VerifySignature Method

Summary

Verifies Digital Signatures in the Data Set.

Syntax

C++/CLI

public bool VerifySignature( 
   DicomElement signatureItem 
)

public: 
bool VerifySignature(  
   DicomElement^ signatureItem 
)

Parameters

signatureItem
The Digital Signatures Sequence Item that corresponds to the Digital Signature to be verified. To verify all the Digital Signatures in the entire Data Set, set this parameter to null.

Return Value

true if The Digital Signature(s) was/were verified successfully; false if the Digital Signature is invalid or at least one of the Digital Signatures is invalid.

Remarks

To verify all the Digital Signatures in the entire Data Set, set the signatureItem parameter to null. If at least one of these Digital Signatures is invalid, the method returns false and does not examine the remaining Digital Signatures, if there are any.

Example

This example will verify a DICOM digital signature and display its details.

using Leadtools; 
using Leadtools.Dicom; 
 
 
public void ExamineSignature(DicomDataSet dataset, DicomElement signatureItem) 
{ 
   // Verify the Digital Signature; if pSignatureItem is NULL, the function 
   // will verify all the Digital Signatures that exist in the Data Set 
   bool ret = dataset.VerifySignature(signatureItem); 
   if (ret == true) 
   { 
      if (signatureItem != null) 
      { 
         Console.WriteLine("Sample: The Digital Signature was verified."); 
 
      } 
      else 
      { 
         Console.WriteLine("Sample: All Digital Signatures were verified (if there are any)."); 
      } 
   } 
   else 
   { 
      if (signatureItem != null) 
      { 
         Console.WriteLine("Sample: The Digital Signature is invalid."); 
      } 
      else 
      { 
         Console.WriteLine("Sample: At least one Digital Signature is invalid."); 
      } 
   } 
   // The Digital Signature UID 
   StringBuilder msg = new StringBuilder(); 
   msg.Append(dataset.GetSignatureUID(signatureItem)); 
 
   // The Digital Signature DateTime 
   DicomDateTimeValue digitalSignatureDateTime = dataset.GetSignatureDateTime(signatureItem); 
   if (digitalSignatureDateTime.IsEmpty == false) 
   { 
      msg.AppendFormat(" Digital Signature DateTime:{0}/{1}/{2} {3}:{4}:{5}.{6} {7}{8}{9}", 
         digitalSignatureDateTime.Month, 
         digitalSignatureDateTime.Day, 
         digitalSignatureDateTime.Year, 
         digitalSignatureDateTime.Hours, 
         digitalSignatureDateTime.Minutes, 
         digitalSignatureDateTime.Seconds, 
         digitalSignatureDateTime.Fractions, 
         (digitalSignatureDateTime.Offset >= 0) ? '+' : '-', 
         digitalSignatureDateTime.Offset, 
         Environment.NewLine); 
   } 
   string macTransferSyntax = dataset.GetMacTransferSyntax(signatureItem); 
   if (macTransferSyntax != null) 
   { 
      msg.AppendFormat("MAC Calculation Transfer Syntax UID: {0}", macTransferSyntax); 
   } 
 
   string macAlgorithm = dataset.GetMacAlgorithm(signatureItem); 
   if (macAlgorithm != null) 
   { 
      msg.AppendFormat("MAC Algorithm: {0}", macAlgorithm); 
   } 
   // The Data Elements Signed 
   if (dataset.GetSignedElementsCount(signatureItem) > 0) 
   { 
      // We will display only one 
      DicomElement element = dataset.GetSignedElement(signatureItem, 0); 
      msg.AppendFormat(" Data Elements Signed:{0}{1}{1}", element.Tag, Environment.NewLine); 
   } 
   msg.AppendFormat("{0}Do you want to save the Certificate of Signer?", Environment.NewLine); 
 
   Console.WriteLine($"Sample: {msg.ToString()}"); 
   dataset.SaveCertificate(signatureItem, Path.Combine(LEAD_VARS.ImagesDir, "CertOfSigner.cer"), DicomCertificateFormat.Pem); 
 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS22\Resources\Images"; 
}