ProviderId

SignOptions.ProviderId property

Specifies the class ID of the signature provider. Default value is Empty (all zeroes) Guid.

public Guid ProviderId { get; set; }

Remarks

The cryptographic service provider (CSP) is an independent software module that actually performs cryptography algorithms for authentication, encoding, and encryption. MS Office reserves the value of {00000000-0000-0000-0000-000000000000} for its default signature provider.

The GUID of the additionally installed provider should be obtained from the documentation shipped with the provider.

In addition, all the installed cryptographic providers are enumerated in windows registry. It can be found in the following path: HKLM\SOFTWARE\Microsoft\Cryptography\Defaults\Provider. There is a key name “CP Service UUID” which corresponds to a GUID of signature provider.

Examples

Shows how to sign a document with a personal certificate and a signature line.

Document doc = new Document();
DocumentBuilder builder = new DocumentBuilder(doc);

SignatureLineOptions signatureLineOptions = new SignatureLineOptions
{
    Signer = "vderyushev",
    SignerTitle = "QA",
    Email = "vderyushev@aspose.com",
    ShowDate = true,
    DefaultInstructions = false,
    Instructions = "Please sign here.",
    AllowComments = true
};

SignatureLine signatureLine = builder.InsertSignatureLine(signatureLineOptions).SignatureLine;
signatureLine.ProviderId = Guid.Parse("CF5A7BB4-8F3C-4756-9DF6-BEF7F13259A2");

Assert.False(signatureLine.IsSigned);
Assert.False(signatureLine.IsValid);

doc.Save(ArtifactsDir + "DocumentBuilder.SignatureLineProviderId.docx");

SignOptions signOptions = new SignOptions
{
    SignatureLineId = signatureLine.Id,
    ProviderId = signatureLine.ProviderId,
    Comments = "Document was signed by vderyushev",
    SignTime = DateTime.Now
};

CertificateHolder certHolder = CertificateHolder.Create(MyDir + "morzal.pfx", "aw");

DigitalSignatureUtil.Sign(ArtifactsDir + "DocumentBuilder.SignatureLineProviderId.docx", 
    ArtifactsDir + "DocumentBuilder.SignatureLineProviderId.Signed.docx", certHolder, signOptions);

// Re-open our saved document, and verify that the "IsSigned" and "IsValid" properties both equal "true",
// indicating that the signature line contains a signature.
doc = new Document(ArtifactsDir + "DocumentBuilder.SignatureLineProviderId.Signed.docx");
Shape shape = (Shape)doc.GetChild(NodeType.Shape, 0, true);
signatureLine = shape.SignatureLine;

Assert.True(signatureLine.IsSigned);
Assert.True(signatureLine.IsValid);

See Also

SignOptions.DecryptionPassword SignOptions.SignatureLineId