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VerifySignature Method
See Also 
Leadtools.Dicom Namespace > DicomDataSet Class : VerifySignature Method



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.
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.
Verifies Digital Signatures in the Data Set.

Syntax

Visual Basic (Declaration) 
Public Function VerifySignature( _
   ByVal signatureItem As DicomElement _
) As Boolean
Visual Basic (Usage)Copy Code
Dim instance As DicomDataSet
Dim signatureItem As DicomElement
Dim value As Boolean
 
value = instance.VerifySignature(signatureItem)
C# 
public bool VerifySignature( 
   DicomElement signatureItem
)
C++/CLI 
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.

Example

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

Visual BasicCopy Code
Public Sub ExamineSignature(ByVal dataset As DicomDataSet, ByVal signatureItem As DicomElement)
   ' Verify the Digital Signature; if pSignatureItem is NULL, the function
   ' will verify all the Digital Signatures that exist in the Data Set
   Dim ret As Boolean = dataset.VerifySignature(signatureItem)
   If ret = True Then
      If Not signatureItem Is Nothing Then
         MessageBox.Show("The Digital Signature was verified.", "Sample")
      Else
         MessageBox.Show("All Digital Signatures were verified (if there are any).", "Sample")
      End If
   Else
      If Not signatureItem Is Nothing Then
         MessageBox.Show("The Digital Signature is invalid.", "Sample")
      Else
         MessageBox.Show("At least one Digital Signature is invalid.", "Sample")
      End If
   End If
   ' The Digital Signature UID
   Dim msg As StringBuilder = New StringBuilder()
   msg.Append(dataset.GetSignatureUID(signatureItem))

   ' The Digital Signature DateTime
   Dim digitalSignatureDateTime As DicomDateTimeValue = dataset.GetSignatureDateTime(signatureItem)
   If digitalSignatureDateTime.IsEmpty = False Then
      If (digitalSignatureDateTime.Offset >= 0) Then
         msg.AppendFormat(" Digital Signature DateTime:{0}/{1}/{3} {4}:{5}:{6}.{7} {8}{9}{10}", digitalSignatureDateTime.Month, digitalSignatureDateTime.Day, digitalSignatureDateTime.Year, digitalSignatureDateTime.Hours, digitalSignatureDateTime.Minutes, digitalSignatureDateTime.Seconds, digitalSignatureDateTime.Fractions, "+"c, digitalSignatureDateTime.Offset, Environment.NewLine)
      Else
         msg.AppendFormat(" Digital Signature DateTime:{0}/{1}/{3} {4}:{5}:{6}.{7} {8}{9}{10}", digitalSignatureDateTime.Month, digitalSignatureDateTime.Day, digitalSignatureDateTime.Year, digitalSignatureDateTime.Hours, digitalSignatureDateTime.Minutes, digitalSignatureDateTime.Seconds, digitalSignatureDateTime.Fractions, "-"c, digitalSignatureDateTime.Offset, Environment.NewLine)
      End If
   End If
   Dim macTransferSyntax As String = dataset.GetMacTransferSyntax(signatureItem)
   If Not macTransferSyntax Is Nothing Then
      msg.AppendFormat("MAC Calculation Transfer Syntax UID: {0}", macTransferSyntax)
   End If

   Dim macAlgorithm As String = dataset.GetMacAlgorithm(signatureItem)
   If Not macAlgorithm Is Nothing Then
      msg.AppendFormat("MAC Algorithm: {0}", macAlgorithm)
   End If
   ' The Data Elements Signed
   If dataset.GetSignedElementsCount(signatureItem) > 0 Then
      ' We will display only one
      Dim element As DicomElement = dataset.GetSignedElement(signatureItem, 0)
      msg.AppendFormat(" Data Elements Signed:{0}{1}{1}", element.Tag, Environment.NewLine)
   End If
   msg.AppendFormat("{0}Do you want to save the Certificate of Signer?", Environment.NewLine)
   If MessageBox.Show(msg.ToString(), "Sample", MessageBoxButtons.YesNo) = DialogResult.Yes Then
      dataset.SaveCertificate(signatureItem, LeadtoolsExamples.Common.ImagesPath.Path + "CertOfSigner.cer", DicomCertificateFormat.Pem)
   End If
End Sub
C#Copy Code
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)
      {
         MessageBox.Show("The Digital Signature was verified.", "Sample");
      }
      else
      {
         MessageBox.Show("All Digital Signatures were verified (if there are any).", "Sample");
      }
   }
   else
   {
      if (signatureItem != null)
      {
         MessageBox.Show("The Digital Signature is invalid.", "Sample");
      }
      else
      {
         MessageBox.Show("At least one Digital Signature is invalid.", "Sample");
      }
   }
   // 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}/{3} {4}:{5}:{6}.{7} {8}{9}{10}",
         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);
   if (MessageBox.Show(msg.ToString(), "Sample", MessageBoxButtons.YesNo) == DialogResult.Yes)
   {
      dataset.SaveCertificate(signatureItem, LeadtoolsExamples.Common.ImagesPath.Path + "CertOfSigner.cer", DicomCertificateFormat.Pem);
   }
}
SilverlightCSharpCopy Code
SilverlightVBCopy Code

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.

Requirements

Target Platforms: Silverlight 3.0, Windows XP, Windows Server 2003 family, Windows Server 2008 family, Windows Vista, Windows 7, MAC OS/X (Intel Only)

See Also

Leadtools.Dicom requires a Medical toolkit server license and unlock key. For more information, refer to: Imaging Pro/Document/Medical Features