Used to sign the XMLDSIG template.

Note
Signature providers are implemented exclusively in custom COM add-ins created in managed and unmanaged code and cannot be implemented in Microsoft Visual Basic for Applications (VBA).

Syntax

expression.SignXmlDsig(QueryContinue, psigsetup, psiginfo, XmlDsigStream)

expression An expression that returns a SignatureProvider object.

Parameters

Name Required/Optional Data Type Description
QueryContinue Required IQueryContinue Provides a way to query the host application for permission to continue the verification operation.
psigsetup Required SignatureSetup Specifies configuration information about a signature line.
psiginfo Required SignatureInfo Specifies information captured from the signing ceremony.
XmlDsigStream Required IStream Represents a steam of data containing XML, which represents an XMLDSIG object.

Remarks

XMLDSIG is a standards-based signature format (http://www.w3.org/TR/xmldsig-core/), verifiable by third parties. This is the default format for signatures in the Microsoft Office system.

Example

The following example, written in C#, shows the implementation of the SignXmlDsig method in a custom signature provider project.

C# 
 public void SignXmlDsig(object queryContinue, SignatureSetup sigsetup, SignatureInfo siginfo, object xmldsigStream) { using (COMStream comstream = new COMStream(xmldsigStream)) { XmlDocument xmldsig = new XmlDocument(); xmldsig.PreserveWhitespace = true; xmldsig.Load(comstream); XmlNamespaceManager nsmgr = new XmlNamespaceManager(xmldsig.NameTable); nsmgr.AddNamespace("ds", "http://www.w3.org/2000/09/xmldsig#"); XmlElement signature = xmldsig.DocumentElement; SignedXml signedXml = new SignedXml(); signedXml.LoadXml(signature); // Cert X509Certificate2 cert = TestSignatureProvider.GetSigningCertificate(siginfo); KeyInfo keyInfo = new KeyInfo(); if (cert.PrivateKey is RSA) keyInfo.AddClause(new RSAKeyValue((RSA) cert.PrivateKey)); else if (cert.PrivateKey is DSA) keyInfo.AddClause(new DSAKeyValue((DSA) cert.PrivateKey)); keyInfo.AddClause(new KeyInfoX509Data(cert)); signedXml.SigningKey = cert.PrivateKey; signedXml.KeyInfo = keyInfo; // Compute signature signedXml.ComputeSignature(); // Copy data from signed signature // REVIEW: Cleaner way to do this? string[] xpathsToCopy = new string[] { "./ds:SignedInfo", "./ds:SignatureValue", "./ds:KeyInfo", }; XmlElement signedSignature = signedXml.GetXml(); foreach (string xpathToCopy in xpathsToCopy) { signature.ReplaceChild( xmldsig.ImportNode(signedSignature.SelectSingleNode(xpathToCopy, nsmgr), true), signature.SelectSingleNode(xpathToCopy, nsmgr)); } // Save signature back to stream comstream.SetLength(0); comstream.Position = 0; xmldsig.Save(new XmlTextWriter(comstream, new UTF8Encoding(false))); } }

See also: