Data Elements included in the Message Authentication Code (MAC) calculation should be encoded. This Transfer Syntax must explicitly include the Value Representation (Explicit VR) and it must use the Little Endian Byte ordering. If the specified Transfer Syntax doesnt fulfill this condition, the function will behave as if the parameter were set to NULL.

If pszMacTransferSyntax is set to NULL, the function will use the Transfer Syntax in which the Data Set is currently encoded if this Transfer Syntax fulfills the condition mentioned in the previous paragraph. If it doesnt, the function will use the Explicit VR Little Endian Transfer Syntax.

You can use the parameters pElementsToSign and uCount to specify the Data Elements to be covered by the new Digital Signature. These Data Elements, which are indicated by their Tags, must be on the root of the Data Set if pItem is set to NULL. If pItem specifies an Item, then they must be located immediately under that Item. Any Tag that doesnt specify an existing Data Element in the expected location will be ignored. Also, any Tag that specifies a Data Element that cannot be signed according to the standard will be ignored as well.

If pElementsToSign is set to NULL, or if uCount is set to 0, the function will sign all the Data Elements that can be signed according to the standard and that exist on the root of the Data Set, if pItem is set to NULL, or immediately under the Item specified by pItem.

Digital Signature Security Profiles put restrictions and add specifications. For example, the Rivest-Shamir-Adleman (RSA) Security Profiles require the use of RSA encryption. Therefore, the function will fail if one of these Security Profiles is used while the specified keys are DSA keys. Another example is that the Creator and Authorization RSA Digital Signature Profiles require that, as a minimum, certain Data Elements must be signed if they exist. Therefore, if one of these Security Profiles is used, the function will sign any existing Data Element that is required, even if this Data Element is not included in the array specified by pElementsToSign.

Required DLLs and Libraries

Platforms

Win32, x64

#define MAKE_IMAGE_PATH(pFileName) TEXT("C:\\Users\\Public\\Documents\\LEADTOOLS Images\\")pFileName 
L_INT DicomCreateSignatureExample(HDICOMDS hDS) 
{ 
   pDICOMELEMENT pSignatureItem; 
   // Create a Digital Signature in the main Data Set 
   L_UINT16 uRet = L_DicomCreateSignature(hDS, 
   NULL, 
   MAKE_IMAGE_PATH(TEXT("Sample Private Key.pem")), 
   MAKE_IMAGE_PATH(TEXT("CA.pem")), 
   NULL, 
   &pSignatureItem, 
   NULL, 
   DICOM_MAC_ALGORITHM_RIPEMD160, 
   NULL, 
   0, 
   DICOM_SECURITY_PROFILE_NONE, 
   0); 
   if (uRet == DICOM_SUCCESS) 
      MessageBox(NULL, TEXT("The Digital Signature was created successfully."), TEXT("Sample"), MB_OK); 
   else 
   { 
      L_TCHAR szMsg[64]; 
      wsprintf(szMsg, TEXT("An error occurred [Error: %hu]."), uRet); 
      MessageBox(NULL, szMsg, TEXT("Sample"), MB_OK); 
      return uRet; 
   } 
   // Save the signed Data Set 
   uRet = L_DicomSaveDS(hDS,MAKE_IMAGE_PATH(TEXT("Signed.dcm")), 0); 
   if (uRet != DICOM_SUCCESS) 
      return uRet; 
   // Examine the Digital Signature we just created 
   // Refer to the example of L_DicomVerifySignature for the 
   // function DicomVerifySignatureExample 
   uRet = (L_UINT16) DicomVerifySignatureExample(hDS, pSignatureItem); 
   return uRet; 
}