DigitalSignatureCollection class

Provides a read-only collection of digital signatures attached to a document.

To learn more, visit the Work with Digital Signatures documentation article.

public class DigitalSignatureCollection : IEnumerable<DigitalSignature>


DigitalSignatureCollection()The default constructor.


Count { get; }Gets the number of elements contained in the collection.
IsValid { get; }Returns true if all digital signatures in this collection are valid and the document has not been tampered with Also returns true if there are no digital signatures. Returns false if at least one digital signature is invalid.
Item { get; }Gets a document signature at the specified index.


GetEnumerator()Returns a dictionary enumerator object that can be used to iterate over all items in the collection.




Shows how to validate and display information about each signature in a document.

Document doc = new Document(MyDir + "Digitally signed.docx");

foreach (DigitalSignature signature in doc.DigitalSignatures)
    Console.WriteLine($"{(signature.IsValid ? "Valid" : "Invalid")} signature: ");
    Console.WriteLine($"\tSign time:\t{signature.SignTime}");
    Console.WriteLine($"\tSubject name:\t{signature.CertificateHolder.Certificate.SubjectName}");
    Console.WriteLine($"\tIssuer name:\t{signature.CertificateHolder.Certificate.IssuerName.Name}");

Shows how to sign documents with X.509 certificates.

// Verify that a document is not signed.
Assert.False(FileFormatUtil.DetectFileFormat(MyDir + "Document.docx").HasDigitalSignature);

// Create a CertificateHolder object from a PKCS12 file, which we will use to sign the document.
CertificateHolder certificateHolder = CertificateHolder.Create(MyDir + "morzal.pfx", "aw", null);

// There are two ways of saving a signed copy of a document to the local file system:
// 1 - Designate a document by a local system filename and save a signed copy at a location specified by another filename.
SignOptions signOptions = new SignOptions { SignTime = DateTime.Now };
DigitalSignatureUtil.Sign(MyDir + "Document.docx", ArtifactsDir + "Document.DigitalSignature.docx",
    certificateHolder, signOptions);

Assert.True(FileFormatUtil.DetectFileFormat(ArtifactsDir + "Document.DigitalSignature.docx").HasDigitalSignature);

// 2 - Take a document from a stream and save a signed copy to another stream.
using (FileStream inDoc = new FileStream(MyDir + "Document.docx", FileMode.Open))
    using (FileStream outDoc = new FileStream(ArtifactsDir + "Document.DigitalSignature.docx", FileMode.Create))
        DigitalSignatureUtil.Sign(inDoc, outDoc, certificateHolder);

Assert.True(FileFormatUtil.DetectFileFormat(ArtifactsDir + "Document.DigitalSignature.docx").HasDigitalSignature);

// Please verify that all of the document's digital signatures are valid and check their details.
Document signedDoc = new Document(ArtifactsDir + "Document.DigitalSignature.docx");
DigitalSignatureCollection digitalSignatureCollection = signedDoc.DigitalSignatures;

Assert.AreEqual(1, digitalSignatureCollection.Count);
Assert.AreEqual(DigitalSignatureType.XmlDsig, digitalSignatureCollection[0].SignatureType);
Assert.AreEqual("CN=Morzal.Me", signedDoc.DigitalSignatures[0].IssuerName);
Assert.AreEqual("CN=Morzal.Me", signedDoc.DigitalSignatures[0].SubjectName);

See Also